Abstract:
Many local vegetables in Thailand contain high capacity in scavenging of reactive oxygen species and the local people in Nan province still consume these local vegetables. This study was aimed to evaluate reactive oxygen species scavenging activities in some local edible plants in Nan province. The top ten high DPPH scavenging activity plants were selected from twenty local edible plants screened and further analyzed for other characters related to reactive oxygen species scavenging, including the contents of phenolic compounds, flavonoid, ascorbic acid, α-tocopherol and antioxidant enzymes. The results showed that the highest DPPH scavenging activity was found in Caesalpinia mimosoides and Bouea macrophylla, respectively. Furthermore, Caesalpinia mimosoides contained high phenolic compounds while Bouea macrophylla not only had high phenolic compounds but also high superoxide anion (O₂¯) and hydrogen peroxide (H₂O₂) scavenging activities. Colubrina asiatica also had high phenolic compounds and flavonoid content. Coleus amboinicus had high O₂¯ scavenging activity, phenolic compounds, ascorbate peroxidase and superoxide dismutase activities. The highest amount of ascorbic acid was found in Dregea volubilis. In addition, the highest α-tocopherol was found in Solanum spirale and Antidesma ghaesembilla, respectively. Moreover, Antidesma ghaesembilla had high catalase, ascorbate peroxidase and superoxide dismutase activities. Furthermore, Solanum spirale had high singlet oxygen (¹O₂) scavenging activity. Erythropalum scandens contained the highest glutathione reductase among selected plants. The result showed that a most local plants had higher reactive oxygen species scavenging activity than economical plants. Therefore, the local plants in Nan province can be considered as a major food source with high capacity in reactive oxygen species scavenging