Inhibition of oxidation of human low-density lipoproteins by phenolic substances in different essential oils varieties

Phenolics antioxidant phytochemicals have been recently implicated for the lower rates of cardiac disease mortality among people consuming a Mediterra nean diet. Essential oils are natural products extracted from vegetable mat erials, which can be used as antibacterial, antifungal, antioxidants, and a nti-carcinogenic agents or to preserve and give specific flavors to foods. The activities of 23 selected essential. oils in inhibiting the copper-cata lyzed oxidation of human-low-density lipoproteins (LDL) were determined in vitro. LDL oxidation was inhibited between 6, 2, and 83% by 2 mu M (GAE) to tal phenolics. The relative inhibition of LDL oxidation was used to categor ize the essential oils into four groups below 2% when they contained methyl chavicol, anethol, p-cymen, apiole, cinnamic ether; 6-10% if they possessed a majority of carvacrol, thymol, p-cymene, or vanillin; 10-50% for moderat e amounts of thymol, carvacrol, cuminol, or eugenol; and 50-100% when eugen ol is the major component. Total phenol content of essential oils gave a co rrelation with LDL antioxidant activity of r = 0.75. The Activity of each p henolics compound could play a role in protecting LDL against oxidation if the substance is absorbed by the body.