Calycosin Ameliorates Cadmium-Induced Testicular Toxicity in Rats

Objective: Cadmium (CAD) is a toxin in the environment which causes damage to the testis and disruptions in hormone levels for men's reproduction. Calycosin (CAL), a naturally occurring isoflavone, is being studied due to the possibility that it provides protection to cells. Aim: the objective of this study was to examine whether CAL can protect adult male Sprague-Dawley rats from testicular damage due to exposure to CAD. Methodology: this study used twenty four adult male Sprague-Dawley rats. The rats were divided into four different treatment groups: Control group; CAD 3 mg/kg group; CAL 5 mg/kg + CAD group; and CAL 10 mg/kg + CAD group. The rats received intraperitoneal administration of CAD (3 mg/kg/day) for 5 days. Oral administration of CAL (5 or 10 mg/kg) was also given. Assessments included sperm concentration and viability and histopathology of the testes. Results: Exposure to CAD produced significant decreases in both sperm concentration and viability when compared to the control group. Along with these changes, the CAD exposed group demonstrated marked histopathological changes in the testes, including necrosis of germ cells; loss of spermatids; multinucleated giant cells; interstitial congestion; fibrosis; and inflammatory cell infiltration. The CAL treated group (at the higher dose) showed significantly increased sperm concentrations and sperm viability as compared to the CAD exposed group. Examination of the histopathology also demonstrated that the architecture of the testes was better preserved in the CAL treated group (at the higher dose) than in the lower-dose CAL treated groups. Therefore, the higher-dose of CAL was more effective at increasing sperm concentrations and improving histopathological changes. Conclusion: CAL treatment significantly improved functional and histopathological changes in CAD -induced testicular toxicity; the improvement was higher with the use of 10 mg/kg of CAL compared to using 5 mg/kg of CAL. Therefore, this study indicated that CAL could protect from CAD -induced damage to the male reproductive system. However, additional research will be necessary to identify how CAL produces its protective effects and if the protective effects provided by CAL will lead to increased fertility.