For several years , scientists tried to find antioxidant compounds that
   inhibit the low density lipoprotein(LDL) oxidation reaction but have no
   destructive effects. Vitamin C and vitamin E can inhibit LDL oxidation.
   Volatile oils posses herbal sources and because of lipophilic properties can
   enter LDL  and their antioxidant effects have not been known. The aim of
   this study is possible use of herbal products such as volatile oils in preventing
   or treating atherosclerosis. Because the probable effects of volatile oils on
   the affinity of LDL to its receptor , this affinity can be influenced and the 
   modification of LDL and atherogenesis be prevented.

          In this study , antioxidant properties of various concentrations of three
   volatile oils include:P-cymol, Limonene and Thymol , and vitamin C  on the
   affinity of  natural-LDL and oxidized-LDL(with Cu+2) to its receptor in bovine
   adrenal tissue cells have been investigated in the presence of labeled-LDL
   with fluoresein isothiocyanate (FITC). First, after purification of LDL-solvent of
   normal serum and incubation it with these compounds, oxidation reaction
   performed and LDL-solvent was labeled with FITC, and then all solvents were
   added to the medium that contains adrenal tissue cells(with LDL-receptor).
   Finally, fluorescence intensity of supernatant of each sample was
   determined in spectrofluorometer. Also, the effects of the best
   concentration of vitamin C (obtained in this study) with each one of these
   compounds was studied.

          Results showed that vitamin C in 100 micromolar concentration has the
   greatest effect on the increasing affinity of LDL to its receptor (for natural-
   LDL 18.5% and for oxidized-LDL 62%). Among the volatile oils used, “Thymol”
   had the best effect (for natural-LDL 27% and for oxidized-LDL 50%). In
   studying the effects of these three volatile oils with the best concentration of
   vitamin C(100 micromolar) , “Thymol” had the highest effect on this affinity.

          These finding showed that some compounds probably can change the
   affinity of LDL to its receptor  and thus may prevent formation of
   atherosclerosis .