Toxic effect of Syzygium guineense ethanolic extract on female reproduction in rats: An evidence from a 10 week repeated-dose toxicity study

Introduction: It has been reported that some herbal products affect reproduction. To date, reproductive toxicity of Syzygium guineense has not been investigated although the plant is widely used in treating fertility related problems. Thus, the objective of the current study was to investigate the toxic effects of 70% ethanol extract of S. guineense leaves on the reproductive function and histopathology of reproductive organs in female rats. Methods: Eighty female Wistar albino rats were randomly divided into four groups where each group consisted of 20 rats. Rats in the first three groups were treated with S. guineense extract at doses of 250, 500 and 1000 mg/kg body weight, respectively. The fourth group served as a control group. The rats were treated for ten consecutive weeks. The length of estrous cycle, reproductive indices, pregnancy outcomes, and number of postnatal deaths were recorded. At necropsy, organ weight was measured, gross and histopathological examinations of ovaries, uterus, and vagina were conducted. Results: Treatment of rats, with high dose (1000 mg/kg) of S. guineense, significantly prolonged the duration of estrous cycle and reduced weight of uterus and ovaries as well as the number of total and live birth pups. However, there were no significant changes observed in reproductive indices and gross morphology as well as histopathology of ovaries, uterus, and vagina. Conclusion: Administration of high doses of S. guineense could be toxic to some aspects of the reproductive system of female rats and might also affect reproduction. Therefore, consuming high dose of S. guineense leaves is not recommended.