effects of administration of co-trimoxazole and folic acid on sperm quality and histological changes of testes in male rats

Background: male infertility has been reported following long-term sulfasalazine, however, the precise effects of co-trimoxazole on sperm quality is controversial. objective: in this study, we evaluated the effects of co-trimoxazole and its co-administration with folic acid on sperm quality and histological changes of testes in male rats. materials and methods: in this experimental study, 136 male wistar rats were divided into 9 groups: i (control), ii (vehicle) received saline, iii: received folic acid (1 mg/kg /daily i.p., and iv- ix received co-trimoxazole (30, 60, and 120 mg/kg/daily; i.p.)+folic acid (1 mg/kg/daily; i.p.) for 14 or 28 days. sperm samples were obtained from each group at the end of 14th and 28th days. sperm numbers, motility, and viability were evaluated on a hemocytometer. hematoxylin and eosin stained testes were done for evaluation ofthe number of leydig cells, vascularity, spermatids, spermatocytes, and means of seminiferous tubules diameter under light microscopy. results: co-trimoxazole treatment for either 14 or 28 days caused a significant decrease in the percentage of sperm number, motility, and viability (p<0.001) compared to the control group. also, high doses of co-trimoxazole caused a significant decrease in testes structural abnormalities means of seminiferous tubules diameter, spermatids, and spermatogonia) compared to the vehicle group (p<0.001). folic acid co-administration with co-trimoxazole partially reversed the decrease in sperm quality and structural abnormalities of high doses of co-trimoxazole (60 and 120 mg/kg/daily) (p<0.001). conclusion: the data showed the adverse effects of co-trimoxazole on sperm quality and testes morphology which was protected partially by folic acid co-administration in rats. the underlying mechanism (s) needs further investigations.