The study was conducted to evaluate the DPPH scavenging property of leaf extracts of plant P. quadrifolius (Benth.). In this study, plant leaves were solvent extracted by soxhlet method using petroleum ether, chloroform and methanol sequentially. The extracts were then analyzed for DPPH scavenging properties. Among the three extracts used, only methanol extract has exhibited the DPPH scavenging property. The results showed that the methanol extract of P. quadrifolius (Benth.) leaf exhibit DPPH scavenging property with IC 50 14.5±1.05 µg mLG 1 . The phytochemical analysis indicated that the methanol extract is a rich source of phenolic compounds and this may be the reason for DPPH radical scavenging property of this extract.

The present study was performed to evaluate the antiproliferative property of (Z)-ethylidene-4, 6-dimethoxycoumaran-3-one (EDC), isolated from Pogostemon quadrifolius (Benth.) leaf against chronic myelogenous leukemia cell line (K-562). The purity and identity of the compound were confirmed by HPLC and ESI-MS analysis. Cell viability assay (MTT) was performed to evaluate the antiproliferative effect of EDC on K-562 cell line. The result showed that EDC inhibited the proliferation of K-562 cell line with an IC 50 of 7.77±0.21 µg mLG 1 (35.3 µM). Further DNA fragmentation assay was performed to identify the mode of action of EDC against K-562 cell line. The clear laddering pattern obtained after treating the cell line for 24 h with 50 µM EDC indicated that EDC induces cell death in K-562 cells by inducing apoptosis. Thus, the present study evidenced the potential antiproliferative property of EDC against chronic myelogenous leukemia cancer in vitro.