| Objective:To explore the anti-hepatoma efficacy of iridoid-rich fraction from Valeriana jatamansi Jones, and further for revealing its mechanism preliminaryly.Methods:1. H22 tumor-bearing mice model was established to observe the effect of iridoid-rich fraction from Valeriana jatamansi Jones on the growth of tumor in mice, and compound tegafur was as the positive control drug. The apoptosis of tumor organization was detected by HE staining and Annexin V-FITC/PI staining. Moreover the contents of SOD, IL-2 and TNF-a of serum in mice were detected with the meathod of WST-1 and ELISA, respectively.2. the scavenging activities of iridoid-rich fraction to DPPH, O2 H2O2 and ·OH were determinated.3. the proliferation and cell cycle of HepG2 cell with the influence of Valjatrate E were measured by MTT and PI staining, respectively. And the apoptosis of HepG2 cell was observed by microscopy fluorescent staining and its rate was measured by Annexin V-FITC/PI staining with flow cytometry.Results:1. Compared with the model group, the growth of tumor in H22 tumor-bearing mice were inhibited in different degree in tegafur and 300mg/kg,200 mg/kg,100 mg/kg of iridoid-rich fraction groups, their inhibition rates were 51.61%,45.85%,31.92%and 28.19%, respectively, and tegafur and 300mg/kg of iridoid-rich fraction groups had significant difference (P< 0.05). HE staining showed the tumor tissues in tegafur and three doses of iridoid-rich fraction groups were observed with cells scattering, inhomogeneous stain, irregular shape, nucleu broke, apoptosis body increased, and companied by number of dead cells; further compared with model group, their apoptosis rates with the obvious rise detected by Annexin V-FITC/PI staining, were 93%(tegafur),63.2%,53.3% and 32.53% (300,200,100 mg/kg iridoid-rich fraction, respectively). And the WTS-1 method proved that the content of SOD in tegafur and three doses of iridoid-rich fraction groups decreased significantly compared with model group (P< 0.05). Moreover ELISA detected the content of TNF-a in 300mg/kg iridoid-rich fraction group had a significant drop (P< 0.05), while IL-2 content in 200 and 300 mg/kg iridoid-rich fraction groups with significant rise (P< 0.05), and TNF-a and IL-2 contents in others group had no statistical significant compared with model group (P> 0.05).2. Iridoid-rich fraction in concentrations of 0.5,1,2,4 and 8mg/mL had scavenging activity towards DPPH、H2O2 and ·OH, with IC50 in 0.46,1.69 and 8.66mg/mL, respectively. While it didn’t show the scavenging activity to O2.3. MTT showed that the proliferation of HepG2 cell was inhibited significantly by Valjatrate E, its IC50 in the time of 24,48 and 72 h were 12.07,7.56 and 5.78ug/mL, respectively. Compared with control group, PI staining proved the S phas of HepG2 cell cycle was reduced significantly by Valjatrate E with the concentration of 20,10, and 4 ug/mL, while its G2/M phas was increased significantly (P＜0.05). Fluorescence microscopy observed a number of HepG2 cell affected by Valjatrate E with the concentration of 20 and 10 ug/mL displayed the state of apoptosis, incμLing the number declined sharply, the shrinkage of cell bodies, chromatin condensation, and nucleus broke; and the method of Annexin V-FITC/PI staining showed 20,10, and 4 ug/mL of Valjatrate E improved distinctly the rates of HepG2 cell apoptosis (P<0.05), they were 91.25%,66.01% and 17.51%, respectively.Conclusion:1. Iridoid-rich fraction from Valeriana jatamansi Jones can obviously inhibit the growth of tumor in mice, induce it to apoptosis, and inhibit the expression of SOD, TNF-a while improve that of IL-2 in blood.2. Iridoid-rich fraction has a certain antioxidant capacity, the order of its scavenging activity is H2O2> DPPH>·OH.3. Valjatrate E can inhibit the proliferation of HepG2 cell by blocking the cell cycle in G2/M phase and inducing the occurrence of celluLar apoptosis.These show that iridoid-rich fraction from Valeriana jatamansi has anti-hepatoma effect through inhibiting the proliferation of tumor cell and inducing it to apoptosis. And its mechanisms may relate to regulate the levels of SOD, TNF-αand IL-2, involved in adjusting the boby of redox state and immune ability. |
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