Immunohistochemical profile of stromal constituents and lymphoid cells over the course of wound healing in murine model

PURPOSE: To assess the evolution profile of the immunohistochemical expression of stromal constituents over the time-course of wound healing in a murine model. METHODS: Surgical wounds were performed in the back of 24 Wistar rats. After three, seven, 14 and 21 days, six rats were euthanized and the wounded histologically processed to assess the immunohistochemical expression of CD3, CD20, CD31, α-SMA and type-I collagen. Non-injured skin samples (NSS) were used as control. Data were subjected to statistical analysis using ANOVA and Tukey test. RESULTS: The mean of CD3 and CD20 positive cells in the wounds was significantly higher than in NSS at seven and 14 days (p<0.001). The blood vessels content was significantly lower than in NSS (p<0.05) at three days, but increased at seven and 14 days (p<0.01). The mean of α-SMA positive cells at seven, 14 and 21 days was higher than in NSS (p<0.05). The relative content of type I collagen increased from three to 21 days, but remained lower than in NSS (p<0.05). CONCLUSIONS: Lymphoid cells, myofibroblasts and microvessels contents varied over the time-course of wound healing, with peak at seven days and progressive reduction until 21 days. The type I collagen content increased over time. .

Modulatory activity of brazilian red propolis on chemically induced dermal carcinogenesis

To evaluate modulatory effects of a hydroalcoholic extract of Brazilian red propolis (HERP) on dermal carcinogenesis using a murine model. METHODS: The HERP was used at concentrations of 10, 50 and 100 mg/kg (PROP10, PROP50 and PROP100, respectively) to modulate dermal carcinogenesis induced by the application of 9,10-dimetil-1,2-benzatraceno (DMBA) on the backs of animals. RESULTS: The chemical compounds identified in HERP included propyl gallate, catechin, epicatechin and formononetin. PROP100 treatment resulted in significantly decreased tumor multiplicity throughout the five weeks of tumor promotion (p<0.05), and this concentration also resulted in the highest frequency of verrucous tumors (p<0.05). All of the tumors that developed in DMBA-treated animals were regarded as squamous cell carcinomas and were either diagnosed as non-invasive verrucous carcinomas or invasive squamous cell carcinomas (SCCs). The average score for malignancy was significantly lower in the PROP100-treated group than the non-treated group (p<0.05), but there was no difference between the other groups (p>0.05). CONCLUSION: The oral administration of hydroalcoholic extract of Brazilian red propolis at a dose of 100 mg/kg had a significant modulatory effect on the formation, differentiation and progression of chemically induced squamous cell carcinoma in a murine experimental model.

Bioassay-guided evaluation of wound healing effect of fatty acids-incorporated collagen-based films

PURPOSE: To evaluate the effects of fatty acids-incorporated collagen-based dressing films on wound healing in rodents. METHODS: Therefore, surgical wounds were performed in the back of 80 Wistar rats, and dressed with collgane-based films (COL), and collagen-based films containing fatty acids (AGEF50 and AGEF100). Undressed wounds were regarded as controls (CTR). The animals were euthanized after three, seven, 14 and 21 days, and the macroscopic wound contraction rates (WRC) were assessed. The wounded area was also analyzed by conventional and polarized light microscope. RESULTS: No sign of abscess or hypertrophic scar formation was observed in none of the groups. At seven days, the WRR of AGEF50 was significantly higher than CTR (p<0.01), whereas at 14 days, both AGE 50 and AGE100 showed a significant increase of the WRR compared to CTR (p<0.001) and COL (p<0.01). Both films promoted increased influx of neutrophils at three days (p<0.01), but reduced significantly the mononuclear infiltrate at 14 days (p<0.05). It was also observed earlier maturation of the granulation tissue, full epithelization and cutaneous appendages development, as well as better collagenization, in AGEF50 and AGEF100. CONCLUSION: The application of AGEF50/100 as wound dressing improved wound healing in rodents.