Protective effect of Rhizophora mangle bark on lipid peroxidation and erythrocyte hemolysis

Excessive peroxidation of biomembranes is thought to contribute to the initiation and progression of numerous degenerative diseases. The present study examined the effects of Rhizophora mangle bark aqueous extract and its polyphenol fraction on the peroxidation of rat-brain lipids and human erythrocyte hemolysis. The lipid peroxidation was assessed by incubating with Fe 3+ / ascorbic acid and erythrocyte hemolysis was induced from 2,2'-azo-bis (2-amidinopropane) dihydrochloride (AAPH). The extract and its polyphenol fraction exhibited dose-dependent protection against peroxidation of rat-brain lipids and human erythrocyte heamolysis. The correlation coefficients for percentage of lipid peroxidation inhibition versus the tannins concentration were, r=0.999 (p<0.05) for extract and r= 0.868 (p<0.05) for polyphenol fraction. In the free radicals-induced hemolysis assay the values of IC50 were 113,99 µg/ml and 204,02 µg/ml for the extract and its polyphenol fraction respectively. In both case, the extract was more efficient than its polyphenol fraction in protecting rat-brain lipids from oxidation and human erythrocyte from heamolysis, it suggests a synergic effect of all components of the extract which increase in its antioxidant activity, although polyphenol fraction plays an important role in these effects. These results show that Rhizophora mangle extract and its polyphenol fraction can provide membrane protective effects.