The Anticancer Effect Of Ursolic Acid And Its Mechanism

Ursolic acid (UA), one of pentacyclic triterpene acids, is ubiquitous in the plant kingdom. Previous studies have shown that ursolic acid acts as an antitumor promoter and inhibits angiogenesis. Ursolic acid also induces differentiation of mouse M, myeloid leukemia and mouse F₉ teratocarcinoma stem cells. However, the mechanisms of anticancer activity of ursolic acid is poorly understood at present. The purpose of this thesis is to make it clear whether ursolic acid effects on proliferation, differentiation, apoptosis and immuno-response or not. The main results of our studies are summarized as follows:1. The anti-proliferative effects of UA on seven cultured cancer cell lines were examined by MTT assay. The cytotoxicity of ursolic acid on the above mentioned cell lines was dependent upon concentration.2. The effect of UA on the induction of differentiation of HL-60 cells was evaluated by NBT reductant ability. HL-60 cells that were treated with 10^-6 mol/L of retinoic acid for 5 days can acquire NBT reductant ability, but those treated with 10^-8 10^-5 mol/L of ursolic acid can't. These results suggest that UA can't induce the differentiation of HL-60 cells.3. When HL-60 cells were exposed to 10^-5 mol/L of ursolic acid for 4 days, a typical "Ladder" pattern fragmentation indicating presence of DNA equivalent to...