Duzhong Butiansu Prescription Improves Heat Stress-Induced Spermatogenic Dysfunction by Regulating Sperm Formation and Heat Stress Pathway

Abstract

Background. Duzhong Butiansu (DZBTS) prescription contains many traditional Chinese medicines and has been shown to have a curative effect on male fertility. However, the efficacy and mechanism of DZBTS in the treatment of male infertility induced by heat stress have not been reported. The aim of the present study is to elucidate the effect and mechanism of DZBTS on spermatogenic function of a heat stress model in rats. Methods. Male Wistar rats (280-320 g) were given different doses of DZBTS (0.4853 g/kg/d or 0.9707 g/kg/d), Shengjing capsule (0.56 g/kg/d), or double distilled water for 15 days. A 43°C hot water bath for 30 minutes was used to stimulate the testis of rats. Sperm count, sperm motility, the organ index of kidney and gonadal organs, serum sex hormone levels, and serum oxidising reaction index were measured. Haematoxylin and eosin (HE) staining was used to observe the morphology of the testis and kidney. The expression of Hsp70 in testes was observed by immunofluorescence. The changes in heat stress, reproductive-related protein, and mRNA were measured by western blot assay and RT-qPCR. Results. Heat stress downregulated the levels of sex hormone (P<0.05 or P<0.01) and its receptor androgen receptor (AR) protein expression and mRNA (P<0.01) in rats. Meanwhile, heat stress downregulated the levels of CAMP-responsive element-binding (CREB1) protein and mRNA (P<0.01), which are involved with spermatogenesis. Heat stress also decreased the oxidative damage index. Furthermore, Hsp70 and the heat shock transcription factor 1 (HSF1) protein pathway and mRNA level were overactivated (P<0.05 or P<0.01). Finally, the organ coefficients of the kidney and gonadal organs of rats were decreased. The sperm concentration and motility also decreased significantly (P<0.01). DZBTS could recover these changes induced by heat stress. Conclusions. Our results for the first time have found that DZBTS can improve spermatogenesis disorder in a heat stress model in rats, which may be mainly by regulating AR, sperm regulatory protein CREB1, and the HSF/Hsp70 signaling pathway to decrease oxidative stress.