Antioxidant/anti-inflammatory activities and total phenolic content of extracts obtained from plants grown in Vietnam

BACKGROUND: Medicinal plants have been used to treat various diseases since ancient times. Their specific activities, such as antioxidant, anti-inflammatory and anti-cancer, have been studied intensively. In particular, plants grown in Vietnam have attracted considerable attention among food chemists as ideal sources of natural medicinal chemicals. RESULTS: The methanol extracts from three edible Vietnamese-grown plants, Tram, Voi and Gac, tested with the DPPH assay showed antioxidant activities of 91.7 +/- 0.4, 63.4 +/- 0.7 and 3.7 +/- 0.1% respectively. The malonaldehyde/gas chromatography assay also revealed strong antioxidant activity in Tram and Voi at a level of 25 mu g mL(-1) (95.5 +/- 0.3 and 78.5 +/- 1.4% respectively). These results were confirmed by the thiobarbituric acid assay. The antioxidant activities correlated positively with the level of total phenolics in all plants. Tram exhibited dose response-related lipoxygenase-inhibitory activity, with values of 74.2 +/- 3.1% at 5 mu gm L-1, 62.0 +/- 0% at 0.5 mu g mL(-1) and 3.0 +/- 1.5% at 0.05 mu g mL(-1). Conversely, Voi and Gac showed negative anti-lipoxygenase activity. CONCLUSION: The antioxidant/ anti-inflammatory activities and total phenolic contents of the three edible plants grown in Vietnam revealed that they are good sources of supplements for human health. (C) 2011 Society of Chemical Industry