Irvingia excelsa Mildbr. ethanolic extract displays in vitro cytotoxic effects on prostate cancer cells and prevents benign prostatic hyperplasia in Wistar rats

Despite much recent progress in prostate research, Benign prostatic hyperplasia (BPH) and prostate cancer continue to represent major causes of morbidity and mortality in men. In our ongoing search of natural alternatives to treat these prostate diseases, ethnobotanical reports indicated the use of Irvingia excelsa in the treatment of prostate inflammation and tumors in Cameroun. To investigate this claim, the cytotoxicity of the plant extract was investigated using MTT assay in three prostate cancer cell lines (LNCaP, DU145 and PC3). In addition, tumor cell growth/proliferation, clonogenic assay and cell cycle analyses were also assessed. In vivo, testosterone-induced benign prostatic hyperplasia (BPH) rats were treated orally with the extract (75, 150 and 300 mg/kg BW) or permixon (50 mg/kg) as standard for 28 days. Irvingia excelsa extract at concentrations of 50, 100 and 500 μg/mL significantly inhibited LNCaP, DU145 and PC3 prostate cancer cell growth and proliferation. The number of PC3 and DU145 clones was considerably diminished in a concentration-dependent manner. In addition, there was increase in the number of S-phase cells and decrease in the number of G0/G1 cells. Meanwhile results from in vivo study showed that I. excelsa extract significantly reduced prostate relative wet weight/volume and prostatic epithelium thickness at all tested doses with an optimal effect at 300 mg/kg BW. These results suggest that I. excelsa extract has in vitro and in vivo antiproliferative properties, which could justify its use by Cameroonian people to alleviate or treat prostate inflammation and tumors.