The Study Of Antitumor Activity Of Oxytropis Kansuensis Bunge Alkaloid Fraction And Its Immunomodulation Activity On Mouse

Objective Oxytropis Kansuensis Bunge is known for its main active components ofswainsonine, and 9% swainsonine was contained in the alkaloid fraction we used. To further investigate its role in anticancer activity, we tested alkaloid fraction on human hepatoma cell line HepG2 in vitro. We also observed its potential mechanism of anticancer activity in vitro. Hence, we evaluated its activity by determining its effects on the growth of mouse transplanted tumors in vivo. To further, we explored its immunological mechanisms by investigating the spleen index, thymus index, as well as the spleen cell proliferation rate, and the effects of alkaloid fraction on acute toxicity were investigated.Methods To investigate the inhibition effect on HepG2 cells, we used ten dosegroups of alkaloid fraction respectively. After treatment with alkaloid fraction for 24 h, 48 h, 72 h, cell proliferation was evaluated by MTT assay. we explored the effect of alkaloid fraction on cell cycle and apoptosis on HepG2 cell through flow cytometry. Moreover ,we investigated the change of cell morphous, and the ability of motility, invasion, and adhesion of HepG2 cells respectively through inverted microscope, Boyden chamber and MTT assay. Then, we further determined its activity on KM mouse in vivo. 60 mice were divided randomly into five groups, three groups of which were administrated alkaloid fraction at 8, 16, 32 mg/kg body weight, two control groups were administrated NS 20 ml/kg and 5-FU 15 mg/kg respectively. The observation on its anti-tumor effects were calculated by the average tumor weight and the inhibition rate. The immune function were observed through spleen index, thymus index, as well as the spleen cell proliferation rate measured by MTT assay. We tested the toxicity by orally administered alkaloid fraction at the most higher dose.Results Upon treatment with alkaloid fraction, a time and dose dependent inhibitionof cell growth was observed. As determined by flow cytometry, after 48 h exposure, alkaloid fraction caused HepG2 cells G₂/M phase arrest in a dose dependent manner; and it also induced cell apoptosis in a low dose. Moreover, we demonstrated that alkaloid fraction could change the potential of metastasis, such as motility, invasion, and adhesion of HepG2 cells. Then, for the activity of alkaloid fraction on KM mouse in vivo, the results showed that alkaloid fraction could inhibit the growth of tumor and promote the spleen index, thymus index, as well as the spleen cell proliferation rate in vivo. The inhibition rate for the maximum: 43% and average tumor weight were 0.59±0.24 g at 32 mg/kg group. The mice spleen index, thymus index and spleen cell proliferation rate of 24h, 48h and 72h at the alkaloid fraction dose groups were all significantly higher than the control group, and 8 mg/kg group has the most obvious effect. In the acute toxicity test, 3000 mg/kg of orally administered alkaloid fraction did not show evident toxicity.Conclusions We conclude that Oxytropis Kansuensis Bunge alkaloid fractioninhibits the growth of both HepG2 cells in vitro and mouse transplanted tumors in vivo. We explore that the possible mechanism of alkaloid fraction is to inducing cell cycle arrest and apoptosis in vitro. It also changes the potential of HepG2 cells' metastasis in vitro. Moreover, alkaloid fraction promotes mice immune function, and has less toxicity on KM mouse at the most higher dose. So in one word, Oxytropis Kansuensis Bunge alkaloid fraction is a safe and effective anticancer agent with immunomodulatory activity.