RESUMO
Malassezia pachydermatis is an important opportunistic agent of dermatitis and otitis in dogs. M. pachydermatis is generally treated with topical therapies using combinations of antifungal, antimicrobial and anti-inflammatory agents. We investigated the in vitro activities of carvacrol (CRV), cinnamaldehyde (CIN) and thymol (THY) alone and in combination with antifungal agents (fluconazole, itraconazole, ketoconazole, clotrimazole, miconazole, terbinafine and nystatin) against M. pachydermatis. The assays were performed according to the Clinical and Laboratory Standards Institute (CLSI), using Sabouraud dextrose broth and checkerboard microdilution. The mean fractional inhibitory concentration index (FICI) showed primary synergies for the combinations carvacrol+nystatin, thymol+nystatin, and carvacrol+miconazole (80%). In conclusion, the results obtained indicate that the phytochemicals tested showed relevant in vitro anti-M. pachydermatis activity. Future in vivo experiments are needed to elucidate the safety and therapeutic potential of these combinations.
Assuntos
Acroleína/análogos & derivados , Antifúngicos/farmacologia , Cimenos/farmacologia , Dermatomicoses/veterinária , Doenças do Cão/tratamento farmacológico , Malassezia/efeitos dos fármacos , Timol/farmacologia , Acroleína/farmacologia , Animais , Dermatomicoses/tratamento farmacológico , Doenças do Cão/microbiologia , Cães/microbiologia , Combinação de Medicamentos , Farmacorresistência Fúngica , Testes de Sensibilidade Microbiana , Compostos Fitoquímicos/química , Compostos Fitoquímicos/farmacologiaRESUMO
The polysaccharide ß-glucan presents beneficial effects on the immune system, although the mechanisms of the immunomodulatory effect remain poorly understood. The potential cytoprotective and genoprotective effects of ß-glucans were evaluated in broiler chicken lymphocytes exposed to increasing concentrations of aflatoxin B1 (AFB1) and/or ß-glucans. AFB1 significantly decreased cell viability at the concentrations of 10 and 20 µg/ml at 72 h of incubation (p<0.01 and p<0.001, respectively). Moreover, the AFB1 concentrations of 1, 10 and 20 µg/ml increased DNA fragmentation levels at 24 h (p<0.001). Conversely, lymphocyte death was prevented by ß-glucans at the concentrations of 1% and 10%, indicating a cytoprotective effect. Reactive oxygen species levels were increased in the cells treated with 20 µg/ml AFB1 at 24 h (p<0.05) and 10% ß-glucans with or without AFB1 at 24, 48 and 72 h of incubation (p<0.001). DNA damage increased by more than 100% in AFB1-treated lymphocytes when compared to control group. ß-glucans at 1% was able to fully revert the AFB1-induced lymphocyte DNA damage, indicating a genoprotective effect and maintaining DNA integrity. In conclusion, ß-glucans showed in vitro dose-dependent cytoprotective and genoprotective effects in broiler chicken lymphocytes exposed to AFB1.
Assuntos
Aflatoxina B1/toxicidade , Antimutagênicos/farmacologia , Galinhas/fisiologia , Dano ao DNA , Linfócitos/efeitos dos fármacos , Substâncias Protetoras/farmacologia , beta-Glucanas/farmacologia , Animais , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Ensaio Cometa , DNA/metabolismoRESUMO
The aim of the present work was to study the in-vitro cytotoxic effects of different concentrations of aflatoxin B1 (AFB1) on broiler lymphocytes. Lymphocyte-rich mononuclear cells were separated by Ficoll-Histopaque density and cultured in 96-wellplates containing the evaluated AFB1 concentrations in 5% CO2 atmosphere at 39°C. Thereafter, MTT, PicoGreen, and reactive oxygen species assays were performed. Cell viability decreased in the presence of 10 µg/mL AFB1 at 48 h (p 0.05) and of 10 and 20 µg/mL AFB1 at 72 h (p 0.01 and p 0.001, respectively) when compared to the control (0 µg/mL). However, a dose-dependent increase in the cell-free DNA at 24 h was observed at 1, 10 and 20 µg/mL (p 0.001). ROS formation significantly increased at 24 h at all concentrations (p 0.001). The in-vitro results demonstrate that AFB1 is cytotoxic and causes biomolecular oxidative damage in broiler lymphocytes.(AU)