Inhibitory effect of capsaicin on interleukin-8 production by Helicobacter pylori-infected MKN-45 cells

Capsaicin is the active ingredient in chili pepper and has an inhibitory effect on Helicobacter pylori growth and NF-κB activation. The present study examined the effect of capsaicin on interleukin (IL)-8 production by H. pylori ATCC 43504-infected MKN-45 cells, a gastric epithelial cell line. The viability of the MKN-45 cells treated with capsaicin at 0, 50, 100, 250, and 500 μM was 99, 98, 99, 99, and 85%, respectively. A capsaicin concentration as low as 50 μM significantly inhibited the IL-8 production induced by H. pylori ATCC 43504 infection (43.2% of control) during 24 h of incubation. However, low concentrations of capsaicin (50 and 100 μM) did not significantly inhibit the IL-8 production by TNF-α- or PMA-treated MKN-45 cells. Therefore, the overall inhibitory effect of capsaicin on H. pylori ATCC 43504 was the sum of H. pylori ATCC 43504 growth inhibition, host cell survival, and NF-κB signal cascade inhibition.