Background: Capsaicin (trans-8-methyl-N-vanillyl-6-nonenamide) is the principal pungent component in hot peppers. The role of capsaicin in carcinogenic processes is quite controversial. Although some investigators suspect that capsaicin is a carcinogen, co-carcinogen, or tumor promoter, others have reported that it has chemopreventive and chemotherapeutic effects. Interestingly, capsaicin has been found to preferentially repress the growth of some transformed human and mouse cells. Although the antiproliferative activity of capsaicin has been ascribed to its ability to induce apoptosis. For example, The American Association for Cancer Research reports studies suggesting capsaicin is able to kill prostate cancer and lung cancer cells by causing them to undergo apoptosis. The present study aimed to evaluate the cytotoxicity and chemosensitizing activities of capsaicin alone and on 5-Flourouracil (5-FU) treated gastric carcinoma cells.

Material and methods: In this study, the gastric cancer cell line HGC-27 was used. Cytotoxicity and chemosensitizing activities were analyzed with MTT assay. Capsaicin used a chemosensitizer and 5-FU was used as chemotherapeutic agent. Supernatant levels of Lactate dehydrogenases (LDH), Glucose (GLU) were detected as biochemical markers of cell viability. Additionally, cytochrome c and apoptosis inducing factor (AIF) were evaluated with western blot. Colonigenic assay and wound healing assays were also employed.

Results: Capsaicin and 5-FU both detected cytotoxic and anticolonigenic on HGC-27 cells dose dependent manner after 24h/48h incubation. Both compounds were found more effective at 48h incubation. Furthermore, it is observed that the concentration of capsaicin higher than 12 µM may cause sensitization to 5-FU. Results suggested that capsaicin had significant anticancer and chemosensitizing abilities; such capsaicin were capable of causing multi-fold decreases in the half maximal inhibitory concentration IC50 value of 5-FU. The chemosensitizing ability of the capsaicin on HGC-27 metastatic lymph node from a gastric cancer patient diagnosed histological as undifferentiated carcinoma cells, in the present study is notable. The cytotoxic effect of capsaicin was observed cytochrome c activation dependent pathway.

Conclusions: The continuing controversy surrounding consumption or topical application of capsaicin clearly suggests that more well-controlled epidemiologic studies are needed to evaluate the safety and efficacy of capsaicin use. In summary, the present study demonstrated that capsaicin has the potential to be used in chemosensitization for treating gastric carcinoma in vitro.

Citation Format: Gorkem Kismali, Merve Alpay, Ogunc Meral, Funda Kosova, Dilek Ulker Cakir, Tevhide Sel. Capsaicin inhibits proliferation and chemosensitizes gastric carcinoma cells to 5-Fluorouracil. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3217. doi:10.1158/1538-7445.AM2014-3217