Reference database of the main physiological parameters in Sprague-Dawley rats from 6 to 32 months

Optimizing environmental enrichment for Sprague Dawley rats: Exemplary insights into the liver proteome

BACKGROUND

Considering the expected increase in the elderly population and the growing emphasis on aging-related biomedical research, the demand for aged laboratory animals has surged, challenging established husbandry practices. Our objective was to establish a cost-effective method for environmental enrichment, utilizing the liver as a representative organ to assess potential metabolic changes in response to differing enrichment levels.

METHODS

We conducted a six-month study involving 24 male Sprague Dawley rats, randomly assigned to four environmental enrichment groups. Two groups were housed in standard cages, while the others were placed in modified rabbit cages. Half of the groups received weekly playtime in an activity focused rat housing unit. We evaluated hormone levels, playtime behavior, and subjective handling experience. Additionally, liver tissue proteomic analysis was performed.

RESULTS

Initial corticosterone levels and those after 3 and 6 months showed no significant differences. Yet, testosterone levels were lower in the control group by the end of the study (p = 0.007). We observed 1871 distinct proteins in liver tissue, with 77% being common across groups. In gene ontology analysis, no specific pathways were overexpressed. In semiquantitative analysis, we observed differences in proteins associated in lipid metabolism such as Apolipoprotein A-I and Acyl-CoA 6-desaturase, which were lower in the control group (p = 0.024 and p = 0.009). Rats in the intervention groups with weekly playtime displayed the least amount of reported distress during inspection or upon room entry and were less prone to accepting treats. Removing animals from their enclosure was most effortless for those in the large cage group. Over time, there was a decrease in conflicts among rats that interacted only twice weekly during playpen time.

DISCUSSION

In summary, refining husbandry practices for aging rats is both simple and budget-friendly, with no apparent adverse effects on stress levels, animal development, or relevant metabolic changes in the liver.

Hematotoxic Effect of Respiratory Exposure to PHMG-p and Its Integrated Genetic Analysis

Polyhexamethylene guanidine phosphate (PHMG-p), the main ingredient of humidifier disinfectants, circulates systemically through the lungs; however, its toxicological assessment has been primarily limited to pulmonary disease. Herein, we investigated the possible abnormalities in hematopoietic function 20 weeks after intratracheal instillation of PHMG-p in a rat model. Notable abnormalities were found out in the peripheral blood cell count and bone marrow (BM) biopsy, while RNA sequencing of BM tissue revealed markedly altered gene expression. Furthermore, signaling involved in hematopoietic dysfunction was predicted by analyzing candidate genes through Ingenuity Pathway Analysis (IPA) program. Respiratory PHMG-p exposure significantly decreased monocyte and platelet (PLT) counts and total protein, while significantly increasing hemoglobin and hematocrit levels in peripheral blood. Histopathological analysis of the BM revealed a reduced number of megakaryocytes, with no significant differences in spleen and liver weight to body weight. Moreover, PHMG-p exposure significantly activated estrogen receptor signaling and RHOA signaling, and inhibited RHOGDI signaling. In IPA analysis, candidate genes were found to be strongly related to 'hematological system development and function' and 'hematological disease.' Accordingly, our results suggest that PHMG-p could affect hematopoiesis, which participates in monocyte differentiation and PLT production, and may induce hematologic diseases via the respiratory tract.

Low-Fouling Zwitterionic Polymeric Colloids as Resuscitation Fluids for Hemorrhagic Shock

Colloids, known as volume expanders, have been used as resuscitation fluids for hypovolemic shock for decades, as they increase plasma oncotic pressure and expand intravascular volume. However, recent studies show that commonly used synthetic colloids have adverse interactions with human biological systems. In this work, a low-fouling amine(N)-oxide-based zwitterionic polymer as an alternative volume expander with improved biocompatibility and efficacy is designed. It is demonstrated that the polymer possesses antifouling ability, resisting cell interaction and deposition in major organs, and is rapidly cleared via renal filtration and hepatic circulation, reducing the risk of long-term side effects. Furthermore, in vitro and in vivo studies show an absence of adverse effects on hemostasis or any acute safety risks. Finally, it is shown that, in a head-to-head comparison with existing colloids and plasma, the zwitterionic polymer serves as a more potent oncotic agent for restoring intravascular volume in a hemorrhagic shock model. The design of N-oxide-based zwitterionic polymers may lead to the development of alternative fluid therapies to treat hypovolemic shock and to improve fluid management in general.

Degradation of mycotoxins in mixtures by combined proteinous nanobiocatalysts: In silico, in vitro and in vivo

New combined proteinous (enzymatic) nanobiocatalysts capable of destructing mycotoxins in mixtures were developed and investigated in vitro and in vivo. Candidate enzymes for such combined biocatalysts were computationally screened using molecular docking of mycotoxins to the proteins. Catalytic characteristics of the 7 selected enzymes were estimated in the potential reactions with various mycotoxins (aflatoxin B₁, citrinin, deoxynivalenol, ergotamine, fumonisin B₁, gliotoxin, ochratoxin A, patulin, sterigmatocystin, T-2 toxin, zearalenone) at different pH values. To stabilize the enzymes hydrolyzing the mycotoxins, special biopolymers were selected using computer modeling. The poly(glutamic acid) was revealed as universal partner for the polyelectrolyte complexes with the selected enzymes. Finally, Sprague-Dawley rats were used for in vivo feeding experiments with feed contaminated by mycotoxin mixture at doses being up to orders of magnitude higher than maximum allowable limits. The treatment of contaminated feed by novel combined enzyme nanocomplexes significantly decreased negative effects of mycotoxin mixture on blood biochemical parameters which indicated huge damage to liver and kidneys of intoxicated animals. Such nanobiocatalysts and enzymatic treatment itself seem to be promising way for ensuring both food and feed chemical safety.

Immunological and Safety Profile of Bacteriophages Therapy: A preclinical Study

AIMS

Numerous pre-clinical and clinical studies have recently demonstrated the significant role of phage therapy in treating multidrug-resistant bacterial infections. However, only a few researchers have focused on monitoring the phage-mediated adverse reactions during phage therapy. The present study aimed to demonstrated the oral acute and sub-acute toxicity of bacteriophages (Klebsiella pneumoniae XDR strain) in Charles Foster rats with special reference to immunological response and adverse effects.

METHODS AND RESULTS

Bacteriophages were orally administered in dosages of 10¹⁰ PFU/mL and a 10¹⁵ PFU/mL to Charles Foster rats as a single dose (in acute toxicity study) and daily dosage for 28 days (in sub-acute toxicity study). One milliliter suspension of bacteriophages was administered through the oral gavage feeding tube. No adverse effect was observed in any of the experimental as well as in the control animals. Further, an insignificant change in food and water intake and body weight was observed throughout the study period compared with the control group rats. On the 28^th day of phage administration, blood was collected to estimate haematological, biochemical, and cytokines parameters. The data suggested no difference in the haematological, biochemical, and cytokine profile compared to the control group. No significant change in any of the treatment groups could be observed on the gross and histopathological examinations. The cytokines estimated, interleukin-1 beta (IL-1β), IL-4, IL-6, and IFN-gamma, were found within the normal range during the experiment.

CONCLUSIONS

The results concluded that no adverse effect, including the severe detrimental impact on oral administration of high (10¹⁰ PFU/mL) and very high dose (10¹⁵ PFU/mL) of the bacteriophages cocktail.

SIGNIFICANCE AND IMPACT OF STUDY

The high and long-term oral administration of bacteriophages did not induce noticeable immunological response as well.

Sex Differences in Intestinal P-Glycoprotein Expression in Wistar versus Sprague Dawley Rats

Wistar and Sprague Dawley are the most common strains of rat used in pharmaceutical research and are used interchangeably in pre-clinical drug development. No studies have assessed whether Wistar and Sprague Dawley rats are equivalent in the gastrointestinal factors that influence oral drug absorption, specifically in relation to intestinal transporters. Enzyme-linked immunosorbent assay (ELISA) and liquid chromatography–tandem mass spectrometry (LC-MS/MS) are two reliable methods for quantifying intestinal protein levels with their own distinct advantages and limitations. In this study, P-glycoprotein (P-gp), a key efflux transporter, was quantified using ELISA and LC-MS/MS along the complete intestinal tract of male and female Wistar and Sprague Dawley rats. This work presents that Sprague Dawley rats have innately higher baseline P-gp expression than Wistar rats. Significant sex differences in P-gp expression were identified in the jejunum, ileum and colon between male and female Wistar rats using both techniques, with males exhibiting higher P-gp levels. Sprague Dawley rats showed no sex differences in P-gp expression through ELISA and LC-MS/MS. Both methods demonstrated similar trends for P-gp quantification, but ELISA could offer faster data acquisition. Our findings report significant sex differences between the strains and highlight that Wistar and Sprague Dawley rats are not equivalent in their P-gp expression. As humans exhibit distinct sex differences in intestinal P-gp levels, Wistar rats may therefore be a more suitable pre-clinical animal strain to model oral drug absorption of P-gp substrates in male and female subjects.

Targeted Intervention of NF2-YAP Signaling Axis in CD24-Overexpressing Cells Contributes to Encouraging Therapeutic Effects in TNBC

Triple-negative breast cancer (TNBC) cells have not been usefully classified, and no targeted therapeutic plans are currently available, resulting in a high recurrence rate and metastasis potential. In this research, CD24^high cells accounted for the vast majority of TNBC cells, and they were insensitive to Taxol but sensitive to ferroptosis agonists and effectively escaped phagocytosis by tumor-associated macrophages. Furthermore, the NF2-YAP signaling axis modulated the expression of ferroptosis suppressor protein 1 (FSP1) and CD24 in CD24^high cells, with subsequent ferroptotic regulation and macrophage phagocytosis. In addition, a precision targeted therapy system was designed based on the pH level and glutathione response, and it can be effectively used to target CD24^high cells to induce lysosomal escape and drug burst release through CO₂ production, resulting in enhanced ferroptosis and macrophage phagocytosis through FSP1 and CD24 inhibition mediated by the NF2-YAP signaling axis. This system achieved dual antitumor effects, ultimately promoting cell death and thus inhibiting TNBC tumor growth, with some tumors even disappearing. The composite nanoprecision treatment system reported in this paper is a potential strategic tool for future use in the treatment of TNBC.

Pre-Clinical Models in Implant Dentistry: Past, Present, Future

Biomedical research seeks to generate experimental results for translation to clinical settings. In order to improve the transition from bench to bedside, researchers must draw justifiable conclusions based on data from an appropriate model. Animal testing, as a prerequisite to human clinical exposure, is performed in a range of species, from laboratory mice to larger animals (such as dogs or non-human primates). Minipigs appear to be the animal of choice for studying bone surgery around intraoral dental implants. Dog models, well-known in the field of dental implant research, tend now to be used for studies conducted under compromised oral conditions (biofilm). Regarding small animal models, research studies mostly use rodents, with interest in rabbit models declining. Mouse models remain a reference for genetic studies. On the other hand, over the last decade, scientific advances and government guidelines have led to the replacement, reduction, and refinement of the use of all animal models in dental implant research. In new development strategies, some in vivo experiments are being progressively replaced by in vitro or biomaterial approaches. In this review, we summarize the key information on the animal models currently available for dental implant research and highlight (i) the pros and cons of each type, (ii) new levels of decisional procedures regarding study objectives, and (iii) the outlook for animal research, discussing possible non-animal options.

The Consequence of Aqueous Extract of Tobacco Leaves (Nicotiana tabacum. L) on Feed Intake, Body Mass, and Hematological Indices of Male Wistar Rats fed under Equal Environmental Conditions

OBJECTIVE

While the dangers of consuming tobacco by smoking has been of concern, the hazardous effect of other forms of tobacco consumption (in smokeless form) on health indices are less well explored. In this paper, we explored the effect of different doses of aqueous extract of tobacco leaves on feed intake, body mass, and hematological indices of male Wistar rats under equal environmental conditions.

METHOD

Using an oral route of administration, the rats (n = 24; w = 65-85 g; 2-3 weeks old) were administered at different doses of 100, 200, 400, 0 mg/kg body weight (b.w.) per day to group A, B, C, and D for 42 days, after phytochemical and acute toxicity testing of the tobacco leaves.

RESULTS

Compared to the negative control group (D), packed cell volume, hemoglobin concentration, red blood cells, and lymphocytes reduced dose-dependently in contrast to the white blood cells, neutrophils, mean corpuscular hemoglobin concentration, mean corpuscular hemoglobin, and mean corpuscular volume. As body mass and feed intake in relation to the different doses of aqueous extract of tobacco leaves reduced significantly (p < 0.05), the reverse was observed for body mass and feed intake in relation to room temperature.

CONCLUSIONS

By influencing hematological indices, feed intake, and body mass, the extract of tobacco leaves can be hazardous to health. However, to assess safety and to come up with a conscious conclusion, future studies should explore the effect of the extract on organs histopathology, biochemical parameters, and lipid profile of the body.

Study on the Effect of Oral Administration of Bacteriophages in Charles Foster Rats With Special Reference to Immunological and Adverse Effects

Numerous pre-clinical and clinical studies have recently demonstrated the significant role of phage therapy in treating multidrug-resistant bacterial infections. However, only a few researchers have focused on monitoring the phage-mediated adverse reactions during phage therapy. Besides adverse reactions, immunological response after short- and long-term oral administration of bacteriophages is also lacking. In this study, we administered the bacteriophages orally against Klebsiella pneumoniae XDR strain in dosages of 10¹⁵ PFU/ml and a 10²⁰ PFU/ml (still higher) to Charles Foster rats as a single dose (in acute toxicity study) and daily dosage for 28 days (in sub-acute toxicity study). One milliliter suspension of bacteriophages was administered through the oral gavage feeding tube. No adverse effect was observed in any of the experimental as well as in the control animals.Further, an insignificant change in food and water intake and body weight was observed throughout the study period compared with the control group rats. On the 28th day of phage administration, blood was collected to estimate hematological, biochemical, and cytokines parameters. The data suggested no difference in the hematological, biochemical, and cytokine profile compared to the control group. No significant change in any of the treatment groups could be observed on the gross and histopathological examinations. The cytokines estimated, interleukin-1 beta (IL-1β), IL-4, IL-6, and INF-gamma, were found within the normal range during the experiment. The results suggested no adverse effect, including the severe detrimental impact on oral administration of high (10¹⁵ PFU/ml) and very high dose (10²⁰ PFU/ml) of the bacteriophages cocktail. The high and long-term oral administration of bacteriophages did not induce noticeable immunological response as well.

The effect of table olive wastewater extract administration on the adult ovariectomised rat model of osteoporosis

Recent efforts for alternative non-pharmaceutical treatments for postmenopausal osteoporosis are focused on nutritional measures. The aim of this study was to investigate the effect of table olive wastewater extract (OE) administration on bone mineral density (BMD) and biomechanical strength in ovariectomised rats. Thirty mature 9-month-old female Wistar rats were separated into three groups of ten: Control, Ovariectomised (OVX) and OVX + OE. BMD was measured before ovariectomy, 3 and 6 months afterwards. At the end of the study, blood, both femurs and tibias, internal organs and abdominal fat were collected. After 3 months, the percentage changes from baseline of the total and proximal tibial BMD of the OVX + OE group were both higher compared with the OVX group (P < 0·005). Similar results were found after 6 months, when the percentage changes from baseline of the total and proximal tibial BMD of the OVX + OE group were both higher compared with the OVX group (P < 0·005). Biomechanical testing of the femurs did not reveal any statistically significant difference between the groups. Body weights throughout the study, organs' and abdominal fat ratios to final body weight and blood results (alanine aminotransferase (ALT), gamma-glutamyltransferase (γ-GT), total cholesterol, HDL-cholesterol, LDL-cholesterol, Ca and P) were within normal limits and did not show any significant difference between the treated and untreated groups. As a conclusion, the administration of OE for 6 months protected tibial BMD loss in comparison with the untreated OVX group without causing adverse effects.

Albumin-based nanoparticles as contrast medium for MRI: vascular imaging, tissue and cell interactions, and pharmacokinetics of second-generation nanoparticles

This multidisciplinary study examined the pharmacokinetics of nanoparticles based on albumin-DTPA-gadolinium chelates, testing the hypothesis that these nanoparticles create a stronger vessel signal than conventional gadolinium-based contrast agents and exploring if they are safe for clinical use. Nanoparticles based on human serum albumin, bearing gadolinium and designed for use in magnetic resonance imaging, were used to generate magnet resonance images (MRI) of the vascular system in rats ("blood pool imaging"). At the low nanoparticle doses used for radionuclide imaging, nanoparticle-associated metals were cleared from the blood into the liver during the first 4 h after nanoparticle application. At the higher doses required for MRI, the liver became saturated and kidney and spleen acted as additional sinks for the metals, and accounted for most processing of the nanoparticles. The multiple components of the nanoparticles were cleared independently of one another. Albumin was detected in liver, spleen, and kidneys for up to 2 days after intravenous injection. Gadolinium was retained in the liver, kidneys, and spleen in significant concentrations for much longer. Gadolinium was present as significant fractions of initial dose for longer than 2 weeks after application, and gadolinium clearance was only complete after 6 weeks. Our analysis could not account quantitatively for the full dose of gadolinium that was applied, but numerous organs were found to contain gadolinium in the collagen of their connective tissues. Multiple lines of evidence indicated intracellular processing opening the DTPA chelates and leading to gadolinium long-term storage, in particular inside lysosomes. Turnover of the stored gadolinium was found to occur in soluble form in the kidneys, the liver, and the colon for up to 3 weeks after application. Gadolinium overload poses a significant hazard due to the high toxicity of free gadolinium ions. We discuss the relevance of our findings to gadolinium-deposition diseases.

Rodent Leukocyte Isolation and Radiolabeling for Inflammation Imaging Study

Purpose

The objective of this study was to describe to develop methods of rodent leukocyte isolation and radiolabeling for in vivo inflammation imaging.

Methods

Thigh muscle inflammation was induced by injection of collagenase. Blood was collected from the jugular vein and separated by Histopaque. The collected cells were incubated in a 37 °C CO₂ incubator for 1~2 h. After incubation, ^99mTc-HMPAO and ¹⁸F-FDG were used to treat leukocytes followed by incubation for 30 min. ^99mTc-HMPAO and ¹⁸F-FDG labeled autologous leukocytes were injected into the tail veins of rats. The images were then acquired at various time points. Image-based lesion to normal muscle ratio was compared.

Results

After Histopaque separation, the proportion of lymphocytes was higher than that of other cell types. After CO₂ incubation, the collected leukocytes were viable, while room temperature exposed leukocytes without CO₂ incubation were non-viable. Granulocytes, especially, were more quickly influenced by various conditions than the mononuclear cells. Labeling efficiencies of ^99mTc-HMPAO and ¹⁸F-FDG were 4.00 ± 2.06 and 1.8%, respectively. ^99mTc-HMPAO- and ¹⁸F-FDG-labeled leukocytes targeted well the inflamed lesion. ^99mTc-HMPAO-labeled leukocytes, but not ¹⁸F-FDG-labeled leukocytes, were found in the abdomen activity.

Conclusion

Inflamed lesions of rats were well visualized using autologous radiolabeled leukocytes. This method might provide good information for understanding inflammatory diseases.

Effect of Maternal Water Restriction on Sexual Behavior, Reproductive Performance, and Reproductive Hormones of Male Rat Offspring

The present study aimed to investigate the effect of maternal water restriction on sexual behavior, reproductive performance, and reproductive hormones of male rat offspring. Forty pregnant female rats were divided into two equal groups: Control (C) and water-restricted (WR). Control dams had ad libitum water access throughout pregnancy, while dams in the WR group were subjected to 50% water-restriction from day 10 of pregnancy onwards. The maternal water restriction provoked a significant reduction (p < 0.05) in body weight of dams before delivery and at birth and litter body weights of offspring at birth. Maternal water restriction did not affect relative weights of reproductive and body organs of male rat offspring. All hormonal concentrations, sperm count, and vitality in male rat offspring were not significantly affected by maternal water restriction. Maternal water restriction exposure induced significant (p < 0.05) reduction in intromission latency, intromission frequency, and post-ejaculation interval in male rat offspring while a significant (p < 0.05) increase in the ejaculation latency was detected in maternal WR group. In conclusion, this study suggests that maternal water restriction had a negative impact on some reproductive characteristics but did not severely affect reproductive performance and reproductive hormones of male rat offspring.

In vitro and in vivo studies of Mg-30Sc alloys with different phase structure for potential usage within bone

Proper alloying magnesium with element scandium (Sc) could transform its microstructure from α phase with hexagonal closed-packed (hcp) structure into β phase with body-cubic centered (bcc) structure. In the present work, the Mg-30 wt% Sc alloy with single α phase, dual phases (α + β) or β phase microstructure were developed by altering the heat-treatment routines and their suitability for usage within bone was comprehensively investigated. The β phased Mg-30 wt% Sc alloy showed the best mechanical performance with ultimate compressive strength of 603 ± 39 MPa and compressive strain of 31 ± 3%. In vitro degradation test showed that element scandium could effectively incorporate into the surface corrosion product layer, form a double-layered structure, and further protect the alloy matrix. No cytotoxic effect was observed for both single α phased and β phased Mg-30 wt% Sc alloys on MC3T3 cell line. Moreover, the β phased Mg-30 wt%Sc alloy displayed acceptable corrosion resistance in vivo (0.06 mm y^-1) and maintained mechanical integrity up to 24 weeks. The degradation process did not significantly influence the hematology indexes of inflammation, hepatic or renal functions. The bone-implant contact ratio of 75 ± 10% after 24 weeks implied satisfactory integration between β phased Mg-30 wt%Sc alloy and the surrounding bone. These findings indicate a potential usage of the bcc-structured Mg-Sc alloy within bone and might provide a new strategy for future biomedical magnesium alloy design. STATEMENT OF SIGNIFICANCE: Scandium is the only rare earth element that can transform the matrix of magnesium alloy into bcc structure, and Mg-30 wt%Sc alloy had been recently reported to exhibit shape memory effect. The aim of the present work is to study the feasibility of Mg-30 wt%Sc alloy with different constitutional phases (single α phase, single β phase or dual phases (α + β)) as biodegradable orthopedic implant by in vitro and in vivo testings. Our findings showed that β phased Mg-30 wt%Sc alloy which is of bcc structure exhibited improved strength and superior in vivo degradation performance (0.06 mm y^-1). No cytotoxicity and systematic toxicity were shown for β phased Mg-30 wt%Sc alloy on MC3T3 cell model and rat organisms. Moreover, good osseointegration, limited hydrogen gas release and maintained mechanical integrity were observed after 24 weeks' implantation into the rat femur bone.

Acute and sub-chronic oral toxicity studies of hesperidin isolated from orange peel extract in Sprague Dawley rats

Citrus sinensis contains glycoside hesperetin-7-rhamnoglucoside (hesperidin) which harbor an array of therapeutic potentials including antioxidant, anticancer, and anti-inflammatory. However, a systematic examination of safety is needed before its utilization. Hence, the present investigation is aimed to evaluate acute and sub-chronic toxicity of hesperidin isolated from the citrus fruit. Hesperidin (73%) was isolated from a methanolic extract of dried peel of the citrus fruit, characterized using FTIR, and standardized by HPLC. Its acute oral toxicity (AOT) and sub-chronic toxicity studies were carried out in Sprague-Dawley rats. Hesperidin (5000 mg/kg) showed 10% mortality in AOT. In sub-chronic toxicity study, hesperidin (250 and 500 mg/kg) did not induce any abnormalities in body weight, food consumption, clinical signs, ophthalmological and neurological observations, urine analysis, hematology, clinical chemistry, organ weights, and gross pathology. However, hesperidin (1000 mg/kg) showed significant (p < 0.05) alterations in body and organ weights, hematology, clinical chemistry, and tissue histopathology. To conclude, hesperidin has median lethal dose (LD₅₀) of 4837.5 mg/kg, and Low Observed Adverse Effect Level (LOAEL) at 1000 mg/kg for both male and female Sprague-Dawley rats. Thus, hesperidin isolated from citrus fruit showed a good safety profile in animal study.

Composition and safety evaluation of tea from New Zealand kawakawa (Piper excelsum)

Kawakawa (Piper excelsum) has food, medicinal and cultural importance to the indigenous Māori people of New Zealand, and is being incorporated into a range of commercial food and therapeutic products, including tea. In this study, the chemical compositions of kawakawa fresh leaves, dried leaves for tea, and hot brewed tea, were analysed and compared. The key metabolites were diayangambin, elemicin, myristicin, unidentified lignans and amides. The safety of brewed tea and tea leaves were evaluated in 8 week old Sprague Dawley rats in a 14 day acute study followed by a 28 day subacute study. In the 14 day study, the rats received the equivalent of 1, 2, 3 or 4 cups of kawakawa tea, and the rats in the 28 day study received daily doses that were equivalent to 4 cups per day. There were no adverse effects observed in the rats, and body weights and food intakes were not significantly different between the control and the kawakawa treated animals. There were small differences in organ weights, biochemical and haematology parameters observed in the rats given the kawakawa tea. In conclusion, the consumption of kawakawa tea could be considered safe within the conditions used in this study.

Lycium shawii Roem. & Schult.: A new bioactive antimicrobial and antioxidant agent to combat multi-drug/pan-drug resistant pathogens of wound burn infections

The Multidrug Drug Resistance (MDR) and Pan-Drug Resistance (PDR) remain an intractable challenge issue in public health, worldwide. Plant extracts-based biological macromolecules containing a diverse array of secondary metabolites could be potentially used as alternative approaches to control or limit MDR/PDR infections. Plants of the Solanaceae family exhibit a wide variety of secondary metabolites with antioxidant and antimicrobial properties, which render them a significant role in food and pharmaceutical applications. To our knowledge, this is the first report on phytochemical constituents, antioxidant, antimicrobial activities and in vivo toxicological safety of Lycium shawii leaf extracts. Results revealed that phenolics and flavonoids were found to be the most abundant compounds in all extracts. Antioxidant activity of extracts was measured using DPPH^• and ABTS^•+ assays and the methanol extract displayed superior scavenging activity (IC₅₀ = 0.06 and 0.007 mg/mL for DPPH^• and ABTS^•+, respectively). Results of the GC-MS analysis revealed the identity of 10 compounds. Moreover, in vivo toxicological assessment can confirm the safety of L. shawii for use. Overall, L. shawii leaves are a promising natural source for the development of novel antimicrobial and antioxidant agents that could potentially combat clinical MDR/PDR pathogens.

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The drug resistance remains an intractable challenge in public health.

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Phenolics and flavonoids were the most abundant compounds in all extracts.

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Methanol extract was the most antioxidant and antimicrobial agent.

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p-coumaric acid, apigenin, and fisetin are the major identified compounds.

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In vivo toxicological assessment can confirm the safety of L. shawii for use.

Reference values for selected hematological, biochemical and physiological parameters of Sprague-Dawley rats at the Animal House, Faculty of Medicine, University of Colombo, Sri Lanka

BACKGROUND

Lack of available reference values in a research setting under local conditions can be a drawback for beginners, as the accuracy of data from control samples cannot be checked at the beginning of a research project. This affects comparisons with data from test samples. To avoid these complications in their research projects, beginners tend to have a greater number of animals in the control group compared to test groups in order to have control group measurements within 2 SDs of the mean.

METHODS

As non-availability of reference values was a long-felt need, the described project was conducted in order to establish a reference database for selected haematological, biochemical and physiological parameters using apparently healthy Sprague-Dawley rats bred in the Animal House of Faculty of Medicine, University of Colombo (UCFM).

RESULTS

Differences in mean values of packed cell volume (PCV), mean corpuscular volume (MCV) and mean corpuscular hemoglobin concentration (MCHC), serum creatinine and blood glucose levels between the two genders were statistically significant. Lipid profile measurements did not differ significantly between genders, but mean and median values of triglycerides (TG) between male and female rats showed a difference of more than 10 mg/dL. The liver enzymes alkaline phosphatase (AP) and aspartate aminotransferase (AST) were also statistically significantly different between sexes. Despite wide variation in mean alanine aminotransferase (ALT) between sexes, the difference was not statistically significant.

CONCLUSION

The findings of this project should support to a certain extent the "Reduction" aspect of the 3Rs concept of Russell and Burch by reducing the number of Sprague-Dawley rats used in future research projects at UCFM.

Long-Term Dietary Intake of Chia Seed Is Associated with Increased Bone Mineral Content and Improved Hepatic and Intestinal Morphology in Sprague-Dawley Rats

Chia seeds (Salvia hispanica) provide an unusually high content of α-linolenic acid with several potential health benefits, but few studies have examined the long-term intake of n-3 fatty acid-rich plant foods such as chia. In this work, we investigated some of the effects of a diet containing 10% chia seeds versus a conventional isocaloric diet for 10 and 13 months on body measurements, musculoskeletal system, the liver, and the intestines of 20 male Sprague-Dawley rats assigned into two groups. The n-6/n-3 ratios for the control and chia diets were 7.46 and 1.07, respectively. For the first 10 months of the diet, the body parameters and weights were similar, but at 13 months, the bone mineral content (BMC) of the chia-fed rats was significantly higher than that of the controls whether in total or proximal areas of the left tibia. Also, significant positive correlations were found between the age of the chia group and the bone mineral density, BMC, weight of the musculoskeletal system, final body weight, and skin weight. Liver and intestinal examinations showed improved morphology associated with lower lipid deposit in hepatocytes and increased intestinal muscle layers and crypt size in the chia group. This study provides new data suggesting the potential benefits associated with the long-term intake of chia seeds.

Impact of Iron-Enriched Aspergillus oryzae on Iron Bioavailability, Safety, and Gut Microbiota in Rats

Iron deficiency is a leading global nutritional problem. Ferrous sulfate (FeSO₄) is the most common iron source used for supplementation. Because of many side effects associated with its consumption, it is important to identify new forms of iron. The objectives of this study were to assess the bioavailability of iron-enriched Aspergillus oryzae, Aspiron (ASP), evaluate the toxicity of high-dose iron supplementation with ASP, and determine the ASP impact on gut microbiota in rats. In this study, we investigated iron bioavailability using the hemoglobin repletion test. Aspartate aminotransferase, alanine aminotransferase, and blood urea nitrogen levels were determined to evaluate the effect on liver and kidney functions. Protein carbonyls were measured to assess oxidative damage to proteins. Fecal samples at the end of the 14 day repletion period were used for 16S rRNA sequencing for gut microbiota analysis. The slope ratio method using a common intercept linear regression model was used to compare the bioavailability of ASP to FeSO₄. Iron repletion increased hemoglobin concentrations with both ASP and FeSO₄ treatments compared to the control group, except in the lowest ASP group. The slope ratio indicated that relative iron bioavailability of ASP was 60% of that of FeSO₄ when hemoglobin change was compared to iron in the diet. Similar results were obtained when absolute iron intake was compared on the basis of food consumption. In comparison to the control, protein carbonyl concentrations were significantly ( p < 0.05) higher in the FeSO₄ group but not with the ASP group. Supplementation with both sources of iron reduced the Enterobacteriaceae population in the gut microbiota of the rats. A higher relative abundance of bacteria from the phylum Verrucomicrobia was also observed with the highest dose of ASP. Iron-enriched A. oryzae with 60% relative bioavailability of FeSO₄ did not show any signs of adverse effects after 14 days of iron supplementation. Future human studies are needed to understand the ASP detailed effect on gut microbiota.

Citrus reticulata peel oil inhibits non-small cell lung cancer cell proliferation in culture and implanted in nude mice

Mandarin peel oil exerts an antiproliferative effect on in vitro and in vivo human tumour cells without toxicity effects.

Anti-obesity effects of Spirulina maxima in high fat diet induced obese rats via the activation of AMPK pathway and SIRT1

Spirulina maxima improved the obese phenotype in high fat diet induced rats by activating AMPK and SIRT1.

Sex-specific reference intervals of hematologic and biochemical analytes in Sprague-Dawley rats using the nonparametric rank percentile method

BACKGROUND

Hematologic and biochemical analytes of Sprague-Dawley rats are commonly used to determine effects that were induced by treatment and to evaluate organ dysfunction in toxicological safety assessments, but reference intervals have not been well established for these analytes. Reference intervals as presently defined for these analytes in Sprague-Dawley rats have not used internationally recommended statistical method nor stratified by sex. Thus, we aimed to establish sex-specific reference intervals for hematologic and biochemical parameters in Sprague-Dawley rats according to Clinical and Laboratory Standards Institute C28-A3 and American Society for Veterinary Clinical Pathology guideline.

METHODS

Hematology and biochemistry blood samples were collected from 500 healthy Sprague-Dawley rats (250 males and 250 females) in the control groups. We measured 24 hematologic analytes with the Sysmex XT-2100i analyzer, 9 biochemical analytes with the Olympus AU400 analyzer. We then determined statistically relevant sex partitions and calculated reference intervals, including corresponding 90% confidence intervals, using nonparametric rank percentile method.

RESULTS

We observed that most hematologic and biochemical analytes of Sprague-Dawley rats were significantly influenced by sex. Males had higher hemoglobin, hematocrit, red blood cell count, red cell distribution width, mean corpuscular volume, mean corpuscular hemoglobin, white blood cell count, neutrophils, lymphocytes, monocytes, percentage of neutrophils, percentage of monocytes, alanine aminotransferase, aspartate aminotransferase, and triglycerides compared to females. Females had higher mean corpuscular hemoglobin concentration, plateletcrit, platelet count, eosinophils, percentage of lymphocytes, percentage of eosinophils, creatinine, glucose, total cholesterol and urea compared to males. Sex partition was required for most hematologic and biochemical analytes in Sprague-Dawley rats. We established sex-specific reference intervals, including corresponding 90% confidence intervals, for Sprague-Dawley rats.

CONCLUSIONS

Understanding the significant discrepancies in hematologic and biochemical analytes between male and female Sprague-Dawley rats provides important insight into physiological effects in test rats. Establishment of locally sex-specific reference intervals allows a more precise evaluation of animal quality and experimental results of Sprague-Dawley rats in our toxicology safety assessment.

Effects of intragastrically-administered Tepary bean lectins on digestive and immune organs: Preclinical evaluation

Previous work showed that Tepary bean (Phaseolus acutifolius) lectins exhibit differential cytotoxic effects on cancer cell lines by apoptosis induction. In vivo studies using a Tepary bean lectin fraction (TBLF, 50 mg/kg of body weight) after colon cancer induction in rats showed that TBLF inhibited early precancerous lesions without systemic toxicity however, loss of body weight gain and activation of immune cells were observed. In order to know more about the possible adverse effects, we evaluated the administration of TBLF on digestive and immune organs. Sprague Dawley rats were administered TBLF for six weeks and allowed to recover for two weeks. Immune activation was observed through an increased lymphocyte-granulocyte ratio, an increased number of lymphoid follicles in intestinal Peyer's patches and a slight expansion of the splenic white pulp. Atrophy was observed in small intestine villi and crypt foci of the colon without normalization after the recovery period. Pancreas histopathology showed hypertrophy after the six-week administration period, particularly vacuolation and trabecular widening; but after the two-week recovery period atrophy was observed, suggesting a partial compensatory type process. Our results show that TBLF activates the immune system and affects digestive organs through direct interaction with intestinal epithelium, and indirectly by producing pancreatic hyperfunction. Further work will focus in longer recuperation periods after TBLF treatment.

Safety pharmacology and subchronic toxicity of jinqing granules in rats

Background

Jinqing granules which are made of a mixture extract that contains Radix Tinosporae and Canarii fructus in proportions according to a longstanding formula have a good effect on the prevention and treatment of gastric ulcer disease. It has not been through safety through systematic toxicological studies, however. To provide basis for clinical application, we performed safety pharmacology and subchronic toxicity experiments in specific pathogen-free Sprague-Dawley rats.

Results

In safety pharmacology experiments, Jinqing granules had no evident adverse effects on the central nervous, cardiovascular, or respiratory systems. In subchronic toxicity study, 2–8 g/kg of Jinqing granules induced no evident adverse effects on Clinical signs, body weight changes, food and water intake, death daily, indicators of urine, hematological assay, serum biochemistry, organ coefficient and histopathological examination. However, the 16 g/kg dose was associated with slightly slowed weight growth, decreased number of sperm in seminiferous tubules and increased values of serum aspartate aminotransferase and bilirubin. During the 30-day feeding test, 3 rats that received the 16 g/kg dose died, but the deaths were most likely due to trauma of oral gavage, not to drug toxicity.

Conclusion

Jinqing granules given to Sprague-Dawley rats orally for 30 days at a dose of 8 g/kg or less appears safe, but higher doses were not proven safe. The significance of these observations with respect to animal usage of Jinqing granules deserves thorough investigation.

Four-Week Consumption of Malaysian Honey Reduces Excess Weight Gain and Improves Obesity-Related Parameters in High Fat Diet Induced Obese Rats

Many studies revealed the potential of honey consumption in controlling obesity. However, no study has been conducted using Malaysian honey. In this study, we investigated the efficacy of two local Malaysian honey types: Gelam and Acacia honey in reducing excess weight gain and other parameters related to obesity. The quality of both honey types was determined through physicochemical analysis and contents of phenolic and flavonoid. Male Sprague-Dawley rats were induced to become obese using high fat diet (HFD) prior to introduction with/without honey or orlistat for four weeks. Significant reductions in excess weight gain and adiposity index were observed in rats fed with Gelam honey compared to HFD rats. Moreover, levels of plasma glucose, triglycerides, and cholesterol, plasma leptin and resistin, liver enzymes, renal function test, and relative organ weight in Gelam and Acacia honey treated groups were reduced significantly when compared to rats fed with HFD only. Similar results were also displayed in rats treated with orlistat, but with hepatotoxicity effects. In conclusion, consumption of honey can be used to control obesity by regulating lipid metabolism and appears to be more effective than orlistat.

Safety assessment of a traditionally used extract from leaves of Boldoa purpurascens

ETHNOPHARMACOLOGICAL RELEVANCE

Boldoa purpurascens Cav. (Nyctaginaceae) is a plant species used in traditional medicine in Cuba as a diuretic.

AIM OF THE STUDY

The aim of the present investigation was to evaluate the safety profile of a hydroalcoholic extract from leaves of Boldoa purpurascens.

MATERIALS AND METHODS

First, an experimental study to assess the oral acute toxicity at a dose of 2000mg/kg body weight of the extract was carried out. Potential genotoxicity of the extract was evaluated using the Ames test and the micronucleus induction assay in mouse bone marrow. In the Ames test a concentration range of 50, 100, 150, 300 and 500µg/plate was tested. In the micronucleus induction assay, doses of 500, 1000 and 2000mg/kg of body weight were tested. For completeness, since the extract contains saponins, the evaluation of the hemolytic activity, ocular and skin irritation were included.

RESULTS

No signs or symptoms of toxicity were observed in the oral acute toxicity test (body weight at baseline, seven days and end of the experiment of 236.41±20.07, 256.81±30.44 and 240.02±26.16 respectively for the treated group). The hydroalcoholic extract from the leaves was not mutagenic in the Ames test, and no genotoxicity was observed in the micronucleus assay. A hemolysis test at concentration of 1mg/mL confirmed hemolytic activity, which is not a safety concern since saponins are not absorbed after oral administration. In order to evaluate the percentage of protein denaturation, the ocular irritability index was calculated. The extract was found to be irritating. Finally, skin irritability was evaluated and the irritation index was equal to zero.

CONCLUSIONS

Based on the toxicological evaluation of a traditionally used hydroalcoholic extract from the leaves of Boldoa purpurascens we can confirm the safety of its oral use.

Evaluation of the acute and sub-chronic oral toxicity of the herbal formula Xiaoer Chaigui Tuire Oral Liquid

ETHNOPHARMACOLOGICAL RELEVANCE

Xiaoer Chaigui Tuire Oral Liquid (XCTOL) is a popular Chinese herbal formula. It is used to treat exogenous fever in children by inducing diaphoresis and clearing interior heat.

AIM OF THE STUDY

To evaluate the acute and sub-chronic toxicity of XCTOL in mice and rats, respectively.

MATERIALS AND METHODS

In the acute toxicity study, mice were orally administered 100g/kg body weight XCTOL three times a day. General behavior, adverse effects and mortality were recorded for 14 days after treatment. In the sub-chronic toxicity study, rats were orally administered 0, 20 or 80g/kg XCTOL for 30 days. The rats were observed daily for clinical signs and mortality. Body weight changes were measured every three days, and relative organ weights, hematological parameters, urinalysis results, biochemical parameters and pathology were monitored at the end of treatment. After treatment, a 30-day withdrawal study was conducted.

RESULTS

In the acute toxicity study, after the mice were administered with 300g/kg (3×100g/kg) XCTOL in the first day, no adverse effects or death were observed in the following 14 days. In the 30-day sub-chronic toxicity study, daily oral administration of 80g/kg XCTOL resulted in significant body weight loss in both male and female rats. In the male rats, the red blood cell distribution width standard deviation (RDW-SD) and red blood cell distribution width coefficient of variability (RDW-CV) in the hematological test and total bilirubin (T-Bil) in the blood biochemistry test were significantly increased (RDW-SD, p<0.01; RDW-CV and T-Bil, p<0.05 vs. the control group). In the female rats, the specific gravity of the urinalysis was significantly increased (p<0.05 vs. the control group). Pathological damage was not observed in the main organs in the 80g/kg group. In the 20g/kg group, the lymphocyte % (LYM%) was significantly increased (p<0.05 the control group) in the female rats.

CONCLUSIONS

The maximum-tolerated dose of XCTOL was greater than 300g/kg in mice. The no-observed-adverse-effect-level was between 20 and 80g/kg body weight for 30 days in rats, which is 2.2-8.8 times higher, respectively, than the dose that has already been used in the clinical practice. Therefore, XCTOL at a dose less than 300g/kg in one day or 20g/kg per day for 30 days is considered safe.

Sex-specific effects of relaxin-3 on food intake and body weight gain

Relaxin-3 (RLN3) is a neuropeptide that is strongly expressed in the pontine nucleus incertus (NI) and binds with high affinity to its cognate receptor RXFP3. Central administration of RLN3 in rats increases food intake and adiposity. In humans, RLN3 polymorphism has been associated with obesity and hypercholesterolaemia. Emerging evidence suggests that the effects of RLN3 may have sex-specific aspects. Thus, the RLN3 knockout female but not male mice are hypoactive. RLN3 produced stronger orexigenic and obesogenic effects in female rats compared with male rats. In addition, female rats demonstrated higher sensitivity to lower doses of RLN3. Repeated cycles of food restriction and stress were accompanied by an increase in RLN3 expression and hyperphagia in female but not in male rats. Furthermore, stress-induced binge eating in female rats was blocked by an RXFP3 receptor antagonist. RLN3 increased the expression of corticotropin releasing factor in the paraventricular hypothalamic nucleus in male but not in female rats. Conversely, in female rats, RLN3 increased the expression of orexin in the lateral hypothalamus. There is evidence that orexin directly activates the RLN3 neurons in the NI. The positive reinforcement of the RLN3 effects by orexin may intensify behavioural activation and feeding in females. Sex-specific effects of RLN3 may also depend on differential expression of RXFP3 receptors in the brain. Given the higher sensitivity of females to the orexigenic effects of RLN3 and the stress-induced activation of RLN3, the overall data suggest a possible role for RLN3 in eating disorders that show a higher propensity in women.

LINKED ARTICLES

This article is part of a themed section on Recent Progress in the Understanding of Relaxin Family Peptides and their Receptors. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.10/issuetoc.

Sex-specific chronic stress response at the level of adrenal gland modified sexual hormone and leptin receptors

Aim

To compare cardiometabolic risk-related biochemical markers and sexual hormone and leptin receptors in the adrenal gland of rat males, non-ovariectomized females (NON-OVX), and ovariectomized females (OVX) under chronic stress.

Methods

Forty six 16-week-old Sprague-Dawley rats were divided into male, NON-OVX, and OVX group and exposed to chronic stress or kept as controls. Weight, glucose tolerance test (GTT), serum concentration of glucose, and cholesterol were measured. Adrenal glands were collected at the age of 28 weeks and immunohistochemical staining against estrogen beta (ERβ), progesterone (PR), testosterone (AR), and leptin (Ob-R) receptors was performed.

Results

Body weight, GTT, serum cholesterol, and glucose changed in response to stress as expected and validated the applied stress protocol. Stressed males had significantly higher number of ERβ receptors in comparison to control group (P = 0.028). Stressed NON-OVX group had significantly decreased AR in comparison to control group (P = 0.007). The levels of PR did not change in any consistent pattern. The levels of Ob-R increased upon stress in all groups, but the significant difference was reached only in the case of stressed OVX group compared to control (P = 0.033).

Conclusion

Chronic stress response was sex specific. OVX females had similar biochemical parameters as males. Changes upon chronic stress in adrenal gland were related to a decrease in testosterone receptor in females and increase in estrogen receptor in males.

Influence of Cyperus esculentus tubers (tiger nut) on male rat copulatory behavior

Background

Cyperus esculentus tubers (tiger nut) are one of the ancient food sources known to humanity. It is traditionally used in the Middle East to stimulate sexual arousal in men. However, there has been no scientific evidence about its assumed aphrodisiac properties. This study aimed to investigate the influence of tiger nut on the copulatory behavior of sexually active male rats.

Methods

Two sets of sexually active male rats -highly active and moderately active- were identified depending on baseline sexual activity. Rats in each set were randomly divided into a control and treated groups. Highly active rats were treated with doses of 1 and 2 g/kg/d of raw tiger nut powder, while moderately active rats were treated with a dose of 2 g/kg/d. After 30 days’ treatment, copulatory behavior and serum hormonal levels were measured and compared between the groups within each experimental set. Phytochemical analyses including liquid chromatography/mass spectrometry and atomic absorption were performed to elucidate the main constituents of tiger nut that may be responsible for altering serum hormones.

Results

Tiger nut stimulated sexual motivation in both highly and moderately active rats, indicated by reduced mount and intromission latencies in these rats compared to controls. Furthermore, tiger nut improved sexual performance, indicated by increased intromission frequency and ratio, in treated moderately active rats compared to controls. Serum testosterone levels increased significantly after tiger nut administration. Lastly, phytochemical analyses revealed the presence of quercetin, vitamin C, vitamin E, and mineral zinc in tiger nut.

Conclusions

Tiger nut has positive effects on the copulatory behavior of adult male rats.

Enriching the drinking water of rats with extracts of Salvia officinalis and Thymus vulgaris increases their resistance to oxidative stress

Nature is an attractive source of therapeutic compounds. In comparison to the artificial drugs, natural compounds cause less adverse side effects and are suitable for current molecularly oriented approaches to drug development and their mutual combining. Medicinal plants represent one of the most available remedy against various diseases. Proper examples are Salvia officinalis L. and Thymus vulgaris L. which are known aromatic medicinal plants. They are very popular and frequently used in many countries. The molecular mechanism of their biological activity has not yet been fully understood. The aim of this study was to ascertain if liver cells of experimental animals drinking extracts of sage or thyme will manifest increased resistance against oxidative stress. Adult Sprague-Dawley rats were divided into seven groups. They drank sage or thyme extracts for 2 weeks. At the end of the drinking period, blood samples were collected for determination of liver biochemical parameters and hepatocytes were isolated to analyze (i) oxidatively generated DNA damage (conventional and modified comet assay), (ii) activities of antioxidant enzymes [superoxide dismutase (SOD), glutathione peroxidase (GPx)] and (iii) content of glutathione. Intake of sage and thyme had no effect either on the basal level of DNA damage or on the activity of SOD in rat hepatocytes and did not change the biochemical parameters of blood plasma. Simultaneously, the activity of GPx was significantly increased and the level of DNA damage induced by oxidants was decreased. Moreover, sage extract was able to start up the antioxidant protection expressed by increased content of glutathione. Our results indicate that the consumption of S.officinalis and T.vulgaris extracts positively affects resistency of rat liver cells against oxidative stress and may have hepatoprotective potential.

Acute Toxicity and Dermal and Eye Irritation of the Aqueous and Hydroalcoholic Extracts of the Seeds of "Zapote" Pouteria mammosa (L.) Cronquist

The common use of Pouteria mammosa (L.) Cronquist, "Mamey or Zapote," in food and ethnobotanic medicine shows its low or absent toxicity as fruit extracts prepared from seeds. However, it is essential to conduct security trials to scientifically support their use in drug therapy. This study evaluated the aqueous and hydroalcoholic extract (25%) Acute Oral Toxicity, obtained from the seeds of P. mammosa, in Sprague Dawley rats and dermal and eye irritability in New Zealand rabbits. The 404 and 405 acute dermal and eye irritation/corrosion guidelines were used, as well as the 423 Acute Oral Toxicity guideline, Acute Toxic Class Method of the Organization for Economic Cooperation and Development (OECD). The aqueous extract was located in the following category: not classified as toxic (CTA 5), while hydroalcoholic extract at 25% was classified as dangerous (CTA 4). Both extracts can be used without side reaction that irritates the skin which permitted classification as potentially not irritant. P. mammosa in the two extracts caused mild and reversible eye irritation, and it was classified as slightly irritating.

The decrease in silicon concentration of the connective tissues with age in rats is a marker of connective tissue turnover

Silicon may be important for bone and connective tissue health. Higher concentrations of silicon are suggested to be associated with bone and the connective tissues, compared with the non-connective soft tissues. Moreover, in connective tissues it has been suggested that silicon levels may decrease with age based upon analyses of human aorta. These claims, however, have not been tested under controlled conditions. Here connective and non-connective tissues were collected and analysed for silicon levels from female Sprague-Dawley rats of different ages (namely, 3, 5, 8, 12, 26 and 43 weeks; n=8-10 per age group), all maintained on the same feed source and drinking water, and kept in the same environment from weaning to adulthood. Tissues (696 samples) were digested in nitric acid and analysed by inductively coupled plasma optical emission spectrometry for total silicon content. Fasting serum samples were also collected, diluted and analysed for silicon. Higher concentrations of silicon (up to 50-fold) were found associated with bone and the connective tissues compared with the non-connective tissues. Although total silicon content increased with age in all tissues, the highest connective tissue silicon concentrations (up to 9.98 μg/g wet weight) were found in young weanling rats, decreasing thereafter with age (by 2-6 fold). Fasting serum silicon concentrations reflected the pattern of connective tissue silicon concentrations and, both measures, when compared to collagen data from a prior experiment in Sprague-Dawley rats, mirrored type I collagen turnover with age. Our findings confirm the link between silicon and connective tissues and would imply that young growing rats have proportionally higher requirements for dietary silicon than mature adults, for bone and connective tissue development, although this was not formally investigated here. However, estimation of total body silicon content suggested that actual Si requirements may be substantially lower than previously estimated which could explain why absolute silicon deficiency is difficult to achieve but, when it is achieved in young growing animals, it results in stunted growth and abnormal development of bone and other connective tissues.

Acute and subchronic toxicity as well as evaluation of safety pharmacology of Galla chinensis solution

Galla chinensis has been popularly used in traditional Chinese medicine which is beneficial for the treatment of various diseases, such as inflammation, dysentery, toxicosis and sore. However, it has not previously been evaluated for safety through systematic toxicological studies. In the present study, acute and subchronic oral toxicity studies and safety pharmacology evaluation of Galla chinensis solution (GCS) were conducted in specific pathogen-free (SPF) Sprague-Dawley (SD) rats. Acute administration of GCS was done as single dose from 3333 mg to 6912 mg per kg/bodyweight (bw) and subchronic toxicity study for 30 days was done by daily oral administration of GCS at doses of 500, 1500 and 2500 mg/kg body weight in SPF SD rats. The acute toxicity study showed the LD50 of GCS was greater than 5000 mg/kg. The results of sunchronic toxicity study showed that the no-observed effect level of GCS was lesser than 1500 mg/kg bw day, which suggested three times higher than that of recommended dose for clinical applications (500 mg/kg bw day). The dose at 2500 mg/kg bw day of GCS may slow down the growth of rats and lead to degeneration and necrosis of tissue cells to some extent. In the safety pharmacology study, GCS did not produce any side effects to rats in central nervous system, cardiovascular system and respiratory system. Therefore, from the results of the study presented herein, it could be concluded that the use of appropriate levels (one to three times of recommended dose for clinical applications) of GCS as a topical preparations is considered safe.

Systemic treatment of acute liver failure with adipose derived stem cells

PURPOSE OF THE STUDY

The definitive treatment for liver failure is, currently, liver transplantation. Research into other possible treatments, focused on achieving regeneration of the liver parenchyma, have led to the development of methods to generate hepatocytes from stem cells. In our study, we transplant allogenic adipose-derived stem cells (ASCs), not previously differentiated to hepatocytes, to treat acute liver failure induced by intraperitoneal administration of carbon tetrachloride (CCl4) in a Sprague-Dawley rat model.

MATERIAL AND METHODS

The ASCs were delivered via the tail vein, having previously been labeled with PKH26, a fluorescent membrane marker. Two control groups were established, Group 1(n = 15) consisting of olive oil (5 mL/kg) and Group 2(n = 15): 1 × 10(6) PKH26-labeled ASCs. Further, two study groups, Group 3(n = 30): CCl4 dissolved in olive oil and Group 4(n = 30): CCl4 dissolved in olive oil and 1 × 10(6) PKH26-labeled ASCs completed the experimental design.

RESULTS

Blood samples were analyzed, finding AST and ALT levels significantly higher in treatment over control groups at 24 and 48 hours. The mortality rates were statistically different between control groups and Group 3 (Group 1-3 p = .04, Group 2-3 p = .04) and between Groups 3 and 4 (p = .02). Examining the liver parenchyma, a significantly higher number of ASCs were observed in Group 4 than in Group 2 at all time points (p = .00).

CONCLUSIONS

The intravenous injection of allogenic ASCs in this model of CCl4-induced liver failure reduced the mortality in treated animals. ASCs injected in the rat tail vein were found in the liver in animals with induced acute liver failure.

Need for gender-specific pre-analytical testing: the dark side of the moon in laboratory testing

Many international organisations encourage studies in a sex-gender perspective. However, research with a gender perspective presents a high degree of complexity, and the inclusion of sex-gender variable in experiments presents many methodological questions, the majority of which are still neglected. Overcoming these issues is fundamental to avoid erroneous results. Here, pre-analytical aspects of the research, such as study design, choice of utilised specimens, sample collection and processing, animal models of diseases, and the observer's role, are discussed. Artefacts in this stage of research could affect the predictive value of all analyses. Furthermore, the standardisation of research subjects according to their lifestyles and, if female, to their life phase and menses or oestrous cycle, is urgent to harmonise research worldwide. A sex-gender-specific attention to pre-analytical aspects could produce a decrease in the time for translation from the bench to bedside. Furthermore, sex-gender-specific pre-clinical pharmacological testing will enable adequate assessment of pharmacokinetic and pharmacodynamic actions of drugs and will enable, where appropriate, an adequate gender-specific clinical development plan. Therefore, sex-gender-specific pre-clinical research will increase the gender equity of care and will produce more evidence-based medicine.

Recombinant adenoassociated virus 2/5-mediated gene transfer is reduced in the aged rat midbrain

Clinical trials are examining the efficacy of viral vector-mediated gene delivery for treating Parkinson's disease. Although viral vector strategies have been successful in preclinical studies, to date clinical trials have disappointed. This may be because of the fact that preclinical studies fail to account for aging. Aging is the single greatest risk factor for developing Parkinson's disease and age alters cellular processes utilized by viral vectors. We hypothesized that the aged brain would be relatively resistant to transduction when compared with the young adult. We examined recombinant adeno-associated virus 2/5-mediated green fluorescent protein (rAAV2/5 GFP) expression in the young adult and aged rat nigrostriatal system. GFP overexpression was produced in both age groups. However, following rAAV2/5 GFP injection to the substantia nigra aged rats displayed 40%-60% less GFP protein in the striatum, regardless of rat strain or duration of expression. Furthermore, aged rats exhibited 40% fewer cells expressing GFP and 4-fold less GFP messenger RNA. rAAV2/5-mediated gene transfer is compromised in the aged rat midbrain, with deficiencies in early steps of transduction leading to significantly less messenger RNA and protein expression.

Safety Assessment of a Hydroethanolic Extract of Caralluma fimbriata

This toxicological assessment evaluated the safety of a hydroethanolic extract prepared from Caralluma fimbriata (CFE), a dietary supplement marketed worldwide as an appetite suppressant. Studies included 2 in vitro genotoxicity assays, a repeated dose oral toxicity study, and a developmental study in rats. No evidence of in vitro mutagenicity or clastogenicity surfaced in the in vitro studies at concentrations up to 5000 μg of extract/plate (Ames test) or 5000 μg of extract/mL (chromosomal aberration test). No deaths or treatment-related toxicity were seen in the 6-month chronic oral toxicity study in Sprague-Dawley rats conducted at 3 doses (100, 300, and 1000 mg/kg body weight (bw)/d). The no observed effect level for CFE in this study was considered to be 1000 mg/kg bw/d. A prenatal developmental toxicity study conducted at 3 doses (250, 500, and 1000 mg/kg bw/d) in female Sprague-Dawley rats resulted in no treatment-related external, visceral, or skeletal fetal abnormalities, and no treatment-related maternal or pregnancy alterations were seen at and up to the maximum dose tested. CFE was not associated with any toxicity or adverse events.

Consumption of a low glycaemic index diet in late life extends lifespan of Balb/c mice with differential effects on DNA damage

BACKGROUND

Caloric restriction is known to extend the lifespan of all organisms in which it has been tested. Consequently, current research is investigating the role of various foods to improve health and lifespan. The role of various diets has received less attention however, and in some cases may have more capacity to improve health and longevity than specific foods alone. We examined the benefits to longevity of a low glycaemic index (GI) diet in aged Balb/c mice and examined markers of oxidative stress and subsequent effects on telomere dynamics.

RESULTS

In an aged population of mice, a low GI diet extended average lifespan by 12%, improved glucose tolerance and had impressive effects on amelioration of oxidative damage to DNA in white blood cells. Telomere length in quadriceps muscle showed no improvement in the dieted group, nor was telomerase reactivated.

CONCLUSION

The beneficial effects of a low GI diet are evident from the current study and although the impact to telomere dynamics late in life is minimal, we expect that earlier intervention with a low GI diet would provide significant improvement in health and longevity with associated effects to telomere homeostasis.