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. .

Chemopreventive effect of Brazilian green propolis on experimental dermal carcinogenesis in murine model / Efecto quimiopreventivo del propóleos verde brasileño sobre la carcinogénesis cutánea en el modelo murino experimental

The aim of this study was to assess the effect of oral administration of Hydroalcoholic Extract of Green Propolis (HEGP) on dermal carcinogenesis in rodent model. For the biological assay, we used 36 mice, assigned into 6 groups (n=6): CTR (treated with 100 mg/kg HEGP and no tumor induction), TUM (treated with water and tumor induction), GP10 (treated with 10 mg/kg HEGP and tumor induction), GP50 (treated with 50 mg/kg HEGP and tumor induction) and GP100 (treated with 100 mg/kg HEGP and tumor induction). Cancer induction was performed in the back of the mice by topical application of DMBA. After 16 weeks, mice were euthanized and their backs were submitted to post-mortem histological analysis. The mean number of lesions developed in TUM (4.14±0.89) was significantly higher than in GP10 (2.05±1.02), GP50 (1.8±1.92) and GP100 (2.5±1.73) (p<0.05). The tumors formed in HEGP-treated groups were histologically more differentiated, but only in PV100 in situ lesions were evidenced. Infiltration of anatomical noble structures was less frequent in HEGP-treated groups (p<0.05). Our data suggest that oral administration of HEGP provided partial inhibition of DMBA-induced dermal carcinogenesis, as well as appeared to modulate the differentiation and infiltrative potential of the carcinomas in rodent model.

El objetivo de este estudio fue evaluar el efecto de la administración oral de extracto hidroalcohólico del propóleos verde (HEGP) sobre la carcinogénesis dérmica en modelo de roedores. Para el ensayo biológico, se utilizaron 36 ratones asignados en 6 grupos (n = 6): CTR (tratado con 100 mg/kg HEGP y sin inducción de tumores), TUM (tratada con agua e inducción de tumores), GP10 (tratado con 10 mg/kg HEGP e inducción de tumores), GP50 (tratado con 50 mg/kg HEGP e inducción de tumores) y GP100 (tratado con 100 mg/kg HEGP e inducción de tumores). La inducción de cáncer se llevó a cabo en la región dorsal de los ratones por aplicación tópica de DMBA. Después de 16 semanas, los ratones fueron sacrificados y sus dorsos fueron sometidos a análisis histológico post-mortem. El número medio de lesiones desarrolladas en TUM (4,14±0,89) fue significativamente mayor que GP10 (2,05±1,02), GP50 (1,8±1,92) y gp100 (2,5±1,73) (p<0,05). Los tumores formados en grupos tratados con HEGP fueron histológicamente más diferenciados, pero sólo en PV100 las lesiones in situ fueron manifiestas. La infiltración de las estructuras anatómicas blanco fue menos frecuente en los grupos tratados con HEGP (p<0,05). Nuestros datos sugieren que la administración oral de HEGP proporciona una inhibición parcial de la carcinogénesis dérmica inducida por DMBA, así como pareció modular la diferenciación y potencial infiltrante de los carcinomas en el modelo animal.

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.