Cholesterol-reducer, antioxidant and liver protective effects of Thymbra spicata L. var. spicata

Ethnopharmacological relevance: Thymbra spicata is a member of the Lamiaceae family; leaves of this plant have recently gained much popularity as a remedy to combat hypercholesterolaemia. Aim of the study: To evaluate the antihypercholesterolaemic, antioxidant and anti-steatohepatitic activities of the diethyl ether (DEE), ethyl acetate.(EtOAc) and remaining aqueous (RA) extracts from Thymbra spicata var. spicata in mice. Materials and methods: In this study, diethyl ether, ethyl acetate and remaining aqueous extracts of Thymbra spicata L var. spicata P.H.Davis (Lamiaceae) were evaluated for the effects on the plasma total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL), triglyceride (TG) and glucose; blood malondialdehyde (MDA) and reduced glutathione (GSH); erythrocyte superoxide dismutase (SOD) and catalase activity (CAT) in mice fed with high-fat diet (HFD). Results: The HFD induced an increase in plasma TC, TG, LDL, MDA concentrations compared to control group. However, administration of DEE with HFD reduced TC, LDL, TG and MDA concentrations, while increased HDL concentration, as well as GSH, SOD and CAT activities compared to HFD. The other extract from the plant was RA, which also showed a similar activity profile with DEE except CAT. On the other hand, administration of EtOAc extract with HFD decreased plasma TC, TG and MDA, while GSH concentration was increased. Histopathologically, best liver conditions were observed in DEE and lesser in RA extracts. Based on the results obtained in this investigation it is suggested that the DEE and partially RA extracts of Thymbra spicata var. spicata displayed significant antihypercholesterolaemic, antioxidant and anti-steatohepatitic activities. HPLC analysis of the DEE extract of Thymbra spicata var. spicata revealed the presence of carvacrol (44.13%). Conclusion: The observed cholesterol-reducer, antioxidant and liver protective effects of the DEE and partially of RA extracts of Thymbra spicata which contain mainly carvacrol indicates that these extracts possess some potential medicinal value and explain their ethnomedical use. (C) 2009 Elsevier Ireland Ltd. All rights reserved.