Table 1.
The effects of tocotrienol on OA.
| Researchers | Study Design | Findings |
|---|---|---|
| Pang et al. (2021) [49] | Disease model: SW1353 chondrocytes challenged with MIA Treatment: annatto tocotrienol (10–20 μg/mL) or palm tocotrienol (25–50 μg/mL) for 24 h before or concurrent with MIA |
Cell viability: |
| Pre-treatment | ||
| Decreased upon receiving annatto tocotrienol (≥20 μg/mL) & palm tocotrienol (≥12.5 μg/mL) → no subsequent test | ||
| Concurrent treatment | ||
| Increased upon receiving annatto tocotrienol (10 and 20 μg/mL)/palm tocotrienol (3.125, 25 and 50 μg/mL) | ||
| 8-Isoprostane F2-α Level: | ||
| Decreased upon receiving palm tocotrienol (50 μg/mL) or annatto tocotrienol (10 and 20 μg/mL) in the presence of MIA | ||
| Collagen I type α1: Decreased in MIA group, not affected by treatment | ||
| Collagen II type α1: Increased upon receiving annatto tocotrienol (10 & 20 μg/mL) in the presence of MIA vs MIA alone or annatto tocotrienol alone | ||
| Collagen II type α1/Collagen I type α1: Increased upon receiving MIA + treatment vs treatment alone. | ||
| Increased upon receiving annatto tocotrienol alone (10 and 20 μg/mL) vs. MIA alone | ||
| Aggrecan and sex-determining region Y box protein 9: | ||
| Increased upon receiving MIA + annatto tocotrienol (10 and 20 μg/mL) vs. MIA alone | ||
| ADAMTS4: Decreased in MIA group, not affected by treatment | ||
| Chin et al. (2019) [48] | Animals: Male Sprague-Dawley rats (3 months old) Disease model: Intra-articular MIA injection at the right knee Treatment: annatto tocotrienol at the dose of 50, 100, 150 mg/kg/day, oral for 4 weeks Normal and OA control were given refined olive oil (vehicle in the study) |
Body weight: |
| Increased in all groups from week 1–week 4 | ||
| Histological scoring: | ||
| Decreased in all aspects for 100 mg/kg/day annatto tocotrienol vs OA control | ||
| Decreased in the number of inflammatory cells and synovial hyperplasia for 100 mg/kg/day vs 50 mg/kg/day annatto tocotrienol groups | ||
| Reduced synovial hyperplasia and erosions in 150 mg/kg/day annatto tocotrienol group vs OA control | ||
| No significant improvement in 50 mg/kg/day annatto tocotrienol group | ||
| Serum COMP: | ||
| Decreased in 50, 100 & 150 mg/kg/day annatto tocotrienol group vs OA control | ||
| Decreased in 100 & 150 mg/kg/day T vs 50 mg/kg/day annatto tocotrienol | ||
| Serum hyaluronic acid: | ||
| Decreased in 50, 100 & 150 mg/kg/day annatto tocotrienol group vs OA control | ||
| Subchondral osteoclast number: | ||
| Decreased in 150 mg/kg/day annatto tocotrienol group vs OA control | ||
| Serum osteocalcin: | ||
| Increased in 50 mg/kg/day annatto tocotrienol group vs OA control. | ||
| Decreased in 100 & 150 mg/kg/day annatto tocotrienol group vs 50 mg/kg/day annatto tocotrienol | ||
| Decreased in 150 mg/kg/day annatto tocotrienol group vs all other groups except normal group | ||
| Serum C-telopeptide of crosslinked collagen type I: | ||
| No significant effect | ||
| Al-Saadi et al. (2021) [47] | Animals: Male Sprague-Dawley rats (3 months old) Disease model: Intra-articular MIA injection at the right knee Treatment: palm tocotrienol treated (100 mg/kg/day; oral) Glucosamine sulphate treated (250 mg/kg/day; oral) palm tocotrienol (100 mg/kg/day) + glucosamine sulphate-treated group (250 mg/kg/day) (oral) Normal and OA control were given refined olive oil (vehicle in the study) Treatment period; 4 weeks |
Grip strength: |
| No significant change between normal control, OA control & palm tocotrienol between week 0–week 4. | ||
| Increased in palm tocotrienol + glucosamine sulphate group vs sham & palm tocotrienol group from week 1–week 3. | ||
| Increased in glucosamine sulphate group in week 4 vs week 1. | ||
| Increased in palm tocotrienol + glucosamine sulphate group in week 4 vs week 1–3. | ||
| Body weight: | ||
| Increased in normal control vs OA control, palm tocotrienol & palm tocotrienol + glucosamine sulphate groups at week 1. | ||
| Increased in palm tocotrienol, glucosamine sulphate and combination group vs OA control at week 3. | ||
| Cartilage histology (Mankin’s score): | ||
| No significant change between OA control, palm tocotrienol, glucosamine sulphate and combination group. | ||
| Serum COMP: | ||
| Increased in OA control vs palm tocotrienol, glucosamine sulphate and combination group. | ||
| No significant change between treated group. | ||
| Haflah et al. (2009) [46] | Subjects: 79 patients with knee OA (Kellgren-Lawrence score of 2 and 3) aged over 40 years Treatment: Oral palm tocotrienol (400 mg daily) for 6 months Positive control: Glucosamine sulphate (500 mg thrice daily) for 6 months Notes: Patients were not allowed to take any other analgesics |
Visual analogue scale: |
| Standing & walking | ||
| Decreased in palm tocotrienol & glucosamine sulphate | ||
| WOMAC score: | ||
| Decreased in palm tocotrienol & glucosamine sulphate | ||
| Serum malondialdehyde: | ||
| Decreased in palm tocotrienol vs glucosamine sulphate | ||
| Serum vitamin E: | ||
| Increased in palm tocotrienol vs glucosamine sulphate |
Abbreviations: ADAMTS4, a disintegrin and metalloproteinase with thrombospondin motifs 4; COMP, circulating cartilage oligomeric matrix protein; MIA, monosodium iodoacetate; WOMAC, Western Ontario and McMaster Universities’ OA index.