Study On Antitumor Effects In Vivo And Mechanism Of Icariside

Epimedium brevicornu Maxim.is a traditional Chinese medicine with multipul bioactivities,its main active ingredient is Epimedium flavanone,which has significant pharmacological activity,such as Zhuang Yang,treating bone shortening,delaying senescence,improving the immune function of the body and inhibiting the growth of tumor.Its effective component has high potential as drug development.In fact,the immunotherapy is a novel anti-tumor strategy which has attracted much attention.In recent years,studies on their anti-tumor effects revealed that one of the major components,the flavonoids,can stimulate passive immunity of organism,and activate the body's own immune system to kill tumor cells.At present,the clinical drugs for immunotherapy are mainly bio-macromolecules,such as antibodies.However,protein and peptide drugs have their limitation due to the poor stability,high costs,and allergic reations.Thus,finding novel chemical entities for immunotherapy has profound significance.Icariside?is one of the flavonoids in Epimedium brevicornu Maxim.From the previous studies,icariside?showed activity on stimulating the production of IFN-?in T lymphoma cells.While icariin and other components in Epimedium brevicornu Maxim.could not show this activity.Moreover,the icariside?has only one more rhamnose base compared with the molecular structure of icaritin which is the new anti hepatoma drug that has already entered the three phase of clinical trials,and the water solubility of icariside?is better and the bioavailability is higher.In this study,the anti-tumor activity and mechanism of icariside?were further studied in vivo and in vitro.The main contents of this paper include the following four parts:1.The antitumor activity of icariside?in C57BL/6J tumor bearing mice.The results of the study show that LD₅₀ value of icariside?is greater than 2000 mg/kg,which indicates a relative high safety.The results in the antitumor experiments showed that icariside?in S180and H22 mice showed obvious tumor inhibiting effect.Increase on the production of IFN-?in these mice were also observed.Besides,icariside?could improve the thymus and spleen weight index,which means an improvement of the immune function in these tumor-bearing mice.2.Evaluation of the activity of icariside?at the cell level.Firstly,CCK8 method was used to study the inhibitory effect of icariside?on hepatoma cell proliferation by CD3⁺T cells.The results showed that icariside?could significantly inhibit the proliferation of hepatoma cells.Further,the secretion of IFN-?from T cells were evaluated by the ELISA assay.The results showed that icariside?could significantly promote the secretion of IFN-?in T cells.3.The effect of icariside?on tumor cells proliferation and related signaling pathways were studied using Western blot,CCK8,flow cytometry analysis.The results showed that the low concentration of icariside?could promote the IFN-?secretion in T cells.Furthermore,these IFN-?bind with the IFN-?receptor on the cell surface to activate the JAK1/STA1 pathway,which increased the expression level of key proteins Noxa,Cytochrome C,cleaved PARP,cleaved Caspase 3 and cleaved Caspase 9 in IFN-?mediated apoptosis pathway and inhibited the expression of antioxidant protein HO-1.Also,icariside?increased the accumulation of ROS in the cells and lead to the loss of mitochondrial membrane potential,which eventually leads to the death of the hepatoma cells.The above research on the anti-tumor activity and mechanism of icariside?in vivo has explored the development of a new natural small molecule anticancer drug and provided a basis for clinical research of Epimedium brevicornu Maxim.and its main active components in tumor immunotherapy.