Interactive deciphering electron-shuttling characteristics of agricultural wastes with potential bioenergy-steered anti-COVID-19 activity via microbial fuel cells

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.