In-vitro antioxidant activity of oxalis carniculata linn and investigation of plausible mechanism of photo-protection by molecular modeling study

Abstract

Oxalis Carniculata Linn belonging to Oxalidaceae family is a small herb with variety of biological activity. The leaves of Oxalis Carniculata was extracted with different solvents and the fractions were screened for antioxidant potential using in-vitro methods such as 2, 2-Diphenyl-2-Picryl hydrazyl (DPPH) and H2O2 radical scavenging activity, and reducing power assay. Total flavonoid, phenolic content and total antioxidant capacity were determined spectrophotometrically. Among the six different fractions ethanolic fraction exhibited highest total flavonoid content (224.2±0.25 mg/g QAE) and methanolic fraction exhibited highest phenolic content (184.31±0.14 mg/g GAE) and total antioxidant capacity (232.79±0.17mg/g AAE). Further methanolic fraction showed highest DPPH and H2O2 radical scavenging activity with IC50 value 23.43±0.12 and 19.71±0.16 respectively. The major cause of skin photoaging is exposure to ultraviolet light that is coupled with the increased expression of matrix metalloproteinases (MMPs) and decreased collagen synthesis. MMPs (especially MMP-1, MMP-3 and MMP-9) expressions are associated with the decreased elasticity of the dermis due to collagen degradation. In the present study, we have assessed the antioxidant effects of Oxalis Carniculata extract, correlated it with skin photoaging and postulated its mechanism of action by molecular docking study. The molecular docking study of flavones present in O. Carniculata revealed that the phyto-constituents of O. Carniculata species have similar mechanism of binding to that of standard drug with MMP-9 inhibitory action. These results can facilitate the further preclinical models, and clinical study upon skin protective potential against UV-induced skin aging of the O. Carniculata flavones.