RESUMEN
Abstract Introduction Bismuth subgallate (BS) is a yellow and odorless powder that has hemostatic astringent properties. Some otorhinolaryngologists and dentists currently use this substance to enhance wound healing. Objective The objective of this study is to evaluate the effects of bismuth subgallate on wound healing, through the analysis of inflammatory process, collagen production, and angiogenesis. Method A standard wound was made on the back of 60 male Wistar rats, using a biopsy punch. We created two groups: the experimental group, which underwent daily application of 0.5mg BS over the entire wound, and the control group, which underwent daily application of sodium chloride 0.9%. We performed a qualitative evaluation of the tissue on the third, seventh, and fourteenth day. We assessed inflammatory markers using Hematoxylin and Eosin (HE) stain, used Picrosirius stain for collagen analysis, and immunohistochemistry was used for angiogenesis analysis through evaluation of smooth muscle proliferation. Results Statistically, we found no significant differences between groups regarding inflammatory response on the third (p= 1), seventh (p= 0.474), and fourteenth day (p= 0.303). Also, collagen type I and III production showed no statistical differences between groups on the third (p= 0.436), seventh (p= 0.853), and fourteenth day (p= 0.436) of analysis. Immunohistochemistry did not present differences on angiogenesis between experimental and control group on the third (p= 0.280), seventh (p= 0.971), and fourteenth day (p= 0.218). Conclusion BS does not promote significant changes in inflammatory response, collagen, and angiogenesis. Thus, it does not influence healing on skin wounds on rats.
RESUMEN
Resumo Contexto O subgalato de bismuto é um metal pesado e insolúvel, utilizado por suas propriedades adstringentes e hemostáticas. Objetivo Avaliar os efeitos do subgalato de bismuto na cicatrização mediante observação de miofibroblastos em pele de ratos. Métodos Foram utilizados 60 ratos da linhagem Wistar, que receberam uma ferida no dorso da pele. Os animais foram divididos em dois grupos: controle (aplicação diária de cloreto de sódio a 0,9%) e experimental (aplicação diária de 0,5 mg de subgalato de bismuto). Cada grupo foi subdividido em três subgrupos, que foram reoperados para retirada da ferida em 3, 7 e 14 dias. Foi realizada coloração de hematoxilina eosina, picrosirius e imuno-histoquímica para avaliar contagem de miofibroblastos, resposta inflamatória e síntese de colágeno. Resultados Não foi encontrada diferença entre os grupos controle e experimento com relação ao processo inflamatório – subgrupos 3 dias (p = 1), 7 dias (p = 0,474) e 14 dias (p = 303). A avaliação dos colágenos tipo I e III no grupo-controle não demonstrou benefícios de cicatrização – 3 dias (p = 0,436), 7 dias (p = 0,853) e 14 dias (p = 0,436); já no grupo experimental, houve aumento dos colágenos tipos I e III nos subgrupos 3 e 14 dias (p = 0,005). A imuno-histoquímica confirmou os resultados encontrados na coloração hematoxilina eosina, na qual a área de miofibroblastos entre os subgrupos, nos grupos experimental (p = 0,4) e controle (p = 0,336), foi indiferente. Conclusão A utilização do subgalato de bismuto em ferida de pele de ratos não evidenciou benefícios na cicatrização, ou seja, não houve diferença na fibroplasia quando comparados os grupos experimental e controle.
Abstract Background Bismuth subgallate is an insoluble heavy metal that is used for its astringent and hemostatic properties. Objective To evaluate the effects of bismuth subgallate on the healing process by observation of myofibroblasts in the skin of rats. Methods A sample of 60 Wistar rats was used. Each rat was subjected to a dorsal skin wound and allocated to one of two groups: a control group, in which 0.9% sodium chloride was administered daily, or an experimental group, in which 0.5 mg of bismuth subgallate was administered daily. Each of these groups was further subdivided into three subsets, which were reoperated after 3, 7 and 14 days respectively for excision and collection of the skin wound specimens. Samples were treated with hematoxylin eosin, picrosirius, and immunohistochemical staining to enable assessment of myofibroblast counts, inflammatory response phase, and collagen synthesis. Results No inflammatory process differences were detected between the control and experimental groups at 3 days (p = 1), 7 days (p = 0.474), or 14 days (p = 303). Evaluation of types I and III collagen in the control group did not demonstrate healing benefits at 3 days (p = 0.436), 7 days (p = 0.853), or 14 days (p = 0.436); whereas in the experimental group there were increases in types I and III collagen at 3 and 14 days (p = 0.005). Immunohistochemical analysis confirmed the results of hematoxylin eosin staining, since there were no differences between subsets in terms of area of myofibroblasts, in the experimental (p = 0.4) or the control (p = 0.336) groups. Conclusions Administration of bismuth subgallate to skin wounds in rats did not result in any evidence of benefits to healing, i.e., no difference in fibroplasia was detected when experimental and control groups were compared.