Alpha-lipoic acid (ALA) is well-known for its antioxidant and anti-inflammatory functions in various disease models. Here, we tested whether pre-exposure to ALA can protect the testes from cellular damage caused by scrotal heat shock (HS) in mice. Methods: Thirty-six Swiss albino mice were divided into control (CTRL, n = 6), HS (n = 10), and two ALA dose (HS + ALA 200 mg/kg, n = 10; and HS + ALA 400 mg/kg, n = 10) groups. ALA supplementation was administered orally for 30 days. Subsequently, the animals, except the controls, were subjected to an HS water bath at 43 °C for 20 min. Two days later, they were euthanized, and biometric data from gonads and accessory sexual glands, testicular samples for histomorphometric and immunohistochemical analyses, and sperm from the epididymis cauda were obtained for evaluation. Results: Animals submitted to HS had a lower body weight, decreased relative mass of testes and prostate, reduced seminiferous epithelium height and tubular diameter, and increased degeneration in seminiferous tubules. Additionally, sperm analysis showed a reduced linear progressive velocity (VSL) and straightness (STR), increased midpiece defects, and fewer sperm with functional membranes. Immunohistochemical evaluation revealed a reduced superoxide dismutase (SOD1) staining intensity in the testes. Preventive exposure to ALA at 200 mg/kg did not normalize the relative testicular mass, but it reduced the number of giant cells, decreased midpiece defects, normalized the number of sperm with functional membranes, and partially preserved SOD1 expression. Although animals treated with ALA 400 mg/kg showed an improvement in relative testicular mass, this dose was less efficient in other parameters. Conclusions: This study showed that while 30 days of oral ingestion of ALA before the induction of acute degenerative injury did not fully protect male mouse gonads at the tissue level, some parameters related to testicular function and sperm quality showed a partial improvement.
Bianca Reis Santos (Sun,) studied this question.