Acute Toxicity and General Pharmacological Action of QGC EXT

It has been shown that QGC isolated and purified from Rumecis folium found protective effects of gastritis and esophagitis which EXT is an ethanol extract of it. We examined acute toxicity and the general pharmacological action of QGC EXT to search for any side effects of it in rats, mice, guinea pigs, and cats. In a single dose toxicity study, QGC EXT didn't show toxicological effects in rats and mice, and the LD50 was over 5 g/kg in both animals, and there were also no changes in weight, feed and water intake during these toxicological experimental periods. We examined the general pharmacological action on central controlled behavior responses, and peripheral organs including blood pressure, heart rate, respiration and gastrointestinal system, We found that there were no significant changes in body temperature, locomotors activity, stereotyped behaviors, sleeping time, and convulsion. In other studies, writhing reaction, normal body temperature, there did not appear to be any changes. The large intestine movement and electrical field stimulation-induced contraction was not changes by its EXT. In addition, the influences on blood pressure, heart rates, and respiration by QGC EXT were not found. These results indicate that QGC EXT may be very safe as a new drug, since its LD50 was very high over 5 g/kg and any side effects were not found.

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

In this study, we focused to identify whether eupatilin (5,7-dihydroxy-3',4',6-trimethoxyflavone), an extract from Artemisia argyi folium, prevents H2O2-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 H2O2 treatment in the absence and presence of inhibitors. When cells were exposed to 600 microM H2O2 for 24 hours, cell viability was decreased to 40%. However, when cells were pretreated with 25~150 microM eupatilin for 12 hours, viability was significantly restored in a concentration-dependent manner. H2O2-treated cells were shown to express 5-lipoxygenase, whereas the cells pretreated with eupatilin exhibited reduction in the expression of 5-lipoxygenase. The H2O2-induced increase of 5-lipoxygenase expression was prevented by SB202190, SP600125, or NAC. We further demonstrated that the level of leukotriene B4 (LTB4) was also reduced by eupatilin, SB202190, SP600125, NAC, or nordihydroguaiaretic acid (a lipoxygenase inhibitor) pretreatment. H2O2 induced the activation of p38MAPK and JNK, this activation was inhibited by eupatilin. These results indicate that eupatilin may reduce H2O2-induced cytotoxicity, and 5-lipoxygenase expression and LTB4 production by controlling the p38 MAPK and JNK signaling pathways through antioxidative action in feline esophageal epithelial cells.