The Antitumor Effects of a Plant Extract Mixture

Abstract

The authors declare no con‰ict of interest. a 福岡大学薬学部医薬品情報学教室（〒814 0180 福岡 市城南区七隈 8 19 1） ， b 株式会社紀文食品国際事業室 (〒206 0812 東京都稲城市矢野口 86） ， c サン自然薬研 究所（〒104 0061 東京都中央区銀座 3 12 6）  e-mail: ononob＠fukuoka-u.ac.jp 本総説は，日本薬学会第 132 年会シンポジウム S28 で 発表したものを中心に記述したものである． Cancer is the most common cause of death in Japan. Fundamental and clinical studies on cancer were conducted from the viewpoint of Western medicine so far. However, a sustained complete remission has not been achieved yet. In order to alleviate the side eŠects of anticancer drugs, some traditional herbal medicines (Kampo medicines) have been prescribed to cancer patients. We have been studying on antitumor substances in medicinal herbs and found an antitumor medicinal herb named Rhus vernici‰ua (lacquer, Urushi in Japanese). To investigate the antitumor eŠect in vitro, a plant extract mixture was prepared from six medicinal herbs containing lacquer. The plant extract mixture containing lacquer (Rv-PEM) inhibited the proliferation of several mouse and human tumor cell lines. Rv-PEM had more potent inhibitory eŠect on the proliferation of human leukemia cell lines (MOLT-3, KG-1) than on other tumor cell lines. The IC 50 values of Rv-PEM on MOLT-3 and KG-1 cells were 0.208 and 0.293 mg/mL, respectively. After treating Rv-PEM to the tumor cells, DNA fragmentation and Caspase-3 and -9 activity increased in the treated cells. The mechanisms of the inhibitory proliferation activity of Rv-PEM would involve apoptosis of human leukemia cells (MOLT-3, KG-1, K-562) by the mitochondrial pathway.

Clinical Effects of a Plant Extract Mixture Containing <i>Rhus verniciflua</i> and Other Herbs in Tumor Bearing Dogs

“…Although no evidence of tumor regression was documented in any of the 12 dogs treated, this study was not designed as an efficacy trial, and a potential role for Rv-PEM01 as a complementary or alternative therapy for cancer treatment, or a role in chemoprevention, remains to be explored. Dosages of Rv-PEM01 evaluated here are significantly less than what is needed to produce antiproliferative effects in vitro [11] [12] suggesting that further studies are warranted in dogs at significantly higher dosage levels.…”

“…The branches and sap from R. verniciflua contain active compounds such as urushiol, fustin, querce tin, butein and sulfuretin; the antioxidant [15] [16], antitumorigenic [17] and cytotoxic [18] effects of these compounds have been reported. The antiproliferative activity of Rv-PEM01 has been demonstrated in human, mouse, and canine cell lines [11] [12]. Notably, D17, the one canine cell line that has been tested, is the most sensitive cell line tested to date [12].…”

“…In our previous reports, we showed the anti-proliferative activities of a plant extract mixture from six kinds of herbs including R. verniciflua (Rv-PEM01) in vitro. Rv-PEM01 had an inhibitory effect on the proliferation of human, mouse and canine tumor cell lines [11] [12]. Based on these encouraging in vitro results, we conducted a clinical study of Rv-PEM01 in dogs with spontaneously occurring cancers to determine the safety and tolerability of Rv-PEM01 in this population and to document evidence of antitumor activity.…”

Antitumour and Apoptotic Effects of a Plant Extract Mixture Containing Rhus verniciflua and Other Herbs in Human Leukaemia Cells

“…The antitumour effects of RvPEM01 have been evaluated in vitro, and the findings showed that Rv-PEM01 exhibited antiproliferative activities in human, mouse, and canine tumour cells. In particular, MOLT-3, KG-1, Colon-26, and D-17 cells were more sensitive to Rv-PEM01 than other cell lines [2,3]. We presumed that Rv-PEM01 induces apoptosis in tumour cells in vitro [3].…”

“…In particular, MOLT-3, KG-1, Colon-26, and D-17 cells were more sensitive to Rv-PEM01 than other cell lines [2,3]. We presumed that Rv-PEM01 induces apoptosis in tumour cells in vitro [3]. However, the underlying mechanism of the antiproliferative effects of RvPEM01 on tumour cells remains unknown.…”