The protecting ability of the Piper betle leaves-derived
phenol,
allylpyrocatechol (APC) against
AAPH-induced membrane damage of human red blood cells (RBCs) was investigated. Compared to control,
AAPH (50 mM) treatment resulted in significant
hemolysis (55%, p < 0.01), associated with increased
malondialdehyde (MDA) (2.9-fold, p < 0.001) and
methemoglobin (6.1-fold, p < 0.001) levels. The structural deformation due to membrane damage was confirmed from scanning electron microscopy (SEM) images and Heinz bodies formation, while the cell permeability was evident from the K(+) efflux (28.7%, p < 0.05) and increased intracellular Na(+) concentration (8%, p < 0.05). The membrane damage, due to the reduction of the
cholesterol/
phospholipids ratio and depletion (p < 0.001) of
ATP,
2,3-DPG by ˜44-54% and Na(+)-K(+)
ATPase activity (43.7%), indicated loss of RBC functionality. The adverse effects of
AAPH on all these biochemical parameters and the resultant oxidative
hemolysis of RBCs were significantly reduced by pretreating the cells with APC (7 μM) or α-
tocopherol (50 μM) for 1 h, prior to incubation with
AAPH.