Biotransformation and toxicokinetics of 2-phenoxyethanol after oral exposure in humans: a volunteer study

2-Phenoxyethanol (PhE) is an aromatic glycol ether and is used in a variety of functions and applications, e.g., as preservative in pharmaceuticals, cosmetic and personal care products, as biocide in disinfectants (e.g. human hygiene), or as a solvent in formulations (e.g. coatings, functional fluids). Despite its widespread use, little is yet known on its biotransformation and toxicokinetics in humans. Therefore, a pilot study was conducted with oral administration of PhE (5 mg/kg body weight) to five volunteers. Blood and urine samples were collected and analyzed for PhE and three of its presumed metabolites up to 48 h post-exposure. Additionally, one volunteer was dermally exposed to PhE and monitored until 72 h post-exposure. PhE was rapidly resorbed following both oral and dermal application with tmax-levels in blood of about 1 h and 3 h, respectively. Metabolism of PhE was observed to be rather extensive with phenoxyacetic acid (PhAA) and 4-hydroxyphenoxyacetic acid (4-OH-PhAA) as the main metabolites found in blood and urine following oral and dermal exposure. PhE was excreted rapidly and efficiently via urine mostly in metabolized form: following oral exposure, on average 77% and 12% of the applied dose was excreted within 48 h as PhAA and 4-OH-PhAA, respectively. A similar metabolism pattern was observed following the single dermal exposure experiment. The obtained data on biotransformation and toxicokinetics of PhE in humans provide valuable information on this important chemical and will be highly useful for pharmacokinetic modelling and evaluation of human PhE exposure.

Preclinical Data Extrapolation to Clinical Reality: A Translational Approach

In vivo investigations are much more complex than trials conducted in a test tube; the results sometimes aren't as illuminating and could raise more questions than answers. Preclinical data projection into clinical truth is a transcriptional science that remains a compelling trial in drug development. Preclinical in vivo and in vitro education is important in novel drug's non-violent or active growth. Pharmacokinetic and metabolic research is necessary to better understand the chemical and biological effects of medicines and their metabolites. Information produced by such a policy can be used to progress Phase I studies, primarily for anticancer medication. Both living and deceased in vitro models are theoretically excellent preclinical tools for calculating the pharmacological action of counterparts from the same family, such as vinca alkaloids. The animal species most closely linked to humans are chosen based on metabolic patterns. The estimation of the duration of drug action, particularly for medicines with varied metabolic clearances (e.g., benzodiazepines); The empathetic or estimate of medicine relations, i.e., those defined for cyclosporin A and macrolide antibiotics; and Sclarification of the metabolic roots of individual inconsistencies in pharmaceutical action.

Novel Pyrimidine-5-Carbonitriles as potential apoptotic and antiproliferative agents by dual inhibition of EGFRWT/T790M and PI3k enzymes; Design, Synthesis, biological Evaluation, and docking studies

A new series of 6-(4-fluorophenyl)-2-(methylthio) pyrimidine-5-carbonitrile derivatives were designed and synthesized as EGFR/PI3K dual inhibitors, and potential antiproliferative agents. The new 22 compounds were screened by DTP-NCI against all NCI60 cell lines. Almost all compounds showed cytotoxic activity. Compound 7c showed a promising antitumour activity on CNS cancer (SNB-75), and ovarian cancer (OVAR-4) with IC50 < 0.01, and 0.64 µM, respectively. Fortunately, 7c exhibited a better safety profile on normal cells (WI-38) than doxorubicin by 2.2-fold. Compound 7c displayed selective inhibitory activity on EGFRt790m over EGFRWT with IC50 = 0.08, and 0.13 µM, respectively, wherefore it might overcome EGFR-TKIs resistance. In addition to its remarkable inhibitory activity on all PI3K isoforms, specifically PI3K-δ with IC50 = 0.64 µM Compared with LY294002 IC50 = 7.6 µM. Compound 7c arrested the cell cycle of SNB-75 & OVAR-4 at the G0-G1 phase coupled with apoptosis induction. The western blotting analysis approved decreasing the expression level of p-AKT coupled with an increase in Casp3, Casp9, and BAX proteins in the SNB-75 & OVAR-4 after being treated with 7c which may support the suggested mechanism of action of 7c as EGFR/PI3K dual inhibitor. Physicochemical parameters were forecasted using SwissADME online tool. MD showed the interaction of 7c with the crucial amino acids of the active domain of both EGFR/PI3K which may explain its potent inhibitory activities. In vivo study disclosed a significant decrease in tumor weight and the number of nodules in the group of mice treated with 7c compared with the control group.

From Sea to Soil: Marine Bacillus subtilis enhancing chickpea production through in vitro and in vivo plant growth promoting traits

Various strategies are used to augment agricultural output in response to the escalating food requirements stemming from population expansion. Out of various strategies, the use of plant growth-promoting bacteria (PGPB) has shown promise as a viable technique in implementing new agricultural practices. The study of PGPB derived from rhizospheric soil is extensive, but there is a need for more exploration of marine microorganisms. The present research aims to investigate the potential of marine microorganisms as promoters of plant growth. The marine microbe Bacillus subtilis used in current study has been discovered as a possible plant growth-promoting bacterium (PGPB) as it showed ability to produce ammonia, solubilize potassium and phosphate, and was able to colonize chickpea roots. Bacillus subtilis exhibited a 40% augmentation in germination. A talc-based bio-formulation was prepared using Bacillus subtilis, and pot experiment was done under two conditions: control (T1) and Bacillus treated (T2). In the pot experiment, the plant weight with Bacillus treatment increased by 14.17%, while the plant height increased by 13.71% as compared to control. It also enhanced the chlorophyll content of chickpea and had a beneficial influence on stress indicators. Furthermore, it was noted that it enhanced the levels of nitrogen, potassium, and phosphate in the soil improving soil quality. The findings showed that B. subtilis functioned as a plant growth-promoting bacteria (PGPB) to enhance the overall development of chickpea.

Assessment of thimerosal effects in sublethal concentrations on zebrafish (Danio rerio) embryos exploring NMR-based metabolomics profile

Thimerosal, a preservative commonly used in the pharmaceutical and cosmetic industry, has raised concerns regarding its potentially toxic effects as an organic mercury compound. Within this context, using an NMR-based metabolomics profile and chemometric analysis, zebrafish embryos were used as an in vivo model to study the effects of thimerosal in metabolic profiles after exposure to sublethal concentrations of the mercury compound. The thimerosal concentrations of 40 and 80 nM were employed, corresponding to 40% and 80% of the LC50, respectively, for zebrafish embryos. The most significant alterations in the metabolic profile included changes in carbohydrates, amino acids, nucleotides, trimethylamine-N-oxide, ethanolamine, betaine, and ethanol. Furthermore, thimerosal exposure affects various metabolic pathways, impairing the nervous system, disrupting protein metabolism, and potentially causing oxidative damage. Therefore, adopting a metabolomics approach in this investigation provided insights into the potentially implicated metabolic pathways contributing to the deleterious effects of thimerosal in biological systems.

Nutritive value of fermented soybean grains for ruminants

Fermented soybean grain (FSBG) is considered improper to use as a protein source in animal nutrition, since it is assumed that defects cause changes on its chemical composition and favor mycotoxins production, but chemical composition data does not support this theory and in vivo studies are missing. Thus, this study aimed to evaluate the effects of FSBG in feedlot lamb diets. For that, two types of FSBG (partially fermented and completely fermented, PFSBG and CFSBG) and one standard soybean grain (SSBG) were obtained and evaluated alone or as a component of experimental diets by in vitro and in vivo studies, where FSBG totally replaced SSBG in feedlot lamb diets, which was included in the experimental diets in 17.4% on dry matter basis as protein source. Before the studies, both soybeans were sent to a specialized laboratory where no mycotoxins were detected. As a result, lower DM and carbohydrate contents but higher crude protein, fiber, and indigestible NDF contents were measured in CFSBG than in SSBG. Furthermore, both types of FSBG showed lower digestibility in vitro dry matter (IVDMD) than SSBG when evaluated separately; however, when evaluated in experimental diets, the substitution of SSBG for FSBG did not affect IVDMD. It was also observed that FSBG also had less rumen-degradable protein than SSBG (mean 47.9 vs 86.4%). In the in vivo study, FSBG did not affect nutrient intake, apparent digestibility, or animal performance (i.e., average daily gain and carcass gain). Thus, mycotoxins-free FSBG may be an alternative to totally replace SSBG in feedlot lamb diets.

In vitro and in vivo removal efficacy of insoluble Prussian blue in combination with calcium polystyrene sulfonate for thallium

The similarities between thallium and potassium have suggested the use of calcium polystyrene sulfonate (CPS), an oral ion exchange resin, as a potential agent against thallium intoxication. Therefore, the study was an attempt to evaluate the efficacy of CPS and Prussian blue when given alone or in combination against thallium toxicity. The effect on binding capacity was investigated in terms of contact time, amount of CPS, influence of pH, simulated physiological solutions and interference of potassium ions. Also, rats were given single dose of thallium chloride (20 mg kg-1) and the treatment with PB and CPS was given for 28 days as CPS 30 g kg-1, orally, twice a day, PB 3 g kg-1, orally, twice a day and their combination. The effect of antidotal treatment was evaluated by calculating the thallium levels in various organs, blood, urine and feces. The results of the in vitro study indicated exceedingly quick binding in the combination of CPS and PB as compared to PB alone. Also, it was found that the binding capacity at pH 2.0 was considerably increased for PB with CPS (184.656 mg g-1) as compared to PB (37.771 mg g-1). Furthermore, statistically significant results were obtained in the in vivo study as after 7th day, thallium levels in blood of rats treated with combination were reduced by 64% as compared to control group and 52% as compared to alone PB treated group. Also, Tl retention in liver, kidney, stomach, colon and small intestine of combination treated rats was significantly reduced to 46%, 28%, 41%, 32% and 33% respectively, as compared to alone PB treated group. These findings demonstrate this as a good antidotal option against thallium intoxication.

Phages for treatment of Klebsiella pneumoniae infections

Klebsiella pneumoniae is an opportunistic pathogen involved in both hospital- and community-acquired infections. K. pneumoniae is associated with various infections, including pneumonia, septicemia, meningitis, urinary tract infection, and surgical wound infection. K. pneumoniae possesses serious virulence, biofilm formation ability, and severe resistance to many antibiotics especially hospital-acquired strains, due to excessive use in healthcare systems. This limits the available effective antibiotics that can be used for patients suffering from K. pneumoniae infections; therefore, alternative treatments are urgently needed. Bacteriophages (for short, phages) are prokaryotic viruses capable of infecting, replicating, and then lysing (lytic phages) the bacterial host. Phage therapy exhibited great potential for treating multidrug-resistant bacterial infections comprising K. pneumoniae. Hence, this chapter emphasizes and summarizes the research articles in the PubMed database from 1948 until the 15th of December 2022, addressing phage therapy against K. pneumoniae. The chapter provides an overview of K. pneumoniae phages covering different aspects, including phage isolation, different morphotypes of isolated phages, in vitro characterization, anti-biofilm activity, various therapeutic forms, in vivo research and clinical studies.

Phytochemical profiling of polyphenols and thyroid stimulatory activity of Ficus religiosa leaf extract in 6-propyl-thiouracil-induced hypothyroid rats

ETHNOPHARMACOLOGICAL RELEVANCE

The plant, Ficus religiosa (L.) from the family Moraceae, has been extensively used in Ayurveda and Unani. Traditionally this plant is known for the treatment of constipation, liver diseases and neurological disorders that are related to hypothyroidism.

AIM OF THE STUDY

This study was primarily designed to evaluate the effect of Ficus religiosa leaf (FL) extract in ameliorating hypothyroidism in rats and to identify the major bioactive compounds in the test extract that might be responsible for the thyroid-altering activity. In addition, the probable mechanism underlying the thyroid regulation of the main FL constituents were analyzed by molecular docking.

MATERIALS AND METHODS

Adult female Wistar rats were used. LC-ESI-MS/MS was performed to identify the compounds present in the extract. HPLC analysis of FL extract was also performed. A pilot study was made using 3 doses of FL extract. Out of 50, 100, and 200 mg/kg, 100 mg/kg appeared to be the most effective one as it could increase thyroid hormones and decreased TSH levels. In the final experiment, propyl-thiouracil (PTU)-induced hypothyroid rats were orally treated with FL extract (100 mg/kg) or L-thyroxine (100 μg/kg, i.p.) daily for 28 consecutive days. On 29th day, all rats were sacrificed and the serum levels of triiodothyronine (T₃), thyroxine (T₄), thyrotropin (TSH), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and hepatic 5' deiodinase-1(5'D1) were estimated by ELISA. Liver marker enzymes (alanine aminotransferase, ALT and aspartate aminotransferase, AST); total cholesterol (TC) and triglycerides (TG); hepatic lipid peroxidation (LPO) and the activities of antioxidants such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione (GSH) content were estimated in liver tissues.

RESULTS

LC-MS-MS analyses of the leaf extract identified 11 compounds including the three major compounds, betulinic acid (BA), chlorogenic acid (CGA), and quinic acid (QA). While the PTU treatment decreased the levels of thyroid hormones and 5'D1 activity, it increased the TSH, ALT, AST, TNF-α, IL-6, TC, and TG levels. Furthermore, hepatic LPO significantly increased with a decrease in reduced GSH, SOD, CAT, and GPx. However, FL treatment in PTU-induced animals nearly reversed these adverse effects and improved liver function by decreasing ALT, AST, hepatic LPO and increasing the levels of antioxidants. FL not only improved the liver histology, but also suppressed the inflammatory cytokines, TNF-α and IL-6 in PTU-induced animals. A molecular docking study towards the understanding of the thyroid stimulatory mechanism of action revealed that BA, CGA, and QA might have augmented thyroid hormones by interacting with the thyroid hormone receptor (TRβ1) and TSH receptor (TSHR).

CONCLUSION

For the first time, we report the pro-thyroidal potential of Ficus religiosa leaf extract. We postulate that its main bioactive compounds, BA, CGA, and QA involved in this action may serve as novel thyroid agonists in ameliorating hypothyroidism.

In vivo tests of a novel wound dressing based on agar aerogel

Aerogels, especially bio-based ones, present a promising option for wound dressing; specifically, because of their low toxicity, high stability, bio-compatibility, and good biological performance. In this study, agar aerogel was prepared and evaluated as novel wound dressing material in an in vivo rat study. Agar hydrogel was prepared by thermal gelation, after that the water inside the gel was exchanged with ethanol, and finally the alcogel was dried by supercritical CO₂. The textural and rheological properties of the prepared aerogel were characterized, showing that the prepared agar aerogels possess high porosity (97-98 %), high surface area (250-330 m²g^-1) as well as good mechanical properties and easiness of removal from the wound site. The results of the in vivo experiments macroscopically demonstrate the tissue compatibility of the aerogels in dorsal interscapular injured rat tissue and a shorter wound healing time comparable to that of gauze-treated animals. The histological analysis underpins the reorganisation and healing of the tissue for the injured skin of rats treated with agar aerogel wound dressing within the studied time frame.

In Vivo Evaluation of Nanoemulsion Formulations for Metformin and Repaglinide Alone and Combination

Repaglinide and Metformin are used to treat Type 2 diabetes. Repaglinide with poor water solubility has relatively low oral bioavailability (56%) and undergoes hepatic first-pass metabolism. The oral bioavailability of metformin HCl is also low (about 50-60%). The purpose of this study was to prepare nanoemulsion formulations containing metformin HCl or repaglinide alone or in combination and characterize them in vitro and in vivo. Nanoemulsion formulations containing metformin HCl and/or repaglinide were successfully prepared and in vitro characterized. In addition, in vivo efficacy of nanoemulsion formulations was evaluated in a streptozotocin-nicotinamide-induced diabetic rat model. Biochemical, histopathological, and immunohistochemical evaluations were also performed. The mean droplet size and zeta potential values of nanoemulsion formulations were in the range of 110.15±2.64-120.23±2.16 nm and -21.95 - -24.33 mV, respectively. The percent entrapment efficiency values of nanoemulsion formulations were in the range of 93.600%-96.152%. All nanoemulsion formulations had a PDI of ≤0.223. A statistically significant decrease was observed in the blood glucose values of the diabetic rats treated with nanoemulsion formulations containing active substance/substances, compared to diabetic rats (control) (p<0.05). Nanoemulsion formulations (especially nanoemulsion containing metformin HCl and repaglinide combination) have a better antidiabetic activity and are more effective in reducing oxidative stress caused by diabetes.

Free-standing multilayer films as growth factor reservoirs for future wound dressing applications

Chronic skin wounds place a high burden on patients and health care systems. The use of angiogenic and mitogenic growth factors can facilitate the healing but growth factors are quickly inactivated by the wound environment if added exogenously. Here, free-standing multilayer films (FSF) are fabricated from chitosan and alginate as opposing polyelectrolytes in an alternating manner using layer-by-layer technique. One hundred bilayers form an about 450 μm thick, detachable free-standing film that is subsequently crosslinked by either ethyl (dimethylaminopropyl) carbodiimide combined with N-hydroxysuccinimide (E-FSF) or genipin (G-FSF). The characterization of swelling, oxygen permeability and crosslinking density shows reduced swelling and oxygen permeability for both crosslinked films compared to non-crosslinked films (N-FSF). Loading of fibroblast growth factor 2 (FGF2) into the films results in a sustained release from crosslinked FSF in comparison to non-crosslinked FSF. Biocompatibility studies in vitro with human dermal fibroblasts cultured underneath the films demonstrate increased cell growth and cell migration for all films with and without FGF2. Especially G-FSF loaded with FGF2 greatly increases cell proliferation and migration. In vivo biocompatibility studies by subcutaneous implantation in mice show that E-FSF causes an inflammatory tissue response that is absent in the case of G-FSF. N-FSF also represents a biocompatible film but shows early degradation. All FSF possess antibacterial properties against gram+ and gram- bacteria demonstrated by an agar diffusion disc assay. In summary, FSF made of alginate and chitosan crosslinked with genipin can act as a reservoir for the sustained release of FGF2, possessing high biocompatibility in vitro and in vivo. Moreover, G-FSF promotes growth and migration of human dermal fibroblasts and has antibacterial properties, which makes it an interesting candidate for bioactive wound.

Characterization of Capsicum oleoresin microparticles and in vivo evaluation of short-term capsaicin intake

•

Modified malt was successfully used in Capsicum oleoresin microencapsulation.

•

High antioxidant activities by ORAC and FRAP were observed for all microparticles.

•

Diet containing Capsicum oleoresin microparticles can promote weight gain control.

•

Liver damage caused by obesity was prevented by high doses of Capsicum's oleoresin.

Gum arabic, modified corn starch (EMCAP), modified malt (MALT), either blended or isolated, were assessed as encapsulating agents for Capsicum oleoresin. Capsicum oleoresin microparticles were obtained by spray drying and analysed for physicochemical properties and in vivo. Obtained powders were adequate for storage, given their low water activity (<0.150), hygroscopicity (<11.43 g/100 g), moisture (<4.76%) and high glass transition temperature (<98.3 °C). FT-IR analysis concluded that carbohydrates matrices were loaded after spray drying, with peaks around 2850 cm ^–1 for aromatic compounds, and bands around 1760 cm⁻¹, pointing to the presence of capsaicin inside the microparticles. All formulations exhibited high antioxidant activity, low contact angles and great solubility in water. Any adverse effect was observed in the experimental assay, neither change on the level of hepatic aminotransferases. The intake of a High-Fat Diet (HFD) supplemented with Capsicum oleoresin microparticles decreased weight gain when compared to the HFD control.

In vivo experimental mouse model to test CD19CAR T cells generated with different methods

Pre-clinical evaluation of CAR T cells includes procedures testing T-cell efficacy and safety in as close to real world conditions as possible. An important step in efficacy testing is the in vivo study, most often using immunodeficient murine models into which both the poison and the cure are injected; namely a human cancer cell line and genetically modified human T cells. The capacity of the T cells to control the cancer progression will provide information about the CAR T-cell efficacy. We here provide a protocol to test CAR T cells in vivo using the validated anti-B-cell marker CD19CAR and an aggressive lymphoma model.

Effects of sub-chronic oral exposure to pyrogenic synthetic amorphous silica (NM-203) in male and female Sprague-Dawley rats: focus on reproductive systems

Synthetic amorphous silica (SAS) consists of agglomerates and aggregates of primary particles in the nanorange (<100 nm) and it is the E551 authorized food additive. The potential risks for human health associated to dietary exposure to SAS are not completely assessed; in particular, data on male and female reproductive systems are lacking. A 90-day oral toxicity study with pyrogenic SAS nanomaterial NM-203 was carried out on the basis of the OECD test guideline 408 in the frame of the NANoREG project. Adult Sprague-Dawley rats of both sexes were orally treated for 90 days with 0, 2, 5, 10, 20 and 50 mg SAS/kg bw per day. Dose levels were selected to be as close as possible to the expected human exposure to food additive E551. The present paper provides specific information on potential effects on male and female reproductive systems, through the evaluation of serum biomarkers, sperm count, histopathological analysis of testis, epididymis, ovary and uterus and real-time PCR on uterus; potential genotoxic alterations were evaluated by comet assay on testis, sperm and ovary. NM-203 did not induce histophatological and genotoxic effects in male reproductive system. In female rats, ovary is not target of NM-203 and only tissue-specific effects on uterus were recorded up to 10 mg/kg bw per day. To our best knowledge, this is the first study providing data on male and female reproductive systems after long-term, repeated oral exposure at dose levels close to dietary human exposure, which identifies a limited concern only for female reproductive health.

Developmental regulation and lateralization of N-methyl-d-aspartate (NMDA) receptors in the rat hippocampus

N-methyl-d-aspartate receptors (NMDARs) are expressed abundantly in the brain and play a crucial role in the regulation of central nervous system (CNS) development, learning, and memory. During early neuronal development, NMDARs modulate neurogenesis, neuronal differentiation and migration, and synaptogenesis. The present study aimed to examine the developmental expression of NMDARs subunits, NR1 and NR2B, in the developing hippocampus of neonatal rats during the first two postnatal weeks. Fifty-four male offspring were randomly divided into three age groups, postnatal days (P) 0, 7, and 14. Real-time-PCR, western blotting, and immunohistochemistry (IHC) analyses were employed to examine and compare the hippocampal expression of the NMDA receptor subunits. The highest mRNA expression of NR1 and NR2B subunits was observed at P7, regardless of its laterality. The mRNA expression of both subunits in the right hippocampus was significantly higher than that of the left one at P0 and P7. Similarly, the highest protein level expression of NR1 and NR2B subunits was also observed at P7 in both sides hippocampi. Although the protein expression of NR1 was significantly higher on the right side in all studied days, the NR2B was significantly higher in the right hippocampus only at P7. The analysis of optical density (OD) has shown a marked increase in the distribution pattern of the NR1 and NR2B subunits at P7 in all hippocampal subregions. In conclusion, there is a marked right-left asymmetry in the expression of NR1 and NR2B subunits in the developing rat hippocampus, which might be considered as a probable mechanism for the lateral differences in the structure and function of the hippocampus in rats.

In vitro and in vivo evaluation of gentamicin sulphate-loaded PLGA nanoparticle-based film for the treatment of surgical site infection

The study focuses on the in vitro and in vivo evaluation of the developed gentamicin sulphate (GS)-loaded poly lactic-co-glycolic acid (PLGA) nanoparticle (PNP)-based pullulan film (PNP-F). Sterilization being an essential pre-requisite for the dosage form was carried out using ethylene oxide. Post-sterilization, PNP-F was evaluated for mechanical properties, percentage drug loading, antimicrobial effectiveness study, test for sterility and in vitro dissolution study using Strat-M® membrane. In vitro dissolution study revealed that GS gradually released from PNP-F and the highest cumulative percentage drug release was found to be 86.76 ± 0.03% at 192 h. Wound healing assay was performed to study the effect of PNP-F over migratory potential of dermal fibroblast cells (NIH-3T3) in the presence of micro-organisms, Pseudomonas aeruginosa (PA) and Staphylococcus aureus (SA). PNP-F inhibited the growth of PA and SA, allowing the growth of fibroblast cells indicating its suitability for application. In vivo study of surgical site was performed by superficial incision model in Wistar rats. Measurement of in vivo incision healing confirmed faster wound healing in the incision which received PNP-F compared to marketed cream containing GS. Graphical abstract.

A novel surgical model for the preclinical assessment of the osseointegration of dental implants: a surgical protocol and pilot study results

BACKGROUND

Dental implants are considered the gold standard replacement for missing natural teeth. The successful clinical performance of dental implants is due to their ability to osseointegrate with the surrounding bone. Most dental implants are manufactured from Titanium and it alloys. Titanium does however have some shortcomings so alternative materials are frequently being investigated. Effective preclinical studies are essential to transfer the innovations from the benchtop to the patients. Many preclinical studies are carried out in the extra-oral bones of small animal models to assess the osseointegration of the newly developed materials. This does not simulate the oral environment where the dental implants are subjected to several factors that influence osseointegration; therefore, they can have limited clinical value.

AIM

This study aimed to develop an appropriate in-vivo model for dental implant research that mimic the clinical setting. The study evaluated the applicability of the new model and investigated the impact of the surgical procedure on animal welfare.

MATERIALS AND METHODS

The model was developed in male New Zealand white rabbits. The implants were inserted in the extraction sockets of the secondary incisors in the maxilla. The model allows a split-mouth comparative analysis. The implants' osseointegration was assessed clinically, radiographically using micro-computed tomography (µ-CT), and histologically. A randomised, controlled split-mouth design was conducted in 6 rabbits. A total of twelve implants were inserted. In each rabbit, two implants; one experimental implant on one side, and one control implant on the other side were applied. Screw-shaped implants were used with a length of 8 mm and a diameter of 2 mm.

RESULTS

All the rabbits tolerated the surgical procedure well. The osseointegration was confirmed clinically, histologically and radiographically. Quantitative assessment of bone volume and mineral density was measured in the peri-implant bone tissues. The findings suggest that the new preclinical model is excellent, facilitating a comprehensive evaluation of osseointegration of dental implants in translational research pertaining to the human application.

CONCLUSION

The presented model proved to be safe, reproducible and required basic surgical skills to perform.

Hippocampal asymmetry and regional dispersal of nAChRs alpha4 and alpha7 subtypes in the adult rat

To better comprehend the relationship between left/right (L/R) differences and hippocampus functions is necessary knowledge of lateral asymmetry and regional distribution. This research was design to examine hippocampal L/R asymmetry and regional distribution profile of the alpha7 and alpha4 subtypes of nicotinic acetylcholine receptors (nAChRs) in the adult rat. 10-12-week-old twenty-four male wistar rats were randomly selected. After removing the brains, immunohistochemistry, real-time PCR, and western blot methods were applied to distinguish the presence of the receptors in the hippocampus. Outcomes stated that the mentioned receptors expression profile was spatial-dependent. As, the hippocampal dispersal of alpha7 and alpha4 subtypes in the left hippocampus (LH) was remarkably maximum compare with the right hippocampus (RH) (p = 0.001, p = 0.005 respectively). Furthermore, the alpha7 optical density (OD) was not significantly different in the diverse regions in hippocampus of adult rat (p = 0.057), while the maximum OD of the alpha4 was detected in the hippocampal dentate gyrus and CA3 regions of LH (p = 0.007, p = 0.009 respectively) and the minimum OD was in the CA1 of the RH (p = 0.019). In real time PCR evaluation, there is a significantly higher expression of alpha7 and alpha4 in LH compared to RH (p = 0.043, p = 0.049 respectively), also, for western blot (p = 0.042, p = 0.030 respectively). According to present data, the alpha7 and alpha4 nAChR subtypes expression profile demonstrated lateral asymmetry, the uniform regional dispersal for alpha7 and different regional dispersal for alpha4 in the adult rat hippocampus.

Vortex-assisted dispersive solid phase microextraction using Fe3O4/FeOOH magnetic nanocomposites for high-performance thin-layer chromatographic determination of zolmitriptan in rabbit plasma samples

In this work, a fast, versatile, and convenient dispersive solid-phase micro-extraction (DSPME) method is combined with a spectro-densitometric technique for the analysis of zolmitriptan (ZOLM) in biological fluids. Fe₃O₄/FeOOH magnetic nanocomposites (MNCs) were prepared by a co-precipitation method in aqueous solutions and utilized subsequently as a sorbent in DSPME. By coupling DSPME with high-performance thin-layer chromatography (HPTLC) with fluorescence detection, the preconcentration and determination of (ZOLM) in presence of metoclopramide (MET) and paracetamol (PARA), which are prescribed as an adjuvant therapy with ZOLM, was accomplished. Adsorption capability was assessed using both Langmuir and Freundlich adsorption isotherm models. The adsorption data was fitted to Langmuir adsorption isotherm model as reflected by high determination coefficient (R² = 0.9944). Moreover, adsorption kinetics was assessed by pseudo-first and pseudo-second order kinetic models. The data was fitted to pseudo-second order kinetics, which proves that ZOLM interaction with the adsorbent is a chemisorption process. Surface complexation with MNCs was suggested to explain the pH dependence of ZOLM sorption. The key parameters of extraction and desorption steps (including pH, extraction time, sample volume, magnetic adsorbent amount, and desorption circumstances) were evaluated. Optimized conditions for solid phase microextraction of ZOLM were pH 2.9, 5.0 mg Fe₃O₄/FeOOH MNCs, 15 min vortex-assisted extraction time and 3 × 200 μL of methanol: 33% ammonia; 4:1 as eluent. The analysis was achieved using ACN: dichloromethane: 33% ammonia (22.5: 6.0: 1.5, v/v/v) as a mobile phase and the fluorescence detection was carried out at 223 nm. The proposed DSPME method was successfully applied for trace quantification of ZOLM in rabbits' plasma (n = 6) after oral administration with a linearity range of 50.0 - 400.0 ng mL^-1 (R² = 0.9931), a detection limit of 12.0 ng mL^-1 and extraction recovery of 97.27-99.89% with an RSD < 2% (n = 9). Moreover, the selectivity of the proposed approach for analysis of ZOLM in the presence of MET and PARA is demonstrated.

Bovine serum albumin/chitosan-nanoparticle bio-complex; spectroscopic study and in vivo toxicological - Hypersensitivity evaluation

This study, investigates the interaction of bovine serum albumin (BSA) with synthesized chitosan nanoparticles (CSNPs) using steady-state fluorescence and UV-vis absorbance spectroscopy as well as picosecond time-resolved fluorescence technique. The fluorescence quenching mechanism of BSA by CSNPs indicates the presence of both static and dynamic mechanism. The loading efficiency of BSA-CSNPs exhibited a decrease by about 6% in neutral pH under physiological temperature. Transmission electron microcopy (TEM) images revealed the Synthesized CSNPs were irregular in shape with size of ~42 nm. The safety and biocompatibility of BSA-CSNPs inside the body was investigated after intraperitoneal (IP) injection of male mice for nine days, analysis of in vivo results, revealed no toxicity with a hypocholesterolemic effect and a predicted mild activation of WBCs due to CSNPs adjuvant and immunogenic peptides in BSA. Accordingly, no signs of hypersensitivity were observed due to the administration of such formulations. The results can be used for a better understanding the interaction of CSNPs within biological protein environment.

Amorphous silica nanoparticles induced spleen and liver toxicity after acute intravenous exposure in male and female rats

Synthetic amorphous silica (SAS) nanomaterial - consisting of aggregates and agglomerates of primary silicon dioxide (SiO₂) particles in the nanorange (<100 nm) - is commonly used as excipient in pharmaceuticals, in cosmetics and as food additive (E551). The available data suggest that SAS nanoparticles (NP) after intravenous (IV) exposure persist in liver and spleen; however, insufficient data exist to verify whether SAS may also induce adverse effects. The aim of the present study was to verify the potential long-term effects of SAS NP (NM-203) on spleen and liver as target organs following short-term exposure. Adult male and female Sprague-Dawley rats were treated by IV injection in the tail vein with a single (1-day) dose (SD) and repeated (5-day) doses (RD) of 20 mg/kg bw per day of SAS dispersed in sterile saline solution as vehicle. Histopathological examinations of target organs were performed after 90 days. Tissue biodistribution and full characterization of NM-203, primary particle size 13-45 nm, was performed within the framework of the Nanogenotox project. No mortality or general toxicity occurred; histopathological analysis showed splenomegaly in the RD group accompanied by inflammatory granulomas in both sexes. Granulomas were also present in liver parenchyma in the RD (both sexes) and SD groups (male only). The histopathological results indicated that SAS NP have the potential to persist and induce sex-specific chronic inflammatory lesions in spleen and liver upon short-term treatment. Overall, the data showed that the widespread use of silica in drugs might elicit chronic reactions in spleen and liver prompting to the need of further investigations on the safety of SAS NP.[Formula: see text].

The Effects of Subcutaneously Injected Novel Biphasic Cross-Linked Hyaluronic Acid Filler: In Vivo Study

BACKGROUND

Biphasic hyaluronic acid (HA) fillers have been used extensively to improve facial skin. However, in some cases, the skin surface is irregular because of the premature loss of HA solution. We propose a new biphasic filler (G-filler) to overcome this problem by using small particles of HA hydrogel instead of HA solution, which can provide a smooth skin surface and good durability.

METHOD

We evaluated the rheologic properties of G-filler and its physiologic effects after subcutaneous injection in a mouse model by histologic analysis.

RESULTS

The G-filler showed a similar elastic modulus (G') and complex viscosity (η*) as the conventional biphasic filler, but had a higher viscous modulus (G″) than the conventional monophasic filler. The highest material elasticity (tan δ) value and the lowest percentage elasticity value indicate the rheologic properties of G-filler are closer to those of liquids. After subcutaneous injection of G-filler, collagen content (~ 2-fold) and elastin fibers (~ 6.5-fold) were significantly increased at 12 weeks compared to those of the saline group. Fibronectin (~ 2.6-fold) and the laminin-immunolabeled cell number (~ 6-fold) were also significantly increased at 12 weeks. Significant increases in the CD31-immunoreactive cell numbers of the G-filler groups were observed at 2, 6, and 12 weeks (~ 3.7-fold) compared to those of the saline groups. There were no significant differences between the G-filler and saline groups in patterns of skin thickness and inflammatory cell numbers around loading sites.

CONCLUSION

These findings demonstrate that the injection of a new biphasic filler with improved rheologic properties can effectively stimulate extracellular matrix production and angiogenesis without safety concerns.

NO LEVEL ASSIGNED

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors - www.springer.com/00266 .

Osseointegration of additive manufacturing Ti-6Al-4V and Co-Cr-Mo alloys, with and without surface functionalization with hydroxyapatite and type I collagen

The introduction of additive manufacturing (AM) technologies has profoundly revolutionized the implant manufacturing industry, with a particularly significant impact on the field of orthopedics. Electron Beam Melting (EBM) and Direct Metal Laser Sintering (DMLS) represents AM fabrication techniques with a pivotal role in the realization of complex and innovative structure starting from virtual 3D model data. In this study, Ti-6Al-4V and Co-Cr-Mo materials, developed by EBM (Ti-POR) and DMLS (Co-POR) techniques, respectively, with hydroxyapatite (Ti-POR + HA; Co-POR + HA) and type I collagen (Ti-POR-COLL; Co-POR-COLL) coatings, were implanted into lateral femoral condyles of rabbits. Osseointegration process was investigated by histological, histomorphometrical and microhardness evaluations at 4 and 12 weeks after implantation. Both Ti-6Al-4V and Co-Cr-Mo implants, with or without HA and COLL coatings, demonstrated good biocompatibility. As expected, HA coating hastened bone-to-implant contact (BIC) process, while collagen did not significantly improved the osseointegration process in comparison to controls. Regarding newly trabecular bone formation (B.Ar/T.Ar), Co-POR presented the highest values, significantly different from those of Co-POR-COLL. Over time, an increase of BIC parameter and a decrease of B.Ar/T.Ar were detected. Higher mineral apposition rate was observed for Ti-POR and Co-POR in comparison to Ti-POR-COLL and Co-POR-COLL, respectively, at 12 weeks. The same behavior was found for bone formation rate between Co-POR and Co-POR-COLL at 12 weeks. In conclusion, the AM materials guarantee a good osseointegration and provide a suitable environment for bone regeneration with the peculiarity of allowing personalized and patient-specific needs customization to further improve the long-term clinical outcomes.

Novel coumarin-pyridazine hybrids as selective MAO-B inhibitors for the Parkinson's disease therapy

The 3-pyridazinylcoumarin scaffold was previously reported as an efficient core for the discovery of reversible and selective inhibitors of MAO-B, a validated drug target for PD therapy which also plays an important role in the AD progress. Looking for its structural optimization, novel compounds of hybrid structure coumarin-pyridazine, differing in polarizability and lipophilicity properties, were synthesized and tested against the two MAO isoforms, MAO-A and MAO-B (compounds 17a-f and 18a-f). All the designed compounds selectively inhibited the MAO-B isoenzyme, exhibiting many of them IC₅₀ values ranging from sub-micromolar to nanomolar grade and lacking neuronal toxicity. The 7-bromo-3-(6-bromopyridazin-3-yl)coumarin (18c), the most potent compound of these series (IC₅₀ = 60 nM), was subjected to further in vivo studies in a reserpine-induced mouse PD model. The obtained results suggest a promising potential for 18c as antiparkinsonian agent. Molecular modeling studies also provided valuable information about the enzyme-drug interactions and the potential pharmacokinetic profile of the novel compounds.

Prenatal bisphenol A exposure contributes to Tau pathology: Potential roles of CDK5/GSK3β/PP2A axis in BPA-induced neurotoxicity

Bisphenol A (BPA) is a well-known endocrine disruptor used to manufacture polycarbonate plastics and epoxy resins. BPA exposure especially occupational perinatal exposure to has been linked to numerous adverse effects for the offspring. Available data have shown that perinatal exposure to BPA contributes to neurodegenerative pathological changes; however, the potential mechanisms remain unclear. This study attempted to investigate the long-term consequences of perinatal exposure to BPA on the offspring mouse brain. The pregnant mice were given either a vehicle control or BPA (2, 10, 100 μg/kg/d) from day 6 of gestation until weaning (P6-PND21, foetal and neonatal exposure). At 3, 6 and 9 months of age, the neurotoxic effects in the offspring in each group were investigated. We found that the spine density but not the dendritic branches in the hippocampus were noticeably reduced at 6 and 9 months of age. Meanwhile, p-Tau, the characteristic protein for tauopathy, was dramatically increased in both the hippocampus and cortex at 3-9 months of age. Mechanically, the balance of kinase and protein phosphatase, which plays critical roles in p-Tau regulation, was disturbed. It indicated that GSK3β and CDK5, two critical kinases, were activated in most of the BPA perinatal exposure group, while protein phosphatase 2A (PP2A), one of the important phosphatases, regulated p-Tau expression through its demethylation, methylation and phosphorylation. Taken together, the present study may be translatable to the human occupational BPA exposure due to a similar exposure level. BPA perinatal exposure causes long-term adverse effects on the mouse brain and may be a risk factor for tauopathies, and the CDK5/GSK3β/PP2A axis might be a promising therapeutic target for BPA-induced neurodegenerative pathological changes.

Pesticide dermal absorption: Case study x in vitro study

In order to evaluate dermal absorption during typical working conditions in family farming, the amount of dimethoate on clothing and in the stratum corneum (SC) was measured in three rural workers. This was achieved by using cotton patches on the worker's clothes and SC quantification by the tape stripping approach. To mimic the above study, an in vitro approach was performed using Franz cells by applying dimethoate (0.4 and 1.8 μg) direct to pig skin or, on a section of cotton before contact with pig skin. The in vivo case results demonstrated the high levels and variability of agrochemicals to which these farmers are subjected, with the total potential dermal absorption between 0.87-2.85 mg/person/h and the estimated SC penetration factor (PF) between 0-54.0 and 0-28.9 % for the back of the neck and the arms respectively. This probably demonstrates the impact of correct protective clothing. For the in vitro study, the amount of pesticide retained in the SC was 52.63 ± 10.73and 135.15 ± 31.8 ng/cm² after applying 0.4 and 1.8 μg of pesticide directly on SC, and demonstrated close agreement with the in vivo approach. Further studies performed with this and other pesticides with different characteristics will contribute to the understanding of their transport through the skin.

Blue light (λ=453 nm) nitric oxide dependently induces β-endorphin production of human skin keratinocytes in-vitro and increases systemic β-endorphin levels in humans in-vivo

β-Endorphin exerts a broad spectrum of physiological activity on mood, immune functions, pain management, reward effects, and behavioral stability. β-Endorphin is produced in certain neurons within the central and peripheral nervous system but also in the skin, especially in response to ultraviolet radiation. In the present study we have investigated the impact of visible blue light at λ = 453 nm (BL) on β-endorphin production of primary human skin keratinocytes (hKC) in-vitro as well as on systemic β-endorphin formation of whole-body exposed subjects in-vivo. We found that BL irradiation significantly enhanced both keratinocytic β-endorphin production of hKC cultures as well as systemic β-endorphin concentrations in light exposed healthy subjects. Interestingly, in hKC cultures elevated β-endorphin formation was paralleled by significantly increased levels of non-enzymatically generated nitric oxide (NO), whereas elevated systemic β-endorphin values of BL-exposed subjects were accompanied by enhanced systemic concentration of bioactive NO-derivates. These findings point to a pivotal role of NO in the molecular mechanism of the observed BL-induced effects, and indeed, exogenously applied NO was able to significantly enhance β-endorphin production in hKC cultures. Thus, our finding of BL-induced increases in systemic β-endorphin concentration in-vivo can be plausibly explained by an event sequence comprising 1.) BL-driven non-enzymatic formation of NO in the exposed skin tissue, 2.) systemic distribution of cutaneously produced NO in the form of bioactive nitroso compounds, 3.) a subsequent NO-dependent induction of β-endorphin synthesis in epidermal keratinocytes, and 4.) probably also a NO-dependent modulation of β-endorphin synthesis in specialized neurons within the central and peripheral nervous system.

Antihyperglycemic activity of Porphyridium cruentum biomass and extra-cellular polysaccharide in streptozotocin-induced diabetic rats

Porphyridium cruentum, known as red microalga, is able to produce extra-cellular polysaccharides (EPs) that have beneficial health effects. In this study, the effect of P. cruentum biomass and EPs with various doses was studied in streptozotocin (STZ)-induced diabetic rats to determine their antihyperglycemic activity and its potential mechanism. The doses of biomass were 600, 1200 and 1800 mg/kg body weight (BW) while the doses of EPs were 150, 300 and 450 mg/kg BW. P. cruentum biomass and EPs could slightly reduce food intake in STZ-diabetic rats as compared with diabetic group. After a 14-day treatment, P. cruentum EPs could decrease blood glucose levels of STZ-induced diabetic rats while P. cruentum biomass at all doses could not. P. cruentum EPs was as effective as glibenclamide in lowering blood glucose levels of diabetic rats. In addition, P. cruentum EPs could significantly increase (p < 0.05) Langerhans islets areas, the number of β-cells and the height of intestinal villi. Treatment with 450 mg/kg BW of EPs resulted in the most effective antihyperglycemic activity. Thus, P. cruentum has the potential to resolve hyperglycemic and diabetic problems.

Tissue diagnosis during colorectal cancer surgery using optical sensing: an in vivo study

Background

In colorectal cancer surgery there is a delicate balance between complete removal of the tumor and sparing as much healthy tissue as possible. Especially in rectal cancer, intraoperative tissue recognition could be of great benefit in preventing positive resection margins and sparing as much healthy tissue as possible. To better guide the surgeon, we evaluated the accuracy of diffuse reflectance spectroscopy (DRS) for tissue characterization during colorectal cancer surgery and determined the added value of DRS when compared to clinical judgement.

Methods

DRS spectra were obtained from fat, healthy colorectal wall and tumor tissue during colorectal cancer surgery and results were compared to histopathology examination of the measurement locations. All spectra were first normalized at 800 nm, thereafter two support vector machines (SVM) were trained using a tenfold cross-validation. With the first SVM fat was separated from healthy colorectal wall and tumor tissue, the second SVM distinguished healthy colorectal wall from tumor tissue.

Results

Patients were included based on preoperative imaging, indicating advanced local stage colorectal cancer. Based on the measurement results of 32 patients, the classification resulted in a mean accuracy for fat, healthy colorectal wall and tumor of 0.92, 0.89 and 0.95 respectively. If the classification threshold was adjusted such that no false negatives were allowed, the percentage of false positive measurement locations by DRS was 25% compared to 69% by clinical judgement.

Conclusion

This study shows the potential of DRS for the use of tissue classification during colorectal cancer surgery. Especially the low false positive rate obtained for a false negative rate of zero shows the added value for the surgeons.

Trail registration This trail was performed under approval from the internal review board committee (Dutch Trail Register NTR5315), registered on 04/13/2015, https://www.trialregister.nl/trial/5175.

Green tea polyphenols and epigallocatechin-3-gallate protect against perfluorodecanoic acid induced liver damage and inflammation in mice by inhibiting NLRP3 inflammasome activation

Perfluorodecanoic acid (PFDA) is a highly toxic food contaminant that is extensively used in food applications as surface antifouling agent. In this present study, we aimed to assess whether green tea polyphenols (GTPs) and epigallocatechin-3-gallate (EGCG) exert protective effects against PFDA-induced liver damage and inflammation in mice. A mouse model to evaluate liver toxicity was established by giving mice drinking water containing different concentrations of PFDA. GTPs or EGCG (0.32%, w/v) were co-administered to mice exposed to PFDA in drinking water. Overall, GTPs and EGCG extended the survival time and inhibited weight loss among mice who received a lower dose of PFDA. Moreover, GTPs and EGCG ameliorated hepatic oxidative stress, cell apoptosis, necrosis, steatosis, edema, and degeneration, reduced hepatic inflammation and NLRP3 inflammasome activation caused by a moderate dose of PFDA. Taken together, these results show that GTPs or EGCG (or green tea intake) supplements can be beneficial for people exposed to PFDA.

In vivo study of microarc oxidation coated Mg alloy as a substitute for bone defect repairing: Degradation behavior, mechanical properties, and bone response

Large segmental bone defect healing remains a great challenge in clinic. Limited by the source of autograft, bone graft substitute tends to be the research focus. In the present study, we propose a strategy by using microarc oxidation (MAO) coated magnesium scaffold as a large segmental bone graft substitute, utilizing its combination of strength, degradability, and controllable corrosion rate. Bare substrate, 10 μm and 20 μm thick MAO coated Mg scaffolds were implanted into ulna bone of New Zealand white rabbits, employing a 15 mm wide bone defect model. The biocompatibility and in vivo degradation of the implants, the bone defect healing response, and mechanical properties of the injured bone were investigated. The surface cytocompatibility evaluation results show that the MAO coated Mg are more suitable for cell proliferation. Micro-CT results show that abundant new bone formed and initially bridged the 15 mm gap at 8 weeks. Histological results indicate the newly formed bone was full of maturation at 12 weeks. Three point bending tests reveal that the injured bone possessed sufficient mechanical strength after 12 weeks. A 3-step in vivo degradation mechanism was proposed for the implants. In summary, we observed an actual trial of 15 mm wide bone defect healing where the newly formed bone bridged the bone gap at 8 weeks successfully. These data suggest a great potential of MAO coated magnesium to be a bone graft substitute.

Application of G-CSF in Congestive Heart Failure Treatment

INTRODUCTION

Congestive Heart Failure (CHF) is a disorder in which the heart is unable to supply enough blood for body tissues. Since heart is an adaptable organ, it overcomes this condition by going under remodeling process. Considering cardiac myocytes are capable of proliferation after MI, stimulation of neovascularization as well as their regeneration might serve as a novel target in cardiac remodeling prevention and CHF treatment. Granulocyte Colony-Stimulating Factor (G-CSF), is a hematopoietic cytokine that promotes proliferation and differentiation of neutrophils and is involved in cardiac repair after MI. So far, this is the first review to focus on GCSF as a novel treatment for heart failure.

METHODS

We conducted a search of some databases such as PubMed for articles and reviews published between 2003 and 2017, with different keywords including "G-CSF", "congestive heart failure", "new therapies for CHF", "filgrastim", "in vivo study".

RESULTS

GCSF exerts its beneficial effects on cardiac repair through either stem cell mobilization or direct angiogenesis promotion. All of which are capable of promoting cardiac cell repair.

CONCLUSION

GCSF is a promising target in CHF-therapy by means of cardiac repair and remodeling prevention through multiple mechanisms, which are effective enough to be used in clinical practice.

In vivo evaluation of a regenerative approach to nasal dorsum augmentation with a polycaprolactone-based implant

Background

Alternative techniques for nasal dorsum augmentation are of paramount importance in reconstructive and plastic surgery. In contrast to autologous cartilage grafts, tissue-engineered grafts can be created de novo and yield low–none donor site morbidity as compared to autologous grafts like rib or ear cartilage. To address this demand, this study investigated the in vivo regenerative potential of polycaprolactone-based implants as an alternative to autologous cartilage grafting during rhinoplasty.

Methods

Implants were placed at the nasal dorsum in two groups of minipigs and kept in situ for 2 and 6 months, respectively. Subsequently, the implants were harvested and examined by histology (hematoxylin–eosin, alcian blue, and safranin O) and immunostaining (collagen I and collagen II). Further analysis was performed to measure diameter and distance of polycaprolactone struts.

Results

Histological examination revealed a persistent formation of connective tissue with some spots resembling a cartilaginous-like matrix after 6 months. In such areas, cells of chondrocyte appearance could be identified. There was a significant decrease in strut diameter but a non-significant difference in strut distance.

Conclusion

Our results indicated that the investigated polycaprolactone-based implants have shown a regenerative and stable nasal dorsum augmentation after 6 months in vivo. Thus, we believe that customized polycaprolactone-based implants could become an alternative technique for nasal dorsum augmentation without the need for autologous cartilage grafts.

Preparation of Responsive Carbon Dots for Anticancer Drug Delivery

Fluorescent carbon dots (CDs) have been extensively utilized as responsive drug nanocarriers to deliver anticancer agents, owing to their facile preparation, excellent water solubility, good photostability, and high quantum yield. Herein, we summarize the protocols for the synthesis and application of responsive CDs toward anticancer drug delivery both in vitro and in vivo. Specially, this chapter includes the preparation and structural characterization of CDs and anticancer prodrug-loaded CDs, in vitro anticancer drug release, in vitro and in vivo fluorescence imaging, and toxicity studies.

Altered deposition of inhaled nanoparticles in subjects with chronic obstructive pulmonary disease

Background

Respiratory tract deposition of airborne particles is a key link to understand their health impact. Experimental data are limited for vulnerable groups such as individuals with respiratory diseases. The aim of this study is to investigate the differences in lung deposition of nanoparticles in the distal lung for healthy subjects and subjects with respiratory disease.

Methods

Lung deposition of nanoparticles (50 and 100 nm) was measured after a 10 s breath-hold for three groups: healthy never-smoking subjects (n = 17), asymptomatic (active and former) smokers (n = 15) and subjects with chronic obstructive pulmonary disease (n = 16). Measurements were made at 1300 mL and 1800 mL volumetric lung depth. Each subject also underwent conventional lung function tests, including post bronchodilator FEV₁, VC, and diffusing capacity for carbon monoxide, D_L,CO. Patients with previously diagnosed respiratory disease underwent a CT-scan of the lungs. Particle lung deposition fraction, was compared between the groups and with conventional lung function tests.

Results

We found that the deposition fraction was significantly lower for subjects with emphysema compared to the other subjects (p = 0.001–0.01), but no significant differences were found between healthy never-smokers and smokers. Furthermore, the particle deposition correlated with pulmonary function tests, FEV_1%Pred (p < 0.05), FEV₁/VC_%Pred (p < 0.01) and D_L,CO (p < 0.0005) when all subjects were included. Furthermore, for subjects with emphysema, deposition fraction correlated strongly with D_L,CO (Pearson’s r = 0.80–0.85, p < 0.002) while this correlation was not found within the other groups.

Conclusions

Lower deposition fraction was observed for emphysematous subjects and this can be explained by enlarged distal airspaces in the lungs. As expected, deposition increases for smaller particles and deeper inhalation. The observed results have implications for exposure assessment of air pollution and dosimetry of aerosol-based drug delivery of nanoparticles.

In vivo study on the slow release of glucose in vacuum fried matrices

In vitro studies have shown that vacuum frying may be an effective process to reduce starch digestibility as it may limit gelatinization; this is significant as overconsumption of starchy foods contributes to obesity and type 2 diabetes. Although in vitro studies are an instrumental tool, in vivo studies allow observation of the overall effect on a living organism. The aim of this research was to assess how in vivo starch digestibility can be reduced when frying under vacuum (9.9 kPa), after feeding Sprague-Dawley rats, while also understanding its relationship to in vitro starch digestibility. Results showed that vacuum-fried dough has a lower degree of gelatinization (∼53.8%) and a maximal blood glucose level at 60 min (slower glycemic response) than atmospheric counterparts (∼98.3% degree of gelatinization and maximal blood glucose level at 30 min). Similarly, in vitro procedures exhibited less rapidly available glucose and higher unavailable glucose fractions in vacuum-fried dough.

A Comparative In Vivo Scrutiny of Biosynthesized Copper and Zinc Oxide Nanoparticles by Intraperitoneal and Intravenous Administration Routes in Rats

During the present time, anti-microbial features of copper (Cu) and zinc oxide (ZnO) nanoparticles (NPs) are extensively used to combat the growth of pathogenic microbes. CuNPs and ZnONPs are recurrently used in cosmetics, medicine and food additives, and their potential for toxic impacts on human and ecosystem is of high concern. In this study, the fate and toxicity of 16- to 96-nm-ranged biosynthesized copper (Bio-CuNPs) and zinc oxide (Bio-ZnONPs) was assessed in male Wistar rats. In vivo exposures of the two nanoparticles are achieved through two different administration routes namely, intraperitoneal (i/p) and intravenous (i/v) injections. The three different concentrations, no observable adverse effect concentration (NOAEC), inhibitory concentration (IC₅₀) and total lethal concentration (TLC), were appraised at the dose range of 6.1 to 19.82 μg/kg and 11.14 to 30.3 μg/kg for Bio-CuNPs and Bio-ZnONPs respectively, for both i/p and i/v routes on 14th and 28th day of observation. These dose ranges are considered based on the previous study of antibacterial dose on multidrug-resistant pathogenic bacteria. In this study, we investigated the toxic effect of Bio-CuNPs and Bio-ZnONPs on animal behaviour, animal mass, haematologic indices, organ indices and histopathology of liver, spleen, kidney and brain organs. We found that i/v and i/p administration of Bio-ZnONPs in three different doses did not cause mortality and body weight was slightly reduced up to second week of administration compared with the vehicle control group. At the dose ranges of 11-16 μg/kg (i/v) and 24-30 μg/kg (i/p), no significant changes were observed in the serum creatinine level as well as serum ALT, serum AST level and ALP level which were 40.7 mg/dl, 37.9 IU/L and 82.4 IU/L normal as compared to vehicle control on 14th and 28th day of observation. These findings are confirmed in liver, kidney and spleen indices and histopathology studies. Furthermore, liver and kidney injury occurred when the concentrations of Bio-CuNPs were at 9.5 μg/kg (IC₅₀) and 11.7 μg/kg (TLC) for i/v route of administration. Similarly, increase in serum ALT (67.7 mg/dl), AST level (70 IU/L) and ALP (128 IU/L) was also observed. And the body weight was significantly lower than in the control group after 14th day, and there were statistically significant differences observed by this route; interestingly, the toxicity of Bio-CuNPs in serum is prolonged (up to 28th day). Effect of Bio-CuNPs through i/p route was considerably low as compare to the control. Results of the present study revealed that Bio-ZnONPs have no effect on kidney and liver function biomarkers (both i/v and i/p) as compared to Bio-CuNPs. Graphical abstract As shown in graphical abstract (Fig. 1), our aim is to assess the toxicity of Bio-CuNPs and Bio-ZnONPs through in vivo protocol. According to Kahru and Dubourguier reviews, AgNPs, CuNPs and ZnONPs have been historically used as biocides, for preventing the growth of microorganisms and algae (Kahru and Dubourguier 2010). Therefore, as like pesticides, nanomaterials should be monitored for their toxic response toward non-target species, including humans and animals. To gain a better understanding whether the accidental release of metal-containing NPs may pose a threat to non-target species, assessing of toxic effect is indispensable.The 'non-target organism' is an organism which will be exposed to NPs after their incidental release into the environment.

Simultaneous size characterization and mass quantification of the in vivo core-biocorona structure and dissolved species of silver nanoparticles

Size characterization of silver nanoparticles with biomolecule corona (AgNP@BCs) and mass quantification of various silver species in organisms are essential for understanding the in vivo transformation of AgNPs. Herein, we report a versatile method that allows simultaneous determination of the size of AgNP@BCs and mass concentration of various silver species in rat liver. Both particulate and ionic silver were extracted in their original forms from the organs by alkaline digestion, and analyzed by size exclusion chromatography combined with inductively coupled plasma mass spectrometry (SEC-ICP-MS). While the silver mass concentrations were quantified by ICP-MS with a detection limit of 0.1μg/g, the effective diameter of AgNP@BCs was determined based on the retention time in SEC separation with size discrimination of 0.6-3.3nm. More importantly, we found that the BC thickness of AgNP@BCs is core size independent, and a linear correlation was found between the effective diameter and core diameter of AgNP@BCs in extracted tissues, which was used to calibrate the core diameter with standard deviations in the range of 0.2-1.1nm. The utility of this strategy was demonstrated through application to rat livers in vivo. Our method is powerful for investigating the transformation mechanism of AgNPs in vivo.

First ex vivo and preliminary sheep model results of the new TRIBIO aortic valve bioprosthesis in small aortic annuli

OBJECTIVES

Small aortic annuli are challenging in aortic valve replacement. Prosthesis-patient mismatch, accompanied by high transvalvular gradients and small orifice area, is an often faced problem impairing postoperative outcome. The new TRIBIO bioprosthesis aims to enable enhanced haemodynamics, being increasingly important with decreasing annular size. This study compares ex vivo hydrodynamics of TRIBIO with 2 established bioprostheses in small annuli at different stroke volumes, simulating 'rest' and 'exercise', and evaluates haemodynamics of TRIBIO in a sheep model.

METHODS

Ex vivo: Porcine aortic roots were hardened with glutaraldehyde, approaching the stiffness of decalcified roots. Each bioprosthesis (TRIBIO, Trifecta™, Perimount® Magna Ease), size 19 mm, was implanted in each aortic root and inserted into a pulse duplicator, determining hydrodynamics and geometric orifice area at different stroke volumes (74, 90, 104 ml). Sheep model: Postoperative transvalvular gradients were assessed after implantation of 19 mm TRIBIO in aortic position.

RESULTS

Ex vivo: Mean transvalvular gradients were lowest in TRIBIO (7.3, 8.7, 10.2 mmHg at 74, 90, 104 ml) with significant difference to Perimount® Magna Ease. Geometric orifice area in TRIBIO was 2.7 cm2 and significantly larger compared to Perimount® Magna Ease and Trifecta™. Opening of TRIBIO was uniform and apparently complete, whereas leaflet's outward movement was restricted particularly in Perimount® Magna Ease. Sheep model: TRIBIO presented with low transvalvular gradients (δpmean 4.1 ± 2 mmHg, δpmax 7.8 ± 4.6 mmHg), unimpaired leaflet motion and no central or paravalvular leakage.

CONCLUSIONS

Ex vivo, the TRIBIO achieved superior hydrodynamics compared to latest generation bioprostheses. These excellent data are supported by very low transvalvular gradients in a preliminary sheep model.

In vivo study of microarc oxidation coated biodegradable magnesium plate to heal bone fracture defect of 3mm width

Microarc oxidation (MAO) coated magnesium (Mg) with improved corrosion resistance appeal increasing interests as a revolutionary biodegradable metal for fractured bone fixing implants application. However, the in vivo corrosion degradation of the implants and bone healing response are not well understood, which is highly required in clinic. In the present work, 10μm and 20μm thick biocompatible MAO coatings mainly composed of MgO, Mg₂SiO₄, CaSiO₃ and Mg₃(PO₄)₂ phases were fabricated on AZ31 magnesium alloy. The electrochemical tests indicated an improved corrosion resistance of magnesium by the MAO coatings. The 10μm and 20μm coated and uncoated magnesium plates were separately implanted into the radius bone fracture site of adult New Zealand white rabbits using a 3mm width bone fracture defect model to investigate the magnesium implants degradation and uninhibited bone healing. Taking advantage of the good biocompatibility of the MAO coatings, no adverse effects were detected through the blood test and histological examination. The implantation groups of coated and uncoated magnesium plates were both observed the promoting effect of bone fracture healing compared with the simple fracture group without implant. The releasing Mg²⁺ by the degradation of implants into the fracture site improved the bone fracture healing, which is attributed to the magnesium promoting CGRP-mediated osteogenic differentiation. Mg degradation and bone fracture healing promoting must be tailored by microarc oxidation coating with different thickness for potential clinic application.

Effects of curcumin-loaded PLGA nanoparticles on the RG2 rat glioma model

BACKGROUND

Curcumin, the active ingredient of turmeric, has a remarkable antitumor activity against various cancers, including glioblastoma. However, it has poor absorption and low bioavailability; thus, to cross the blood-brain barrier and reach tumor tissue, it needs to be transferred to tumor site by special drug delivery systems, such as nanoparticles.

OBJECTIVE

We aimed to evaluate the antitumor activity of curcumin on glioblastoma tissue in the rat glioma-2 (RG2) tumor model when it is loaded on poly(lactic-co-glycolic acid)-1,2-distearoyl-glycerol-3-phospho-ethanolamine-N-[methoxy (polyethylene glycol)-2000] ammonium salt (PLGA-DSPE-PEG) hybrid nanoparticles.

METHODS

Glioblastoma was induced in 42 adult female Wistar rats (250-300g) by RG2 tumor model. The curcumin-loaded nanoparticles were injected by intravenous (n=6) or intratumoral route (n=6). There were five control groups, each containing six rats. First control group was not applied any treatment. The remaining four control groups were given empty nanoparticles or curcumin alone by intravenous or intratumoral route, respectively. The change in tumor volume was assessed by magnetic resonance imaging and histopathology before and 5days after drug injections.

RESULTS

Tumor size decreased significantly after 5days of intratumoral injection of curcumin-loaded nanoparticle (from 66.6±44.6 to 34.9±21.7mm³, p=0.028), whereas it significantly increased in nontreated control group (from 33.9±21.3 to 123.7±41.1mm³, p=0.036) and did not significantly change in other groups (p>0.05 for all).

CONCLUSION

In this in vivo experimental model, intratumoral administration of curcumin-loaded PLGA-DSPE-PEG hybrid nanoparticles was effective against glioblastoma. Curcumine-loaded nanoparticles may have potential application in chemotherapy of glioblastoma.

Nose to brain delivery in rats: Effect of surface charge of rhodamine B labeled nanocarriers on brain subregion localization

Nose to brain delivery and nanotechnology are the combination of innovative strategies for molecules to reach the brain and to bypass blood brain barriers. In this work we investigated the fate of two rhodamine B labeled polymeric nanoparticles (Z-ave <250nm) of opposite surface charge in different areas of the brain after intranasal administration in rats. A preliminary screening was carried out to select the suitable positive (chitosan/poly-l-lactide-co-glycolide) nanocarrier through photon correlation spectroscopy and turbiscan. Physico-chemical and technological characterizations of poly-l-lactide-co-glycolide (negative) and chitosan/poly-l-lactide-co-glycolide (positive) fluorescent labeled nanoparticles were performed. The animals were allocated to three groups receiving negative and positive polymeric nanoparticles via single intranasal administration or no treatment. The localization of both nanocarriers in different brain areas was detected using fluorescent microscopy. Our data revealed that both nanocarriers reach the brain and are able to persist in the brain up to 48h after intranasal administration. Surface charge influenced the involved pathways in their translocation from the nasal cavity to the central nervous system. The positive charge of nanoparticles slows down brain reaching and the trigeminal pathway is involved, while the olfactory pathway may be responsible for the transport of negatively charged nanoparticles, and systemic pathways are not excluded.

Acceleration of bone regeneration in bioactive glass/gelatin composite scaffolds seeded with bone marrow-derived mesenchymal stem cells over-expressing bone morphogenetic protein-7

In this research, the osteoinduction effect of a novel variant of bone morphogenetic protein-7 (BMP-7), delivered through bone marrow mesenchymal stem cells (BM-MSCs) seeded on bioactive glass/gelatin nanocomposite scaffolds, was evaluated in a calvarial critical size defect in rats. After being harvested and characterized in vitro, BM-MSCs were infected by a plasmid vector containing BMP-7 encoding gene enriched with a heparin-binding site (B2BMP-7) to assess its osteogenic effects in vivo. The animals were randomly categorized into three groups receiving the scaffold alone (group I), the scaffold seeded with BM-MSCs (group II), and the scaffold seeded with manipulated BM-MSCs (group III). After 2, 4 and 12 postoperative weeks, the animals were sacrificed and the harvested specimens were analyzed using histological and immunohistochemical staining. The results of in vitro tests (preliminary screening) showed that the synthesized scaffolds were biocompatible constructs supporting cell attachment and expansion. The in vivo results revealed higher osteogenesis in the defects filled with the B2BMP-7 excreting BM-MSCs/scaffolds compared to the other two groups. After 12weeks of implantation, fully mature newly formed bone was detected throughout the damaged site, which indicates a synergistic effect of cells, scaffolds and growth factors in the process of tissue regeneration. Therefore, bioactive glass-containing scaffolds pre-seeded with manipulated BM-MSCs exhibit an effective combination to improve osteogenesis in bone defects, and the approach followed in this work could have a significant impact in the development of novel tissue engineering constructs.

Slow lung clearance and limited translocation of four sizes of inhaled iridium nanoparticles

Background

Concerns have been expressed that inhaled nanoparticles may behave differently to larger particles in terms of lung clearance and translocation, with potential implications for their toxicity. Studies undertaken to investigate this have typically involved limited post-exposure periods. There is a shortage of information on longer-term clearance and translocation patterns and their dependence on particle size, which this study aimed to address.

Methods

Rats were exposed (<3 h) nose-only to aerosols of spark-generated radioactive iridium-192 nanoparticles of four sizes: 10 nm, 15 nm, 35 nm and 75 nm (count median diameter) (aerosol mass concentrations 17, 140, 430, and 690 μg/m³, respectively). The content of iridium-192 in the whole animal, organs, tissues, and excreta was measured at various times post-exposure to ≥ 1 month. Limited toxicological investigations were undertaken for the 10 nm aerosol using bronchoalveolar lavage fluid. Elemental maps of tissue samples were produced using laser ablation inductively coupled plasma mass spectrometry and synchrotron micro-focus x-ray fluorescence. The chemical speciation of the iridium was explored using synchrotron micro focus x-ray near-edge absorption spectroscopy.

Results

Long-term lung retention half-times of several hundred days were found, which were not dependent on particle size. There was significant variation between individual animals. Analysis of bronchoalveolar lavage fluid for the 10 nm aerosol indicated a limited inflammatory response resolving within the first 7 days. Low levels of, particle size dependent, translocation to the kidney and liver were found (maximum 0.4% of the lung content). Any translocation to the brain was below the limits of detection (i.e. < 0.01% of the lung content). The kidney content increased to approximately 30 days and then remained broadly constant or decreased, whereas the content in the liver increased throughout the study. Laser ablation inductively coupled plasma mass spectrometry analysis indicated homogeneous iridium distribution in the liver and within the cortex in the kidney.

Conclusions

Slow lung clearance and a pattern of temporally increasing concentrations in key secondary target organs has been demonstrated for inhaled iridium aerosol particles < 100 nm, which may have implications for long-term toxicity, especially in the context of chronic exposures.

Electronic supplementary material

The online version of this article (doi:10.1186/s12989-017-0185-5) contains supplementary material, which is available to authorized users.

Chlorambucil conjugates of dinuclear p-cymene ruthenium trithiolato complexes: synthesis, characterization and cytotoxicity study in vitro and in vivo

Four diruthenium trithiolato chlorambucil conjugates have been prepared via Steglich esterification from chlorambucil and the corresponding trithiolato precursors. All conjugates are highly cytotoxic towards human ovarian A2780 and A2780cisR cancer cell lines with IC50 values in the nanomolar range. The conjugates exhibit selectivity towards A2780 cells as compared to non-cancerous HEK293 cells, while being only slightly selective for RF24 and A2780cisR cells. In vivo, the conjugate [10]BF4 suppressed the growth of a solid Ehrlich tumor in immunocompetent NMRI mice but did not prolong their overall survival. The reactivity of the chlorambucil conjugates with glutathione, a potential target of the dinuclear ruthenium motive, and with the 2-deoxyguanosine 5'-monophosphate (dGMP-a model target of chlorambucil) was studied by mass spectrometry and NMR spectroscopy. The conjugates did not show catalytic activity for the oxidation of glutathione nor binding to nucleotides, indicating that glutathione oxidation and DNA alkylation are not key mechanisms of action. Four highly cytotoxic diruthenium trithiolato chlorambucil conjugates have been prepared. All conjugates exhibit selectivity towards A2780 cells as compared to HEK293 cells, while being only slightly active in RF24 and A2780cisR cells. In vivo, the best candidate suppressed the growth of a solid Ehrlich tumor in immunocompetent NMRI mice but did not prolong their overall survival.

Biological markers of mesenchymal stromal cells as predictors of response to autologous stem cell transplantation in patients with amyotrophic lateral sclerosis: an investigator-initiated trial and in vivo study

Bone marrow mesenchymal stromal cells (MSCs) can modify disease progression in amyotrophic lateral sclerosis (ALS) model. However, there are currently no accurate biological markers for predicting the efficacy of autologous MSC transplants in ALS patients. This open-label, single-arm, investigator-initiated clinical study was designed to identify markers of MSCs that could be used as potential predictors of response to autologous MSC therapy in patients with ALS. We enrolled 37 patients with ALS who received autologous MSCs via intrathecal injection in two monthly doses. After a 6-month follow-up period, the patients were categorized as responders and non-responders based on their scores on the revised ALS Functional Rating Scale (ALSFRS-R). Biological markers including β-fibroblast growth factor-2, stromal cell-derived factor-1α, vascular endothelial growth factor (VEGF), insulin-like growth factor-1, brain-derived neurotrophic factor, angiogenin (ANG), interleukin (IL)-4, IL-10, and transforming growth factor-β (TGF-β) were measured in the MSC cultures and their levels were compared between the responders and nonresponders. To confirm the markers' predictive ability, MSCs isolated from one patient in each group were transplanted into the cisterna magna of mutant SOD1(G93A) transgenic mice to measure their lifespans, locomotor activity, and motor neuron numbers. The levels of VEGF, ANG, and TGF-β were significantly higher in responders than in nonresponders. In the mouse model, the recipients of responder MSCs had a significantly slower onset of symptoms and a significantly longer lifespan than the recipients of nonresponders or controls. Our data suggest that VEGF, ANG, and TGF-β levels in MSCs could be used as potential biological markers to predict the effectiveness of autologous MSC therapy and to identify those patients who could optimally benefit from MSC treatment.

In vivo analysis of IgE autoantibodies in bullous pemphigoid: a study of 100 cases

BACKGROUND

Bullous pemphigoid (BP) is an acquired autoimmune blistering disease characterized by subepidermal blister formation, in vivo linear deposition of immunoglobulin G (IgG) and complements at the dermal-epidermal junction (DEJ). The circulating IgG autoantibodies are directed against two epidermal hemidesmosomal glycoproteins: BP180, also known as type XVII collagen (COL17), and BP230. In addition, recent studies have shown that IgE autoantibodies may be involved in the pathogenesis of BP, although in vivo IgE deposition in lesional skin has not been fully characterized in large numbers of BP patients.

OBJECTIVE

This study investigated the incidence of in vivo deposition of IgE autoantibodies at the DEJ in lesional skin from a large number of BP patients.

METHODS

Peri-lesional skin samples from 100 patients who met the clinical and histopathological criteria for BP were investigated by direct immunofluorescence for the deposition of autoantibodies and complement. Patients' sera were also investigated by enzyme-linked immunosorbent assay and indirect immunofluorescence.

RESULTS

18% of BP patients were found to show IgE deposition at the DEJ. Disease severity, clinical course and outcome did not differ between IgE-positive and IgE-negative patients. In 3 IgE-positive cases, IgG was undetectable in vivo, and these cases showed atypical manifestations.

CONCLUSION

The results of in vivo IgE deposition may not be useful in predicting the disease course of BP, although predominant IgE deposition could alter the pattern of clinical manifestations.

Evaluation of anti-inflammatory, analgesic, and antipyretic activities of the ethanol extract from Murdannia loriformis (Hassk.) Rolla Rao et Kammathy

Introduction:Murdannia loriformis (hassk) Rolla Roa et Kammathy, family Commelinaceae, is used by Chinese practitioners as a remedy for cancer in an early stage, and also for treating other diseases including colds, throat infections, pneumonia, diabetes mellitus, flu and inflammation. Although anticancer as well as other pharmacological effects of M. loriformis have been reported, its anti-inflammatory and other activities related to inflammation are still limited.

Methods: The anti-inflammatory activity was evaluated using carrageenan- and arachidonic acid-induced paw edema in rats, and cotton pellet-induced granuloma formation in rats. The analgesic and antipyretic activities were determined by formalin test in mice and yeast-induced hyperthermia in rats, respectively.

Results: The ethanol extract of the aerial part of M. loriformis exhibited anti-inflammatory activity on the rat paw edema induced by carrageenan and arachidonic acid. It also showed an inhibitory effect on the granuloma and the transudative formation of the rat implanted with cotton pellets as well as lowered the elevated serum alkaline phosphatase activity to normal level. It exerted potent analgesic effect on both the early and late phase of formalin test as well as the antipyretic effect on yeast-induced hyperthermic rats. The oral single high dose of the extract of 5,000 mg/Kg did not produce death or any abnormalities or changes of the internal organs of rats during 14 days of the observed period.

Conclusion: The results obtained from this study support the use of the plant in traditional medicine for inflammatory ailments.

[Effect of SSRIs on bone metabolism]

INTRODUCTION

SSRIs have been shown to affect bone health in adults, but this has been poorly studied in children. Given the frequency of SSRI prescription in children and adolescents, it is crucial to evaluate the impact of SSRIs on bone growth because the bone mass attained early in life is the most important predictor of a normal bone constitution. Experimental studies have demonstrated a direct functional role of serotonin in bone metabolism, independently of hyperprolactinemia or growth hormone levels. We have reviewed the literature on serotonin and bone metabolism, including experimental studies, clinical studies in adults as well as in the pediatric population.

EXPERIMENTAL STUDIES

Experimental studies have shown that 5-HT transporter (5-HTT) is expressed in all kind of bone cells and is highly specific of the 5-HT recapture. 5-HTT inhibition by the SSRIs in these cells affects their function in vitro. Even though a few studies have suggested exposure to SSRIs could be beneficial by an anabolic effect on the trabecular bone, more concluding studies have demonstrated that SSRIs negatively affect bone growth, resulting in a specific bone phenotype including a reduction in bone mass, an altered bone architecture, and decreased mechanical properties. This phenotype is most probably the consequence of a decrease in bone formation, rather than an increase in bone resorption and is a direct and dose-dependent effect. However, many aspects of this bone effect of 5-HTT inhibition need to be further clarified, including the signal ways for 5-HTT and 5-HT receptors, origins of 5-HT in bone, and methods to isolate the inhibitory effect of 5-HTT specifically on bone.

CLINICAL STUDIES

Metabolic and neuroendocrine side effects have been documented in children and adolescents taking SSRIs but the specific and direct effect of these molecules on bone metabolism has been poorly studied in this population. In adults, clinical studies have shown an association between the use of SSRIs and bone demineralization as well as reduction in bone mass, especially in the elderly and post-menopausal women. However, depression itself has been associated with a lower bone mass and increased risk of osteoporosis. In children, case reports show a decrease in growth due to a decreased secretion of growth hormone, but not by a direct effect. One cross-sectional study suggests a decrease in bone mass following SSRI treatment that is independent of variation in prolactin levels, but without elevation of fracture risk. These results, however, need to be replicated in further studies.

CONCLUSION

Our review shows that experimental studies have demonstrated the implication of the serotonin system in bone metabolism. Mice with genetic disruption of 5-HTT have a bone phenotype of decreased bone mass, altered architecture, and decreased mechanical properties. Clinical studies exploring the effect of SSRIs on bone metabolism are scarce in children. However, results in adults tend to show a deleterious effect in the elderly. Regarding the frequency of SSRI prescription in the pediatric population, it is becoming urgent to better explore the effect of SSRIs on bone growth of children, as it can have major implications on the ulterior follow-up and on the precautions to take.