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An exploration of the ability of tepoxalin to ameliorate the degradation of articular cartilage in a canine in vitro model.

Macrory L, Vaughan-Thomas A, Clegg PD, Innes JF - BMC Vet. Res. (2009)

Bottom Line: PGE2 concentration in culture media at day 7 was significantly increased by IL-1beta and OSM and treatment with both tepoxalin and its metabolite showed a trend towards dose-dependent reduction of PGE2 production.Cytotoxicity assays suggested that neither tepoxalin nor its metabolite had a toxic effect on the cartilage chondrocytes at the concentrations and used in this study.We can conclude that, in this model, tepoxalin can partially inhibit the development of cartilage degeneration when it is available locally to the tissue.

View Article: PubMed Central - HTML - PubMed

Affiliation: Musculoskeletal Research Group, Faculty of Veterinary Science, University of Liverpool, Leahurst Campus, Neston, Wirral, CH64 7TE, UK. L.Macrory@liverpool.ac.uk

ABSTRACT

Background: To study the ability of tepoxalin, a dual inhibitor of cyclooxygenase (COX) and lipoxygenase (LOX) and its active metabolite to reduce the catabolic response of cartilage to cytokine stimulation in an in vitro model of canine osteoarthritis (OA).Grossly normal cartilage was collected post-mortem from seven dogs that had no evidence of joint disease. Cartilage explants were cultured in media containing the recombinant canine interleukin-1beta (IL-1beta) at 100 ng/ml and recombinant human oncostatin-M (OSM) at 50 ng/ml. The effects of tepoxalin and its metabolite were studied at three concentrations (1 x 10(-5), 1 x 10(-6) and 1 x 10(-7) M). Total glycosaminoglycan (GAG) and collagen (hydroxyproline) release from cartilage explants were used as outcome measures of proteoglycan and collagen depletion respectively. PGE2 and LTB4 assays were performed to study the effects of the drug on COX and LOX activity.

Results: Treatment with IL-1beta and OSM significantly upregulated both collagen (p = 0.004) and proteoglycan (p = 0.001) release from the explants. Tepoxalin at 10(-5) M and 10(-6) M caused a decrease in collagen release from the explants (p = 0.047 and p = 0.075). Drug treatment showed no effect on GAG release. PGE2 concentration in culture media at day 7 was significantly increased by IL-1beta and OSM and treatment with both tepoxalin and its metabolite showed a trend towards dose-dependent reduction of PGE2 production. LTB4 concentrations were too low to be quantified. Cytotoxicity assays suggested that neither tepoxalin nor its metabolite had a toxic effect on the cartilage chondrocytes at the concentrations and used in this study.

Conclusion: This study provides evidence that tepoxalin exerts inhibition of COX and can reduce in vitro collagen loss from canine cartilage explants at a concentration of 10(-5) M. We can conclude that, in this model, tepoxalin can partially inhibit the development of cartilage degeneration when it is available locally to the tissue.

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Effect of tepoxalin and its metabolite on proteoglycan degradation expressed as an average value from four dogs after 7 days of culture. Explants were cultured in serum free media containing IL-1β (100 ng/ml) and OSM (50 ng/ml) along with tepoxalin (T) or its metabolite (M) at ×10-5, ×10-6 or ×10-7 M concentrations. Proteoglycan release (GAG in medium) is expressed as milligrams of GAG per gram of wet weight of cartilage. Data represents means + standard error, n = 7. P values correspond to comparisons to the positive control.
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Figure 1: Effect of tepoxalin and its metabolite on proteoglycan degradation expressed as an average value from four dogs after 7 days of culture. Explants were cultured in serum free media containing IL-1β (100 ng/ml) and OSM (50 ng/ml) along with tepoxalin (T) or its metabolite (M) at ×10-5, ×10-6 or ×10-7 M concentrations. Proteoglycan release (GAG in medium) is expressed as milligrams of GAG per gram of wet weight of cartilage. Data represents means + standard error, n = 7. P values correspond to comparisons to the positive control.

Mentions: Our previous studies of cultured cartilage explants have shown that treatment with IL-1β and OSM significantly increase proteoglycan degradation after seven days in culture compared with controls [13]. We used this information to determine whether the addition of tepoxalin or it metabolite would influence the amount of proteoglycan released into the culture media. As shown previously, treatment with IL-1β and OSM significantly upregulated proteoglycan degradation by a mean value of 2.7-fold (n = 7, p = 0.001). Treatment with tepoxalin or its metabolite over the concentrations ranges used showed no significant effect on the amount of proteoglycan released from the explants (figure 1).


An exploration of the ability of tepoxalin to ameliorate the degradation of articular cartilage in a canine in vitro model.

Macrory L, Vaughan-Thomas A, Clegg PD, Innes JF - BMC Vet. Res. (2009)

Effect of tepoxalin and its metabolite on proteoglycan degradation expressed as an average value from four dogs after 7 days of culture. Explants were cultured in serum free media containing IL-1β (100 ng/ml) and OSM (50 ng/ml) along with tepoxalin (T) or its metabolite (M) at ×10-5, ×10-6 or ×10-7 M concentrations. Proteoglycan release (GAG in medium) is expressed as milligrams of GAG per gram of wet weight of cartilage. Data represents means + standard error, n = 7. P values correspond to comparisons to the positive control.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2719625&req=5

Figure 1: Effect of tepoxalin and its metabolite on proteoglycan degradation expressed as an average value from four dogs after 7 days of culture. Explants were cultured in serum free media containing IL-1β (100 ng/ml) and OSM (50 ng/ml) along with tepoxalin (T) or its metabolite (M) at ×10-5, ×10-6 or ×10-7 M concentrations. Proteoglycan release (GAG in medium) is expressed as milligrams of GAG per gram of wet weight of cartilage. Data represents means + standard error, n = 7. P values correspond to comparisons to the positive control.
Mentions: Our previous studies of cultured cartilage explants have shown that treatment with IL-1β and OSM significantly increase proteoglycan degradation after seven days in culture compared with controls [13]. We used this information to determine whether the addition of tepoxalin or it metabolite would influence the amount of proteoglycan released into the culture media. As shown previously, treatment with IL-1β and OSM significantly upregulated proteoglycan degradation by a mean value of 2.7-fold (n = 7, p = 0.001). Treatment with tepoxalin or its metabolite over the concentrations ranges used showed no significant effect on the amount of proteoglycan released from the explants (figure 1).

Bottom Line: PGE2 concentration in culture media at day 7 was significantly increased by IL-1beta and OSM and treatment with both tepoxalin and its metabolite showed a trend towards dose-dependent reduction of PGE2 production.Cytotoxicity assays suggested that neither tepoxalin nor its metabolite had a toxic effect on the cartilage chondrocytes at the concentrations and used in this study.We can conclude that, in this model, tepoxalin can partially inhibit the development of cartilage degeneration when it is available locally to the tissue.

View Article: PubMed Central - HTML - PubMed

Affiliation: Musculoskeletal Research Group, Faculty of Veterinary Science, University of Liverpool, Leahurst Campus, Neston, Wirral, CH64 7TE, UK. L.Macrory@liverpool.ac.uk

ABSTRACT

Background: To study the ability of tepoxalin, a dual inhibitor of cyclooxygenase (COX) and lipoxygenase (LOX) and its active metabolite to reduce the catabolic response of cartilage to cytokine stimulation in an in vitro model of canine osteoarthritis (OA).Grossly normal cartilage was collected post-mortem from seven dogs that had no evidence of joint disease. Cartilage explants were cultured in media containing the recombinant canine interleukin-1beta (IL-1beta) at 100 ng/ml and recombinant human oncostatin-M (OSM) at 50 ng/ml. The effects of tepoxalin and its metabolite were studied at three concentrations (1 x 10(-5), 1 x 10(-6) and 1 x 10(-7) M). Total glycosaminoglycan (GAG) and collagen (hydroxyproline) release from cartilage explants were used as outcome measures of proteoglycan and collagen depletion respectively. PGE2 and LTB4 assays were performed to study the effects of the drug on COX and LOX activity.

Results: Treatment with IL-1beta and OSM significantly upregulated both collagen (p = 0.004) and proteoglycan (p = 0.001) release from the explants. Tepoxalin at 10(-5) M and 10(-6) M caused a decrease in collagen release from the explants (p = 0.047 and p = 0.075). Drug treatment showed no effect on GAG release. PGE2 concentration in culture media at day 7 was significantly increased by IL-1beta and OSM and treatment with both tepoxalin and its metabolite showed a trend towards dose-dependent reduction of PGE2 production. LTB4 concentrations were too low to be quantified. Cytotoxicity assays suggested that neither tepoxalin nor its metabolite had a toxic effect on the cartilage chondrocytes at the concentrations and used in this study.

Conclusion: This study provides evidence that tepoxalin exerts inhibition of COX and can reduce in vitro collagen loss from canine cartilage explants at a concentration of 10(-5) M. We can conclude that, in this model, tepoxalin can partially inhibit the development of cartilage degeneration when it is available locally to the tissue.

Show MeSH
Related in: MedlinePlus