Histostereological Effects of Crude Methanolic Bark Extract of Prunus africanus on Testosterone-Induced Benign Prostatic Hyperplasia in Wistar Rats (Rattus norvegicus)

Abstract

Benign prostatic hyperplasia (BPH) is the non-cancerous proliferation of epithelial and smooth muscle cells of the prostatic tissue surrounding the urethra in males causing urethral constriction, backflow of urine, acute kidney failure and associated complications. Today, BPH is a major killer of men above the age 45 years worldwide. Various treatment regimen for BPH have been advanced among them being ethnomedical oral use of crude bark extract of P.africanus by the local communities. Though data exist on its phytotherapeutic and ethnopharmacological activities in the management of BPH, there is paucity of anatomical histostereological data on its restorative and inhibitory effects in management of BPH. Further, data on whether the restorative and inhibitory effects P.africanus are dose-dependent is yet to be established. The broad objective of this study, therefore, was to examine the histostereological effects of P.africanus on testosterone induced BPH in Wistar rats. In carrying out the study, sixty Wistar were sourced from SAFARI animal house were used as the experimental model. The 60 rats were broadly divided into two study groups of 30 rats in the restorative group and 30 rats in the inhibitory group. Each group was further categorized into 5 control and 25 experimental rats. The experimental rats were further subdivided into 5 sub-groups based on varying doses of the crude methanolic bark extract of P.africanus (0 mg, 25 mg, 50 mg, 125 mg, and 200 mg). BPH in experimental animal was induced by subcutaneous injection of testosterone propionate (7.5 mg/kg) for 10 days. The findings of the study showed that the restorative group had a statistical significant dose dependent reduction of the prostate volume (p=0.003), the stromal (p=0.000) and epithelium volume (p=0.000) was observed. While in the inhibitory group a statistical significant dose-related inhibition, in the increase of the prostate volume (p=0.000), the stromal (p=0.000) and epithelium volume (p=0.000) was observed. In conclusion, the bark extract of P.africanus has both restorative and inhibitory effects to BPH and this restorative and inhibitory effects observed could be attributed to the phytochemical ingredients present in the extract that included triterpenes, flavonoids, saponins, glycoside and alkaloids. Further, the maximal restorative effect was observed to be up to 85.6% and at a dose of 200 mg, while the optimal inhibitory effects was observed to be between 66.7- 68.4% in the dose range of 100-200 mg/kg/bw. This study, therefore, recommends that future research using nonhuman primates need to be carried out to ascertain the findings of this study using the second order stereology to determine the effects of crude methanolic extract of P.africanus on the prostatic cell volumes, cellular characterization and cell densities in BPH as these nonhuman primates have closer genetic association to humans.