Efeitos da exposição in vivo de derivados de vitanolídeos sobre a senescência em ovários de camundongos fêmeas

Abstract

Chemotherapy remains the main therapeutic strategy in cancer treatment; however, its use is associated with the induction of premature ovarian failure, severely impacting the quality of life of women of reproductive age. Antineoplastic agents can accelerate ovarian aging through the induction of cellular senescence, a state of irreversible cell cycle arrest associated with an inflammatory secretory phenotype (SASP). In this context, the aim is to identify new compounds with antitumor potential that exhibit lower gonadotoxicity. Among these candidates, withanolides stand out, which are secondary metabolites isolated from the plant Athenaea velutina that have demonstrated relevant antiproliferative properties. Thus, this study evaluated, in the long term, the effects of in vivo exposure to withanolide derivatives on follicular survival, activation, and induction of senescence in mouse ovaries. For this purpose, C57BL/6J female mice were used, distributed into week old (6w) and 1 year old (1y) control groups and treated with 2 mg/kg of Withaferin A (WTA), 27-deoxy-24,25-epoxywithaferin A (WT1), and 27-deoxywithaferin (WT2) on alternate days for 14 days. After one year, the analysis of morphology, follicular development and survival (PAS); quantification of lipofuscin (Sudan Black B); evaluation of stromal fibrosis (Masson's Trichrome); and detection of DNA fragmentation (TUNEL) were performed. The results demonstrated that natural aging (group 1y) reduced follicular development and significantly increased lipofuscin deposition in the ovarian tissue. Treatment with WT1 prevented the accumulation of this pigment and preserved the proportion of developing follicles at levels similar to those of the young control (6w); however, it induced high DNA fragmentation and moderate fibrosis, suggesting a condition of cellular toxicity and follicular burnout. On the other hand, WT2 exhibited a cytoprotective profile on the stroma, maintaining tissue integrity with basal levels of fibrosis and DNA fragmentation equivalent to those of the young group. In contrast, WTA presented itself as the most gonadotoxic derivative, triggering premature senescence associated with an exacerbated accumulation of lipofuscin and intense fibrotic deposition in the stroma. These findings indicate that withanolide derivatives exert distinct long-term effects on the ovary. Although WT1 avoids the accumulation of some senescence markers, its action is associated with apoptotic toxicity and follicular burnout. In contrast, WT2 stands out for the protection of stromal integrity by inducing cellular quiescence. The study demonstrates the potential of these compounds in the modulation of ovarian senescence, highlighting the derivative WT2 as a promising chemotherapeutic candidate capable of aiming not only at combating the tumor, but also at reducing late damage to the ovarian reserve.