L-Carnitine Tartrate Downregulates the ACE2 Receptor and Limits SARS-CoV-2 Infection.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been responsible for one of the worst pandemics in modern history. Several prevention and treatment strategies have been designed and evaluated in recent months either through the repurposing of existing treatments or the development of new drugs and vaccines. In this study, we show that L-carnitine tartrate supplementation in humans and rodents led to significant decreases of key host dependency factors, notably angiotensin-converting enzyme 2 (ACE2), transmembrane protease serine 2 (TMPRSS2), and Furin, which are responsible for viral attachment, viral spike S-protein cleavage, and priming for viral fusion and entry. Interestingly, pre-treatment of Calu-3, human lung epithelial cells, with L-carnitine tartrate led to a significant and dose-dependent inhibition of the infection by SARS-CoV-2. Infection inhibition coincided with a significant decrease in ACE2 mRNA expression levels. These data suggest that L-carnitine tartrate should be tested with appropriate trials in humans for the possibility to limit SARS-CoV-2 infection.

Antiviral activity of ethanolic extract of Nilavembu Kudineer against dengue and chikungunya virus through in vitro evaluation.

BACKGROUND: Currently, no vaccines or modern drugs are available for dengue and chikungunya and only symptomatic relief is provided to the patients. Siddha medicine, a traditional form of indigenous medical system uses specific polyherbal formulations for the treatment of such infections with considerable success. One such polyherbal formulation for the treatment of chikungunya and dengue is Nilavembu kudineer (NVK). The mechanistic details of this drug as an antiviral for chikungunya virus (CHIKV) and dengue virus (DENV) is poorly understood. OBJECTIVES: The current study was undertaken to study the efficacy of NVK as an antiviral formulation against CHIKV and DENV. MATERIALS AND METHODS: Cytotoxicity assays (MTT) were performed to determine the role of NVK as an antiviral during chikungunya and dengue infections in the following conditions-i). post infection, ii). during active infections and iii) protective, not allowing virus infection. RESULTS: It was observed that NVK provides protection against CHIKV and DENV-2 during active infection as well can help to prevent virus infection in the cells and it mainly depends on the cellular availability of drugs for maximum protection against both the infections. CONCLUSION: Our study establishes that extraction protocols are important to ensure maximum efficacy of NVK along with the time of addition of the drug during CHIKV and DENV infections in the cells. This study provides insights to the possible mode of action of NVK in in vitro condition during CHIKV and DENV infection.

In Vivo Evaluation of Withania somnifera-Based Indian Traditional Formulation ( Amukkara Choornam), Against Chikungunya Virus-Induced Morbidity and Arthralgia.

Chikungunya viral fever results in extreme morbidity and arthralgia in affected individuals. Currently, modern medicines providing symptomatic relief for the acute febrile phase and the chronic arthritic phase are only options available. Traditional Indian medical system, however, uses specific formulations for treatment of this infection; one such polyherbal formulation used to treat the postpyretic phase of chikungunya is amukkara choornam. The current study was undertaken to study the efficacy of amukkara choornam in the treatment of chikungunya in C57BL/6J mice. The formulation when administered to chikungunya-infected mice relieved morbidity and joint swelling. Analysis of virus clearance in brain and joint tissues on formulation treatment revealed a direct correlation of viral load in brain to morbidity during infection; likewise, joint swelling receded prior to complete viral clearance explaining possible immunomodulatory effect of amukkara choornam. This study provides insight into the possible mode of action of amukkara choornam during chikungunya.