Antioxidant and Antibacterial Activities of Vegetables and Fruits Commonly Consumed in Thailand

Abstract

The vegetables and fruits commonly consumed in Thailand have been suggested as rich sources of beneficial phytochemicals. In this study, vegetables and fruits native to the Northeast region of Thailand were evaluated for antioxidant and antibacterial activities. For vegetables, the extracts of Limnophila aromatica (Lamk.) Merr. (extracted by 80% ethanol) and Sauropus androgynus (Linn.) Merr. (extracted by distilled water) were found to have significant levels of antioxidant activities measured by DPPH scavenging (IC5o at 4.92+/-0.01 and 4.71+/-0.01 mg mL-1, respectively) and FRAP antioxidant assays (74.38+/-0.25 and 74.00+/-0.04 mmol FeSO4 g-' of dry weight of vegetable, respectively) and also total phenolic compounds (10.96+/-0.02 and 10.34+/-0.01 mg gallic acid eq g-1 of dry weight of vegetable). For fruits, the extracts derived from Terminalia chebula Retz. when using distilled water and 80% ethanol as solvents were shown to have significantly high levels of DPPH scavenging (IC50 at 3.73+/-0.01 and 3.81+/-0.01 mg mL-1, respectively), FRAP antioxidant activities (80.85+/-0.10 and 65.93+/-0.11 mmol FeSO4 g-1of dry weight of fruit, respectively) and total phenolic compounds (13.10+/-0.06 and 10.66+/-0.02 mg gallic acid eq g-1 of dry weight of fruit, respectively). The antibacterial assays showed that Moringa oleifera Lam., Limnophila aromatica (Lamk.) Merr., Terminalia chebula Retz. and Phyllanthus emblica Linn. that were extracted using 80% ethanol as solvent were found to have antibacterial activities against Staphylococcus aureus, Straphylococcus epidermidis, Streptococcus pyogenes and Propionibacterium acnes. The results in this study may be useful for future application of edible plants that are native to Thailand to be used as cosmetic or therapqutic products.