The Protective Effect of Eupatilin against Hydrogen Peroxide-Induced Injury Involving 5-Lipoxygenase in Feline Esophageal Epithelial Cells

• Published in: The Korean journal of physiology & pharmacology Vol. 16; no. 5; pp. 313 - 320
• Main Authors: Lim, Jae-Chun, Park, Sun-Young, Nam, Yoon-Jin, Nguyen, Thanh Thao, Sohn, Uy-Dong
• Format: Journal Article
• Language: Korean
• Published: 대한생리학회-대한약리학회 01.01.2012; The Korean Journal of Physiology & Pharmacology Editorial Office
• Subjects: Hydrogen peroxide; Esophageal epithelial cell; Eupatilin; 5-lipoxygenase; Flavonoid
• ISSN: 1226-4512; 2093-3827

In this study, we focused to identify whether eupatilin (5,7-dihydroxy-3',4',6-trimethoxyflavone), an extract from Artemisia argyi folium, prevents $H_2O_2$-induced injury of cultured feline esophageal epithelial cells. Cell viability was measured by the conventional MTT reduction assay. Western blot analysis was performed to investigate the expression of 5-lipoxygenase by $H_2O_2$ treatment in the absence and presence of inhibitors. When cells were exposed to 600 ${\mu}M$ $H_2O_2$ for 24 hours, cell viability was decreased to 40%. However, when cells were pretreated with 25~150 ${\mu}M$ eupatilin for 12 hours, viability was significantly restored in a concentration-dependent manner. $H_2O_2$-treated cells were shown to express 5-lipoxygenase, whereas the cells pretreated with eupatilin exhibited reduction in the expression of 5-lipoxygenase. The $H_2O_2$-induced increase of 5-lipoxygenase expression was prevented by SB202190, SP600125, or NAC. We further demonstrated that the level of leukotriene $B_4$ ($LTB_4$) was also reduced by eupatilin, SB202190, SP600125, NAC, or nordihydroguaiaretic acid (a lipoxygenase inhibitor) pretreatment. $H_2O_2$ induced the activation of p38MAPK and JNK, this activation was inhibited by eupatilin. These results indicate that eupatilin may reduce $H_2O_2$-induced cytotoxicity, and 5-lipoxygenase expression and $LTB_4$ production by controlling the p38 MAPK and JNK signaling pathways through antioxidative action in feline esophageal epithelial cells.