Treatment of benign prostatic hyperplasia with Croton membranaceus in an experimental animal model

Abstract

Ethnopharmacological relevance: Croton membranaceus leaf extracts are used in the Bahamas to aromatize tobacco. In Nigeria it is used to improve digestion and in Ghana, the root extract is used for the treatment of benign prostatic hyperplasia (BPH). Despite claims of efficacy no data exists to support this. The aim of this study was to determine if Croton membranaceus aqueous root extract (CMARE) could attenuate the development of BPH in an animal model.

Materials and methods: Fifty (50) adult male Sprague-Dawley rats weighing 200-250g were randomly divided into 5 groups. Group 1 served as the control and received normal saline p.o. Groups 2-5 were castrated and injected with 5mg/kg b.wt. testosterone propionate subcutaneously for 28 days. Group 2 (model group) had no further treatment. Group 3 was simultaneously given 0.5mg/kg b.wt. finasteride p.o. throughout. Groups 4 and 5 received 30mg/kg b.wt. [low dose (LD)] and 300mg/kg b.wt. [high dose (HD)] CMARE, respectively, for 28 days. Rats were sacrificed at the end of the study and all prostate organs harvested. Wet weights, volumes and prostatic index (PI) were determined. Tissues were histologically examined. Serum prostate specific antigen (PSA) and dihydrotestosterone (DHT) levels were determined.

Results: Prostate volume of the control group was 0.67±0.23cm(3). The model, finasteride, CMARE LD and HD groups had the following volumes: 0.92±0.12, 0.84±0.16, 0.79±0.16 and 0.80±0.19cm(3), respectively. Only the model group showed significant statistical differences with the control (p=0.007). PI for control, model, finasteride, LD and HD groups was as follows: 0.19±0.04, 0.30±0.04, 0.25±0.04, 0.21±0.05 and 0.22±0.05. No statistical differences between the control PI and the CMARE treated groups were observed. Histologically, the model group had massive growth of columnar stromal and epithelial cells. CMARE and finasteride attenuated this growth with a resultant thin layer of stromal and epithelial cells similar to the control. PSA levels were significantly lower in the treatment groups.

Conclusion: CMARE reduces stromal and epithelial cell growth, and subsequently shrinks enlarged prostate. This is the first scientific proof validating the anecdotal evidence of CMARE efficacy in the management of BPH.

Keywords: Benign prostatic hyperplasia; Croton membranaceus; Finasteride; Prostate; Testosterone.