Hibiscus sabdariffa leaf induces apoptosis of human prostate cancer cells in vitro and in vivo

Hibiscus sabdariffa leaf, the edible part of H. sabdariffa Linne, is usually ignored and discarded. The object of the study was to examine the anticancer properties of H. sabdariffa L. leaf extract (HLE). First, HLE was demonstrated to be rich in polyphenols, including catechin and ellagic acid (EA). 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) data showed that among three kinds of human prostate cancer (CaP) cells, androgen-dependent LNCaP cells were the most susceptible to HLE. HLE and its purified compound EA were evaluated for apoptotic activities. Molecular data showed the effect of HLE in LNCaP cells might be mediated via both intrinsic and extrinsic apoptotic pathways. Finally, HLE inhibited the growth of LNCaP cells in xenograft tumour studies. As a result, our data presented the first evidence of HLE as an apoptosis inducer in LNCaP cells, and these findings may open interesting perspectives to the strategy in human CaP treatment.