Using rat liver mitochondria, as model systems, we have examined the ability of the natural compound and the food-
flavoring agent,
vanillin to protect membranes against oxidative damage induced by
photosensitization at concentrations normally used in food preparations.
Vanillin, at a concentration of 2.5 mmol/L, has afforded significant protection against
protein oxidation and lipid peroxidation in hepatic mitochondria induced by
photosensitization with
methylene blue plus light. The effect observed was both time- and concentration-dependent. The inhibitory effect is similar to
ascorbic acid and the
singlet oxygen quencher,
diazabicyclo[2.2.2]octane (
DABCO) but less effective than
sodium azide and
glutathione. Examination of possible mechanisms responsible for the observed protection, showed that
vanillin has a significant ability to quench
singlet oxygen (1O2), a reactive species responsible for damage induced during
photosensitization by Type II mechanism. Hence, this flavoring compound, due to its
antioxidant ability, may have potential to prevent oxidative damage to membranes in mammalian tissues and thereby the ensuing diseased states.