Investigating the enhancing effects of traditional processing on the pharmacological and electrochemical functions of Polygonum multiflorum using THSG as a key marker

Polygonum multiflorum (PM), a traditional Chinese medicinal herb, contains key polyphenolic compounds, including 2,3,5,4’-tetrahydroxystilbene-2-O-β-D-glucoside (THSG), emodin, and physcion. This study examines how traditional processing methods, particularly steaming with black soybean juice, affect the chemical profile and functional potential of PM, with a focus on THSG as a marker substance of quality and bioactivity. Quantitative analyses using high-performance liquid chromatography (HPLC) and matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) imaging revealed that processing significantly enhances THSG levels, especially in the epidermis, while emodin and physcion remain more stable. THSG demonstrated strong antioxidant capacity and moderately enhanced power output in microbial fuel cells (MFCs), suggesting a redox-modulating effect despite lacking a classical electron shuttle (ES) structure. Molecular docking predicted high binding affinities of THSG with neuroprotective and immunomodulatory targets (e.g., 1JS3, 1ALU), surpassing those of standard drugs such as levodopa and thiopurine. Principal component analysis (PCA) confirmed THSG as the most responsive compound to processing and environmental variation. These findings support the use of THSG as a multifunctional marker, linking traditional pharmacological applications with emerging bioelectrochemical innovations.