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: This first-attempt study explored indigenous herbs from agricultural waste with bioenergy and biorefinery-stimulating potentials for possible anti-COVID-19 drug development. As prior novel study revealed, medicinal herbs abundant in ortho-dihydroxyl substituents and flavonoid-bearing chemicals were likely not only electron shuttle (ES)-steered, but also virus transmission-resisted. Methods: Herbal extract preparation from agricultural wastes were implemented via traditional Chinese medicine (TCM) decoction pot. After filtration and evaporation, a crude extract obtained was used for evaluation of bioenergy-stimulating and electron-mediating characteristics via microbial fuel cells (MFCs). Combined with cyclic voltammetric analysis, MFCs provided a novel platform to distinguish electron shuttles from antioxidants with electron-transfer steered antiviral potentials of herbal extracts. Significant findings: After 50 serial cyclic voltammogram traces, considerable ES activities of herbal extracts still stably remained, indicating that possible medication-associated capabilities could be persistent. This work also extended to explore bioenergy-stimulating herbs from agricultural waste recycling for bioenergy and biorefinery applications. Water extract of Coffea arabica was more biotoxic than ethanolic extract, resulting in its lower power-generating capability. The findings revealed that water extract of Trichodesma khasianum and Euphorbia hirta could exhibit considerable bioenergy-enhancing effects. For cradle-to-cradle circular economy, agricultural waste could be specifically screened for possible regeneration of value-added anti-COVID-19 drugs via bioenergy selection.