Cytotoxic flavonoids from the seeds of Dracaena steudneri Engl against leukemia cancer cell lines

Background: Leukemia is the most common type of childhood cancer. Numerous flavonoids isolated from plants have been reported as potential chemotherapeutic agents against malignant growth while taking care of healthy cells. Purpose: To discover new anticancer agents from the seeds of Dracaena steudneri Engl for their potential uses as candidate compounds against leukemia cell lines. Methods: A panel of chromatography techniques (CC, Sephadex LH-20 and semi-preparative HPLC) were used to isolate these compounds from the MeOH/CH2Cl2 (1:1) crude extract of the seeds of D. steudneri. Their structure elucidation was achieved based on spectral evidence (UV, NMR and HRESIMS). Resazurin reduction assays were performed to assess the cytotoxicity of the crude extract and isolates. Results: From the seeds of D. steudneri 8 compounds were isolated (1 – 8). Quercetin derivatives: 3,3′-di-O-methylquercetin-4′-O-β-D-glucoside (5) and 3,3′-di-O-methylquercetin (7) displayed significant cytotoxicity against the two leukemia cell lines tested with IC50 < 10 µM. Doxorubicin (reference drug) exhibited strong cytotoxic potency; IC50 of 0.01 µM (against CCRF-CEM cells) and moderate activity; IC50 of 26.78 µM (towards CEM/ADR5000 cells). To the best of our knowledge, this is the first report of flavonoids glycosides from the genus Dracaena. Conclusion: The results obtained in this study showed that flavonoids isolated from Dracaena steudneri are promising candidates for cancer chemotherapy. The mode of action and the cytotoxicity of the most active compounds (5 and 7) should be further investigated.