plaunotol and Stomach-Neoplasms

Although some isoprenoids, such as taxans and geranylgeraniol (GGOH), have been reported to have strong anticancer activities, the effect of plaunotol, the isoprenoid extracted from the leaves of Plau-noi, on cancer has not yet been evaluated. Here, we aimed to investigate the effect of plaunotol on gastric cancer cell lines. Three gastric cancer cell lines, namely MKN-45, MKN-74 and AZ-521 were used. Plaunotol was tested at 10, 20, 30 and 40 micromol/L. Plaunotol dose-dependently inhibited the growth of all gastric cancer cells, dependent on the induction of apoptosis. Caspases-8, -9 and -3, were found to be activated in the apoptotic cells. The expression of Bax protein was increased, but Bcl-2 and Bcl-xL protein expressions were not significantly affected. Plaunotol should be a promising new antitumor agent, and since it is already available for clinical use in Japan, its anticancer properties should be confirmed in clinical trials.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Caspases; Cell Line, Tumor; Croton; Diterpenes; Dose-Response Relationship, Drug; Fatty Alcohols; Flow Cytometry; Humans; In Situ Nick-End Labeling; Phytotherapy; Plant Extracts; Stomach Neoplasms

It has been suggested that gastric mucosal injury induced by Helicobacter pylori infection is mediated by interleukin-8 (IL-8).. We studied the effect of plaunotol, a drug extracted from the Plau-noi tree of Thailand, and reported it to be effective in the treatment of ulcers, of IL-8 secretion induced by H. pylori and of the inhibitory adhesion activity of the bacterium to gastric epithelial cells. Moreover, the therapeutic effect of plaunotol on H. pylori infection was assessed by using the gnotobiotic murine model.. Plaunotol inhibited the growth of H. pylori (1.5 x 10(4) c.f.u./mL) at high doses (24-48 microg/mL), but not at low doses (3-6 microg/mL). Interleukin-8 secretion induced by H. pylori was inhibited by coculture with plaunotol in a dose-dependent manner. The adhesion of H. pylori to MKN45 cells was also suppressed by coculture with plaunotol in a dose-dependent manner. An in vivo study showed that plaunotol improved histological gastritis and decreased the H. pylori antibody titre.. These findings suggest that plaunotol has a therapeutic effect on gastritis induced by H. pylori.

Topics: Administration, Oral; Animals; Anti-Ulcer Agents; Antibodies, Bacterial; Bacterial Adhesion; Diterpenes; Dose-Response Relationship, Drug; Epithelial Cells; Fatty Alcohols; Gastric Mucosa; Helicobacter Infections; Helicobacter pylori; Humans; Immunoassay; Interleukin-8; Male; Mice; Mice, Inbred BALB C; Rabbits; Stomach Neoplasms; Stomach Ulcer; Tumor Cells, Cultured