Isolation and characterization of caffeic acid from Cobra Lily (Arisaema propinquum) and evaluation of its biological activities

This study investigates the antioxidant and antimicrobial potential of Arisaema propinquum, a medicinal herb from the Pir Panjal range of the Kashmir Himalayas. Caffeic acid was isolated and characterized from methanolic extracts of its aerial parts. Fourier-transform infrared (FTIR) spectroscopy confirmed the presence of functional groups indicative of polyphenols, flavonoids, terpenoids, esters, and other metabolites. In vitro antioxidant activity was assessed using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, superoxide dismutase (SOD) mimetic, and deoxyribose degradation assays. The deoxyribose assay showed dose-dependent inhibition of 63.2%, 69.7%, and 80.3% at concentrations of 100, 150, and 200 µg/mL, respectively, while the methanolic extract exhibited an IC₅₀ of 49.74 µg/mL in the H₂O₂ scavenging assay. Total phenolic and flavonoid contents were quantified as 40.33 ± 1.9 mg GAE/g DW and 32.77 ± 1.35 mg rutin equivalent/g DW, respectively. In vivo antioxidant activity was evaluated using Saccharomyces cerevisiae, where the extract supported 76.17 ± 0.58% cell survival under oxidative stress. The findings suggest that the antioxidant and antimicrobial properties of A. propinquum are attributable to its rich phytochemical profile, supporting its potential in therapeutic applications.