Pharmacodynamics And Mechanism Of Anti-gastric Cancer BGC823 Model By Polyphylloside

【Objective】Observe the Acute toxicity and anti-tumor effect of polyphylloside (DRG) and explore its anti-tumor mechanism to study the feasibility of its treatment for gastric cancer.【Methods】①Acute toxicity experiment: use 0.5% sodium carboxymethyl cellulose (CMC-Na) as the solvent to dissolve DRG, design a certain experiment dose for ICR mice and observe its survival situation, use Sun Karber method to calculate the half lethal dose of DRG(LD₅₀).â‘¡Study on anti-BGC823 gastric cancer model of DRG: 40BALB/C nude mice , inject 0.5ml(about containing 7.5×10⁶cells) of well prepared human gastric cancer cell lines (BGC823) cell suspension into the subcutaneous of the left hypochondrium of each mouse in the third day. Divide the BALB/C mice being inoculated with cells into high, medium, low group according to DRG dose,cyclophospha mide (CTX) group and negative control group at 8 mice of each group and administrate them drug from the fourth day of cells being inoculated. High medium and low dose group were dosed DRG LD50/10 (250mg/kg), LD50/20 (125mg/kg), LD₅₀/40 (62.5mg/kg), with the solvent of 0.5% CMC-Na and drug concentration of 10mg/ml, 5mg/ml, 2.5mg/ml respectively. They were dosed with the same volume of 0.25ml/10g for consecutive 13 days; CTX group were conducted intraperitoneal of CTX20mg/kg per day;negative control group were conducted by gavage with a volume of 0.25ml/10g of salinewater containing 0.5% CMC-Na for consecutive 13 days. Execute all mice after 24 hours from the ultimate gavage. Weigh the mice of each group once every other day from the gavage and measure the length of tumor diameter with a vernier from the tumor formation(about the fourth day) and calculate the volume of the tumor. Peel the tumor tissue and spleen to calculate tumor inhibition rate, spleen index after mice execution. Fix tissue immediately with 10% formaldehyde solution, the pathological, immunohistochemical detection of Bcl-2, Bax, VEGF protein.【Consequences】①Acute toxicity experiment: Calculated through the karber method, the LD₅₀ of DRG is 2471mg/kg, the confidence limit for DRG 95% is 2291mg/kg-2630mg/kg.â‘¡observation for inhibitory rate of DRG of nude mice bearing human gastric: After 13 days of continuous administration for the mice of tumor-bearing, execute the mice in the fourteenth day , then peel and weigh their tumor tissue to get the conclusion that the average tumor weight of Negative group was 1.2525±0.4521g, DRG low, medium and high dose group was: 0.9688±0.4458g, 0.4843±0.1770g, 0.2100±0.1371g, respectively, CTX group was: 0.3750±0.2395 g. The inhibition rate of DRG low, medium and high dose group was 22.65%, 61.33%, 83.23% respectively, CTX group was 70.06%. According to statistical analysis, tumor weight of medium, high dose group and CTX group obviously went down (P＜0.01) compared with that of negative group, furthermore there was apparent tumor weight difference(P＜0.01) among the high dose group of the DRG.â‘¢DRG of human gastric cancer nude mouse spleen index observations: The continuous administration of tumor-bearing mice 13 days later, the mice were killed 14 days to divest spleen weighing, according to the formula to calculate the spleen index. Negative group the average spleen index for 6.8311±1.3965mg/g, DRG low, medium and high dose group the average spleen index were: 6.4510±1.6828 mg/g, 4.8393±0.8049 mg/g, 4.1178±1.3365 mg/g, CTX average spleen index for 6.0721±0.9579 mg/g. Spleen index and negative group comparison, DRG, the high dose group spleen index decreased significantly (P＜0.01).â‘£Observation for protein Bcl-2 expression of DRG of gastric cancer in nude mice bearing human tumor: select two slices randomly in each group and observe 5 visions In each slice totally of 10 and calculate the expression rate of positive cells to get the conclusion that the positive rate of negative tumor cells' expression for protein Bcl-2 was 62.0%±11.69%, while that of DRG low, medium and high dose group was 55.6%±9.57%, 11.4%±4.27 %, 9.0%±2.67%, CTX group was 10.2±3.22%. The positive rate of tumor cells' expression for Bcl-2 protein in the high dose group of DRG and CTX group obviously went down compared with that of negative group. (P＜0.01).⑤Observation for protein Bax expression of DRG of gastric cancer in nude mice bearing human tumor: select two slices randomly in each group and observe 5 visions In each slice totally of 10 and calculate the expression rate of positive cells to get the conclusion that the positive rate of negative tumor cells' expression for protein Bax was 10.7%±2.83%, while that of DRG low, medium and high dose group was 10.4%±3.66%, 52.0%±7.86%, 59.4%±12.05% respectively, CTX group was 58.7%±10.12% .The positive rate of tumor cells' expression for protein Bax in the high dose group of DRG and CTX group apparently went down compared with that of negative group. (P＜0.01).â‘¥Observation for protein VEGF expression of DRG of gastric cancer in nude mice bearing human tumor: select two slices randomly in each group and observe 5 visions In each slice totally of 10 and calculate the expression rate of positive cells to get the conclusion that the positive rate of negative tumor cells' expression for protein VEGF was 49.5%±9.06%, while that of DRG low, medium and high dose group was 46.2%±9.02%, 18.9%±6.03%, 12.1%±4.15% respectively, CTX group was 13.2%±4.76%.The positive rate of tumor cells' expression for protein VEGF in the high dose group of DRG and CTX group apparently went down compared with that of negative group. (P＜0.01),furthermore, there was obvious difference in the protein VEGF expression of high dose group(P＜0.01).【Conclusion】①The experiment results of acute toxicity show that the oral administration of DRG belongs to low toxic compound, its LD50＝2471mg/kg, confidence limit of 95% is 2291mg/kg-2630mg/kg.â‘¡DRG has obvious anti-tumor activity in vivo, can inhibit human gastric cancer through the growth of the tumor transplanted in the nude mice to a certain extent, and have the dose-response relationship, The inhibition rate of 250mg/kg dose group reached 83.23%.â‘¢DRG can reduce the spleen index nude mice, it is speculated to have a certain toxicity to immune organ,but at the same time can also be guessed to be used in Splenomegaly of malignant diseases such as chronic myeloid leukemia, malignant histiocytosis, etc., which can be studied further.â‘£DRG can induce the protein Bcl-2 expression decrease and the protein Bax increase to promote tumor cell apoptosis and exert anti-tumor effect.⑤DRG's exertion of antitumor effects may have something to do with its interdiction and the protein VEGF expression of tumor tissue.