Antioxidant effects of Citrus aurantifolia (Christm) juice and peel extract on LDL oxidation

BACKGROUND We studied the antioxidant effects of fresh juice and peel extract of Citrus aurantifolia (Christm). METHODS Low density lipoprotein (LDL) was separated from one hypercholesterolemic human serum by modified Bronzert and Brewer procedure. Oxidation of LDL was measured at 234 nm against 0, 5, 10, 20, 25, 30 and 40 μl of fresh lime juice and 0, 5, 10, 15 and 20 μl of peel polyphenolic extract solution in DMSO. RESULTS 5 μl of lime juice didn't change LDL oxidation. 10 μl of juice inhibited LDL oxidation, and with increasing the juice concentration, LDL was oxidized faster. The higher concentrations of peel extract prevented LDL oxidation better than the lower ones. CONCLUSIONS Both juice and peel demonstrated antioxidant properties, but the excessive consumption of lime juice seems not to be beneficial. Regarding the intensity and type of flavonoids, lime juice and peel may show different effects.