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 µg 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 µg mL(-1) , 62.0 ± 0% at 0.5 µg mL(-1) and 3.0 ± 1.5% at 0.05 µg 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.