Protective effects of tribulus terrestris extract and angiotensin blockers on testis steroidogenesis in copper overloaded rats

Abstract

The rational of the current study was to assess whether Tribulus terrestris extract (TTE) could alleviate long-term copper (Cu) overload-induced testicular dysfunction compared to enalapril and losartan. Rats were administered either vehicle (control group, n = 10) or copper sulfate pentahydrate (CuSO4·5H2O, 200 mg/kg, p.o) for 90 days (n = 40). Cu-treated rats were randomized into four equal groups. One group was left untreated (Cu group) while the remaining three groups were daily co-treated with one of the following treatments along with CuSO4: TTE (10 mg/kg, p.o); enalapril (30 mg/kg, p.o); losartan (10 mg/kg, p.o). Excess Cu intake resulted in Cu overload coupled with a significant elevation in systolic blood pressure and serum angiotensin II levels along with a reduction in serum nitric oxide level. All concomitant treatments led to an alleviation of such deleterious effects. However, only losartan failed to ameliorate angiotensin II elevation. Additionally, all treatments protected the testes against Cu-overload-elicited zinc depletion and oxidative stress. Regarding reproductive function, the relative weights of testes, serum levels of testosterone and luteinizing hormone; the expression of steroidogenic genes; the protein levels of angiotensin II type 1 receptor and angiotensin converting enzyme 1, in addition to its activity, they were significantly reduced. Amongst all treatments, only TTE and E were able to revert these reproductive changes. In conclusion TTE and E were able to protect against Cu overload-induced impairment of testicular steroidogenesis. Thus, they might be considered as prophylactic drugs of choice against hypertension and testicular dysfunction to ameliorate Cu overload risk.