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Sci Rep ; 11(1): 9849, 2021 05 10.
Article in English | MEDLINE | ID: covidwho-1223110


Several studies have examined the transmission dynamics of the novel COVID-19 disease in different parts of the world. Some have reported relationships with various environmental variables, suggesting that spread of the disease is enhanced in colder and drier climates. However, evidence is still scarce and mostly limited to a few countries, particularly from Asia. We examined the potential role of multiple environmental variables in COVID-19 infection rate [measured as mean relative infection rate = (number of infected inhabitants per week / total population) × 100.000) from February 23 to August 16, 2020 across 360 cities of Chile. Chile has a large climatic gradient (≈ 40º of latitude, ≈ 4000 m of altitude and 5 climatic zones, from desert to tundra), but all cities share their social behaviour patterns and regulations. Our results indicated that COVID-19 transmission in Chile was mostly related to three main climatic factors (minimum temperature, atmospheric pressure and relative humidity). Transmission was greater in colder and drier cities and when atmospheric pressure was lower. The results of this study support some previous findings about the main climatic determinants of COVID-19 transmission, which may be useful for decision-making and management of the disease.

COVID-19/transmission , Environment , SARS-CoV-2/isolation & purification , Seasons , Altitude , Atmospheric Pressure , COVID-19/epidemiology , COVID-19/virology , Chile/epidemiology , Humans , Humidity , Pandemics , SARS-CoV-2/physiology , Temperature , Tundra
Biomed Pharmacother ; 137: 111356, 2021 May.
Article in English | MEDLINE | ID: covidwho-1062250


All the plants and their secondary metabolites used in the present study were obtained from Ayurveda, with historical roots in the Indian subcontinent. The selected secondary metabolites have been experimentally validated and reported as potent antiviral agents against genetically-close human viruses. The plants have also been used as a folk medicine to treat cold, cough, asthma, bronchitis, and severe acute respiratory syndrome in India and across the globe since time immemorial. The present study aimed to assess the repurposing possibility of potent antiviral compounds with SARS-CoV-2 target proteins and also with host-specific receptor and activator protease that facilitates the viral entry into the host body. Molecular docking (MDc) was performed to study molecular affinities of antiviral compounds with aforesaid target proteins. The top-scoring conformations identified through docking analysis were further validated by 100 ns molecular dynamic (MD) simulation run. The stability of the conformation was studied in detail by investigating the binding free energy using MM-PBSA method. Finally, the binding affinities of all the compounds were also compared with a reference ligand, remdesivir, against the target protein RdRp. Additionally, pharmacophore features, 3D structure alignment of potent compounds and Bayesian machine learning model were also used to support the MDc and MD simulation. Overall, the study emphasized that curcumin possesses a strong binding ability with host-specific receptors, furin and ACE2. In contrast, gingerol has shown strong interactions with spike protein, and RdRp and quercetin with main protease (Mpro) of SARS-CoV-2. In fact, all these target proteins play an essential role in mediating viral replication, and therefore, compounds targeting aforesaid target proteins are expected to block the viral replication and transcription. Overall, gingerol, curcumin and quercetin own multitarget binding ability that can be used alone or in combination to enhance therapeutic efficacy against COVID-19. The obtained results encourage further in vitro and in vivo investigations and also support the traditional use of antiviral plants preventively.

COVID-19 , Catechols/pharmacology , Curcumin/pharmacology , Fatty Alcohols/pharmacology , Medicine, Ayurvedic/methods , Quercetin/pharmacology , SARS-CoV-2 , Antiviral Agents/pharmacology , COVID-19/drug therapy , Drug Repositioning/methods , Humans , Molecular Docking Simulation , SARS-CoV-2/drug effects , SARS-CoV-2/physiology , Viral Proteins/antagonists & inhibitors
Phytochem Anal ; 32(4): 629-639, 2021 Jul.
Article in English | MEDLINE | ID: covidwho-917100


INTRODUCTION: Immunity boosting has emerged as a global strategy to fight the SARS-CoV-2 pandemic situation. In India, AYUSH systems of medicine have been promoted as an immune-protection strategy. Andrographis paniculata (Burm. F) Nees (AP) mentioned in Ayurveda has been widely used for treating sore throat, flu, and upper respiratory tract infections which may provide possible novel therapeutic approaches, exclusively targeting SARS-CoV-2 and its pathways. OBJECTIVES: The present work uses liquid chromatography-tandem mass spectrometry (LC-MS/MS) metabolomics and combination synergy analysis based on network pharmacology to mine multimode evidence to understand the possible mechanism of action, diseases association, protein-protein interaction and major pathways involved therein. MATERIAL AND METHODS: Metabolite profiling was performed by Agilent QTOF LC-MS/MS system. Network pharmacology analysis was performed by using functional annotation analysis based on databases like Binding DB, STRING, DAVID and KEGG for further data mining. Further combination synergy was evaluated using "neighbourhood approach" and networks were constructed through Cytoscape 3.2.1. RESULTS: The molecules from kalmegh provides immune-protection and anti-viral response via involving different pathways, like toll-like receptor pathway, PI3/AKT pathway and MAP kinase pathways against COVID-19 infection. The KEGG analysis showed that in a vast majority of the most enriched pathways, AP were associated with viral infections and upper respiratory tract infections. CONCLUSIONS: The results suggest a synergy between andrographolide and other molecules identified as safe and efficacious anti-inflammatory agent having effects on upper respiratory tract infections and can significantly decrease the production of cytokines and pro-inflammatory factors in viral infections.

Andrographis , COVID-19 , Diterpenes , Chromatography, Liquid , Humans , India , Medicine, Ayurvedic , Plant Extracts/pharmacology , SARS-CoV-2 , Tandem Mass Spectrometry