RESUMO
Introduction: Antibacterial properties of honey vary according to its floral origin; few studies report the percentage of pollen types in honey, making it difficult to reproduce and compare the results. This study compares the antibacterial and wound-healing properties of three kinds of monofloral Ulmo honey with different percentages of pollen from Eucryphia cordifolia. Methods: The pollen percentage of the honey was determined by melissopalynological analysis, and they were classified into three groups: M1 (52.77% of pollen from Eucryphia cordifolia), M2 (68.41%), and M3 (82.80%). They were subjected to chemical analysis and agar diffusion test against Staphylococcus aureus. A total of 20 healthy adult guinea pigs (Cavia porcellus) of both sexes were randomly assigned to four groups for experimental burn skin wound (uninfected) production and treatment with Ulmo honey. On day 10 post-injury, biopsies were obtained, and histological analysis was performed to assess wound-healing capacity following the treatment with honey. Results: The chemical analysis showed that M3 differed significantly from M1 in terms of pH (P = 0.020), moisture (P = 0.020), total sugars (P = 0.034), and total solids (P = 0.020). Both strains of Staphylococcus aureus were susceptible to M1 and M2 at 40% w/v but were resistant to M3 at all concentrations. All groups (I-IV) were in the initial proliferative phase, with complete or partial re-epithelialization of the epidermis. Discussion: The antibacterial activity showed a wide range of variation in the different types of honey studied, with no significant differences between wound healing and pollen percentage in the groups studied. Higher pH and the absence of Tineo in M3 conferred a lower antibacterial capacity but not a lower wound healing capacity. Despite its variability in the percentage of Eucryphia cordifolia like primary pollen in Ulmo's monofloral honey, this has the same properties in relation to wound healing.
RESUMO
Copaiba oil is widely used in medicine, but there are no reports regarding its application in ophthalmology. Therefore, the objective of this study was to evaluate the clinical, histopathological and toxicogenetic effects of eye drops containing 0.1 and 0.5% of Copaifera multijuga Hayne oil on superficial corneal ulcers induced with alkali in the left eye of rats. For histological analysis, the percent reduction in ulcers and thickness of the corneal epithelium and stroma were evaluated 48 and 72 h after ulcer induction. Additionally, neovascularization and polymorphonuclear infiltration were classified in the stroma. The bone marrow micronucleus test was used for toxicogenetic assessment. None of the animals exhibited clinical signs of immediate ocular discomfort after instillation and the eye drops were harmless to the ocular surface. There was a significant difference in percent ulcer reduction and corneal stroma thickness between animals treated with the C. multijuga eye drops and untreated animals with corneal injury and the negative control, respectively, suggesting a healing effect of the oleoresin. Analysis of the thickness of the corneal epithelium at the two time points showed that the eye drops formulated did not significantly reduce the damage caused by alkali. The same was observed for the treatments with the reference drugs. No difference in stromal neovascularization or inflammatory infiltration was observed between the treated groups. The toxicogenetic results revealed the absence of cytotoxicity and genotoxicity of the treatments. In conclusion, the C. multijuga eye drops did not cause damage to the ocular surface under the present experimental conditions and corneal epithelization was similar to the conventional treatments. These results indicate that eye drops containing C. multijuga oleoresin are a promising option for the treatment of superficial keratitis.
Assuntos
Córnea/efeitos dos fármacos , Fabaceae/química , Cicatrização/efeitos dos fármacos , Animais , Córnea/patologia , Epitélio Corneano/efeitos dos fármacos , Epitélio Corneano/patologia , Masculino , Óleos Voláteis/efeitos adversos , Óleos Voláteis/farmacologia , Soluções Oftálmicas/efeitos adversos , Soluções Oftálmicas/farmacologia , Extratos Vegetais/efeitos adversos , Extratos Vegetais/farmacologia , Ratos , Ratos Wistar , Toxicogenética/métodosRESUMO
The pathogenesis of dermonecrosis induced by the venom of the African spitting cobra Naja nigricollis was investigated in a mouse model. Intradermal injection of venom induced a macroscopic necrotic lesion. Histological examination revealed early edema of the dermis, followed by blistering, loss of skin appendages and reduction in cellularity. By 24 h, necrosis of the dermis was evident, sections of epidermis were lost, and a fibrinoid hyaline material filled the damaged areas. Abundant inflammatory infiltrate was present in the hypodermis and basal dermis, and there was an increment in the expression of matrix metalloproteinases (MMPs). Thrombi were observed in blood vessels. Abundant cells were present in the dermis by 7 days. By 14 and 28 days, re-epithelization had occurred, collagen was widespread in the dermis, and few skin appendages were present. The RP-HPLC fractions that reproduced the necrotic activity were composed of low molecular mass cytotoxins of the three-finger toxin family and, to a lesser extent, of phospholipases A2 (PLA2). Inhibition of PLA2 of venom by p-bromophenacyl bromide did not reduce the area of necrosis, but modified the appearance of necrotic regions. Depletion of neutrophils and inhibition of venom metalloproteinases and tissue MMPs did not affect dermonecrosis. IgG and F(ab')2 antivenoms were effective in the neutralization of dermonecrosis when incubated with venom prior to injection. However, when antivenoms were administered immediately after venom injection, dermonecrosis was reduced only to a partial extent, underscoring the difficulties in neutralizing this effect with antivenoms.