A Review on Ayurvedic Medicinal Herbs as Remedial Perspective for COVID-19

Introduction: Recent outbreaks in a new type of coronavirus, novel coronavirus (COVID-19) disease causing respiratory infection have significantly hampered the public health. Medicinal plants used in traditional practices provide enormous scope to bring out viable alternatives against viral diseases, considering non-availability of suitable drug and increasing resistance to existing drug as well as re-emerging viral diseases. The present review on use of plants and related phytochemicals for the treatment of viral diseases particularly COVID-19, preclinical and clinical information is increased concern Methods: The methodological activities involved during a literature review were; (1) designing the review concept, (2) conducting the review on review papers, research papers, bulletins, official websites, (3) analysis of previous publications and (4) writing up the review paper. The integrative literature review and paper preparation process was done from our own practical experience and influenced by various standards and guidelines suggested in the publications. Results: Herbal medicines and their active phytochemicals against some viral pathogens including severe acute respiratory syndrome (SARS), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) the virus that causes COVID-19 pandemic, middle east respiratory syndrome (MERS-COV), rhinovirus, human herpes virus (HSV-I & II), human immunodeficiency virus (HIV), coxsackievirus (CV), enterovirus 71 (EV71), hepatitis B virus (HBV), hepatitis C virus (HCV), herpes simplex virus, influenza A/H1N1 virus, coronavirus (CoV) etc were extensively reviewed. Ayurvedic herbal products could be useful to select as an alternative and integrated approach to decrease the morbidity and mortality associated with coronavirus infection and enhance host immunity against viral attack in the context of treatment vaccine of COVID-19 could be years away. Conclusion: The traditional practices and scientific evidence of several medicinal herbs and their phytochemicals against lethal viral infections in-vivo and in-vitro studies could be useful for the future as a novel source of natural products in particular focus on COVID-19

Chemical Composition, Enantiomeric Distribution, Antimicrobial and Antioxidant Activities of Origanum majorana L. Essential Oil from Nepal

This study was conducted to examine the chemical constituents of Origanum majorana L. essential oils (EOs) that originate in Nepal, as well as their biological activities, antioxidant properties, and enantiomeric compositions. The EOs were extracted by the hydro-distillation method using a Clevenger-type apparatus and their chemical compositions were determined through gas chromatography and mass spectrometry (GC-MS). Chiral GC-MS was used to evaluate the enantiomeric compositions of EOs. The minimum inhibitory concentrations (MICs) of the essential oils were determined by the micro-broth dilution method, and the antioxidant activity was evaluated by the 2,2-diphenyl-1-picrylhydrazyl scavenging assay and ferric-reducing antioxidant power (FRAP). GC-MS analysis showed the presence of 50 and 41 compounds in the EO samples, (S1) and (S2), respectively, representing the Kathmandu and Bhaktapur districts. The oxygenated monoterpenoids, along with terpinen-4-ol, were predominant constituents in both EO samples. However, the EOs from two locations showed some variations in their major components. The chiral terpenoids for two EO samples of marjoram have also been reported in this study in an elaborative way for the first time in accordance with the literature review. A hierarchical cluster analysis based on the compositions of EOs with 50 compositions reported in the literature revealed at least 5 different chemotypes of marjoram oil. The antioxidant activity for the sample (S2) was found to be relatively moderate, with an IC50 value of 225.61 ± 0.05 μg/mL and an EC50 value of 372.72 ± 0.84 µg/mL, as compared to the standard used. Furthermore, with an MIC value of 78.1 µg/mL, the EO from sample (S2) demonstrated effective antifungal activity against Aspergillus niger and Candida albicans. Moreover, both samples displayed considerable antimicrobial activity. The results suggest that EOs of Origanum majorana possess some noteworthy antimicrobial properties as well as antioxidant activity, and hence can be used as a natural preservative ingredient in the food and pharmaceutical industries