Antioxidant, immunomodulatory and anti-breast cancer activities of phenolic extract from pine (Pinus massoniana Lamb) bark

In the present study, the antioxidant activities of phenolic extract from pine (Pinus massoinana Lamb) bark (PEPB) were investigated, employing five in vitro established systems which included the total antioxidant activity in ferric thiocyanate (FTC) system, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, reducing power, metal chelating ability and nitric-oxide radical scavenging activity. The effects of PEPB on in vitro proliferation trials of mouse splenocytes, human breast cancer cell MCF-7 and human embryonic lung fibroblast (HELF), were also evaluated. It was found that PEPB had stronger antioxidant activities to inhibit the oxidation of linoleic-acid in the FTC system than the standards, vitamin E and C. PEPB had the highest inhibition (90.38%), followed by vitamin E (88.61%) and C (85.68%) at 100 mu g/ml in the FTC system. Furthermore, PEPB showed strong DPPH radical scavenging activity, reducing power, nitric-oxide scavenging activity and ferrous-ion chelating ability. These data suggested that PEPB could be a potential source of natural antioxidant. On the other hand, PEPB significantly stimulated in vitro proliferation of mouse splenocytes in a dose-dependent manner within the testing range from 32.5 to 500 mu g/ml. Furthermore, the results showed that PEPB could inhibit the growth of human breast cancer cell MCF-7 in the range of 32.5-125 mu g/ml in terms of in vitro proliferation trials of human breast cancer cell MCF-7 and HELF, which had a lower toxicity to HELF than paclitaxel. (C) 2007 Elsevier Ltd. All rights reserved.