Abstract

Abdah Akim*, Lim Chooi Ling, Asmah Rahmat and Zainul Amiruddin Zakaria

Roselle (Hibiscus sabdariffa Linn) extract has been scientifically proven to possess high antioxidant activity, antiproliferation and anti-carcinogenic properties. This study was conducted to evaluate the antioxidative capacity of commercialized Roselle juice (RJ) at three storage periods and its anti-proliferative effect on breast (MCF- 7 and MDA-MB -231), ovarian (Caov-3) and cervical (HeLa) cancer cell lines. The antioxidant activity of 1 week (WRJ), 1 month (MRJ) and 1 year (YRJ) juice samples each at 0.001 to 10% concentration range were determined through 1- diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay with L-ascorbic acid as positive control. EC50 values of WRJ, MRJ, and YRJ were found to be 3.733±0.247, 3.717±0.637 and 3.383±0.711%, respectively. These values were compared to 0.217±0.616% for positive control. The difference in antioxidant activity between different storage periods of RJ was not significant (p>0.05) but all samples exhibited increasing activity with increasing concentrations. RJ at the same concentrations were tested using the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) assay on the four cell lines to obtain the percentage viability of the cells. The cells were incubated for 72 h after inoculation with RJ and the control group was without treatment. The IC50 was found to be highest for Caov-3 cells (2.267±1.193%) whereas MCF-7 cells exhibited the lowest (0.432±0.278%) IC50 value after treatment with MRJ. All determinations were analyzed using ANOVA through SPSS with p0.05). The study showed that commercialized Roselle juice has strong antioxidant capacity and anti-proliferative activity on the four cancer cell lines despite different storage periods. However, further study should be conducted to establish its anti-cancer mechanisms.