Anti-oxidant Effects of Annona muricata Ethanol Stem Bark Extract in N-nitroso- N- Methylurea (NMU)-Induced Prostate Cancer in Albino Rats

Background: Evidence has suggested that the pathogenesis of prostatic hyperplasia and prostate cancer is closely related to the state of oxidative stress in prostate tissue. This study evaluated the anti-oxidative stress effects of A. muricata ethanol stem bark extract in N-nitroso- N- Methylurea (NMU)-induced prostate cancer in albino rats. Materials and Methods: Fresh A. muricata stem barks were harvested from a compound at Ihiagwa Owerri, Imo State. They were washed, dried and ground. The acute oral toxicity was determined. Twenty-five (25) male albino rats of body weights (b.w.) mean of 96g were used for this study. After 2 weeks of acclimatization, Induction of prostate cancer with N-nitroso- N- Methylurea (NMU) lasted for 21 days and treatment with A. muricata stem bark extract commenced immediately via oral administration and lasted for 28 days. The rats were divided into five (5) groups as follows; group 1 served as the normal control group, group 2 served as the negative prostate cancer group, group 3 served as the standard group treated with finasteride, group 4 was induced and treated with 250 mg/kg of stem bark extract of A. muricata and group 5 was induced and treated with 500 mg/kg of stem bark extract of A. muricata. At the end of the study, the animals were sacrificed and liver homogenate was obtained for assessment of antioxidant parameters, whilst the prostates were excised for histopathological examinations. Results: Significant reductions in GSH, SOD, and CAT levels (p ≤ 0.05) were observed in NMU-treated rats, which were reversed upon treatment with A. muricata extract. Also, there was significant increase (p≤0.05) in MDA level following NMU administration to rats in group 2 when compared to the normal control group (group 1). The result also showed significant decrease in MDA level following treatment of NMU exposed rats with finasteride (standard drug) and A. muricata stem bark extracts. Histo-pathological findings reveal that normal prostatic architecture were evident in the treated groups when compared to the negative control group. Conclusion: N-nitroso- N- Methylurea (NMU) proved to be a potent in vivo carcinogen by generating reactive oxygen species and prostate cancer in the experimental albino rats. Treatment with the A. muricata ethanol stem bark demonstrated strong anti-oxidant effects by mitigating these free radicals and restoring normalcy in the oxidative biomarkers and prostate tissue architecture. The findings suggest a dose-dependent protective effect of Annona muricata ethanol stem bark extract against NMU-induced prostatic damage. Hence, this study supports the potential of Annona muricata stem bark as a natural therapeutic agent for mitigating prostate cancer-associated diseases.