Protective effects of Nymphaea lotus Linn (Nymphaeaceae) on L-NAME-induced tissular oxidative damages and erectile dysfunction in hypertensive male rat

To investigate Nymphaea lotus aqueous extract on L-NAME-mediated sexual dysfunction and tissular oxidative stress in male Wistar rats. Methods: Fifty adult male Wistar rats were randomly classified into 5 groups; Control, L-NAME (10 mg/kg), L-NAME + losartan (10 mg/kg), L-NAME + N. lotus at the dose of 75 mg/kg and 200 mg/kg. L-NAME was administered during 8 weeks, but others treatments started from the 4th week and were administered continuously with L-NAME (10 mg/kg) during 4 additional weeks. Results: L-NAME administration caused marked hit of sexual behaviour, specifically failure of penile insertion or difficulty to ejaculate during the test interval. Further L-NAME causes a significant decrease in antioxidant products as reduced gluthatione (GSH) and nitrites (NO) in aorta and penile tissues, as compared to control group. N. lotus co-treatment for 4 weeks increased markedly the erectile index and the ejaculation rates contrarily to losartan in comparison to negative control receiving only L-NAME. N. lotus, but not the positive drug losartan, induced a significant increase in the anti-oxidant enzymes activities and GSH and NO levels, as well as a significant decrease in MDA levels compared to L-NAME group. These results suggests N. lotus may provide significant protection against L-NAME-induced tissular oxidative damages by up-regulation of antioxidant systems and promotion of the vasodilator factors in chronic NO-deficient rats. These alleviating effects of Nymphaea lotus denote a pro-sexual, antioxidant and vasodilatatory properties that was more appreciated after histological examination where remodeling of aorta were visibly reduced. Conclusion: N. lotus may be considered as a potentially useful strategy to limit erectile dysfunction and toxicity associated with hypertension.