Effect of some Teucrium species (Lamiaceae) on lipid peroxidation in rat lever microsomes

Certain Teucrium species (Lamiaceae), T. montanum L. , T. polium L. and T. chamaedrys L., have long been recognized in folk medicine in the treatment of gastrointestinal disorders, inflammations and diabetes [1]. The antioxidant action of diethyl ether (E), ethyl acetate (EA) and n-butanole (B) extracts – (0.01mg/mL), obtained from the aerial parts of Macedonian Teucrium chamaedrys L. , Teucrium polium L. and Teucrium montanum L. were studied in a lipid peroxide system using microsomes from rat liver. HPLC method is employed for quantitative determination of flavones in the extracts. The NADPH-induced lipid peroxidation, was inhibited by the addition of the extracts [2]. The order of the inhibitory potencies of the extracts tested seems to be T. polium (EA), 39% > T. polium (B), 36% > T. montanum (E and B), 35% > T. polium (E), 28% > T. montanum (EA), 21% > T. chamaedrys (E and B), 20% > T. chamaedrys (EA), 8%. The effect of Teucrium extracts was compared with that of reference compounds with confirmed antioxidant activity. The activities of luteolin, thymol and BHT were as potent as that of the extracts, 19, 37 and 36%, respectively. Caffeic and rosmarinic acid, carvacrol, silymarin and BHA showed 42, 52, 50, 54 and 49% inhibition, respectively. Quercetin had the strongest inhibitory effect on the NADPH lipid peroxidation among all the samples tested. These findings indicate those Teucrium extract act as an antioxidant in lipid peroxidation carried out by rat liver microsomes. References : 1. Tariq, M. et al. (1989), Int. J. Tissue React., 11: 185–188. 2. Gutterige, J.M.C. (1988), Lipid peroxidation: some problems and concepts. In : Oxygen Radicals and Tissue Injury, Halliwell, B. (Ed.). Bethesda, Federation of American Societies of Experimental Biology, pp. 9–19.