P18 Comparative effect of pomegranate extract (PFE) and sodium salicylate (NaSal) on SbCl-1 melanoma cellular proliferation

Abstract

Introduction Acetylsalicylic acid (aspirin) were found to suppress growth in B16 melanoma cells. In addition farnesyl thiosalicylic acid (FTS) treatment was reported to significantly increase the proportion of apoptotic cells after 72 h. We recently showed that pomegranate fruit extract (PFE) possesses remarkable antitumor-promoting effects in mouse skin, PC3 prostate cancer cells and human A540 lung carcinoma. The purpose of this study was to compare the effect of NaSal and PFE on SbCl-1 melanoma cell viability and to explore their mechanism of action. Methods The effect of NaSal (Sigma, Germany) and PFE (Biotrek, Greece) on the viability of cells was determined by SLB assay. The SbCl-1 cells were plated in complete culture medium containing 150 μg/ml concentrations of PFE or 20 mmol/l final concentrations of NaSal in 96-well microtiter plates for 72 h. Results Our study of the antiproliferative effect of PFE and NaSal on SbCl-1 melanoma cells showed that both treatments resulted in a statistically significant decrease in cell viability relative to the control at 72 h, i.e. 81 and 86% respectively (P<0.001, one-way Analysis of variance ANOVA). However the decrease in cell viability between PFE and NaSal was not statistically significant at 72 h and was similar to the viability at incubation time zero (P>0.05, one-way Analysis of variance ANOVA). Conclusion It has been suggested that pomegranate extract may have a anti-proliferative effect in various human cancers. The extract contains certain species of flavonoids and anthocyanins. These species in other plants have shown anti-proliferative activity against human melanoma cells. In addition flavonoid-treatment of A375 cells led to sustained activation of p38 and JNK MAP kinases. On the other hand it has been reported that aspirin induces the activation of JNK and p38 in B16 cells, such as FTS of p38 in Colo853 cells. Finally our previous study showed that salicylic acid induced the activation of p38 in SbCl-1 melanoma cells. Taken together with the results of our present study strongly suggest that NaSal and PFE induce apoptotic death of SbCl-1 cells mediated by the same mechanism i.e. via the p38 and JNK cascade.