Table 1.
Total phenolic (TPC) and total flavonoid (TFC) contents, xanthine oxidase (XO) inhibition, superoxide (O2•−) quenching, metal chelating capacity (MCC), proteinase (PTA) and lipoxygenase (15-LOX) inhibitory activities of Tamanu oil (TO), its de-resinated lipid fraction (DTO), methanolic (MeTO and MeETR) and ethanolic (EtTO) extracts and neutral (NTR) and acidic (ATR) subfractions of EtTO.
| Compound | TPC a | TFC b | XO Inhibition | O2•− Quenching | MCC | PTA Inhibition d | 15-LOX Inhibition e |
|---|---|---|---|---|---|---|---|
| (mg GAE/g) | (mg RUE/g) | IC50 c (µg/mL) | IC50 (µg/mL) | (µmol EDTAE/g) | (%) | (%) | |
| Oils and fractions | |||||||
| Tamanu oil (TO) | 14 ± 2 | 3.8 ± 0.5 | 951 ± 6 | 565 ± 6 | 21 ± 1 | 10 ± 1 | 12 ± 1 |
| Sesame oil | 12 ± 1 | 1.5 ± 0.4 | 831 ± 4 | 469 ± 5 | 20 ± 2 | 12 ± 1 | 13 ± 3 |
| DTO | ~0 | ~0 | >1000 | >1000 | ~0 | ~0 | ~0 |
| MeTO | 44 ± 3 * | 15.4 ± 0.7 *# | 152 ± 2 *# | 22.1 ± 0.5 *# | 31 ± 3.1 *# | 31 ± 2 *# | 25 ± 2 *# |
| EtTO | 51 ± 2 * | 19.4 ± 0.2 * | 102 ± 1 * | 18.0 ± 0.1 * | 45 ± 2 * | 62 ± 4 * | 31 ± 2 * |
| MeETR | 35 ± 2 * | 10.9 ± 0.8 * | 152 ± 2 *# | 25.1 ± 0.5 *# | 30 ± 3 *# | 29 ± 4 *# | 19 ± 1 *# |
| NTR | 79 ± 2 *# | 22.3 ± 0.3 * | 93 ± 2 *# | 20.7 ± 1.1 * | 95 ± 4 *# | 72 ± 5 *# | 45 ± 2 *# |
| ATR | 57 ± 2 *# | 34.9 ± 0.4 *# | 71 ± 6 *# | 17.7 ± 0.1 * | 83 ± 5 *# | 69 ± 3 *# | 60 ± 4 *# |
| Fraction P f | – | – | 120 ± 8 * | 14.1 ± 0.2 *# | 34 ± 2 *# | 65 ± 4 * | 56 ± 2 *# |
| Standard phenolic and flavonoid compounds | |||||||
| Caffeic acid | – | – | 39.5 ± 2.1 | 0.013 ± 0.06 | 125± 5 | – | 45 ± 1 |
| Gallic acid | – | – | 41.1 ± 1.2 | 0.022 ± 0.01 | 90 ± 3 | – | 28 ± 2 |
| Quercetin | – | – | 1.52 ± 0.12 | 0.083 ± 0.06 | 105 ± 3 | – | 83 ± 2 |
| Allopurinol | – | – | 0.13 ± 0.01 | – | – | – | – |
| Diclofenac | – | – | – | – | – | 64 ± 2 | – |
Data represent means ± SEM of 3–6 independent experiments performed in triplicate. a Values are expressed as mg of gallic acid equivalent (GAE) per gram of extract. b RUE, rutin equivalent. c IC50 = concentration resulting in a 50% decrease in initial activity or concentration. d Percentage values are indicated for compounds at 150 µg/mL. e Percent inhibition values are indicated for compounds at 100 µg/mL. f Fraction P composition: inophyllum P (70%), tamanolide P (20%) and calanolide B (10%). Statistics: * p < 0.05 vs. TO and # p < 0.05 vs. EtTO, by one-way ANOVA followed by Newman-Keuls test.