The effects of aqueous extract of Zanthoxylum macrophylla
(formerly Fagara xanthoxyloides
) roots on the membrane stabilities of human erythrocyte from HbAA, HbAS and HbSS blood were investigated. The determination of mean corpuscular fragility (MCF), which is the concentration of saline causing 50% haemolysis of the erythrocytes, showed that the aqueous plant extract increased the MCF values of the various erythrocytes. There was no significant difference (p>0.05) between the MCF values of HbAA and HbAS erythrocytes. However, significant difference (p<0.05) was noted between HbAA and HbSS erythrocytes. Percentage stabilization, calculated from the MCF values showed stabilization by the plant extract of 11.11, 10.30 and 14.39 % for the erythrocytes from HbAA, HbAS and HbSS, respectively. At a concentration of 400 μM, phenylalanine, a known anti-sickling compound, produced a stabilization of 17.85% for HbSS erythrocyte under the same experimental conditions used for the aqueous plant extract. Blood viscosity studies indicated a decrease in viscosity of the HbSS blood by the aqueous extract and this reduction was significantly different (p<0.05) from that for HbAA and HbAS bloods. The plant extract also showed pronounced reversion of 2% sodium metabisulphite-induced sickling, an effect also observed with phenyl alanine (400 μM). These findings suggest that the plant extract has some role in stabilizing the erythrocyte membranes, thus providing possible molecular basis for earlier reports on the anti-sickling effects of Zanthoxylum macrophylla
and its use in the management of the sickle cell disease.