Abstract
We screened ethanol extracts from a total of 134 species of edible Thai plants for their suppressive effects on superoxide (O2-) generation using a xanthine (XA)-xanthine oxidase (XOD) assay system. When the extracts were tested at a concentration of 500 μg/ml, 28.4% significantly suppressed O2- generation. Of these active extracts, it was found that in 17.9% of cases the action was due to XOD inhibition, in 1.5% due to O2- scavenging activity, and in 9% due to both XOD inhibition and O2- scavenging. In addition, some plant extracts (25 species) which had been known to possibly possess anti-tumor promoting activity were tested for O2- and NO generation in cellular systems. In this test, 13 species exhibited strong inhibitory activity toward both O2- and NO generation. From the fruit pods of Oroxylum indicum (Bignoniaceae), a traditional vegetable in Thailand, two flavones, oroxylin A and chrysin, and a triterpene carboxylic acid, ursolic acid (UA), were identified as inhibitors of O2- generation in XA/XOD system. These compounds also showed marked inhibitory effects on the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced O2- generation in dimethylsulfoxide (DMSO)-differentiated HL-60 cells. Our results suggest that, as we have reported earlier, edible Thai plants are promising sources of antioxidants with chemopreventive potential.
Original language | English (US) |
---|---|
Pages (from-to) | 215-223 |
Number of pages | 9 |
Journal | Asian Pacific Journal of Cancer Prevention |
Volume | 3 |
Issue number | 3 |
State | Published - 2002 |
Externally published | Yes |
Keywords
- Anti-oxidation
- Chrysin
- Oroxylin A
- Oroxylum indicum
- Thai plants
- Ursolic acid
ASJC Scopus subject areas
- Epidemiology
- Oncology
- Public Health, Environmental and Occupational Health
- Cancer Research