Characterisation and biological activities of proanthocyanidins from the barks of Pinus massonian and Acacia mearnsii

Abstract

The biological activities and characterisation of proanthocyanidins (PAs) from the barks of Pinus massonian and Acacia mearnsii have been studied in our research. The free-radical scavenging activity of the PAs was measured by means of the DPPH method, and it was clear that the PA product had a strong radical scavenging ability. Furthermore, anti-tumour activities of PAs on different human cancer cells were investigated. The results indicated that PAs from the bark of A. mearnsii had better anti-tumour activities than those from the bark of P. massonian, and the PAs extracted from the ethyl acetate fraction had better anti-tumour activities than those from the water fraction. PAs from the bark of A. mearnsii in an ethyl acetate fraction (PAE) had an effective inhibition on human mammary cancer cells (MDA- MB-231) and human liver cancer cells (BEL-7402), a weak effect on human cervical cancer cells (Hela), but no effect on human lung cancer cells (A549); while the PAs from the bark of A. mearnsii in a water fraction (PAW) had weak effect on MDA- MB-231, Hela and A549, but no effect on BEL-7402. PAs from the bark of P. massonian in ethyl acetate fraction (PPE) had weak effect on Hela and BEL-7402; whereas the PAs from the bark of P. massonian in a water fraction (PPW) had a weak effect on Hela, but no effect on the other cells. PAs were characterised by HPLC- ESI-MS analysis and the PA dimers and trimers were identified, respectively.