Protective effects of ginseng stem-leaf saponins on D-galactose-induced reproductive injury in male mice

Abstract

Panax ginseng is a perennial plant in the Araliaceae family. In this study, we investigated the protective effects of ginseng stem-leaf saponins (GSLS) isolated from P. ginseng against D-galactose-induced reproductive function decline, oxidative stress, and inflammatory response. Reproductive injuries were induced in mice via the subcutaneous injection of D-galactose (300 mg/kg) for six weeks. The mice were then treated with GSLS by intragastric administration. GSLS inhibited markers of oxidative stress and inflammatory cytokines induced by D-galactose in serum, liver and kidney, whereas GSLS increased the activities of antioxidant enzymes. Compared to the mice treated only with D-galactose, GSLS treatment significantly increased the average path velocity, straight line velocity, curvilinear velocity, and amplitude of the lateral head displacement of mouse sperm. Meanwhile, GSLS significantly increased the testosterone level and reduced the cortisol, FSH, and LH levels. Histopathological examination revealed alterations in the number and the arrangement of spermatogenic cells in the seminiferous tubules of the mice in the GSLS group. GSLS treatment suppressed MAPKs pathway activation in testes. These results suggest that GSLS can attenuate D-galactose-induced oxidative stress and inflammatory response in serum, liver and kidney, and ameliorate reproductive damage by inhibiting MAPKs signaling pathway.

Keywords: D-galactose; ginseng stem-leaf saponins; inflammatory response; oxidative stress; reproductive function.

Figure 1

Effects of GSLS on body weight and liver and kidney function. (A) body weight; (B) alanine-aminotransferase (ALT); (C) aspartate-aminotransferase (AST); and (D) uric acid (UA); (E) serum creatinine (Scr). All data are represented as mean ± SEM (n = 6). *p < 0.05, **p < 0.01 compared to the NG; ^#p < 0.05, ^##p < 0.05 compared to the MG. NG: normal group, MG: D-gal model group, GS-L: D-gal + low dosage of GSLS group, GS-H: D-gal + high dosage of GSLS group.

Figure 2

Effect of GSLS on D-gal-induced changes in oxidative stress markers and pro-inflammatory cytokines in liver and kidney tissues. (A) 8-hydroxy deoxyguanosine (8-OHdG) in liver; (B) superoxide dismutase (SOD) in liver; (C) tumor necrosis factor-α (TNF-α) in liver; (D) interleukin-1β (IL-1β) in liver; (E) 8-hydroxy deoxyguanosine (8-OHdG) in kidney; (F) superoxide dismutase (SOD) in kidney; (G) tumor necrosis factor-α (TNF-α) in kidney; (H) interleukin-1β (IL-1β) in kidney. All data are represented as mean ± SEM (n = 6). *p < 0.05, **p < 0.01 compared to the NG; ^#p < 0.05, ^##p<0.05 compared to the MG. NG: normal group, MG: D-gal model group, GS-L: D-gal + low dosage of GSLS group, GS-H: D-gal + high dosage of GSLS group.

Figure 3

Effects of GSLS on D-gal-induced changes in oxidative stress markers and pro-inflammatory cytokines in serum of D-gal-induced mice. (A) malondialdehyde (MDA); (B) 8-hydroxy deoxyguanosine (8-OHdG); (C) glutathione peroxidase (GSH-Px); and (D) superoxide dismutase (SOD); (E) tumor necrosis factor-β1 (TNF-β1); (F) tumor necrosis factor-α (TNF-α); (G) interleukin-4 (IL-4); and (H) interleukin-6 (IL-6). All data are represented as mean ± SEM (n = 6). *p < 0.05, **p < 0.01 compared to the NG; ^#p < 0.05, ^##p <0.05 compared to the MG. NG: normal group, MG: D-gal model group, GS-L: D-gal + low dosage of GSLS group, GS-H: D-gal + high dosage of GSLS group.

Figure 4

Effects of GSLS on the kinematic parameters of mouse sperm. (A) straight line velocity (VSL); (B) continuous line velocity (VCL), (C) average path velocity (VAP); and (D) amplitude of lateral head displacement (ALH). All data are represented as mean ± SEM (n = 6). *p < 0.05, **p < 0.01 compared to the NG; ^#p < 0.05, ^##p < 0.05 compared to the MG. NG: normal group, MG: D-gal model group, GS-L: D-gal + low dosage of GSLS group, GS-H: D-gal + high dosage of GSLS group.

Figure 5

Effects of GSLS on sex hormones in the serum of D-gal-induced mice. (A) testosterone; (B) cortisol; (C) follicle-stimulating hormone (FSH); and (D) luteinizing hormone (LH). All data are represented as mean ± SEM (n = 6). *p < 0.05, **p < 0.01 compared to the NG; ^#p < 0.05, ^##p < 0.05 compared to the MG. NG: normal group, MG: D-gal model group, GS-L: D-gal + low dosage of GSLS group, GS-H: D-gal + high dosage of GSLS group.

Figure 6

Effects of GSLS on histological changes in testes of D-gal-induced mice. Representative images at 400× magnification; bar indicates 50 μm. Black arrow head: Sertoli cell vacuolization. Yellow arrow head: interrupted basement membrane. n=3 per group. NG: normal group, MG: D-gal model group, GS-L: D-gal + low dosage of GSLS group, GS-H: D-gal + high dosage of GSLS group.

Figure 7

Effects of GSLS on MAPKs signaling pathway in testes of D-gal-induced mice. n=3 per group. NG: normal group, MG: D-gal model group, GS-L: D-gal + low dosage of GSLS group, GS-H: D-gal + high dosage of GSLS group.