关键词: 黑荆树树皮, 原花色素, 抗肿瘤, 清除自由基

Abstract: The extraction conditions of proanthocyanidins from bark of black wattle (Acacia mearnsii De Wilde) and their biological activities were investigated in this study. Different types of solvents such as water, methanol and ethanol were used as extraction solvent, respectively. Experiments were conducted to study the effects of temperature, liquid-solid ratio and concentration of ethanol on the extraction efficiency. The focus of this study is to evaluate the biological activities of the extracted proanthocyanidins products. The anti-tumor activity of proanthocyanidins was determined by MTT colorimetric method, and DPPH method referred to the radical scavenging capacity was used to test the anti-oxidation ability of the proanthocyanidins. The results showed that black wattle bark is rich in proanthocyanidins. Ethanol was considered to be a suitable solvent, in which there was higher extract yield and stronger biological activities of proanthocyanidins. It was found that the optimum conditions of extraction were as follows: concentration of ethanol 70, temperature 60℃,and the ratio of solution to solid 7:1. Furthermore, the results of anti-tumor test of proanthocyanidins crude products on human cancer cells cultured in vitro showed that the proanthocyanidins had medium effect on promyelocytic cell line HL-60, weak effect on human stomach adenocarcinoma BGC-823 and human hepatocellular carcianoma BEL-7402. Meanwhile, the results of radical scavenging ability assay indicated that the proanthocyanidins had strong anti-oxidation activity.

Key words: black wattle bark, proanthocyanidins, anti-tumor, radical scavenging