Study On The Anti-tumor Effects And Its Mechanism Of Ampelopsin Sodium Combined With Carboplatin On Lewis Cell In Vitro And Vivo

Objective:To study the anti-tumor effects and its mechanism.of ampelopsin sodium (Amp-Na) alone or in combination with carboplatin on mouse Lewis lung cancer cells in vivo and in vitroMethods:1. The cytotoxic effects of Amp-Na alone or in combination with carboplatin were examined by MTT colorimetric assay.2. The apoptosis and the expression of Caspase-3, Bax and Bcl-2 were surveyed by the flow cytometer assay.3. The anti-tumor effects of AMP-Na alone or in combination with carboplatin on mouse Lewis lung cancer in tumor-bearing C57BL/6 mice were observed.Results:1. Proliferation of mouse Lewis lung cancer cells was inhibited by AMP-Na alone in a concentration-dependent manner ranging from 12.5-200μg/ml, and its IC₅₀ is 63.1μg/ml.Combined with carboplatin, AMP-Na 6.25,12.5,25 and 50μg/ml had synergistic inhibitory effect on the proliferation of Lewis cells , and its CDI was less than one.2. The apoptotic ratio in cells treated with AMP-Na (12.5, 25, 50 and 100μg/ml) after 48h (3.91%±4.58%,4.77%±1.59%,3.80%±0.15% and 13.37%±5.76%,respectively) was higher than that of control (2.66%±2.52%). The apoptotic ratio in those treated with carboplatin (25μg/ml) combined with AMP-Na (12.5,25,50 and 100μg/ml) after 48 h (20.00%±3.54%,33.85%±0.21%,34.13%±3.91% and 26.57%±3.48%,respectively) was significant higher than that of control, among which, the apoptotic ratio of combination groups with AMP-Na (25,50,100μg/ml) was significant higher than carboplatin group (7.55%±3.56%)(P＜0.01).3. The ratio of Bcl-2/Bax was decreased significantly in Lewis cells treated with AMP-Na (12.5, 25, 50,100μg/ml) or in combination with carboplatin (25μg/ml) 48 h.4. The expression of Caspase-3 in cells treated with AMP-Na (25,50 and 100μg/ml) after 12 h was increased significantly and higher than that of control, (P＜0.05); The expression of Caspase-3 in those treated with carboplatin (12.5μg/ml) combined with AMP-Na (25,50 and 100μg/ml) after 12 h was significant higher than carboplatin group(12.5μg/ml) (P＜0.01).5. The anti-tumor effects of AMP-Na alone almost had not been observed after administered alone in tumor-bearing mice, however, the anti-tumor effects of AMP-Na in combination with carboplatin were potent on mouse Lewis lung cancer in C57BL/6 mice (P＜0.01).Conclusions:1. AMP-Na decreases Lewis cells survival rate in a concentration-dependent manner; Combined with carboplatin, AMP-Na has synergistic inhibitory effect on the proliferation of Lewis cells.2. There is a significant synergistic action of inducing apoptosis of Lewis cells treated with AMP-Na (25-100μg/ml) in combination with carboplatin.3. The apoptosis inducing effect is partially mediated by Bcl-2/Bax in Lewis cells treated with Amp-Na alone or in combination with carboplatin.4. One of the mechanisms to induce apoptosis by AMP-Na is probably that activation of Caspase-3 mediated signal transduction pathway in cells.5. The result of experiment in vivo shows that ampelopsin sodium used alone has not a manifest anti-tumor effect, while combined with carboplatin, it can increase the anti-tumor effects of carboplatin on the transplanted mouse Lewis lung cancer in C57BL/6 mice.