Avaliação dos efeitos dos liofilizados dos extratos hidroalcóolicos da casca do fruto e da folha de Spondias tuberosa Arruda em modelo de senescência induzida por radiação UVA em células de queratinócitos humanos imortalizados (HaCaT)

Abstract

UVA radiation, predominant in sunlight, induces photoaging through oxidative stress, DNA damage, and activation of inflammatory pathways. In this scenario, natural products rich in antioxidant metabolites, such as Spondias tuberosa Arruda, show potential for modulating cellular senescence, although they still require further scientific investigation. This study aimed to evaluate the effects of lyophilized hydroalcoholic extracts of the fruit peel (LEHCST) and leaf (LEHFST) of Spondias tuberosa Arruda (umbu tree) in a UVA radiation-induced senescence model using immortalized human keratinocyte cell culture (HaCaT). Preliminary chemical characterization assays were performed using nuclear magnetic resonance (NMR), allowing the structural identification of secondary metabolites. Initially, a model of UVA radiation-induced cellular senescence was standardized in HaCaT cells exposed to UVA radiation (6, 13, and 19 J/cm²) for 20, 40, and 60 minutes, respectively, using viability assays, senescence assays, superoxide anion production assays, and morphological analyses with evaluations immediately, 24, and 48 hours post-radiation. The 40-minute exposure, evaluated 24 and 48 hours after radiation, was defined as the most suitable model, as it induced a significant increase in oxidative stress and senescence without causing excessive cellular damage. The cultivated HaCaT were divided into two groups: Basal (CTL: without radiation and treated only with LEHCST or LEHFST extracts at concentrations of 0.01, 0.05, 0.1, 0.5, and 1.0 μg/mL) and UVA (CTL, UVA 40’, and the groups exposed to UVA radiation and treated with LEHCST or LEHFST extracts at concentrations of 0.01, 0.05, 0.1, 0.5, and 1.0 μg/mL) for 24 and 48 hours for evaluation of the assays mentioned above. NMR analysis revealed signals compatible with phenolic compounds and other aromatic structures. The LEHCST and LEHFST extracts did not alter viability, senescence, or superoxide anion production in the basal group. In the UVA-induced model, both extracts significantly reduced the production of superoxide anions and the percentage of senescent cells when compared to CTL (p<0.05). The results indicate that the extracts exhibit anti-senescent activity in HaCaT cells exposed to UVA radiation, possibly associated with their antioxidant action. The novelty of these findings is noteworthy, reinforcing the potential of the extracts in preventing cutaneous photoaging. Keywords: U