INHIBITORY ACTION AND MECHANISM OF CEMBRANE-TYPE DITERPENES COLLECTED IN CERIOPS TAGAL ON MICE BEARING H22 ASCITIC TUMOR

Objective To study the inhibitory action and mechanism of cembrane-type diterpenes(CTD) collected in ceriops tagal on mice bearing H22 ascitic tumor. Methods A model of ascitic tumor in mice with hepatoma-22(H22) was created.All the models were randomized to five groups: group 1,normal saline group;group 2,low-dose CTD(5 mg/kg);group 3,middle-dose CTD(10 mg/kg);group 4,high-dose CTD(20 mg/kg);group 5,cyclophosphamide(CTX 10 mg/kg).Medication started at 24 hours after the models were created.Different doses of CTD were lavaged for mice in groups 2,3 and 4 for seven days,those in group 1 were given normal saline,and those in group 5,intraperitoneal CTX was administered for seven days.Half of the mice of each group were killed 24 hours after the last medication.The average volume of ascites,inhibition rate of ascites,tumor cell number and the cell survival rate,the levels of cytokine interleukin-2(IL-2) and interferon-γ(IFN-γ) in ascites were detected.The other half of the mice were continuely followed up for their living condition and life span. Results Compared with group 1,the volume of ascites in groups 3 and 4 reduced obviously(F=28.37;q=2.92,4.76;P0.05),the inhibition rate of ascites increased with the increase of the dose of CTD.The number of tumor cells and survival rate in groups 2,3 and 4 were less than that in group 1(F=7.21-19.13;q=2.41-4.75;P0.05).The mean survival duration of mice in groups 2,3 and 4 was longer than that in group 1,the extension rate was 20.21%,42.10% and 51.02%,respectively(F=35.77;q=2.91-4.76;P0.05).In comparison with group 5,those in groups 2 and 4 were better in terms of the condition of eating,drinking,and activities.The appetide of mice in group 4 was poor and less activities during medication,but improved after drug withdrawal.The differences of levels of cytokine IL-2 and IFN-γ in ascites between groups 2,3,and 4 were significant(F=21.17,35.47;q=2.93-4.77;P0.05). Conclusion The cembrane-type diterpenes has a significant inhibitory effect on mice brearing H22 ascitic tumor.Its mechanism may be associated with cellular immunity,which is likely to be a potential in the development of a novel marine anti-tumor drug.