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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 PGE2 levels released into culture media of canine cartilage explants. Media was harvested after seven days of treatment with tepoxalin (T) or its active metabolite (M) at concentrations of ×10-5, ×10-6 or ×10-7 M. Values are shown as the mean and SDs from a single donor. P values correspond to comparisons to the positive control; * significant at p ≤ 0.05.
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Figure 3: Effect of tepoxalin and its metabolite on PGE2 levels released into culture media of canine cartilage explants. Media was harvested after seven days of treatment with tepoxalin (T) or its active metabolite (M) at concentrations of ×10-5, ×10-6 or ×10-7 M. Values are shown as the mean and SDs from a single donor. P values correspond to comparisons to the positive control; * significant at p ≤ 0.05.

Mentions: Treatment with OSM and IL-1β caused a significant 98-fold increase of PGE2 release into the media from explants in the positive control group when compared to media from the negative controls. Treatment with tepoxalin at 1 × 10-5 M, 1 × 10-6 M or 1 × 10-7 M concentrations reduced this level by 4.80-fold, 1.66-fold and 1.55-fold, respectively (figure 3). Treatment with the active metabolite at concentrations of 1 × 10-5 M, 1 × 10-6 M or 1 × 10-7 M also caused a large reduction in the levels of PGE2 released from the explants (8.26-fold, 9.22-fold and 2.25-fold, respectively). Concentrations of LTB4 in media harvested from explants on day seven were not able to be quantified due to the low levels present (data not shown). Monolayer cultures that were performed for 24 h in an attempt to obtain quantifiable levels of LTB4 also failed to achieve levels of LTB4, which could be quantified using available assays (data not shown).


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 PGE2 levels released into culture media of canine cartilage explants. Media was harvested after seven days of treatment with tepoxalin (T) or its active metabolite (M) at concentrations of ×10-5, ×10-6 or ×10-7 M. Values are shown as the mean and SDs from a single donor. P values correspond to comparisons to the positive control; * significant at p ≤ 0.05.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 3: Effect of tepoxalin and its metabolite on PGE2 levels released into culture media of canine cartilage explants. Media was harvested after seven days of treatment with tepoxalin (T) or its active metabolite (M) at concentrations of ×10-5, ×10-6 or ×10-7 M. Values are shown as the mean and SDs from a single donor. P values correspond to comparisons to the positive control; * significant at p ≤ 0.05.
Mentions: Treatment with OSM and IL-1β caused a significant 98-fold increase of PGE2 release into the media from explants in the positive control group when compared to media from the negative controls. Treatment with tepoxalin at 1 × 10-5 M, 1 × 10-6 M or 1 × 10-7 M concentrations reduced this level by 4.80-fold, 1.66-fold and 1.55-fold, respectively (figure 3). Treatment with the active metabolite at concentrations of 1 × 10-5 M, 1 × 10-6 M or 1 × 10-7 M also caused a large reduction in the levels of PGE2 released from the explants (8.26-fold, 9.22-fold and 2.25-fold, respectively). Concentrations of LTB4 in media harvested from explants on day seven were not able to be quantified due to the low levels present (data not shown). Monolayer cultures that were performed for 24 h in an attempt to obtain quantifiable levels of LTB4 also failed to achieve levels of LTB4, which could be quantified using available assays (data not shown).

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