RESUMO
We investigated the anti-inflammatory effect of trilobatin, the flavonoid isolated from the leaves of Lithocarpus polystachyus Rehd, as well as the underlying molecular mechanisms. Treatment with trilobatin (0.005-5 µM) dose-dependently inhibited the lipopolysaccharide (LPS)-induced mRNA expression and secretion of pro-inflammatory cytokines, including tumor necrosis factor α (TNFα), interleukin-1ß (IL-1ß) and interleukin-6 (IL-6), in RAW 264.7 macrophages. However, no further inhibition was detected when the concentration of trilobatin was increased to 50 µM. Western blot analysis confirmed that the mechanism of the anti-inflammatory effect was correlated with the inhibition of LPS-induced inhibitor of nuclear factor-kappa B α (IκBα) degradation and nuclear factor-kappa B (NF-κB) p65 phosphorylation. In addition, trilobatin also showed a significant inhibition of LPS-induced TNFα and IL-6 at both the mRNA and protein levels in a mouse model. Our results suggest that trilobatin potentially inhibits the LPS-induced inflammatory response by suppressing the NF-κB signaling pathway.
Assuntos
Anti-Inflamatórios/farmacologia , Flavonoides/farmacologia , Lipopolissacarídeos/efeitos adversos , NF-kappa B/metabolismo , Polifenóis/farmacologia , Transdução de Sinais , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Fagaceae/química , Feminino , Proteínas I-kappa B/genética , Proteínas I-kappa B/metabolismo , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Inibidor de NF-kappaB alfa , NF-kappa B/genética , Fosforilação/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fator de Transcrição RelA/genética , Fator de Transcrição RelA/metabolismo , Fator de Necrose Tumoral alfa/metabolismoRESUMO
The flavonoid phlorhizin is abundant in the leaves of Sweet Tea (ST, Lithocarpus Polystachyus Rehd). Phlorhizin was preparatively separated and purified from a crude ST extract containing 40% total flavonoids by static adsorption and dynamic desorption on ADS-7 macroporous resin and neutral alumina column chromatography. Only water and ethanol were used as solvents and eluants throughout the whole separation and purification process. Using a phlorhizin standard as the reference compound, the target compound separated from the crude ST extracts was analyzed by thin layer chromatography (TLC), high performance liquid chromatography (HPLC) and electrospray ionization mass spectrometry (EIS-MS) and identified as 99.87% pure (by HPLC-UV) phlorhizin. The results showed that 10 g of the target compound could be obtained from 40 g of the crude extracts in a single operation, indicating a 40% recovery. Therefore, this represents an efficient and environmentally-friendly technology for separating and purifying phlorhizin from ST leaves.
