Current Topics in Medicinal Chemistry - Volume 21, Issue 10, 2021

Given their primacy in governing the action potential (AP) of excitable cells, voltage-gated Na+ (Nav) channels are important pharmacological targets of therapeutics for a diverse array of clinical indications. Despite historically being a traditional drug target, therapeutics targeting Nav channels lack isoform selectivity, giving rise to off-target side effects. To develop isoform-selective modulators of Nav channels with improved target-specificity, the identification and pharmacological targeting of allosteric sites that display structural divergence among Nav channel isoforms represents an attractive approach. Despite the high homology among Nav channel α subunit isoforms (Nav1.1-Nav1.9), there is considerable amino acid sequence divergence among their constituent C-terminal domains (CTD), which enables structurally and functionally specific protein: protein interactions (PPI) with auxiliary proteins. Although pharmacological targeting of such PPI interfaces between the CTDs of Nav channels and auxiliary proteins represents an innovate approach for developing isoform-selective modulators of Nav channels, appreciable modulation of PPIs using small molecules has conventionally been difficult to achieve. After briefly discussing the challenges of modulating PPIs using small molecules, this current frontier review that follows subsequently expounds on approaches for circumventing such difficulties in the context of developing small molecule modulators of PPIs between transmembrane ion channels and their auxiliary proteins. In addition to broadly discussing such approaches, the implementation of such approaches is specifically discussed in the context of developing small molecule modulators between the CTD of Nav channels and auxiliary proteins. Developing allosteric modulators of ion channels by targeting their PPI interfaces with auxiliary proteins represents an innovative and promising strategy in ion channel drug discovery that could expand the “druggable genome” and usher in first-in-class PPI-targeting therapeutics for a multitude of channelopathies.

Diabetes Mellitus (DM) is an endocrine disease, which is the 3rd leading cause of death in humans; additionally, it is one of the major key concerns over the globe. The high levels of glucose in the blood stream are as well characterized by hyperglycaemia leading to serious damage to the heart, blood vessels, kidney, eyes, and nerves. The best treatment of DM is still not available; many scientists worldwide are trying hard to seek out suitable treatment of DM. Though numerous synthetic drugs are developed for the treatment of diabetes but their utility has been hampered because of several side effects and poor efficacy. Among various approaches for the treatment of DM, herbal medicine, enriched extracts, and naturally derived molecules are most effective. Plant based herbal medicines contain many bioactive phytochemicals, such as terpenoids, alkaloids, flavonoids & phenolics, etc. which are used in the treatment of many diseases. The plant-derived molecules and their suitable structure modification have given many leads or drugs to the world like sesquiterpene; artemisinin and their derivatives artemether & artesunate as an antimalarial drugs. Sesquiterpenes are available in the human diet and are largely taken as components of the many folk medicines and dietary supplements. Sesquiterpenes have a wide range of biological activities, such as anti-cancer, anti-inflammatory, anti-nociceptive, immunomodulatory, antidiabetic and antimicrobial, which make them potential targets for the development of new therapeutics and their usage for medical purposes. Natural products have gained the attention of the world due to their large number of biological activities, high safety and fewer side effect. The review mainly focuses on bioactive sesquiterpenes such as β-caryophyllene, dysidine, farnesol & eremanthin, etc., a class of terpenoids that may play an important role in the treatment or prevention of this gruesome disorder like diabetes, with their underlying mechanisms for the blood-glucose-lowering property.

Obesity has become a worldwide health problem. It triggers additional co-morbidities like cardiovascular diseases, cancer, depression, sleep disorders, gastrointestinal problems and many more. Excess accumulation of fat in obesity could be caused by many factors like sedentary lifestyle, consumption of high-fat diet, genetic predisposition, etc. Imbalanced energy metabolism i.e., greater energy consumption than utilisation, invariably underlies obesity. Considering the high prevalence and continuous, uncontrolled increase of this major public health issue, there is an urgent need to find appropriate therapeutic agents with minimal or no side effects. The high prevalence of obesity in recent years has led to a surge in the number of drugs available in the market that claim to control obesity. Although there is a long list of medicines and management strategies that are available, selecting the right therapeutic intervention and feasible management of obesity is a challenge. Several phytochemicals like hydroxycitric acid, flavonoids, tannins, anthocyanins, phytohaemagglutinin, thymoquinone and epigallocatechin gallate have been shown to possess promising anti-obesity properties. However, studies providing information on how various phytochemicals exert their anti-obesity effects are inadequate. This calls for more experimentation in this less explored area of research. Additionally, the complication of obesity arises when it is a result of multiple factors and associated with a number of co-morbidities. In order to handle such complexities, combinatorial therapeutic interventions become effective. In this review, we have described the medicinal chemistry of different highly effective phytochemicals which can be used in the effective treatment and management of obesity.

Brain function activity is regulated by several mechanisms of genetic and epigenetic factors such as histone modelling, DNA methylation, and non-coding RNA. Alterations in these regulatory mechanisms affect the normal development of neurons that causes Neuropsychiatric Disorders (ND). However, it is required to analyse the functional significance of neuropsychiatric disorders associated with a molecular mechanism to bring about therapeutic advances in early diagnosis and treatment of the patients. The CRISPR/Cas 9 (Clustered Regularly Interspaced Short Palindromic Repeats) genome editing tools have revolutionized multiple genome and epigenome manipulation targets the same time. This review discussed the possibilities of using CRISPR/Cas 9 tools during molecular mechanism in the ND as a therapeutic approach to overcome ND that is caused due to genetic and epigenetic abnormalities.

Introduction: Endophyte is considered a source of natural bioactive secondary metabolites that provides an array of bioactive lead compounds. The present study was aimed to determine the antimicrobial and anti-inflammatory potential of fungal endophytes isolated from Catharanthus roseus. Methods: A total of seven fungal endophytes crude extract were screened against bacterial pathogens. Of these, Curvularia geniculata CATDLF7 crude extract exhibited the most potent inhibitory activity against bacterial pathogens. Hence, CATDLF7 crude extract was subjected to chromatographic separation. This purification leads to the isolation of six pure compounds (1PS - 6PS). Of these, 3PS was found to be a major constituent and most effective against clinical isolates of methicillin- resistant Staphylococcus aureus (MRSA) with minimum inhibitory concentration (MIC) values ranging from 100 to 200 μg/ml. Based on the spectroscopic data, 3PS was characterized as α,β- dehydrocurvularin. This compound also showed synergistic interaction with norfloxacin and reduced its MIC up to 32-folds with a fractional inhibitory concentration index (FICI) of 0.09. Results: To understand the possible antibacterial mechanism of action, α,β-dehydrocurvularin alone (100 μg/ml) exhibited efflux pump inhibitory potential by 0.84 fold decreasing in ethidium bromide (EtBr) fluorescence. In addition, α,β-dehydrocurvularin inhibited inflammatory cytokines TNF-α and IL-6 production, which is further validated by molecular docking scores -4.921 and -5.641, respectively, for understanding orientation and binding affinity. Conclusion: Overall, the results highlighted identifying bioactive compound α,β-dehydrocurvularin, which could be used as an antimicrobial and anti-inflammatory agent.

Background: In the present study, we have explored the utility of QSAR modelling, in silico ADMET, docking, chemical semi-synthesis, and in vitro evaluation studies for the identification of active camptothecin (CPT) derivatives against cancer-targeting human liver (HepG2) and lung (A549) cancer cell lines. Methods: Two QSAR models were developed as screenings tools using the multiple linear regression (MLR) method followed by ADMET and docking studies. The regression coefficient (r²) and cross-validation regression coefficients (rCV^2T) of the QSAR model for the HepG2 cell line was 0.95 and 0.90, respectively, and for the A549 cell line, it was 0.93 and 0.81, respectively. Results: In silico studies show that CPT derivatives (CPT-1 and CPT-6) possess drug-like properties. Docking performed on DNA Topoisomerase-I showed significant binding affinity. Finally, predicted active derivatives were chemically semi synthesized, spectroscopically characterized, and evaluated in-vitro for cytotoxic/anticancer activity against HepG2 and A549 cell lines. Conclusion: The experimental results are consistent with the predicted results. These findings may be of immense importance in the anticancer drug development from an inexpensive and widely available natural product, camptothecin.

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), known as Coronavirus disease-2019 (COVID-19), has caused the sixth world’s public health emergency. Healthcare staff, as the frontline population fighting the pandemic, are exposed to a high risk of infection. Therefore, developing a protective intervention for medical staff is of significant importance. Objective: The aim of the study was to explore the effectiveness and safety of recombinant human interferon alpha (rhIFN-α) nasal drops for the prevention of coronavirus disease 2019 (COVID-19) through administering it to medical staff. Methods: This was a prospective open-label clinical trial with parallel intervention assignment conducted on 2944 medical staff including both doctors and nurses from Taihe Hospital, Shiyan City, Hubei Province, China from January 21, 2020 to July 30, 2020. The participants were bifurcated into two groups of low risk and high risk groups according to the level of direct exposure to COVID-19 patients. The individuals of the low-risk group received rhIFN-α nasal drops for one month in addition to first level protection, and the high-risk group received a combination of rhIFN-α nasal drops coupled with thymosin-α1 with either second or third-level protection protocol. Moreover, the new-outset of COVID-19 pneumonia diagnosed by chest computed tomography (CT), after thirty days, was the primary outcome. The adverse reactions were recorded in all participants. Results: 2415 of 2944 individuals belonged to the low-risk group, while 529 to the high-risk group. There was no COVID-19 pneumonia in either of the group after thirty days. The pulmonary CT scans were negative for COVID-19 pneumonia in both the groups with no new clinical symptoms. No serious adverse event was observed during the course of the intervention. Conclusion: The rhIFN-α nasal drops along with augmented safeguards based on standard physical isolation could effectively protect medical staff against COVID-19 pneumonia.