<b>Background and Objective:</b> <i>Eurycoma longifolia</i> roots hold traditional medicinal value, but scientific evaluation of their bioactivity and safety is lacking. This study investigated the antioxidant and anticancer potential of <i>E. longifolia</i> extracts and assessed cytotoxicity. <b>Materials and Methods:</b> Methanol and ethyl acetate extraction were used to obtain <i>E. longifolia</i> root extracts. Antioxidant activity was measured by DPPH assay and antiproliferative and cytotoxic effects were assessed against various cell lines. A one-way ANOVA was conducted to compare the IC<sub>50</sub> values among the different groups. <b>Results:</b> The highest DPPH radical scavenging activity was detected in methanol extract (IC<sub>50</sub> = 65.50±6.74 μg/mL) and ethyl acetate extract (IC<sub>50</sub> = 463.52±59.81 μg/mL). The methanol extract displayed potent cytotoxicity against all tested cell lines, with IC<sub>50</sub> values ranging from 4.71-6.70 μg/mL. The ethyl acetate extract exhibited moderate cytotoxicity towards the non-cancerous LLC-MK2 cell line (IC<sub>50</sub> = 25.00±5.64 μg/mL), but retained high cytotoxicity against the cancer cell lines (MDA-MB-231 and HeLa), with IC<sub>50</sub> values of 6.09±1.32 and 6.70±1.87 μg/mL, respectively. <b>Conclusion:</b> Methanol extract displayed strong antioxidant and antiproliferative activity, but also cytotoxicity in both cancerous and non-cancerous cells. Further research using <i>in vivo</i> models is needed to assess safety and identify specific bioactive compounds for responsible future use.
Keywords: Antioxidant activity; Eurycoma longifolia Jack; anticancer activity; cytotoxic activity; methanol extraction.