Enhancing the antioxidant and antimicrobial activities of Cotinus coggygria scop. leaf extracts through fermentation

Cotinus coggygria Scop. (Anacardiaceae), known as 'smoke tree' or 'smoke bush' is a medicinal plant with recognised anti-inflammatory, antioxidative, antibacterial, antiviral, anticancer, antigenotoxic, and hepatoprotective activity. This study investigated the effect of spontaneous lactic acid fermentation on the extraction yield of bioactive compounds with antioxidant, antibacterial, and anti-inflammatory activities from C. coggygria via high-performance thin-layer chromatography (HPTLC) coupled with (bio)assays in effect-directed analysis (EDA). Results showed that spontaneous fermentation increased the extraction of phenolics by 45%, but not flavonoids. There was no significant increase in α-amylase and COX-1 inhibition, but a significant increase in terpenoid content, antioxidant activity, and antimicrobial activity. These findings confirm that lipophilic antioxidants are more potent and also suggest that antimicrobial activity is associated with the increased extraction of triterpenoids. The FTIR spectra of eluted bioactive zones with high antimicrobial activity also indicate the presence of fatty acids, phytosterols, and triterpenoids.