METHODS: Primary cultures of young, pre-senescent, and senescent fibroblast cells were incubated with γ-tocotrienol for 24 h. The expression levels of ELN, COL1A1, MMP1, CCND1, RB1, and IL6 genes were determined using the quantitative real-time polymerase chain reaction. Cell cycle profiles were determined using a FACSCalibur Flow Cytometer.
RESULTS: The cell cycle was arrested in the G(0)/G(1) phase, and the percentage of cells in S phase decreased with senescence. CCND1, RB1, MMP1, and IL6 were upregulated in senescent fibroblasts. A similar upregulation was not observed in young cells. Incubation with γ-tocotrienol decreased CCND1 and RB1 expression in senescent fibroblasts, decreased cell populations in the G(0)/G(1) phase and increased cell populations in the G(2)/M phase. γ-Tocotrienol treatment also upregulated ELN and COL1A1 and downregulated MMP1 and IL6 expression in young and senescent fibroblasts.
CONCLUSION: γ-Tocotrienol prevented cellular aging in human diploid fibroblasts, which was indicated by the modulation of the cell cycle profile and senescence-associated gene expression.
METHODS: Sprague-Dawley female rats (12 weeks old) were divided randomly into five groups (n = 6): healthy; nontreated OA; OA + diclofenac (5 mg/kg); OA + extract (200 mg/kg); and OA + extract (400 mg/kg). Two weeks after bilaterally ovariectomy, OA was induced by intra-articular injection of monosodium iodoacetate into the right knee joints. After 28 days of treatment, the rats were evaluated for knee OA via physical (radiological and histological observations), biochemical, enzyme-linked immunosorbent assay, and gene expression analysis, for inflammation and cartilage degradation biomarkers.
RESULTS: The osteoarthritic rats treated with the extract, and diclofenac showed significant reduction of cartilage erosion (via radiological, macroscopic, and histological images) compared with untreated osteoarthritic rats. The elevated serum interleukin-1β, prostaglandin E2, and C-telopeptide type II collagen levels in osteoarthritic rats were significantly reduced by F deltoidea leaf extract comparable to diclofenac. The extract significantly down-regulated the interleukin-1β, prostaglandin E2 receptor, and matrix metalloproteinase-1 mRNA expressions in the osteoarthritic cartilages, similar to diclofenac.
CONCLUSIONS: F deltoidea leaf extract mitigated postmenopausal osteoarthritic joint destruction by inhibiting inflammation and cartilage degradation enzymes, at an effective extract dose equivalent to about 60 mg/kg for humans. The main bioactive compounds are probably the antioxidative flavonoids vitexin and isovitexin.