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

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.