A randomized, double-blind, prospective, placebo-controlled study of the efficacy of a diet supplemented with curcuminoids extract, hydrolyzed collagen and green tea extract in owner's dogs with osteoarthritis.

BACKGROUND: We have previously demonstrated that a mixture of Curcuminoids extract, hydrolyzed COllagen and green Tea extract (CCOT) inhibited inflammatory and catabolic mediator's synthesis by bovine and human chondrocytes. A randomly allocated, double-blind, prospective, placebo-controlled study was performed to evaluate the efficacy of a diet containing this CCOT mixture on dogs with naturally occurring osteoarthritis (OA). Therefore, 42 owner's dogs with OA were randomly assigned to receive for 3 months an experimental diet (control) or the same diet supplemented with CCOT. RESULTS: Ground reaction forces did not show statistical differences between groups. After 3 months of feeding, there was a significant reduction of pain at manipulation in the CCOT group, but not in the control group. The evolution for pain at manipulation depended on the diet. The three other parameters evaluated by veterinary subjective assessment (lameness, pain at palpation and joint mobility) did not show statistical differences. Concerning owner subjective assessment, pain severity score worsened in the control group but remained stable in CCOT group. The evolution for pain severity depended on the diet. No statistical difference was found for pain interference, except for the ability to rise to standing from lying down, which was significantly improved in the CCOT compared to the control group. Serum OA biomarkers did not show statistical differences. CONCLUSIONS: Objective variables measured, such as ground reaction forces and OA biomarkers, did not show statistical differences. However, indicators of pain appeared reduced in dogs receiving CCOT mixture for 3 months. The difference of evolution between groups suggests that a greater number of dogs may be necessary to reach a stronger effect on other parameters.

Identification of Targets of a New Nutritional Mixture for Osteoarthritis Management Composed by Curcuminoids Extract, Hydrolyzed Collagen and Green Tea Extract.

OBJECTIVE: We have previously demonstrated that a mixture of curcuminoids extract, hydrolyzed collagen and green tea extract (COT) inhibited inflammatory and catabolic mediator's synthesis by osteoarthritic human chondrocytes. The objective of this study was to identify new targets of COT using genomic and proteomic approaches. DESIGN: Cartilage specimens were obtained from 12 patients with knee osteoarthritis. Primary human chondrocytes were cultured in monolayer until confluence and then incubated for 24 or 48 hours in the absence or in the presence of human interleukin(IL)-1ß (10-11M) and with or without COT, each compound at the concentration of 4 µg/ml. Microarray gene expression profiling between control, COT, IL-1ß and COT IL-1ß conditions was performed. Immunoassays were used to confirm the effect of COT at the protein level. RESULTS: More than 4000 genes were differentially expressed between conditions. The key regulated pathways were related to inflammation, cartilage metabolism and angiogenesis. The IL-1ß stimulated chemokine ligand 6, matrix metalloproteinase-13, bone morphogenetic protein-2 and stanniocalcin1 gene expressions and protein productions were down-regulated by COT. COT significantly decreased stanniocalcin1 production in basal condition. Serpin E1 gene expression and protein production were down-regulated by IL-1ß. COT reversed the inhibitory effect of IL-1ß. Serpin E1 gene expression was up-regulated by COT in control condition. CONCLUSION: The COT mixture has beneficial effect on osteoarthritis physiopathology by regulating the synthesis of key catabolic, inflammatory and angiogenesis factors. These findings give a scientific rationale for the use of these natural ingredients in the management of osteoarthritis.

Curcuminoids extract, hydrolyzed collagen and green tea extract synergically inhibit inflammatory and catabolic mediator's synthesis by normal bovine and osteoarthritic human chondrocytes in monolayer.

The main objective of this study was to assess the in vitro effects of curcuminoids extract, hydrolyzed collagen and green tea extract in normal bovine chondrocytes and osteoarthritic human chondrocytes cultured in monolayer. This study also investigated the synergic or additive effects of these compounds. Enzymatically isolated primary bovine or human chondrocytes were cultured in monolayer until confluence and then incubated for 24 hours or 48 hours in the absence or in the presence of interleukin-1ß and with or without curcuminoids extract, hydrolyzed collagen or green tea extract, added alone or in combination, at different concentrations. Cell viability was neither affected by these compounds, nor by interleukin 1ß. In the absence of interleukin-1ß, compounds did not significantly affect bovine chondrocytes metabolism. In human chondrocytes and in the absence of interleukin 1ß, curcuminoids extract alone or in combination with hydrolyzed collagen and green tea extract significantly inhibited matrix metalloproteinase-3 production. In interleukin-1ß-stimulated bovine chondrocytes, interleukin-6, inducible nitric oxide synthase, cyclooxygenase2, matrix metalloproteinase 3, a disintegrin and metalloproteinase with thrombospondin type I motifs 4 and a disintegrin and metalloproteinase with thrombospondin type I motifs 5 expressions were decreased by curcuminoids extract alone or in combination with hydrolyzed collagen and green tea extract. The combination of the three compounds was significantly more efficient to inhibit interleukin-1ß stimulated matrix metalloproteinase-3 expression than curcuminoids extract alone. In interleukin-1ß-stimulated human chondrocytes, nitric oxide, interleukin-6 and matrix metalloproteinase 3 productions were significantly reduced by curcuminoids extract alone or in combination with hydrolyzed collagen and green tea extract. These findings indicate that a mixture of curcuminoids extract, hydrolyzed collagen and green tea extract has beneficial effects on chondrocytes culture in inflammatory conditions and provide a preclinical basis for the in vivo testing of this mixture.