Assessment of the effects of bismuth subgallate on proliferation of myofibroblasts: an experimental study in rats

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.

Keywords:
wound healing; myofibroblasts; otolaryngology