ABSTRACT
Due to the pandemics of COVID-19, herbal medicine has recently been explored for possible antiviral treatment and prevention via novel platform of microbial fuel cells. It was revealed that Coffea arabica leaves was very appropriate for anti-COVID-19 drug development. Antioxidant and anti-inflammatory tests exhibited the most promising activities for C. arabica ethanol extracts and drying approaches were implemented on the leaf samples prior to ethanol extraction. Ethanol extracts of C. arabica leaves were applied to bioenergy evaluation via DC-MFCs, clearly revealing that air-dried leaves (CA-A-EtOH) exhibited the highest bioenergy-stimulating capabilities (ca. 2.72 fold of power amplification to the blank). Furthermore, molecular docking analysis was implemented to decipher the potential of C. arabica leaves metabolites. Chlorogenic acid (-6.5 kcal/mol) owned the highest binding affinity with RdRp of SARS-CoV-2, showing a much lower average RMSF value than an apoprotein. This study suggested C. arabica leaves as an encouraging medicinal herb against SARS-CoV-2.
ABSTRACT
Background: Traditional Chinese medicine (TCM) has been used as an "immune booster" for disease prevention and clinical treatment since ancient China. However, many studies were focused on the organic herbal extract rather than aqueous herbal extract (AHE; decoction). Due to the COVID-19 pandemics, this study tended to decipher phytochemical contents in the decoction of herbs and derived bioactivities (e.g., anti-oxidant and anti-inflammatory properties). As prior works revealed, the efficacy of Parkinson's medicines and antiviral flavonoid herbs was strongly governed by their bioenergy-stimulating proficiency. Methods: Herbal extracts were prepared by using a traditional Chinese decoction pot. After filtration and evaporation, crude extracts were used to prepare sample solutions for various bioassays. The phytochemical content and bioactivities of AHEs were determined via ELISA microplate reader. Microbial fuel cells (MFCs) were used as a novel platform to evaluate bioenergy contents with electron-transfer characteristics for antiviral drug development. Significant findings: Regarding 18 TCM herbal extracts for the prevention of SARS and H1N1 influenza, comparison on total polyphenol, flavonoid, condensed tannins and polysaccharides were conducted. Moreover, considerable total flavonoid contents were detected for 11 herb extracts. These AEHs were not only rich in phytonutrient contents but also plentiful in anti-oxidant and anti-inflammatory activities. Herbs with high polyphenol content had higher antioxidant activity. Forsythia suspensa extract expressed the highest inhibition against nitric oxide production for anti-inflammation. MFC bioenergy-stimulating studies also revealed that top ranking COVID-19 efficacious herbs were both bioenergy driven and electron mediated. That is, electron transfer-controlled bioenergy extraction was significant to antiviral characteristics for anti-COVID-19 drug development.