[Effects of Rhizoma kaempferiae volatile oil on tumor growth and cell cycle of MKN-45 human gastric cancer cells orthotopically transplanted in nude mice].

OBJECTIVE To evaluate the effects of Rhizoma kaempferiae volatile oil on tumor growth and cell cycle of MKN-45 human gastric cancer cells orthotopically transplanted in nude mice. METHODS One hundred and five nude mice orthotopically transplanted with MKN-45 human gastric cancer cells were randomly divided into seven groups: untreated group, normal saline-treated group, dissolvant-treated group, cyclophosphamide (CTX)-treated group and high-, medium-, and low-dose Rhizoma kaempferiae volatile oil-treated groups. Corresponding interventions were implemented in each group except the untreated group. The antitumor effects in vivo were evaluated. Cell cycle distribution and apoptosis of MKN-45 human gastric cancer cells were determined by using flow cytometry (FCM). The ultrastructure of MKN-45 gastric cancer cells was observed by a transmission electron microscope. RESULTS In the high-, medium-, and low-dose Rhizoma kaempferiae volatile oil-treated groups, the growth inhibition rates of gastric cancer were 57.2%, 28.0% and 5.0% respectively, and the gastric cancer cells were arrested at G(0)/G(1) phase. This antitumor effect was dose-dependent. The apoptotic cells occurred more frequently in the high-dose Rhizoma kaempferiae volatile oil-treated group and the CTX-treated group than those in the medium- and low-dose Rhizoma kaempferiae volatile oil-treated groups. CONCLUSION The Rhizoma kaempferiae volatile oil is an effective composition for growth inhibition of gastric cancer, and its mechanism may be related to regulating the cell cycle and inducing apoptosis.