Effects of Methanolic Extract of Citrullus lanatus Seed on Experimentally Induced Prostatic Hyperplasia

Abstract

Aims: To investigate the effects of methanolic extract of Citrullus lanatus seed (MECLS) on experimentally induced benign prostate hyperplasia. Study design: Animal model of experimentally induced prostatic hyperplasia. Place and Duration of Study: Department of Anatomy, Faculty of Basic Medical Sciences, Ikenne Campus, Ikenne, Ogun State, Nigeria, between May 2010 and August 2010. Methodology: Twenty adult male Wistar rats weighing about 135-180g were randomly divided into four groups of five animals each. Group I, Normal control (NC) was given corn oil as placebo 1g/Kg BW; Group II, Hormone treated control (HTC), Groups III, and IV hormone and extract treated (HTEC), received continuous dosage of 300µg and 80µg of testosterone (T) and estradiol (E2) respectively on alternate days for three weeks subcutaneously in the inguinal region while the extract treated received an additional 2g/Kg BW (low dose) and 4g/Kg BW (high dose) of extract orally for 4 weeks after the successful induction of prostate enlargement. Immediately after induction some animals were randomly selected and sacrificed for gross inspection of prostate enlargement and sperm count evaluation, these procedures were repeated again after four weeks of extract treatment. Portion of the prostate were taken and processed routinely for paraffin embedding and stained with H&E. Results: Hormone treatment did not affect the body weight of the animals; however it caused a significant decrease in the weight of the testes and rendered all the rats azoospermia. In addition, treatment with extracts caused a significant decrease in the enlarged prostate, seminal vesicle and testes sizes in a dose related manner (P<0.05) compared to the hormone treated control. Histological examination of prostate revealed that the methanolic extract caused significant changes in its histo-architecture. There was an increase in the fibromuscular layer, decrease in prostatic acini size, shrinkage of epithelium, and no infolding of the epithelium into the lumen, rather, it appeared flat compared to the very distinct columnar epithelium of the hormone treated control and conspicuousness of the acini. The extracts further caused a dose dependent reduction in the prostates weight. PSA level was significantly lowered in both HTEC at low and high doses (P<0.05) in dose dependent manner. Conclusion: Administration of MECLS for one month reduced the prostate size significantly (P< 0.05), both at high and low dose, but could not restore the initial size of shrunken testes and severe oligospermia caused by the hormones. The histological studies clearly establish MECLS as a potential candidate in management of androgen dependent conditions like benign prostate hyperplasia.