THE ANTIOXIDATIVE AND CYTOTOXIC EFFECTS OF TWO MEDICINAL LAMIACEAE PLANTS FROM TURKEY IN CONNECTION WITH THEIR PROXIMATE PARAMETERS AND MINERAL ELEMENTS

Abstract

The present study was designed to examine the total phenolic, flavonoid, tannin contents, antioxidant and cytotoxic properties of hydroethanolic and hydromethanolic extracts of Origanum sipyleum and Thymus zygioides and to determine their proximate parameters (ash, carbohydrate, protein, fat, energy) and mineral elements (P, Mg, K, Zn, Fe, Cu). The antioxidant properties of these plants were evaluated using radical scavenging methods (DPPH and ABTS), total antioxidant test systems (beta-carotene/linoleic acid and phosphomolybdenum), metal chelating and reducing power assays. Among the extracts, the hydromethanolic extract of T zygioides exhibited the highest scavenging (DPPH, 40.14 mu g/mL, ABTS, 49.17 mu g/mL) and antioxidant capacity (phosphomolybdenum, 72.21 mu g/mg). There were no statistical differences among the chelating activity of the extracts. The hydroethanolic extract of T zygioides showed the highest reducing capacity. The total antioxidant activity of the extracts with beta-carotene/Linoleic acid test was in the range of 87.91-92.69 %. In addition, O. sipyleum and T zygioides also possessed rich total phenolic, flavonoid and tannin contents. With regard to cytotoxite, all extracts exhibited high cytotoxic activities. The phenolic content of the hydroethanolic extracts was examined using HPLC and determined major phenolics: caffein acid, rutin and epicatechin. Based on the results, these medicinal plants may be considered as an alternative source of antioxidant and cytotoxic agents for pharmacological applications, as well as potential sources of nutritional requirements for human dietary components and the food industry.