MOTILIPERM Ameliorates Immobilization Stress-Induced Testicular Dysfunction via Inhibition of Oxidative Stress and Modulation of the Nrf2/HO-1 Pathway in SD Rats

Abstract

It is well established that physiological stress has an adverse effect on the male reproductive system. Experimental studies have demonstrated the promising effects of MOTILIPERM in male infertility. MOTILIPERM extract is composed of three crude medicinal herbs: Morinda officinalis How (Rubiaceae) roots, Allium cepa L. (Liliaceae) outer scales, and Cuscuta chinensis Lamark (convolvulaceae) seeds. The present study aimed to investigate the possible mechanisms responsible for the effects of MOTILIPERM on testicular dysfunction induced by immobilization stress. Fifty male Sprague Dawley rats were divided into five groups (10 rats each): a normal control group (CTR), a control group administered MOTILIPERM 200 mg/kg (M 200), an immobilization-induced stress control group (S), an immobilization-induced stress group administered MOTILIPERM 100 mg/kg (S + M 100), and MOTILIPERM 200 mg/kg (S + M 200). Stressed rats (n = 30) were subjected to stress by immobilization for 6 h by placing them in a Perspex restraint cage, while controls (n = 20) were maintained without disturbance. Rats were administrated 100 or 200 mg/kg MOTILIPERM once daily for 30 days 1 h prior to immobilization. At the end of the treatment period, we measured body and reproductive organ weight; sperm parameters; histopathological damage; reproductive hormone levels; steroidogenic acute regulatory protein (StAR); biomarkers of oxidative stress; and apoptosis markers. MOTILIPERM treatment improved testicular dysfunction by up-regulating (p < 0.05) sperm count, sperm motility, serum testosterone level, StAR protein level, Johnsen score, and spermatogenic cell density in stressed rats. MOTILIPERM decreased oxidative stress by increasing (p < 0.05) testicular superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione peroxidase-4 (GPx 4), catalase, nuclear factor erythroid 2-related factor 2 (Nrf2), and heme oxygenase 1 (HO-1) levels and decreasing (p < 0.05) malondialdehyde (MDA) and reactive oxygen species/reactive nitrogen species (ROS/RNS) levels. Furthermore, MOTILIPERM down-regulated (p < 0.05) cleaved caspase 3 and BCL2 associated X protein (Bax) levels; increased pro caspase-3 and B-cell lymphoma 2 (Bcl-2) levels; and upregulated testicular germ cell proliferation in stressed rats. The number of terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL)-positive cells and serum luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels also significantly (p < 0.05) decreased after pretreatment with MOTILIPERM in stressed rats. Collectively, our results suggest that, in immobilization-mediated stress-induced testicular dysfunction, MOTILIPERM sustains normal spermatogenesis via antioxidant and anti-apoptotic activities by activating the NRF/HO-1 signaling pathway.