RESUMO
PURPOSE: To evaluate the effects and mechanisms of andiroba-based emulsion (ABE) topical treatment on full-thickness cutaneous wounds in rats. METHODS: The wounds were harvested on days 3, 7, 15, and 20 post-surgery. Wound contraction rate, quantitative immunohistochemistry [macrophages, myofibroblasts, capillaries, collagens (col) I and III, transforming growth factor ß3ß (TGFß3)], and tensile strength were assessed. RESULTS: Treated wounds were smaller, contracted earlier and had increased angiogenesis, fewer CD68+ and M2 macrophages on days 7 and 15, but higher on day 20. Myofibroblasts appeared on days 3 to 7 in untreated wounds and on days 7 to 15 in treated wounds. TGFß3 levels were higher in the treated wounds, less dense collagen fibers, lower col I/III ratios and a higher tensile strength. CONCLUSION: These results demonstrate the important anti-inflammatory role of treatment and the associated modulation of macrophages, myofibroblasts, and TGFß3 levels. Collagen fibers in the treated wounds were more organized and less dense, similar to unwounded skin, which likely contributed to the higher tensile strength.
Assuntos
Anti-Inflamatórios/farmacologia , Meliaceae/química , Óleos de Plantas/farmacologia , Pele/efeitos dos fármacos , Fator de Crescimento Transformador beta3/efeitos dos fármacos , Cicatrização/efeitos dos fármacos , Administração Cutânea , Animais , Colágeno Tipo I/análise , Colágeno Tipo III/análise , Emulsões , Matriz Extracelular/efeitos dos fármacos , Imuno-Histoquímica , Masculino , Miofibroblastos/efeitos dos fármacos , Ratos Wistar , Reprodutibilidade dos Testes , Pele/patologia , Fator de Crescimento Transformador beta3/análise , Resultado do TratamentoRESUMO
Abstract Purpose: To evaluate the effects and mechanisms of andiroba-based emulsion (ABE) topical treatment on full-thickness cutaneous wounds in rats. Methods: The wounds were harvested on days 3, 7, 15, and 20 post-surgery. Wound contraction rate, quantitative immunohistochemistry [macrophages, myofibroblasts, capillaries, collagens (col) I and III, transforming growth factor β3β (TGFβ3)], and tensile strength were assessed. Results: Treated wounds were smaller, contracted earlier and had increased angiogenesis, fewer CD68+ and M2 macrophages on days 7 and 15, but higher on day 20. Myofibroblasts appeared on days 3 to 7 in untreated wounds and on days 7 to 15 in treated wounds. TGFβ3 levels were higher in the treated wounds, less dense collagen fibers, lower col I/III ratios and a higher tensile strength. Conclusion: These results demonstrate the important anti-inflammatory role of treatment and the associated modulation of macrophages, myofibroblasts, and TGFβ3 levels. Collagen fibers in the treated wounds were more organized and less dense, similar to unwounded skin, which likely contributed to the higher tensile strength.
Assuntos
Animais , Masculino , Pele/efeitos dos fármacos , Cicatrização/efeitos dos fármacos , Óleos de Plantas/farmacologia , Meliaceae/química , Fator de Crescimento Transformador beta3/efeitos dos fármacos , Anti-Inflamatórios/farmacologia , Pele/patologia , Administração Cutânea , Imuno-Histoquímica , Reprodutibilidade dos Testes , Resultado do Tratamento , Ratos Wistar , Colágeno Tipo I/análise , Colágeno Tipo III/análise , Emulsões , Matriz Extracelular/efeitos dos fármacos , Fator de Crescimento Transformador beta3/análise , Miofibroblastos/efeitos dos fármacosRESUMO
BACKGROUND: We have demonstrated that the administration of delta-iodolactone (i.e., 5-iodo-delta lactone) of arachidonic acid (IL-delta), a mediator in thyroid autoregulation, prevents goiter induction by methylmercaptoimidazol (MMI) in rats. Other studies have shown that transforming growth factor beta-1 (TGF-beta1) mimics some of the actions of excess iodide, but its participation in autoregulation is disputed. The present studies were performed to test the hypotheses that IL-delta decreases thyroid growth by inhibition of cell proliferation and/or by stimulation of apoptosis due to oxidative stress, that TGF-beta is stimulated by an excess of iodide and by IL-delta, and that c-Myc and c-Fos expression are upregulated during goiter induction and downregulated during goiter inhibition. METHODS: Rats were treated with MMI alone or together with iodide or IL-delta. Thyroid weight, cell number, cell proliferation, apoptosis, and oxidative stress were determined. Proliferating cell nuclear antigen (PCNA), TGF-beta1, TGF-beta3, c-Myc, and c-Fos were measured by Western blot. RESULTS: MMI caused a progressive increase in thyroid weight accompanied by an increase in cell number, asymmetry of the ploidy histograms, and PCNA, c-Fos, and c-Myc expression. In addition, an early increase of apoptosis was observed. Peroxides as well as glutathione peroxidase and catalase activities were also increased in goitrous animals. The inhibitory action of IL-delta on goiter formation was accompanied by the inhibition of cell proliferation evidenced by a significant decrease in cell number, PCNA expression, and asymmetry of the ploidy histograms. A transient stimulation of apoptosis after 7 days of treatment was also observed. MMI administration stimulated TGF-beta1 but not TGF-beta3 synthesis. IL-delta alone caused a slight increase of TGF-beta3 but not TGF-beta1, whereas potassium iodide (KI) stimulated both isoforms and MMI reversed KI effect on TGF-beta1 expression but not on TGF-beta3. CONCLUSIONS: The goiter inhibitory action of IL-delta is due to the inhibition of cell proliferation and the transient stimulation of apoptosis. This latter action does not involve oxidative stress. TGF-beta1 does not play a role in the autoregulatory pathway mediated by IL-delta. Iodide stimulates TGF-beta3 without the need of being organified. These results suggest that there may be more than one pathway involved in the autoregulatory mechanism.