Justicia gendarussa methanolic leaf extracts from five different locations in the Southern region of Peninsular Malaysia and two
flavonoids,
kaempferol and
naringenin, were tested for cytotoxic activity.
Kaempferol and
naringenin were two
flavonoids detected in leaf extracts using gas chromatography-flame ionization detection (GC-FID). The results indicated that highest concentrations of
kaempferol and
naringenin were detected in leaves extracted from Mersing with 1591.80 mg/kg and 444.35 mg/kg, respectively. Positive correlations were observed between
kaempferol and
naringenin concentrations in all leaf extracts analysed with the Pearson method. The effects of
kaempferol and
naringenin from leaf extracts were examined on
breast cancer cell lines (MDA-MB-231 and MDA-MB-468) using MTT assay. Leaf extract from Mersing showed high cytotoxicity against MDA-MB-468 and MDA-MB-231 with IC50 values of 23 μg/mL and 40 μg/mL, respectively, compared to other leaf extracts.
Kaempferol possessed high cytotoxicity against MDA-MB-468 and MDA-MB-231 with IC50 values of 23 μg/mL and 34 μg/mL, respectively. These findings suggest that the presence of
kaempferol in Mersing leaf extract contributed to high cytotoxicity of both MDA-MB-231 and MDA-MB-468
cancer cell lines.