RESUMO
This study was to investigate the anti-inflammatory activities in vitro of various carrageenans (Car) fractions (κ-, ι-, and λ-types) with well characterized molecular properties, using murine microglia BV-2 cell line treated with lipopolysaccharide (LPS) as model. It is indicated that pretreatments with the oligosaccharide fractions from κ- or ι-carrageenan acid hydrolysates (κ- and ι-CarAOS, respectively) at 125-500⯵g/mL significantly and dose-dependently decreased the levels of tumor necrosis factor α (TNF-α) secreted from LPS-treated BV-2 cells, showing promisingly anti-inflammatory effects. Differently, pretreatments of most of polymeric carrageenans at 250-500⯵g/mL significantly increased the TNF-α level, implying the co-inflammatory effects with LPS. The co-inflammatory effectiveness of pure carrageenans at 125⯵g/mL was notable for λ-Car, followed by ι-Car, and insignificantly for κ-Car. Generally, cytokine TNF-α was a more sensitive biomarker to the presence of carrageenans than was the IL-6. The TNF-α level varied greatly at a low carrageenan concentration (125⯵g/mL) and high polymer percentage (e.g. purified κ- and ι-Car). Conclusively, the anti-inflammatory effects on LPS-treated BV-2 cells could be attenuated by pretreatments with κ- and ι-CarAOS at 125-500⯵g/mL.
Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Carragenina/química , Lipopolissacarídeos/antagonistas & inibidores , Microglia/efeitos dos fármacos , Oligossacarídeos/farmacologia , Polissacarídeos/farmacologia , Animais , Anti-Inflamatórios não Esteroides/isolamento & purificação , Linhagem Celular Transformada , Fracionamento Químico/métodos , Relação Dose-Resposta Imunológica , Hidrólise , Interleucina-6/antagonistas & inibidores , Interleucina-6/biossíntese , Interleucina-6/imunologia , Lipopolissacarídeos/farmacologia , Camundongos , Microglia/citologia , Microglia/imunologia , Oligossacarídeos/isolamento & purificação , Polissacarídeos/isolamento & purificação , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Fator de Necrose Tumoral alfa/biossíntese , Fator de Necrose Tumoral alfa/imunologiaRESUMO
A two-frequency laser scanning confocal fluorescence microscope (TF-LSCFM) based on intensity modulated fluorescence signal detection was proposed. The specimen-induced spherical aberration and scattering effect were suppressed intrinsically, and high image contrast was presented due to heterodyne interference. An improved axial point spread function in a TF-LSCFM compared with a conventional laser scanning confocal fluorescence microscope was demonstrated and discussed.