Objective: To investigate the total phenolic, flavonoids, tannin contents of Simarouba glauca leaves and evaluate the antioxidant potential and cytotoxic activity in different human cell lines.Methods: The methanol, ethanol and water extracts of S. glauca leaves were examined for total phenolics, flavonoid and tannin content. Its antioxidant properties using FRAP, Phosphomolybdenum, Ferric ferrozine assays and free radical scavenging using DPPH were determined. Further, the reducing power and iron chelating effect of the extract using spectrophotometric assays were estimated. Finally, the cytotoxic activity against few human cancer cell lines were also examined using MTT assay.Results: The phytochemical investigations revealed that S. glauca leaves has only 0.14 to 0.18% of flavonoids, 250-400µg/mg phenolics and 67-200µg/mg tannin content in various solvent extracts. The extracts exhibited good reducing power with similar EC50 values aproximately in the range of 57-61µg /ml. Further, the leaf extracts showed iron chelation effect which was more pronounced in aqueous extract with IC50 value of 332µg/ml and exhibited very strong DPPH radical scavenging activity with IC50 vlaues ranging from 9-13µg/ml in various extracts. The methanolic extracts showed good antioxidant potential using FRAP and phopshomolybdenum methods, whereas the aqueous extract exihibited more pronounced antioxidant activty using sensitive ferric ferrozine assay with 580µg AAE/mg extract. The methanolic extract showed strong cytotoxic effect on SCC9 cancer cell line and less potent on HCT116 cancer cells.Conclusion: The findings suggests that Simarouba glauca leaf extract contain bioactive molecules which exhibit antioxidant activity that could be synergisticaly influencing the cytotoxic activity in selected cancer cell lines.Â
