Eugenol Prevents Sodium Nitrate-induced Altered Antioxidant Status of Spermatozoa: An In Vitro Study

Rajini S.V.; Chaithra B.; Shiva basavaiah

Abstract

Background: High level of nitrate (NO3) induces oxidative stress which affects the male and female reproductive system. In this regard, there is a great concern for the prevention of NO3-induced oxidative stress in the reproductive system by using herbal products. Eugenol is one such natural product found in clove extracted from cloves (Syzygium aromaticum) and is known for its antioxidant, anti-nociceptive, anti-inflammatory, and anti-apoptotic properties. Aim and Objectives: The present study was undertaken to estimate the protective effect of eugenol in preventing sodium nitrate (NaNO3) induced oxidative stress in spermatozoa under in vitro conditions. Methods: Epididymal sperm suspension was treated with 10 mg/ml of eugenol along with NaNO3 (100 mg/ml) for 15 min of a time interval. In addition, different experimental groups viz., control (without eugenol and NaNO3), vehicle control (30% Dimethyl sulfoxide), and NaNO3 (100 mg/ml) alone were maintained. After the treatment period, sperm motility was analyzed. Further, different oxidative stress markers viz., activities of superoxide dismutase (SOD) and catalase (CAT) and concentrations of malondialdehyde (MDA) and nitric oxide (NO) were evaluated. Results and Discussion: There was a complete loss of sperm motility in NaNO3-treated groups compared to control and vehicle control groups. In addition, treatment of NaNO3 caused a significant increase in the activities of SOD and CAT, and MDA levels compared to control and vehicle control groups. Further, there was a significant increase in the concentration of NO in the NaNO3-treated group compared to that of the control and vehicle control groups. These results established the fact that NO3 is reduced to NO and induced oxidative stress in spermatozoa. In addition, a significant increase in NO concentration revealed the negative correlation between NO concentration and sperm motility. In the present study, treatment of eugenol prevented NaNO3-induced alterations in the antioxidant system as the activities of SOD and CAT and concentrations of MDA and NO in eugenol + NaNO3 treated groups were similar to that of control and vehicle control groups. In contrast, the sperm motility in the eugenol + NaNO3 treated group was significantly higher than NaNO3 alone treated group and lower than that of the control and vehicle control groups. These findings suggested the protective effect of eugenol against NaNO3-induced altered antioxidant status of spermatozoa. Conclusion: Exposure to a high level of NO3 causes the overproduction of free radicals and subsequent induction of oxidative stress which will affect sperm motility and thereby reduce the capacity of spermatozoa in fertilization. Eugenol is effectively preventing NO3-induced oxidative stress in spermatozoa.

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