RESUMO
Mast cells are effector cells that initiate allergic inflammatory immune responses by inducing inflammatory mediators. Boehmeria nivea (Linn.) Gaudich is a natural herb in the nettle family Urticaceae that possesses numerous pharmacological properties. Despite the various pharmacological benefits of Boehmeria nivea, its effects on allergic inflammation have not yet been determined. Here, we investigated the effect of the ethanol extract of Boehmeria nivea (BNE) on degranulation rat basophilic leukemia (RBL)-2H3 mast cells stimulated with anti-dinitrophenyl (anti-DNP) and bovine serum albumin (BSA) during immunoglobulin E (IgE)-mediated allergic immune response. The results showed inhibition of the release of ß-hexosaminidase and histamine from the cells. BNE suppressed pro-inflammatory cytokines (Tumor necrosis factor (TNF)-α, Interleukin (IL)-1ß, and IL-6) and reduced T helper (Th)2 cytokine IL-4 expression and/or secretion correlated with the downregulation of p38, extracellular signal-regulated kinases (ERK) mitogen-activated protein kinase (MAPK), and nuclear factor-κB (NF-κB) signaling pathways in treated RBL-2H3 mast cells. In passive cutaneous anaphylaxis, treatment with BNE during IgE-mediated local allergic reaction triggered a reduction in mouse ear pigmentation and thickness. Taken together, these results indicated that BNE suppressed mast cell-mediated inflammation, suggesting that BNE might be a candidate for the treatment of various allergic disorders.
Assuntos
Boehmeria/química , Hipersensibilidade/tratamento farmacológico , Inflamação/tratamento farmacológico , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Mastócitos/efeitos dos fármacos , NF-kappa B/efeitos dos fármacos , Extratos Vegetais/farmacologia , Anafilaxia/metabolismo , Animais , Antialérgicos/farmacologia , Linhagem Celular Tumoral , Citocinas/metabolismo , Histamina/química , Liberação de Histamina/efeitos dos fármacos , Imunoglobulina E/química , Mediadores da Inflamação/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Anafilaxia Cutânea Passiva/efeitos dos fármacos , Pigmentação , Folhas de Planta/química , Ratos , Soroalbumina Bovina/química , beta-N-Acetil-Hexosaminidases/químicaRESUMO
BACKGROUND: Euphorbia supina (ES) has been widely used in folk medicine owing to its antibacterial, hemostatic, and anti-inflammatory properties. The aim of this study was to evaluate the antioxidant and skin-whitening effects of a 70% ethanol extract of ES. METHODS: The aerial parts of ES plant were extracted with 70% ethanol. The viability of B16F10 cells was evaluated by MTT assay to determine the non-toxic doses for further experiments. The tyrosinase and cellular tyrosinase activities were then measured using an enzyme-substrate assay. In addition, the expression of whitening-related proteins was measured using western blot. RESULTS: The antioxidant activity of the ES samples increased in a dose-dependent manner, as confirmed by their radical scavenging activities in the 2,2-diphenyl-1-1-picrylhydrazyl and 2,2-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) assays. The ES extract significantly reduced tyrosinase activity and melanin content in a dose-dependent manner. Furthermore, it decreased α-melanocyte stimulating hormone (MSH)-induced protein expression of tyrosinase and microphthalmia-associated transcription factor (MITF). CONCLUSIONS: Our results indicate that the ES extract attenuated α-MSH-stimulated melanin synthesis by modulating tyrosinase and MITF expression. Therefore, the ES extract could be a promising therapeutic agent to treat hyperpigmentation and as an ingredient for skin-whitening cosmetics.