An Investigation into the Antioxidant Potential of Polygonum salicifolium through Experimental and Computational Approaches

This study presents a novel approach for discovering potent antioxidants from natural sources. We explored Polygonum salicifolium, a medicinal plant, using combined experimental and computational methods. The crude extract exhibited significant concentration-dependent free radical scavenging activity. GC-MS analysis revealed 33 components, with 5 exhibiting key bioactivity. DFT calculations suggest Hydrogen Atom Transfer (HAT) as the dominant mechanism for the 5 bioactive compounds under study, as compared to single electron transfer followed by proton transfer (SET-PT) and sequential proton loss electron transfer (SPLET). In addition, molecular docking simulations were conducted to assess the interaction of these compounds with the SOD2 receptor. The results indicated that compounds PS1, PS2, PS3, PS4, and PS5 exhibited re-rank scores of -82.9522, -81.4507, -71.1435, -82.9793, and -77.4562 kcal/mol, respectively, surpassing the reference antioxidant (Nebivolol = -63.9865 kcal/mol). The ADMET profiling indicated that all the studied compounds are generally safe for potential medicinal applications. These findings suggest that P. salicifolium extract is a promising natural source of antioxidants with potential applications in the treatment and prevention of oxidative stress-related diseases.