IN VITRO EVALUATION OF ANTIOXIDANT AND ANTICANCER PROPERTIES OF METHANOLIC EXTRACTS OF Ulva paschima AGAINST A549 AND H1299 LUNG CANCER CELL LINES

The present study focused on the antiproliferative effect of methanolic extracts of Ulva paschima (MEUP) on lung cancer cell lines A549 and H1299. The superoxide dismutase, catalase and glutathione reductase activities in MEUP were assayed. The intracellular reactive oxygen species, antioxidant potential, mitochondrial membrane potential and cell proliferation ability were also determined using standard methods while the extracts were analysed by GCMS. The study showed that MEUP had selective antiproliferative effect on cancer cell lines with IC50 0.187 +/- 0.120 mu g mu L-1 for A549 and 0.130 +/- 0.031 mu g mu L-1 for H1299 cells as determined by 3-(4,5-dimethylthiazol-2-cyl)-2,5-diphenyltetrazolium bromide (MTT) assay. MEUP induced oxidative stress in dose-dependent manner as measured by dihydro-ethidium (DHE) and 2 ',7 '-dichloro-dihydro-fluorescein diacetate (H2DCFDA) assays. Due to the induced oxidative stress by MEUP treatment, a rise in intracellular levels of antioxidant enzymes (glutathione reductase, superoxide dismutase, and catalase) was observed. A dose-dependent depolarization of mitochondrial membrane potential by 38% for A549 and 41% for H1299 cell lines was observed. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity was 61.69% as compared to the ascorbic acid with EC50 of 176.7 +/- 0.09 mu g mL-1. GC-MS analysis of MEUP showed the presence of 1-dodecanol, 5-eicosene, neophytadiene, stearic acid, lauric acid, hexadecanoic acid, margaric acid, linoleic acid, L-alpha-terpineol, oleic acid, 9-octadecenamide, myristic acid and phytol known for their anticancerous properties. The phytochemical profile was evaluated for potential for serving as novel anticancer drug candidates.