In vitro antioxidant activity of Podophyllum hexandrum rhizome extract: Evaluation of superoxide and hydroxyl radical scavenging potential

Podophyllum hexandrum Royle (Berberidaceae), commonly known as Himalayan Mayapple, is a high-altitude medicinal plant traditionally used in Ayurveda for treating various ailments. The rhizome is a rich source of bioactive compounds, including podophyllotoxin, with reported pharmacological activities. However, scientific validation of its antioxidant potential from different geographical regions remains limited. The present study aimed to evaluate the superoxide anion and hydroxyl radical scavenging activities of hydromethanolic rhizome extract of P. hexandrum collected from Jageshwar, Uttarakhand, India. Rhizomes were extracted using 80% methanol, yielding 13.5% extract. Superoxide radical scavenging activity was assessed using the PMS-NADH-NBT system, while hydroxyl radical scavenging activity was evaluated using the Fe³⁺-EDTA-ascorbate-H₂O₂ system with 2-deoxyribose degradation, with ascorbic acid serving as the reference standard. The extract demonstrated significant concentration-dependent antioxidant activity. Superoxide radical scavenging reached 67.19 ± 0.6% at 100 µg/mL with an IC₅₀ value of 53.96 µg/mL, compared to ascorbic acid (IC₅₀ = 25.88 µg/mL). Hydroxyl radical scavenging achieved 68.57% inhibition at 100 µg/mL with an IC₅₀ value of 56.26 µg/mL, compared to ascorbic acid (IC₅₀ = 29.81 µg/mL). The extract exhibited superior efficacy compared to previously reported studies, achieving comparable activity at significantly lower concentrations. The hydromethanolic rhizome extract of P. hexandrum from Jageshwar possesses notable free radical scavenging potential, validating its traditional medicinal use and suggesting its potential as a natural antioxidant source for therapeutic applications.