Bioactive Bismuth Compounds: Is Their Toxicity a Barrier to Therapeutic Use?

Bismuth compounds are considered relatively non-toxic, with their low solubility in aqueous solutions (e.g., biological fluids) being the major contributing factor to this property. Bismuth derivatives are widely used for the treatment of peptic ulcers, functional dyspepsia, and chronic gastritis. Moreover, the properties of bismuth compounds have also been extensively explored in two main fields of action: antimicrobial and anticancer. Despite the clinical interest of bismuth-based drugs, several side effects have also been reported. In fact, excessive acute ingestion of bismuth, or abuse for an extended period of time, can lead to toxicity. However, evidence has demonstrated that the discontinuation of these compounds usually reverses their toxic effects. Notwithstanding, the continuously growing use of bismuth products suggests that it is indeed part of our environment and our daily lives, which urges a more in-depth review and investigation into its possible undesired activities. Therefore, this review aims to update the pharmaco-toxicological properties of bismuth compounds. A special focus will be given to in vitro, in vivo, and clinical studies exploring their toxicity.

New Scaffolds of Proteasome Inhibitors: Boosting Anticancer Potential by Exploiting the Synergy of In Silico and In Vitro Methodologies

Cancer is a complex multifactorial disease whose pathophysiology involves multiple metabolic pathways, including the ubiquitin-proteasome system, for which several proteasome inhibitors have already been approved for clinical use. However, the resistance to existing therapies and the occurrence of severe adverse effects is still a concern. The purpose of this study was the discovery of novel scaffolds of proteasome inhibitors with anticancer activity, aiming to overcome the limitations of the existing proteasome inhibitors. Thus, a structure-based virtual screening protocol was developed using the structure of the human 20S proteasome, and 246 compounds from virtual databases were selected for in vitro evaluation, namely proteasome inhibition assays and cell viability assays. Compound 4 (JHG58) was shortlisted as the best hit compound based on its potential in terms of proteasome inhibitory activity and its ability to induce cell death (both with IC50 values in the low micromolar range). Molecular docking studies revealed that compound 4 interacts with key residues, namely with the catalytic Thr1, Ala20, Thr21, Lys33, and Asp125 at the chymotrypsin-like catalytic active site. The hit compound is a good candidate for additional optimization through a hit-to-lead campaign.

Resveratrol as an Inhibitor of the NorA Efflux Pump and Resistance Modulator in Staphylococcus aureus

Staphylococcus aureus can exhibit resistance to various antibiotics. Among its resistance mechanisms, the active efflux of antibiotics can be seen as relevant. This study aimed to evaluate the ability of resveratrol to modulate norfloxacin resistance in S. aureus. The antimicrobial activity of resveratrol was assessed using the broth microdilution method to determine the minimum inhibitory concentration (MIC). Then, the modulatory effect of resveratrol was evaluated using the MIC determination for the antibiotic or ethidium bromide in the presence and absence of resveratrol at a sub-MIC level. The MIC of norfloxacin against S. aureus SA1199B (NorA-overexpressing strain) decreased 16-fold when in the presence of resveratrol, with a similar behavior being observed for ethidium bromide. An evaluation of the ethidium bromide accumulation was also performed, showing that in the presence of resveratrol, the SA1199B strain had augmented fluorescence due to the accumulation of ethidium bromide. Altogether, the results suggested that resveratrol may act by inhibiting NorA. These in vitro data were supported by docking results, with interactions between resveratrol and the NorA efflux pump predicted to be favorable. Our findings demonstrated that resveratrol may modulate norfloxacin resistance through the inhibition of NorA, increasing the effectiveness of this antibiotic against S. aureus.

Innovative Aqueous Nanoemulsion Prepared by Phase Inversion Emulsification with Exceptional Homogeneity

Formulating low-solubility or low-permeability drugs is a challenge, particularly with the low administration volumes required in intranasal drug delivery. Nanoemulsions (NE) can solve both issues, but their production and physical stability can be challenging, particularly when a high proportion of lipids is necessary. Hence, the aim of the present work was to develop a NE with good solubilization capacity for lipophilic drugs like simvastatin and able to promote the absorption of drugs with low permeability like fosphenytoin. Compositions with high proportion of two lipids were screened and characterized. Surprisingly, one of the compositions did not require high energy methods for high droplet size homogeneity. To better understand formulation factors important for this feature, several related compositions were evaluated, and their relative cytotoxicity was screened. Optimized compositions contained a high proportion of propylene glycol monocaprylate NF, formed very homogenous NE using a low-energy phase inversion method, solubilized simvastatin at high drug strength, and promoted a faster intranasal absorption of the hydrophilic prodrug fosphenytoin. Hence, a new highly homogeneous NE obtained by a simple low-energy method was successfully developed, which is a potential alternative for industrial application for the solubilization and protection of lipophilic actives, as well as (co-)administration of hydrophilic molecules.

Fighting Epilepsy with Nanomedicines-Is This the Right Weapon?

Epilepsy is a chronic and complex condition and is one of the most common neurological diseases, affecting about 50 million people worldwide. Pharmacological therapy has been, and is likely to remain, the main treatment approach for this disease. Although a large number of new antiseizure drugs (ASDs) has been introduced into the market in the last few years, many patients suffer from uncontrolled seizures, demanding the development of more effective therapies. Nanomedicines have emerged as a promising approach to deliver drugs to the brain, potentiating their therapeutic index. Moreover, nanomedicine has applied the knowledge of nanoscience, not only in disease treatment but also in prevention and diagnosis. In the current review, the general features and therapeutic management of epilepsy will be addressed, as well as the main barriers to overcome to obtain better antiseizure therapies. Furthermore, the role of nanomedicines as a valuable tool to selectively deliver drugs will be discussed, considering the ability of nanocarriers to deal with the less favourable physical-chemical properties of some ASDs, enhance their brain penetration, reduce the adverse effects, and circumvent the concerning drug resistance.

Thymus hirtus Willd. ssp. algeriensis Boiss. and Reut: A Comprehensive Review on Phytochemistry, Bioactivities, and Health-Enhancing Effects

Members of the Lamiaceae family are considered chief sources of bioactive therapeutic agents. They are important ornamental, medicinal, and aromatic plants, many of which are used in traditional and modern medicine and in the food, cosmetic, and pharmaceutical industries. In North Africa, on the Mediterranean side, there is the following particularly interesting Lamiaceous species: Thymus hirtus Willd. sp. Algeriensis Boiss. Et Reut. The populations of this endemic plant are distributed from the subhumid to the lower arid zone and are mainly employed as ethnomedicinal remedies in the following Maghreb countries: Algeria, Libya, Morocco, and Tunisia. In fact, they have been applied as antimicrobial agents, antispasmodics, astringents, expectorants, and preservatives for several food products. The species is commonly consumed as a tea or infusion and is used against hypercholesterolemia, diabetes, respiratory ailments, heart disease, and food poisoning. These medicinal uses are related to constituents with many biological characteristics, including antimicrobial, antioxidant, anticancer, anti-ulcer, anti-diabetic, insecticidal, and anti-inflammatory activities. This review aims to present an overview of the botanical characteristics and geographical distribution of Thymus algeriensis Boiss. Et Reut and its traditional uses. This manuscript also examines the phytochemical profile and its correlation with biological activities revealed by in vitro and in vivo studies.

Role of Aducanumab in the Treatment of Alzheimer’s Disease: Challenges and Opportunities

Aducanumab is a monoclonal antibody selective for amyloid β (Aβ) aggregates. In June 2021, aducanumab became the first drug underlying the pathophysiology of Alzheimer’s disease (AD) approved by the US Food and Drug Administration (FDA), under the accelerated approval pathway. The decision was based on the ability of aducanumab to remove Aβ plaques, without any evidence that the Aβ clearance is correlated with less cognitive or functional decline. This decision has generated a considerable debate in the scientific community, especially because the results from the two Phase 3 trials, EMERGE and ENGAGE, were divergent and, even after the post hoc analysis, the data were insufficient to prove aducanumab efficacy. Moreover, some researchers think that this approval will be an obstacle to the progress and also demonstrated concerns about aducanumab cost and its safety profile. The European Medicines Agency’s rejection of aducanumab in December 2021 just brought more controversy over FDA’s decision. Now, Biogen is designing the FDA’s required confirmatory study, named ENVISION, which should be complete in 2026. Despite the controversy, the aducanumab showed to affect downstream tau pathology, which could open doors for a combination therapy approach for AD (anti-tau and anti-amyloid drug). This review summarizes the clinical development of aducanumab until regulatory agencies’ decisions, the available trials data and the controversy over aducanumab approval for AD.

10β-Hydroxyestra-1,4-diene-3,17-dione as potential antiproliferative agent: in vitro biological evaluation and in silico studies

10β-Hydroxyestra-1,4-diene-3,17-dione (HEDD) is a natural product described as having neuroprotective activity. However, the cytotoxic properties of this quinol are barely studied. Thus, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed in six cell lines (MCF-7, T47-D, LNCaP, HepaRG, Caco-2 and NHDF). Additionally, an in vitro estrogenicity assay and a cell viability analysis together with in silico molecular docking studies were carried out in order to understand the potential mechanism of cytotoxicity. Computational predictions of its pharmacokinetic and toxicity properties were also performed. Surprisingly, HEDD displayed marked cytotoxic activity, particularly against hormone-dependent cancer cells and the flow cytometry analysis revealed that HEDD markedly reduced the viability of hepatic cancer cells. Molecular docking studies suggested a high affinity towards the estrogen receptor α and 17β-hydroxysteroid dehydrogenase type 1. Moreover, it was predicted that HEDD may have good oral bioavailability and a low maximum tolerated dose in humans.

Assessment of suspected adverse drug reactions in elderly patients with diabetes mellitus based on a Portuguese spontaneous reporting database: analysis of reporting from 2008 to 2018

BACKGROUND

Age is one of the most important risk factors in the development of diabetes mellitus and certain drug classes indicated for this condition may be associated with clinically important adverse drug reactions (ADRs). The aim of this study was to analyze the suspected ADRs in older patients with diabetes mellitus, reported to the Portuguese Pharmacovigilance System from 2008 to 2018.

RESEARCH DESIGN AND METHODS

A retrospective analysis of suspected ADRs reports was performed, involving patients aged ≥65 years.

RESULTS

Of a total of 751 reports collected, 439 were considered serious, 199 led to hospitalization and in 19 of them occurred a fatal outcome. Most of them were observed in females (n = 393) and involved patients belonging mainly to the age group 65-74 years (n = 405). Taking into account a total of 2134 suspected ADRs, the most frequent were hypoglycemia (2.67%) and lactic acidosis (2.62%). The drugs specifically indicated for glycemic control were the most frequently involved in ADRs.

CONCLUSIONS

Most of the ADRs were reported as serious and were mainly associated to drugs in diabetes mellitus. In addition, the majority of them, such as hypoglycemia, are preventable, highlighting the importance to identify possible factors that determine this occurrence, especially in the elderly.

Recent Developments in New Therapeutic Agents against Alzheimer and Parkinson Diseases: In-Silico Approaches

Neurodegenerative diseases (ND), including Alzheimer's (AD) and Parkinson's Disease (PD), are becoming increasingly more common and are recognized as a social problem in modern societies. These disorders are characterized by a progressive neurodegeneration and are considered one of the main causes of disability and mortality worldwide. Currently, there is no existing cure for AD nor PD and the clinically used drugs aim only at symptomatic relief, and are not capable of stopping neurodegeneration. Over the last years, several drug candidates reached clinical trials phases, but they were suspended, mainly because of the unsatisfactory pharmacological benefits. Recently, the number of compounds developed using in silico approaches has been increasing at a promising rate, mainly evaluating the affinity for several macromolecular targets and applying filters to exclude compounds with potentially unfavorable pharmacokinetics. Thus, in this review, an overview of the current therapeutics in use for these two ND, the main targets in drug development, and the primary studies published in the last five years that used in silico approaches to design novel drug candidates for AD and PD treatment will be presented. In addition, future perspectives for the treatment of these ND will also be briefly discussed.

Eustigmatophyte strains with potential interest in cancer prevention and treatment: partial chemical characterization and evaluation of cytotoxic and antioxidant activity

The interest in bioactive compounds from microalgae is increasing since they have medicinal and nutritional areas. The present work aims to evaluate the potential pharmaceutical interest of extracts from three eustigmatophyte strains from the Coimbra Collection of Algae (ACOI): Chlorobotrys gloeothece, Chlorobotrys regularis and Characiopsis aquilonaris. Antioxidant and antiproliferative activities were determined as well as chlorophyll a, carotenoid and phenolic total contents. In addition, major pigments and sterols were identified and quantified. The three strains were grown until the stationary phase and then the biomass was extracted. Antioxidant activity was measured by TEAC, DPPH and FRAP assays and antiproliferative effect was assessed by the MTT method on MCF-7, PC-3 and NHDF cells. The pigment and phenolic total contents were determined by spectrophotometry. Of these strains, C. aquilonaris showed the highest antioxidant activity measured by TEAC and FRAP assays (23.98 ± 0.01 μmol TE eq g^-1 DW and 42.57 ± 0.04 μmol TE eq g^-1 DW, respectively), a selective effect in reduting MCF-7 cells proliferation and a larger amount of chlorophyll a, carotenoids and phenolic content (18.40 ± 0.00 μg chlorophyll a mg^-1 DW, 2.27 ± 0.00 mg carotenoids g^-1 DW and 6.23 ± 0.01 mg GAE g^-1 DW, respectively). A positive correlation between chlorophyll a and TEAC assay was observed, as well as between carotenoids and TEAC and FRAP assays, suggesting these compounds as important contributors to significant antioxidant activity. Violaxanthin, cholesterol and stigmasterol were present in larger amount in C. aquilonaris while C. regularis showed a higher amount of β-carotene. These results suggest that these three ACOI eustigmatophytes are promising for applications in the improvement of human health, particularly in cancer prevention and treatment.

Antimicrobial and antitumor activity of S-methyl dithiocarbazate Schiff base zinc(II) complexes

Schiff bases (SB) obtained from S-methyl dithiocarbazate and aromatic aldehydes: salicylaldehyde (H₂L¹), o-vanillin (H₂L²), pyridoxal (H₂L³) and 2,6-diformyl-4-methylphenol (H₃L⁴), and their corresponding Zn(II)-complexes (1-4), are synthesized. All compounds are characterized by elemental analyses, infrared, UV-Vis, nuclear magnetic resonance spectroscopy and mass spectrometry. The structures of H₂L² and [Zn₂(L¹)₂(H₂O)(DMF)] (1a) (DMF = dimethylformamide) are solved by single crystal X-ray diffraction. The SB coordinates the metal center through the O_phenolate, N_imine and S_thiolate atoms. The radical scavenging activity is tested using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, with all ligand precursors showing IC₅₀ values ~40 μM. Cytotoxicity studies with several tumor cell lines (PC-3, MCF-7 and Caco-2) as well as a non-tumoral cell line (NHDF) are reported. Interestingly, 1 has relevant and selective antiproliferative effect against Caco-2 cells (IC₅₀ = 9.1 μM). Their antimicrobial activity is evaluated in five bacterial strains (Klebsiella pneumoniae, Acinetobacter baumannii, Listeria monocytogenes, Pseudomonas aeruginosa and Staphylococcus aureus) and two yeast strains (Candida albicans and Candida tropicalis) with some compounds showing bacteriostatic and fungicidal activity. The minimal inhibitory concentration (MIC₉₀) of H_nL against Mycobacterium tuberculosis is also reported, with H₂L² and H₃L⁴ showing very high activity (MIC₉₀ < 0.6 μg/mL). The ability of the compounds to bind bovine serum albumin (BSA) and DNA is evaluated for H₃L⁴ and [Zn₂(L⁴)(CH₃COO)] (4), both showing high binding constants to BSA (ca. 10⁶ M^-1) and ability to bind DNA. Overall, the reported compounds show relevant antitumor and antimicrobial properties, our data indicating they may be promising compounds in several fields of medicinal chemistry.

The Synthesis of 2-Spiroindolin-3-one-(thio)barbiturates from 2,1-Benzisoxazoles: A Rearrangement Promoted by Thermal Conditions

A new thermal process to prepare spiroindolin-3-ones from 3-substituted 2,1-benzisoxazoles in good yields (70–85%) is described. The highest yields were observed when microwave irradiation was used. The method does not require the use of any additive or catalyst. A possible reaction mechanism involving a nitrene key intermediate is proposed.

Nimesulide analogues: From anti-inflammatory to antitumor agents

Nimesulide is a nonsteroidal anti-inflammatory drug possessing analgesic and antipyretic properties. This drug is considered a selective cyclooxygenase-2 (COX-2) inhibitor and, more recently, has been associated to antitumor activity. Thus, numerous works have been developed to modify the nimesulide skeleton aiming to develop new and more potent and selective COX-2 inhibitors as well as potential anticancer agents. This review intends to provide an overview on analogues of nimesulide, including the general synthetic approaches used for their preparation and structural diversification and their main anti-inflammatory and/or antitumor properties.

Steroidal Oximes: Useful Compounds with Antitumor Activities

BACKGROUND

Steroids play an important role in life because they can regulate a variety of biological processes and have been widely used in medicine namely as antiinflammatory, anabolic, contraceptives and anticancer drugs. In recent years, there has been an increasing interest in the introduction of the oxime group in a large variety of molecules in order to increase their biological effects. This review highlights steroidal oximes with anticancer properties and their potential mechanisms of action, as well as data on their relative potencies reported in literature in the last few years.

METHODS

To prepare this review, an extensive literature search was performed on three databases, PubMed, ISI Web of Knowledge and Science Direct, to generate a critical but comprehensive overview of the potential antitumor activities of steroidal oximes. The main keywords used for the search consisted of combinations of the following terms or their synonyms: steroidal oximes, anticancer activity and enzymatic inhibitory activity. The abstracts and full texts were evaluated for their clarity and scientific merit and to further help on the selection of other articles.

RESULTS

Over the last decades the introduction of oxime groups in the steroid scaffold is originating molecules with relevant antitumor activities, as well as steroid sulfatase, aromatase, 17α-hydroxylase-17,20-lyase, 5α-reductase and 17β-hydroxysteroid dehydrogenase type 1 inhibitory activities. As relevant examples, pregnenolone 20-oximes showed high activity as 17α-hydroxylase-17,20-lyase and 5α-reductase inhibitors and the introduction of an oxime group at C-6 in androstane series also led to relevant results as aromatase inhibitors. Interestingly, the introduction of this functional group frequently improves the bioactivity when compared with non-oxime analogous compounds, which can be due to extra interactions with biological targets. In addition, it has been observed that varying the position of the hydroximino group on the parent skeleton leads to remarkable changes in the antitumor activity.

CONCLUSION

The recent advances in synthesis and in vitro bioactivity studies of steroidal oximes contributed to understand the potential interest of the introduction of this functional group in the steroidal nucleus in the development of anticancer molecules. Moreover, the cytotoxic/enzyme inhibitory activity usually depends on the position of the oxime group in different steroid scaffolds. However, despite the promising results, it is necessary to perform more in vitro and in vivo assays not only to better explore the mechanisms of action but also to confirm the potential effectiveness and safety of this interesting family of compounds in clinical practice.

Considerations and Pitfalls in Selecting the Drug Vehicles for Evaluation of New Drug Candidates: Focus on in vivo Pharmaco-Toxicological Assays Based on the Rotarod Performance Test

Purpose - During the discovery and development of new drugs, compounds with low aqueous solubility pose special challenges in their pharmacological evaluation and, therefore, the selection of appropriate vehicles to administer the compounds of interest is determinant for the quality of the results generated during the in vivo non-clinical studies. This work aimed to evaluate the motor deficit (as a surrogate of neurotoxicity) of several administration/delivery vehicles through the rotarod performance test. Methods - Trained male CD-1 mice were intraperitoneally administered with the following vehicles: dimethyl sulfoxide (DMSO), aqueous sodium chloride (NaCl) 0.9%, aqueous carboxymethylcellulose (CMC) 0.5%, polyethylene glycol (PEG)-400, propylene glycol (PG), and solutions of these vehicles containing 5% and 10% DMSO. Results - It was observed that the aqueous vehicles (NaCl 0.9% and CMC 0.5%) did not affect the performance of the animals on the rod. On the other hand, a vehicle consisting solely of DMSO led to significant motor impairment and only a small improvement was recorded over time. Additionally, a strong neuromotor toxicity was observed in the early evaluation points of the experiment using vehicles constituted by PG and PEG-400 or by mixtures of PG/DMSO (5% and 10%) and PEG-400/DMSO (5% and 10%). Conclusion - This study provides useful data about the neurotoxicity inherent to several vehicles frequently used in non-clinical pharmaco-toxicological assays, aiming to draw especial attention to the need of a careful selection of drug vehicles in order to avoid the impact of such confounding variables on the accuracy of the results and in decision-making processes. This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's contents page.

Diosgenin: Recent Highlights on Pharmacology and Analytical Methodology

Diosgenin, a steroidal sapogenin, occurs abundantly in plants such as Dioscorea alata, Smilax China, and Trigonella foenum graecum. This bioactive phytochemical not only is used as an important starting material for the preparation of several steroidal drugs in the pharmaceutical industry, but has revealed also high potential and interest in the treatment of various types of disorders such as cancer, hypercholesterolemia, inflammation, and several types of infections. Due to its pharmacological and industrial importance, several extraction and analytical procedures have been developed and applied over the years to isolate, detect, and quantify diosgenin, not only in its natural sources and pharmaceutical compositions, but also in animal matrices for pharmacodynamic, pharmacokinetic, and toxicological studies. Within these, HPLC technique coupled to different detectors is the most commonly analytical procedure described for this compound. However, other alternative methods were also published. Thus, the present review aims to provide collective information on the most recent pharmacological data on diosgenin and on the most relevant analytical techniques used to isolate, detect, and quantify this compound as well.

Gastrodia elata and epilepsy: Rationale and therapeutic potential

BACKGROUND

Gastrodia elata Blume (G. elata) is a traditional Chinese herb used for centuries in folk medicine. Due to the claimed anticonvulsant properties of G. elata, it is expected that this herb continues to be a target of research, aiming to deepen the available knowledge on its biological activity and safety.

PURPOSE

The current review aims to discuss the most recent advances on the elucidation of the phytochemical composition and anticonvulsant potential of G. elata.

METHODS

Available literature was reviewed from PubMed, ISI Web of Knowledge and Science Direct, using combinations of the following keywords: Gastrodia elata, tianma, epilepsy, anticonvulsant and pharmacokinetics. Abstracts and full texts were evaluated for their clarity and scientific merit.

RESULTS

G. elata rhizome, as well as specific phenolic compounds isolated from this herb, have demonstrated anticonvulsant potential in a variety of in vitro and in vivo models. The pharmacological mechanisms potentially involved in the anticonvulsant activity have been extensively studied, being similar to the known mechanisms claimed for the available antiepileptic drugs. In addition, the pharmacokinetics of the main bioactive component of G. elata (gastrodin) has also been studied.

CONCLUSION

Due to its recognised therapeutic properties, G. elata has gained an increasing interest within the scientific community and, therefore, new medicinal preparations containing G. elata rhizome itself or its bioactive components are expected to be developed in the coming years. Moreover, specific phytochemical constituents isolated from G. elata may also be considered to integrate programs of discovery and development of new anticonvulsant drug candidates.

Potential antitumoral 3,4-dihydropyrimidin-2-(1H)-ones: synthesis, in vitro biological evaluation and QSAR studies

The search for novel anticancer agents with higher selectivity and lower toxicity remains a medical need.

Effects of Hypericum perforatum extract and its main bioactive compounds on the cytotoxicity and expression of CYP1A2 and CYP2D6 in hepatic cells

AIMS

Hypericum perforatum (H. perforatum) is one of the most used medicinal plants. However, it has been associated with relevant interactions with several drugs. This situation is probably mediated by cytochrome P450 enzymes (CYP450), namely the 1A2 (CYP1A2) and 2D6 (CYP2D6) isoforms This study aims to assess the cytotoxic and CYP1A2 and CYP2D6 inductive and/or inhibitory effects of a H. perforatum extract and its main bioactive components in hepatic cell lines.

MAIN METHODS

A MTT proliferation assay was performed in WRL-68, HepG2 and HepaRG cells after exposition to different concentrations of H. perforatum extract, hypericin and hyperforin for 24 and 72 h. Then, a real-time PCR analysis was accomplished after incubating the cells with these products evaluating the relative CYP1A2 and CYP2D6 expression.

KEY FINDINGS

These products have relevant cytotoxicity at a 10 μM concentration and it was also demonstrated for the first time that H. perforatum can lead to a significant CYP1A2 and CYP2D6 induction in all cell lines. Moreover, hypericin seems to induce CYP1A2 in HepG2 cells and to inhibit its expression in HepaRG cells while hyperforin induced CYP1A2 in HepG2 and in WRL-68 cells. Additionally, hypericin and hyperforin induce CYP2D6 in HepG2 cells but inhibits its expression in HepaRG and in WRL-68 cells.

SIGNIFICANCE

This study not only evidenced that H. perforatum extract and two of its bioactive components can have toxic effects in hepatic cell lines but also emphasized the potential risk of the consumption of H. perforatum with CYP1A2- and CYP2D6-metabolized drugs.

3,3'-Diamino-N-methyldipropylamine as a versatile affinity ligand

Currently, in biomedicine and biotechnology fields, there is a growing need to develop and produce biomolecules with a high degree of purity. To accomplish this goal, new purification methods are being developed looking for higher performance, efficiency, selectivity, and cost-effectiveness. Affinity chromatography is considered one of the most highly selective methods for biomolecules purification. The purpose of this work is to explore a new type of a structurally simple ligand immobilized onto an agarose matrix to be used in affinity chromatography. The ligand in this study, 3,3'-diamino-N-methyldipropylamine has shown low toxicity and low cost of preparation. Moreover, the ability of the ligand to be used in affinity chromatography to purify proteins and nucleic acids was verified. An increasing sodium chloride gradient, using salt concentrations up to 500 mM, was suitable to accomplish the purification of these biomolecules, meaning that the new support allows the recovery of target biomolecules under mild conditions. Thus, the 3,3'-diamino-N-methyldipropylamine ligand is shown to be a useful and versatile tool in chromatographic experiments, with very good results either for proteins or supercoiled plasmid isoform purification.

Contribution of sociodemographic characteristics, occupation, diet and lifestyle to DDT and DDE concentrations in serum and adipose tissue from a Bolivian cohort

The organochlorine pesticide p,p'-Dichlorodiphenyltrichloroethane (DDT) was widely used in the early 1960s-70s for vector control in tropical and subtropical areas of South America. Due to its persistence, DDT has a high potential to bioaccumulate in the food chain and living organisms and is a major public health concern, especially in South America. The main purpose of the present study was to investigate predictors of serum and adipose tissue concentrations of p,p'-DDT and its main metabolite, p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE), in an adult cohort (n=112) from Santa Cruz de la Sierra, Bolivia, using multiple linear regression models. These models explained 29.3-47.8% of the variability in adipose tissue concentrations of p,p'-DDT and p,p'-DDE, respectively, and 32.9-47.0% of that in serum. Main exposure predictors included age, occupational class, residence, diet, smoking habit, and accumulated breastfeeding time. This is one of the few studies to explore predictors of human exposure to these chemicals using a multivariate approach in a South American population. Results show that predictors of human exposure to p,p'-DDT and p,p'-DDE in Santa Cruz de la Sierra may diverge from those found in other populations of the world, due to particular sociodemographic and lifestyle characteristics of this region.

Targeting of mitochondria-endoplasmic reticulum by fluorescent macrocyclic compounds

Background

Useful probes of the intracellular environment that target a specific organelle in order to allow direct observation of the changes in these regions is of high current interest. Macrocyclic ligands have already revealed themselves as important selective hosts in some biological applications, forming stable and specific complexes. Therefore, in this paper, several macrocyclic ligands are evaluated as potential molecular probes.

Methodology

Four polyammonium macrocycles and one macrotricyclic bearing pyridine and phenanthroline chromophores have been synthesised and evaluated as molecular probes. The cytotoxicity of the compounds has been analyzed using human breast cancer cells (MCF-7), non-cancerous human dermal fibroblasts (NHDF) and human adult dermal skin fibroblasts from a breast cancer patient (P14). All the compounds showed low toxicity at concentrations ranging from 10 nM to 10 µM, except for [32]phen₂N₄ which proved to be highly cytotoxic for MCF-7 cells. Flow cytometry studies evidenced that the percentage of apoptotic and necrotic MCF-7 and NHDF cells induced by the compounds is considerably low. Also, flow cytometry analysis showed that some compounds seem to modify the mitochondrial membrane potential (MMP) of the cells. Fluorescence microscopy evidenced that compounds easily cross the plasma membrane (5 min) and accumulated into the mitochondria, as confirmed by co-localization with MitoTracker Green™. The fluorescence images also evidenced an intact mitochondria structure after 48 h. Moreover, reticular staining suggestive of endoplasmic reticulum (ER) localization, in addition to the mitochondrial one, has been found by confocal microscopy.

Conclusion

Our study reveals that compounds Me₂[28]py₂N₆, cryptphen, [16]phenN₂, [30]phen₂N₆, have low toxicity and localize in mitochondria and ER. The ability of these compounds for translocating the cellular membrane (5 min) without special conditioning of the cells or derivatization of the probe, the time-dependent localization (48 h) and the cellular viability provide a proof-of-concept towards their use as promising probes towards biomedical studies.

Sodium Tripolyphosphate: an excipient with intrinsic in vitro anti-Candida activity

Sodium Tripolyphosphate (STPP) is a food additive that is being used in the development of micro and nanoparticles as it induces ionic interactions with chitosan molecules. Although the ability of STPP to inhibit the growth of several food contaminants has been reported, studies on its activity against clinical isolates are scarce. Candida spp. are common causative agents of mucocutaneous infections including the vulvovaginal tegument and new therapeutic approaches are needed in order to treat resistant and recurrent cases. The aim of this study was to evaluate in vitro both antifungal (anti-Candida spp.) activity, and cytotoxicity, on human dermal fibroblasts, of STPP solutions. STPP showed an inhibitory species-dependent activity against several Candida spp. strains being particularly active on C. glabrata, followed by C. guilliermondii. In vitro, STPP showed a concentration dependent cytotoxicity. Therefore STPP use, in low concentrations, seems to be interesting in the development of drug delivery systems for the treatment of vulvovaginal candidosis.