Modulation of lipid peroxidation by dietary components.

The aqueous extracts of commonly consumed Indian spices and vegetables were tested for their antioxidant properties in human erythrocyte membranes against lipid peroxidation induced by FeSO(4)-ascorbate (10:100 mumol/system). Aqueous extracts of curry leaves (Murraya koneigii) at 10 mug/ml and of asafoetida (Ferula spp), omam (Carum ajowan) and mustard (Brassica nigra) at 300 mug/ml inhibited lipid peroxidation by 90, 85, 75 and 70%, respectively. The aqueous extracts of cabbage (Brassica oleracea), ginger (Zinziber officinale) and onion (Allium cepa) inhibited lipid peroxidation by 65, 72 and 66%, respectively. The aqueous extracts of spices were also found to inhibit the formation of diene, triene and tetraene conjugates in human erythrocyte membrane. Addition of lipid peroxides extracted from peroxidized human erythrocyte membrane substantially increased erythrocyte lysis over that caused by exposure to 0.54% saline alone. Aqueous extracts of omam, coriander seeds (Coriandrum sativum) and curry leaves, at 300 mug/ml, inhibited peroxidized lipid-induced lysis by 67, 72 and 87%, respectively. Lipid peroxides induced considerable activation of polymorphonuclear leucocytes activation and this activation was inhibited by the aqueous extract of curry leaves.