Exploring the Therapeutic Potential: Antiplatelet and Antioxidant Activities of Some Medicinal Plants in Morocco

Background: Thrombotic events and oxidative stress are major complications of certain ischemic disorders. The fight against these complications requires very intense research to develop new therapeutic agents of natural origin. Objective: The general objective of this work is the scientific valorization of five medicinal plants: Rhus pentaphylla, Zizyphus lotus, Ammodaucus leucotrichus, Inula viscosa, and Cinnamomum zeylanicum by exploring their effects on rat platelet aggregation, antioxidant potential and determining their phytochemical composition. Methodology: The aggregation test was monitored by stimulating isolated washed platelets suspension in the absence and presence of extracts. The antioxidant activity was conducted in vitro according to three methods: DPPH free radical scavenging activity, β-carotene bleaching test, and ferric reducing antioxidant power test. The quantitative determination of total polyphenols and flavonoids are determined respectively according to the Folin-Ciocalteu method and the colorimetric method with aluminum chloride. Results: The results obtained show that the aqueous extract of the fruits of Rhus pentaphylla and the aerial part of Inula viscosa, as well as the stalk peel of Cinnamomum zeylanicum, significantly (p<0.001) inhibit thrombin-platelet aggregation, while the other plant extracts have a slightly, but significant effect. These extracts exert a remarkable antioxidant activity with the three methods used. But, their IC50 values are still higher than those of the antioxidant references (ascorbic acid and butyl hydroxyanisole). Qualitative phytochemical analysis revealed the presence of secondary metabolites with varying contents. Additionally, the results of quantitative phytochemical analysis showed that the aqueous extracts of the leaves of Rhus pentaphylla and the aerial part of Inula viscosa contain the highest amount of polyphenols and flavonoids. These secondary metabolites are also present in the other extracts but in smaller quantities. Conclusion: These results could contribute to the validation of the medical use of these extracts that exert an antiplatelet effect to treat hemostatic and thrombotic disorders.