M Segment-Based Minigenome System of Severe Fever with Thrombocytopenia Syndrome Virus as a Tool for Antiviral Drug Screening

Severe fever with thrombocytopenia syndrome virus (SFTSV) is an emerging tick-borne bunyavirus that causes severe disease in humans with case fatality rates of approximately 30%. There are few treatment options for SFTSV infection. SFTSV RNA synthesis is conducted using a virus-encoded complex with RNA-dependent RNA polymerase activity that is required for viral propagation. This complex and its activities are, therefore, potential antiviral targets. A library of small molecule compounds was processed using a high-throughput screening (HTS) based on an SFTSV minigenome assay (MGA) in a 96-well microplate format to identify potential lead inhibitors of SFTSV RNA synthesis. The assay confirmed inhibitory activities of previously reported SFTSV inhibitors, favipiravir and ribavirin. A small-scale screening using MGA identified four candidate inhibitors that inhibited SFTSV minigenome activity by more than 80% while exhibiting less than 20% cell cytotoxicity with selectivity index (SI) values of more than 100. These included mycophenolate mofetil, methotrexate, clofarabine, and bleomycin. Overall, these data demonstrate that the SFTSV MGA is useful for anti-SFTSV drug development research.

Mitochondrial dysfunction in Alzheimer’s disease: Opportunities for drug development

: Alzheimer’s disease (AD) is one of the major reasons for 60-80% of cases of senile dementia occurring as a result of the accumulation of plaques and tangles in the hippocampal and cortical neurons of the brain leading to neurodegeneration and cell death. The other pathological features of AD comprise of abnormal microvasculature, network abnormalities, interneuronal dysfunction, increased β-amyloid production, and reduced clearance, increased inflammatory response, elevated production of reactive oxygen species, impaired brain metabolism, hyperphosphorylation of tau, and disruption of acetylcholine signaling. Among all these pathologies, mitochondrial dysfunction (MD), regardless of being an inciting insult or a consequence of the alterations, is related to all the associated AD pathologies. Observed altered mitochondrial morphology, distribution, and movement increased oxidative stress, dysregulation of enzymes involved in mitochondrial functioning, impaired brain metabolism, and impaired mitochondrial biogenesis in AD subjects suggest the involvement of mitochondrial malfunction in the progression of AD. Various pre-clinical and clinical evidence establishing MD as a key mediator in the progression of neurodegeneration in AD are reviewed and discussed with an aim to foster future MD-based drug development research for the management of AD.

M Segment-Based Minigenome System of Severe Fever with Thrombocytopenia Syndrome Virus as a Tool for Antiviral Drug Screening

Severe fever with thrombocytopenia syndrome virus (SFTSV) is an emerging tick-borne bunyavirus that causes severe disease in humans with case fatality rates of approximately 30%. There are few treatment options for SFTSV infection. SFTSV RNA synthesis is conducted using a virus-encoded complex with RNA-dependent RNA polymerase activity that is required for viral propagation. This complex and its activities are, therefore, potential antiviral targets. A library of small molecule compounds was screened using a high-throughput screening (HTS) based on an SFTSV minigenome assay (MGA) in a 96-well microplate format to identify potential lead inhibitors of SFTSV RNA synthesis. The assay confirmed inhibitory activities of previously reported SFTSV inhibitors, favipiravir, and ribavirin. A small-scale screening using MGA identified four candidate inhibitors that inhibited SFTSV minigenome activity by more than 80% while exhibiting less than 20% cell cytotoxicity with selectivity index (SI) values of more than 100. These included mycophenolate mofetil, methotrexate, clofarabine, and bleomycin. Overall, these data demonstrate that the SFTSV MGA is useful for anti-SFTSV drug development research.

Molecular profiling and anti-infective potency of endophytic actinomycetes inhabiting Madhuca insignis Radlk., from Western Ghats of India

Background Endophytic actinomycetes are well known for their diverse bioactive entities and considered as an important source for drug development research. Results We isolated and identified four potential endophytic Streptomyces species, i.e., Streptomyces misionensis MI22, Streptomyces roietensis MI24, Streptomyces glaucescens MI29, and Streptomyces sp. MI04 inhabiting Madhuca insignis by its characteristic morphological features and 16S rRNA gene sequence analysis. S. misionensis MI22 exhibits a broad spectrum of anti-microbial activity against methicillin-resistant Staphylococcus aureus (25.00 ± 1.00 mm) followed by Bacillus subtilis (23.66 ± 0.57 mm), Escherichia coli (22.00 ± 0.00 mm), and Candida albicans (18.00 ± 0.00 mm). Minimum inhibitory concentrations of the ethyl acetate fraction of S. misionensis MI22 against test pathogens were ranged from 25 to 100 μg/mL. Indeed, strain MI22 also exhibited significant anti-proliferative activity against HeLa cell line with IC50 value 98 μg/mL and showed no cytotoxicity effect to the normal human embryonic kidney cell line in the MTT assay. The anti-microbial metabolites from strain MI22 were detected at Rf 0.55 as depicted by the inhibition zone on the intensive band in TLC-bioautography assay. Conclusion The study indicates that, anti-microbial metabolites of these endophytic Streptomyces species, especially S. misionensis MI22 as a prolific source to discover novel bioactive metabolites to combat multidrug-resistant pathogens.

The Extracts of Epilobium Parviflorum Inhibit MCF-7 Breast Cancer Cells

Background: Traditional medicine is inspiring in drug development research. Epilobium parviflorum extracts have shown promising therapeutic effects on prostate cancer cells. The similarities between breast and prostate cancers at molecular and metabolic levels prompted us to explore its effects on human breast cancer. Methods: The root, aerial parts and flowers of the plant were, collected and dried separately at ambient temperature and away from direct sunlight. The aquatic and methanolic extracts of each part was prepared. The effect of each extract on the growth of MCF-7 breast carcinoma cells and HEK293 normal cell line was evaluated, using MTT assay. Each experiment was repeated at least three times independently. The IC50 values for each treatment time point were analyzed, using ANOVA at P<0.05. Results: While none of the extracts had considerable toxicity on normal HEK293 cells, some of them showed varying levels of toxicity on the MCF-7 cells. The methanolic extracts were more cytotoxic than the aqueous counterpart. The roots’ methanolic extract showed the strongest cytotoxicity on the MCF-7 cells in a dose and exposure time dependent manner. The IC50 after 48 hours of treatment was determined at 73µg/ml. Conclusion: This study is the first to demonstrate that Epilobium parviflorum had a strong growth inhibiting property on MCF-7 cell line, as a potential model to treat human breast cancer cells. The most cytotoxic effect was noted for the methanolic root extract. Determination of the effective biochemical constituents of the extract against cancer cells is the focus of our future research.

Animal models in antihypertensive drug development research

Hypertension is one of the most common diseases in the world. However, its pathogenesis is not fully understood and its treatment is not yet satisfying. Animal models of hypertension have been useful to understand the pathogenesis of hypertension and to test novel therapeutic agents. There are several kinds of hypertension animal models. Each model has different characteristics. Knowing the characteristic of each model is important to obtain valid research. This review will describe several available methods to develop animal model for hypertension.

Variation in biosynthesis of an effective anticancer secondary metabolite, mahanine in Murraya koenigii, conditional on soil physicochemistry and weather suitability

Murraya koenigii (MK) leaf being a rich source of bioactive secondary metabolites has received inordinate attention in drug development research. Formation of secondary plant metabolite(s) in medicinal plants depends on several factors and in this study the cause of variation in bioavailability and content of a vital bioactive phytochemical, mahanine in the MK leaves from different geographical locations of varying soil properties and weather parameters was determined. Accordingly, MK leaves and soil samples around the plant base in quintuplicate from each site across five states of India at similar time point were collected. Mahanine content was determined and compared among samples from different regions. The quantitative analysis data comprised that MK-leaves of southern part of India contains highest amount of mahanine, which is 16.9 times higher than that of MK-leaves of north-eastern part of India (which measured as the lowest). The results suggested that pH, conductivity and bacterial populations of the soil samples were positively correlated with mahanine content in the MK-leaves. For examples, the average soil pH of the southern India sites was in basic range (8.8 ± 0.6); whereas that of the north-east India sites was in slightly acidic ranges (6.1 ± 0.5) and mean soil conductivity value for the north east India soils was 78.3 ± 16.3 µS/cm against mean value of 432.4 ± 204.5 µs/cm for south India soils. In conclusion, this study proclaims that higher level of bioactive phytochemical, mahanine in MK leaves depending upon geographical location, weather suitability and soil’s physiochemical and microbial parameters of its cultivation sites.

An Insight in Pathophysiological Mechanism of Alzheimer’s Disease and its Management using Plant Natural Products

: Alzheimer’s disease (AD) is an age-associated nervous system disorder and a leading cause of dementia worldwide. Clinically it is described by cognitive impairment, and pathophysiologically by deposition of amyloid plaques and neurofibrillary tangles in the brain and neurodegeneration. This article reviews the pathophysiology, course of neuronal degeneration, and the various possible hypothesis of AD progression. These hypotheses include amyloid cascade, tau hyperphosphorylation, cholinergic disruption, metal dysregulation, vascular dysfunction, oxidative stress, and neuroinflammation. There is an exponential increase in the occurrence of the AD in recent few years that indicate an urgent need to develop some effective treatment. Currently, only 2 classes of drugs are available for AD treatment namely acetylcholinesterase inhibitor and NMDA receptor antagonist. Since AD is a complex neurological disorder and these drugs use a single target approach, alternatives are needed due to limited effectiveness and unpleasant side-effects of these drugs. Currently, plants have been used for drug development research especially because of their multiple sites of action and fewer side effects. Uses of some herbs and phytoconstituents for the management of neuronal disorders like AD have been documented in this article. Phytochemical screening of these plants shows the presence of many beneficial constituents like flavonoids, triterpenes, alkaloids, sterols, polyphenols, and tannins. These compounds show a wide array of pharmacological activities such as anti-amyloidogenic, anticholinesterase, and antioxidant. This article summarizes the present understanding of AD progression and gathers biochemical evidence from various works on natural products that can be useful in the management of this disease.

Human Organoids: Tools for Understanding Biology and Treating Diseases

Organoids are in vitro–cultured three-dimensional structures that recapitulate key aspects of in vivo organs. They can be established from pluripotent stem cells and from adult stem cells, the latter being the subject of this review. Organoids derived from adult stem cells exploit the tissue regeneration process that is driven by these cells, and they can be established directly from the healthy or diseased epithelium of many organs. Organoids are amenable to any experimental approach that has been developed for cell lines. Applications in experimental biology involve the modeling of tissue physiology and disease, including malignant, hereditary, and infectious diseases. Biobanks of patient-derived tumor organoids are used in drug development research, and they hold promise for developing personalized and regenerative medicine. In this review, we discuss the applications of adult stem cell–derived organoids in the laboratory and the clinic.