Investigation of Pre-Exposure Prophylactic Role of Psidium guajava (Guava) Leaf Extract in Lead Acetate-Induced Reproductive Dysfunction in Male Albino Rats

Introduction: Guava (Psidium guajava L.) is a widely consumed fruit in the tropical region and other parts of the world. The leaves, especially, have been reported to have both nutritional and medicinal benefits due to their rich phytochemical content. Studies have reported post-exposure benefits of guava leaf extract against heavy metal-induced reproductive derangements. Therefore, this study was designed to investigate the pre-exposure prophylactic potential of guava leaf extracts in rats exposed to lead. Methodology: A total of 35 male albino rats weighing 200 g were randomly divided into 5 groups of 7 rats per group. Group A is the negative control, given food and water only ad libitum. Group B is a positive control, treated with 30mg/kg of lead acetate daily for 14 days while Groups F, G, and H were treated with 250, 500, and 750mg/kg of guava leaf extracts respectively for 14 days followed by exposure to 30mg/kg of lead acetate for another 14 days. At the end of the experiment, rats were anesthetized, sacrificed, and blood samples were collected by cardiac puncture for assay of luteinizing hormone (LH), follicle stimulating hormone (FSH), testosterone, malondialdehyde (MDA) and superoxide dismutase (SOD). Epididymis samples were collected for semen analysis, and testes were processed for histological examination. Statistical analysis was performed using GraphPad Prism, with significance set at p<0.05. Results: The phytochemical analysis showed flavonoids as the most abundant phytochemical present in the leaf extract. The results of sperm motility and counts were greatly improved in rats treated with the extract but not in a dose-dependent manner. More so, the significantly higher values of LH induced by lead acetate were lowered considerably than the rats treated with the guava leaf extract. Similarly, the lead acetate-induced higher values of FSH and MDA were also significantly reduced in the 250 and 500 mg/kg treated rats but not to the same degree in the 750 mg/kg treated rats. In addition, the lead acetate-induced lower testosterone values indicated a significantly dose-dependent highest value in the 250 mg/kg treated group, followed by the 500 mg/kg treated rats and then the 750 mg/kg treated rats. Also, the induced higher and lower values of the LH-FSH and FSH-LH ratios were significantly lowered and increased in the 750 mg/kg treated groups. Finally, the lead-induced lowered values of SOD and T-LH ratio were significantly improved in the 250 and 500mg/kg treated rats but not in the same measure as observed in the 750 mg/kg treated rats. Conclusion: The study revealed that guava leaf extract does not confer pre-exposure prophylactic in a dose-dependent incremental manner. Rather, an unusually lower dose of 250 mg/kg was observed to be more protective than 500mg/kg and 750mg/kg doses, particularly in testosterone production.