Determination of Sunscreen activity of Viola odorata (Banafsha) ethanolic extract and its formulated Gel by UV Spectroscopy

Abstract

In the present study, ethanolic extract of Banafsha i.e., Viola odorata (Violaceae) and its gel formulations was evaluated for its sun protection activity by ultraviolet spectroscopy method. The phytoconstituents like flavonoids, phenolics present in Viola odorata may be responsible for scavenging action on UV-induced reactive oxygen species.  Extraction of aerial parts of the plant was done in the Soxhlet apparatus using ethanol as solvent. 1ml, 2ml, and 4ml of ethanol extract (200µg/ml) of the plant were used to formulate three gels (F1-F3) using Carabopol 940, 0.5% Methyl paraben, 0.2% Propyl paraben, Propylene glycol 400 and Triethanolamine.  Mansur et al. UV spectrophotometric method was used to investigate the in vitro SPF of the Viola odorata ethanolic extracts (100&200µg/ml) and its formulated gels (F1-F3).  Physical parameters like color, appearance, spreadability, pH, homogeneity, viscosity were determined to evaluate formulated gels. Based on the calculated SPF value, F3 formulation was chosen for the stability study. Ethanolic extract of Viola odorata (100 µg/ml and 200µg/ml) have SPF value 4.05±0.07 and 11.66±0.04, respectively. Gel formulations (F1-F3) containing 1, 2,4ml of 200µg/ml of ethanol extract have SPF values about 2.89±0.11, 4.20±0.08, and 5.63±0.07, respectively. The SPF values determined to confirm the capacity of gels to absorb UV radiation. No significant alterations in physicochemical parameters and SPF values were observed during the stability evaluation of F3 gel. Results proves that Viola odorata is a safe alternative which can be used over harmful chemical sunscreens used now a days in the industry and in the future plant can be explored for active component for better protection against sun rays.