Interactive deciphering electron-shuttling characteristics of Coffea arabica leaves and potential bioenergy-steered anti-SARS-CoV-2 RdRp inhibitor via microbial fuel cells

Interactive network pharmacology and electrochemical analysis reveals electron transport-mediating characteristics of Chinese medicine formula Jing Guan Fang

Background

Jing Guan Fang (JGF) is an anti-COVID-19 Chinese Medicine decoction comprised of five medicinal herbs to possess anti-inflammatory and antiviral properties for treatment. This study aims to electrochemically decipher the anti-coronavirus activity of JGF and show that microbial fuel cells may serve as a platform for screening efficacious herbal medicines and providing scientific bases for the mechanism of action (MOA) of TCMs.

Methods

Electrochemical techniques (e.g., cyclic voltammetry) and MFCs were adopted as the bioenergy-based platforms to assess the bioenergy-stimulating characteristics of JGF. Phytochemical analysis correlated polyphenolic and flavonoid content with antioxidant activity and bioenergy-stimulating properties. Network pharmacology on the active compounds was employed to identify anti-inflammatory and anti-COVID-19 protein targets, and molecular docking validated in silico results.

Significant findings

This first-attempt results show that JGF possesses significant reversible bioenergy-stimulation (amplification 2.02 ± 0.04) properties suggesting that its antiviral efficacy is both bioenergy-steered and electron mediated. Major flavonoids and flavone glycosides identified by HPLC (e.g., baicalein and baicalin, respectively) possess electron-shuttling (ES) characteristics that allow herbal medicines to treat COVID-19 via (1) reversible scavenging of ROS to lessen inflammation; (2) inhibition of viral proteins; and (3) targeting of immunomodulatory pathways to stimulate the immune response according to network pharmacology.

Deciphering Houttuynia cordata extract as electron shuttles with anti-COVID-19 activity and its performance in microbial fuel cells

Background

Traditional herbal medicines usually contain electron shuttle (ES)-like structures compounds which are potential candidates for antiviral compounds selection. Houttuynia cordata is applied as a biomaterial to decipher its potential applications in bioenergy extraction in microbial fuel cells (MFCs) and anti-COVID-19 via molecular docking evaluation.

Methods

H. cordata leaves extracts by water and 60% ethanol solvent were analyzed for total polyphenols, antioxidant activity, cyclic voltammetry (CV), and MFCs. The bioactive compounds of H. cordata leaves extracts were assayed via LC/MS analysis. Identification of the marker substances for potential antiviral activity using a molecular docking model was provided.

Significant findings

60% ethanol extract exhibits the highest total polyphenols and antioxidant activity compared with water extracts. Bioenergy extraction in MFCs showed that 60% ethanol extracts could give 1.76-fold more power generation compared to the blank. Flavonoids and their sugar-to-glycan ratios increased after CV scanning and they are expected to be effective ES substances. Quercitrin, from the H. cordata extract that shares an ES-like structure, was found to exhibit strong binding affinities towards ACE2 and RdRp. This indicated the potential of H. cordata leaves as a promising antiviral herb.