Biological activities of Prunella vulgaris extract.

The organic fraction (OF; 25.7% w/w of rosmarinic acid) of Prunella vulgaris (total extract) was found to exhibit the following: scavenging activity on diphenylpicrylhydrazyl radical (DPPH), inhibition of in vitro human LDL Cu(II)-mediated oxidation, protection of rat mitochondria and rat hepatocytes exposed to either tert-butyl hydroperoxide, or to Cu(II) and Fe(III) ions. OF also showed a potential to inhibit rat erythrocyte haemolysis and it reduced the production of LTB(4) in bovine PMNL generated by the 5-lipoxygenase pathway. Other observations included antiproliferative effects against HaCaT cells and mouse epidermal fibroblasts and a moderate OF antimicrobial activity on gram-positive bacteria. Rosmarinic, caffeic and 3-(3,4-dihydroxyphenyl)lactic acids exhibited less potent activity than the plant extract in all bioassays. The antioxidative, antimicrobial, together with antiviral effects offer good prospects for the medicinal applications of P. vulgaris.