Severe Acute Respiratory Syndrome Coronavirus -2 (SARS-CoV-2): A Review on Pathophysiology, Diagnosis, and Investigational Therapeuti.

There is a new public health crisis threatening the world with the emergence and spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The disease was later named novel coronavirus disease or COVID-19. It was then declared a pandemic by the World Health Organization on March 11, 2020. The virus originated in bats and was transmitted to humans through unknown intermediary animals in Wuhan, Hubei province, China, in December 2019. As of February 5, 2021, 103 million laboratory-confirmed cases and nearly 2.3 million deaths were reported globally. The number of death tolls continues to rise, and a large number of countries have been forced to maintain social distance in public place and enforce lockdown. As per literature, coronavirus is transmitted human to human or human to animal via airborne droplets. Coronavirus enters the human cell through the membrane ACE-2 exopeptidase receptor. WHO, ECDC, and ICMR advised avoiding public places and close contact with infected persons and pet animals. To date, there is no evidence of any effective treatment for COVID-19. The main therapies being used to treat the disease are antiviral drugs, chloroquine/hydroxychloroquine, and respiratory therapy. Although several therapies have been proposed, quarantine is the only intervention that appears to be effective in decreasing the contagion rate. We conducted a literature review of publicly available information to summarize knowledge about the pathogen and the current epidemic. In the present literature review, the causative agent of the pandemic, epidemiology, pathogenesis, and diagnostic techniques are discussed. Further, currently used treatment, preventive strategies along with vaccine trials and computational tools are all described in detail.

Development and Structural Modifications of Cholinesterase Reactivators against Chemical Warfare Agents in Last Decade: A Review.

Organophosphate (OP) pesticides and nerve agents are responsible for suicidal and accidental poisonings. The acute toxicity of nerve agents leads to progressive inhibition of the enzyme acetylcholinesterase (AChE) by phosphylation of serine residue at the active site of gorge. The recent massive destruction of Syrian civilians by nerve gas sarin, has again renewed the research attention of global science fraternity towards nerve agents, their mode of action and most prominently their therapeutic treatment. This review is principally focused on nerve agent intoxication. The common approach to deal with OP-intoxication is, application of antimuscarinic drug (atropine), anticonvulsant drug (diazepam) and clinically used oximes (pralidoxime, trimedoxime, obidoxime and asoxime). However, the existing therapeutic approach is arguable and has several failings to cure all kinds of nerve agent poisonings. Considering this issue, numerous oximes have been synthesized and screened through various in-vitro and in-vivo studies in last decade to overcome the downsides. At present, only a few oximes (bis pyridinum-oximes) exhibit sound efficacy against selective OPs. In spite of extensive efforts, till date no oxime is available as a universal antidote against all the classes of OPs. This review is centered on the recent developments and structural modification of AChE reactivators against nerve agent toxicity. In particular, a deeper look has been taken into chemical modifications of the reactivators by incorporation of different structural moieties targeted towards the increased reactivation affinity and improved blood brain barrier (BBB) penetration.

Oxime K027: novel low-toxic candidate for the universal reactivator of nerve agent- and pesticide-inhibited acetylcholinesterase.

Oxime K027 is a low-toxic bisquaternary compound originally developed as a reactivator of acetylcholinesterase (AChE) inhibited by nerve agents. The reactivation potency of K027 has been tested as a potential reactivator of AChE inhibited by tabun, sarin, cyclosarin, soman, VX, Russian VX, paraoxon, methylchlorpyrifos, and DDVP. The results show that oxime K027 reactivated AChE inhibited by almost all tested inhibitors to more than 10%, which is believed to be enough for saving the lives of intoxicated organisms. In the case of cyclosarin- and soman-inhibited AChE, oxime K027 did not reach sufficient reactivation potency.