Lotus seed (Nelumbo nucifera Gaertn.) extract at low dose ameliorates reproductive dysfunction in l-NAME-induced hypertension and oxidative stress in male rats

Abstract

Background and aim

Nelumbo nucifera Gaertn. (Lotus) seeds have been traditionally used to treat hypertension and are reported to have antioxidant effects. The role of lotus seeds in reproductive dysfunction associated with hypertension has not yet been investigated. Therefore, we aimed to evaluate lotus seed extract (LSE) on reproductive functions in N^ω-nitro-l-arginine methyl ester hydrochloride (l-NAME) induced hypertension and oxidative stress in rats.

Experimental procedure

Male Sprague–Dawley rats were allocated into six groups: i) normotensive rats, ii) rats treated with l-NAME (40 mg/kg), iii-vi) rats treated with l-NAME + either 10, 100, 300 mg/kg LSE or 5 mg/kg captopril for 5 weeks. Systolic blood pressure (SBP), sperm concentrations, viability and motility and the serum testosterone were measured. The morphology, malondialdehyde (MDA) and superoxide dismutase (SOD) activities were evaluated in testis and epididymis.

Results and conclusion

l-NAME-treated rats exhibited high SBP (181.9 ± 6.5 mmHg, P < 0.01) and reduced SOD activities in comparison to the normal group. These were significantly improved by the administration of 10, 100, 300 mg/kg LSE or captopril (P < 0.05). l-NAME also led to a significant increase in MDA, and reductions in sperm count, viability and motility, testosterone levels, as well as the diameter and epithelial thickness of the seminiferous tubules. Treatment with 10 mg/kg LSE or captopril significantly attenuated these effects (P < 0.05), whereas 100 and 300 mg/kg LSE showed no significant differences compared to the l-NAME group. Thus, our study demonstrates that a low dose of LSE has therapeutic potential in alleviating reproductive dysfunction associated with hypertension.