Effects of Stinging Nettle Root Extracts and Their Steroidal Components on the Na⁺, K⁺-ATPase of the Benign Prostatic Hyperplasia¹

Abstract

The effects of organic-solvent extracts of Urtica dioica (Urticaceae) on the Na⁺,K⁺-ATPase of the tissue of benign prostatic hyperplasia (BPH) were investigated. The membrane Na⁺,K⁺-ATPase fraction was prepared from a patient with BPH by a differential centrifugation of the tissue homogenate. The enzyme activity was inhibited by 10^-4-10^-5M of ouabain. The hexane extract, the ether extract, the ethyl acetate extract, and the butanol extract of the roots caused 27.6-81.5% inhibition of the enzyme activity at 0.1 mg/ml. In addition, a column extraction of stinging nettle roots using benzene as an eluent afforded efficient enzyme inhibiting activity. Steroidal components in stinging nettle roots, such as stigmast-4-en-3-one, stigmasterol, and campesterol inhibited the enzyme activity by 23.0-67.0% at concentrations ranging from 10^-3-10^-6M. These results suggest that some hydrophobic constituents such as steroids in the stinging nettle roots inhibited the membrane Na⁺,K⁺-ATPase activity of the prostate, which may subsequently suppress prostate-cell metabolism and growth.

Key words

Urtica dioica - Urticaceae - stinging nettle roots - organic-solvent extract - membrane Na⁺,K⁺-ATPase - stigmast-4-en-3-one - benign prostatic hyperplasia