Antiproliferative effect of a polysaccharide fraction of a 20% methanolic extract of stinging nettle roots upon epithelial cells of the human prostate (LNCaP)

In Germany, plant extracts are often used in the treatment of early stages of benign prostate hyperplasia (BPH). The effects of different concentratio ns of the polysaccharide fraction of the 20% methanolic extract of stinging nettle roots (POLY-M) on the cellular proliferation of lymph node carcinom a of the prostate (LNCaP) cells were determined by measurement of the genom ic DNA content of the samples. All concentrations of POLY-M showed an inhib itory effect on the growth of the LNCaP cells during 7 days except the two lowest concentrations. The reduced proliferation of POLY-M treated LNCaP ce lls was significantly (p < 0.05) different from the untreated control. The inhibition was time- and concentration-dependent with the maximum suppressi on (50%) on day 6 and at concentrations of 1.0E-9 and 1.0E-11 mg/ml. No cyt otoxic effect of POLY-M on cell proliferation was observed. The in vitro, r esults show for the first time an antiproliferative effect of Urtica compou nds on human prostatic epithelium and confirm our previous in vivo findings .