Supplementation of l-tryptophan (an aromatic amino acid) in tris citric acid extender enhances post-thaw progressive motility, plasmalemma, mitochondrial membrane potential, acrosome, and DNA integrities, and in vivo fertility rate of buffalo (Bubalus bubalis) bull spermatozoa.

The aromatic amino acid l-tryptophan is an essential and versatile molecule, acts by transferring an electron to free radicals and protects the plasma membrane from injuries. The aim of the present study was to investigate the effects of l-tryptophan in extender on semen quality parameters, in vitro longevity and in vivo fertility rate of buffalo spermatozoa during cryopreservation. Two ejaculates were collected from each bull (n = 2 ejaculates and n = 4 bulls) with artificial vagina at 42 °C followed by initial evaluation for volume, motility, concentrations and were diluted in five extenders (C = lacking l-tryptophan, D1 = 25 µ M l-tryptophan, D2 = 50 µ M l-tryptophan, D3 = 75 µ M l-tryptophan, and D4 = 100 µ M l-tryptophan) respectively, and cryopreserved. The experiment was repeated four times (n = 4 replicates). At post-dilution, sperm plasma membrane integrity (PMI, %), supravital plasma membrane integrity (SVPMI, %), hypo-resistivity (HR, %) and acrosome integrity (ACR-I, %) were significantly higher (P < 0.05) in extender supplemented with D4 than control. At post-thawing, progressive motility (PM, %), PMI, SVPMI, HR, ACR-I, and DNA-I of buffalo bull spermatozoa were significantly higher in D4 than control. Sperm in vitro longevity (%) assessed in terms of PM, SVPMI, and ACR-1 were significantly higher in D4 than control. Sperm mitochondrial membrane potential (%) was higher in treated groups than the control. The in vivo fertility rate was significantly higher in D4 than control (60.17% vs. 44.17%, P < 0.05). It is concluded that the supplementation of l-tryptophan in tris citric acid extender improves semen quality parameters, in vitro longevity and in vivo fertility rate of buffalo spermatozoa during freezing and thawing process.

Supplementation of green tea extract (GTE) in extender improves structural and functional characteristics, total antioxidant capacity and in vivo fertility of buffalo (Bubalus bubalis) bull spermatozoa.

The aim of this study was to elucidate the beneficial effects of green tea extract (GTE) in tris citric acid extender on post thaw structural and functional characteristics, DNA fragmentation (%), total antioxidant capacity (TAC, µM/L), lipid peroxidation (LPO, µM/mL) levels and in vivo fertility of buffalo (Bubalus bubalis) bull spermatozoa. GTE is a acknowledged natural antioxidant, act as a free radical scavenger and protects spermatozoa against oxidative stress. Three mature and donor buffalo bulls were used in this experiment. Two ejaculates were collected per bull on each collection day, followed by initial evaluation for consistency (colour), volume (mL), progressive motility and concentration (x109) and were diluted in five extenders @ 50 x 106/ mL (C = control, no GTE; T1 = treatment 1, GTE 0.1%; T2 = treatment 2, GTE 0.5%; T3 = treatment 3, GTE 0.75% and T4 = treatment 4, GTE1.0%). The experiment was repeated thrice. Data analysis showed that sperm progressive motility (%), plasma membrane integrity (%), supravital plasma membrane integrity (%), viable sperm with intact acrosome (%) and TAC were significantly higher (P < 0.05) in extender supplemented with T4 as compared to control. Furthermore, sperm DNA fragmentation and occurrance of LPO in buffalo bull spermatozoa were significantly lowered in T4 than control. In vitro longevity (%) of spermatozoa was significantly higher in T4 compared to control during 45 and 90 min of incubation at 37 °C. In vivo fertility rate of buffalo bull spermatozoa was significantly higher in T4 compared to control (64.96 vs. 48.40%, P < 0.05). It is concluded that supplementation of tris citric acid extender with 1.0% GTE improved structural and functional characteristics, TAC, in vitro longevity (%) and in vivo fertility, whereas decreased DNA fragmentation and LPO occurrence in buffalo bull spermatozoa after freezing and thawing protocol.

Protective effects of different antioxidants against cadmium induced oxidative damage in rat testis and prostate tissues.

The present study was performed to determine the effects of different antioxidants on testicular histopathology and oxidative damage induced by cadmium (Cd) in rat testis and prostate. Twenty five rats were equally divided into five groups (n = 5/group). The control group was injected subcutaneously with saline while the Cd alone treated group received a subcutaneous injection of 0.2 mg/kg CdCl(2). Other groups were treated with sulphoraphane (25 µg/rat), vitamin E (75 mg/kg), and Ficus Religiosa plant extract (100 mg/kg) orally along with subcutaneous injections of 0.2 mg/kg CdCl(2) for fifteen days. Oxidative damage in the testicular and prostate tissues were assessed by the estimation of catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), and glutathione reductase (GSR) activity. Lipid peroxidation (TBARS), protein estimation, and histomorphology were also assessed. Cadmium exposure caused a significant decrease in antioxidant enzymes like CAT, POD, SOD, GSR, protein concentrations, and a marked increase in TBARS activity in rat testis and prostate. Histological examination of adult male rat testes showed a disruption in the arrangement of seminiferous tubules along with a reduction in the number of germ cells, Leydig cells, tunica albuginea thickness, diameter of seminiferous tubules, and height of germinal epithelium. Co-treatment with vitamin E, sulphoraphane, and Ficus religiosa were found to be effective in reversing Cd induced toxicity, representing potential therapeutic options to protect the reproductive tissues from the detrimental effects of Cd toxicity.

Comparative analysis of antioxidants against cadmium induced reproductive toxicity in adult male rats.

The present study was conducted to compare and evaluate the potential benefits of three different antioxidants in reversing cadmium (Cd)-induced reproductive toxicity in adult male rats. Rats (n = 5) weighing 180 +/- 20 gm were divided into five groups (control, Cd, Cd + sulforaphane, Cd + vitamin E, and Cd + plant extract). Treated groups received CdCl2 (0.2 mg/kg), sulforaphane (25 µg/rat), vitamin E (75 mg/kg), and plant extract (100 mg/kg) for 15 days. Blood samples and testicular tissues were obtained for estimation of testosterone, Zn, and Cd concentration and daily sperm production/efficiency of sperm production. Cadmium exposure caused a significant decrease in final body weight (p < 0.0001). The plasma concentrations of Cd were significantly increased and Zn concentration decreased (p < 0.0001) in the Cd group as compared to the control group. The testicular concentrations of Cd were significantly increased and Zn concentration decreased (p < 0.0001) in the Cd group as compared to the control group. Cadmium exposure caused a significant decrease (p < 0.0001) in plasma testosterone concentrations and daily sperm production as compared to the control group. More significant effects were observed with Cd+sulforaphane, Cd + vitamin E, and Cd + plant extract treated groups in slashing Cd-induced toxicity. Present findings suggest that Ficus religiosa and sulforaphane are more powerful antioxidants as compared to vitamin E in reversing the oxidative stress and can have a protective role against Cd induced reproductive toxicity in adult male rats. Part of the mechanism involved in this protective role seems to be associated with the antioxidant properties of these agents in reducing reproductive damage.