Biological activities of procyanidins from the bark of Pinus caribaea Morelet.

The extraction and biological activities of procyanidins from the bark of Pinus caribaea Morelet (P. caribaea) have been studied for the first time in our research. The main factors influencing the extraction, including solvent, temperature and liquid-to-solid (L/S) ratio, were discussed. The results illustrate that the suitable conditions for the extraction of procyanidins from the bark of P. caribaea are as follows: extraction temperature at 50 degrees C, L/S ratio at 11 : 1 and ethanol volume fraction at 70%. The focus of this study is to investigate the biological activities of the procyanidins from the bark of P. caribaea. Free-radical scavenging activity of the procyanidins was measured by means of 2,2-diphenyl-1-picrylhydrazyl (DPPH) method, and it was clear that the procyanidins product had a strong radical scavenging ability. Furthermore, the inhibition effect of the procyanidins from the bark of P. caribaea on different human cancer cells cultured in vitro was investigated. The results indicated that the procyanidins extracted with water had a stronger inhibition on promycelocytic cells HL-60, an effective inhibition on human stomach adenocarcinoma cells BGC-823 and human hepatocellular carcinoma cells BEL-7402, but no effect on human lung carcinoma cells A549, whereas the procyanidins extracted with ethanol had an effective inhibition on HL-60 and BGC-823, but no effect on A549 or BEL-7402.