Anti-platelet aggregation of mixtures of betulinic oleanolic and maslinic acids and derivatives from medicinal plants

Purpose: To evaluate the antiplatelet aggregation and cytotoxic potential of betulinic acid (BA), oleanolic acid (OA), maslinic acid (MA) and their derivatives (3-β-acetyloleanolic acid (OAA) and 3-β- acetylbeutulinic (BAA) from medicinal plants. Methods: The compounds were characterized by nuclear magnetic resonance (NMR, both carbon 13 and hydrogen 1) (NMR), infra-red (FTIR) and mass spectroscopy (MS). The platelet aggregation inhibitory activities of the compounds (1, 3, 5 and 10 mg/ml) were investigated separately on adenosine diphosphate (ADP) and thrombin-induced rat platelet aggregation. Cytotoxicity studies were carried out on human embryonic kidney (HEK293) and hepatocellular carcinoma (HEPG2) cell lines using 3, 4, 5- dimethylthiazol-2-yl)-2-5-diphenyltetrazoliumbromide assay. Results: The compounds significantly (p < 0.05) inhibited platelet aggregation in a dose-dependent manner on thrombin and ADP agonist. BAA/OAA showed the highest activity on both agonists with IC₅₀of 2.86 and 3.05 mg/mL respectively. BAA/OAA also showed better antiplatelet activity than aspirin (IC₅₀of 6.45 and 7.36 mg/mL, respectively). In addition the compound (BA/OA, BAA/OAA and MA/OA) exhibited low cytotoxic effect on both HEK293 cells (IC₅₀: 724.43, 269.08 and 407.89 mg/mL respectively) and HEPG2 (IC₅₀: 585.38, 499.78 and 499.78 mg/mL, respectively). Conclusion: BAA/OAA demonstrate the best antiplatelet potential and low cytotoxicity of in all the tests, and therefore can serve as safer antiplatelet agents.