Photoprotective and antioxidant activities of leaves and bark of Solanum paniculatum L. (Solanaceae)

Abstract

Solanum paniculatum, commonly known as jurubeba-verdadeira, is a species native to Brazil with several uses in cooking and traditional medicine. This study aimed to conduct a preliminary phytochemical analysis and evaluate the photoprotective and antioxidant activities of leaf and bark extracts from a specimen of S. paniculatum found in the southern region of Mato Grosso do Sul. Qualitative analytical tests were performed on ethanolic and aqueous extracts to identify the main classes of secondary metabolites. Sun protection factor (SPF) was evaluated in vitro using the spectrophotometric method, and the antioxidant potential was determined using the free radical reduction methods DPPH^• (2,2-diphenyl-1-picrylhydrazyl) and ABTS^•+ (2,2´-azinobis-3-ethylbenzothiazoline-6-sulfonic acid). Phenols, flavonoids, tannins, and total alkaloids were quantified using spectrophotometry in the visible region. Phytochemical analysis revealed the presence of alkaloids and tannins in extracts from both plant parts, while flavonoids, triterpenes, steroids, and purines were only detected in leaf extracts. In general, the extracts exhibited high levels of alkaloids and phenolic compounds, effectively eliminated free radicals, demonstrated significant antioxidant potential, and showed promise for use in photoprotective formulations. These results suggest that photoprotective and antioxidant activities are related to the presence of alkaloids and phenolic compounds quantified in this study.