Cytotoxic Activity of Annona Muricata L, Momordica Charantia L. and Launaea Taraxacifolia Willd. from Benin: A Flow Cytometric Approach

Background: Cancer is rising worldwide, causing approximately 9.7 million deaths in 2022. Treatments are costly, have significant side effects, and are sometimes unavailable in Benin. Medicinal plants offer promising avenues for new therapeutic agents. Objective: This study uses flow cytometry method to evaluate the cytotoxic activity of Annona muricata (Annonaceae), Momordica charantia (Cucurbitaceae) and Launaea taraxacifolia (Asteraceae), three plants from the Beninese pharmacopoeia known for their anti-cancer properties. Materials and Methods: The leaves of A. muricata, L. taraxacifolia and whole plants of M. charantia were collected in southern Benin. Extracts were prepared by aqueous decoction and sequential extraction with solvents of increasing polarity (dichloromethane, ethyl acetate, methanol). The phytochemical profiles of the extracts were determined using TLC and tube tests. The cytotoxicity of the extracts was evaluated on THP-1 cancer cells and PBMC healthy cells. After treatment with the extracts, cell viability was measured by flow cytometry after staining with Thiazole Orange and Hoechst 33258. Results: The dichloromethane extracts of A. muricata and M. charantia, and the ethyl acetate extract of M. charantia and L. taraxacifolia showed significant cytotoxic effects on THP-1 cells. Their half-maximal inhibitory concentrations (IC₅₀) were 139.6 μg/mL, 72.89 μg/mL, 81.88 μg/mL and 106.3 μg/ mL, respectively. These extracts also demonstrated good selectivity toward normal cells. Phytochemical screening revealed the presence of alkaloids, coumarins, flavonoids, anthracene glycosides and triterpenes in the active extracts. Conclusion: This study demonstrated the cytotoxic potential of three medicinal plants from the Beninese pharmacopoeia which may serve to develop further new anticancer therapies.