Zanthoxylum fruit extract from Japanese pepper promotes autophagic cell death in cancer cells.

Zanthoxylum fruit, obtained from the Japanese pepper plant (Zanthoxylum piperitum De Candolle), and its extract (Zanthoxylum fruit extract, ZFE) have multiple physiological activities (e.g., antiviral activity). However, the potential anticancer activity of ZFE has not been fully examined. In this study, we investigated the ability of ZFE to induce autophagic cell death (ACD). ZFE caused remarkable autophagy-like cytoplasmic vacuolization, inhibited cell proliferation, and ultimately induced cell death in the human cancer cell lines DLD-1, HepG2, and Caco-2, but not in A549, MCF-7, or WiDr cells. ZFE increased the level of LC3-II protein, a marker of autophagy. Knockdown of ATG5 using siRNA inhibited ZFE-induced cytoplasmic vacuolization and cell death. Moreover, in cancer cells that could be induced to undergo cell death by ZFE, the extract increased the phosphorylation of c-Jun N-terminal kinase (JNK), and the JNK inhibitor SP600125 attenuated both vacuolization and cell death. Based on morphology and expression of marker proteins, ZFE-induced cell death was neither apoptosis nor necrosis. Normal intestinal cells were not affected by ZFE. Taken together, our findings show that ZFE induces JNK-dependent ACD, which appears to be the main mechanism underlying its anticancer activity, suggesting a promising starting point for anticancer drug development.

The History of Dai-kenchu-to and the Component Crude Drugs / 日本東洋医学雑誌

A Kampo medicine, Dai-kenchu-to, has been used clinically for treatments of various ailments such as vomiting, stomachache, and abnormal intestinal peristalsis caused by abdominal chill. Recently, it is often used to prevent intestinal obstruction after abdominal operations. We searched ancient Chinese and Japanese medical texts for the indications and pharmacological characteristics of Dai-kenchu-to and its constituent herbs (<i>Zanthoxylum</i> fruit, dried Ginger rhizome, Ginseng root, and Malt sugar). We clarified the applications and the cautions of Dai-kenchu-to in this paper. Dai-kenchu-to has rarely been used in China. However, it was often used for the remedy of severe abdominal pain caused by chilling, worm-ileus and hernia in the medieval period of the Edo era in Japan. For these reasons, evidence is considered as described below. i) Japanese people did not have the habit of eating meat in those days. ii) Japanese people used to drink a lot of water. iii) Severe abdominal pain occurred frequently due to wearing traditional Japanese clothing, which does not protect well against cold. iv) Abdominal diagnosis was advanced in Kampo medical methods. We found two precautions in the ancient Japanese medical texts. One is that a purgative should be avoided when used in an applicable case of Dai-kenchu-to. The other is that Dai-kenchu-to should not be given in the case of high fever. It is supposed that the botanical origins and processing of the four herbs used in the medieval period of the Edo era are the same as those of today. Our findings suggest that the pharmacological contribution of the four herbs in Dai-kenchu-to is mainly due to <i>Zanthoxylum</i> fruit and dried Ginger rhizome, and that Ginseng root and Malt sugar harmonize between the condition of patient and the pharmacological action of <i>Zanthoxylum</i> fruit and dried Ginger rhizome.