Cancer Lett. 2000 Aug; 157(1): 9-14.

Suppressive effect of the herbal medicine Oren-gedoku-to on cyclooxygenase-2 activity and azoxymethane-induced aberrant crypt foci development in rats.

Fukutake M, Miura N, Yamamoto M, Fukuda K, Iijima O, Ishikawa H, Kubo M, Okada M, Komatsu Y, Sasaki H, Wakabayashi K, Ishige A, Amagaya S.

Kampo & Pharmacognosy Laboratory, R & D Division, Tsumura & Co., 3586 Yoshiwara, Ami-machi, Inashiki-gun, Ibaraki, Japan. [email protected]

The present study is part of a program to obtain effective chemopreventive agents with low toxicity from medicinal herbs and traditional herbal medicines. We previously reported that Oren (Coptidis rhizoma) and Ogon (Scutellariae radix) inhibit azoxymethane (AOM)-induced aberrant crypt foci (ACF) formation. In the present investigation, we found Sanshishi (Gardeniae fructus) and the traditional herbal medicine Oren-gedoku-to (OGT), composed of Ogon, Oren, Sanshishi and Obaku, also have preventive potential. Sanshishi and OGT decreased the numbers of ACF to 25.2 and 59.4% of the control value at 2% in the diet, respectively. Adverse effects, evidenced by body weight loss, were weaker with OGT than component herbs. To investigate their mechanisms of action, the influence on cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) activities was studied. Both OGT and Sanshishi inhibited COX-2 but not COX-1, this presumably contributing to their suppressive effects on ACF development. The results suggest that OGT may be useful for colon cancer chemoprevention in terms of efficacy and toxicity.