nothofagin and Inflammation

Mast cells play a major role in immunoglobulin E-mediated allergic inflammation, which is involved in asthma, atopic dermatitis, and allergic rhinitis. Nothofagin has been shown to ameliorate various inflammatory responses such as the septic response and vascular inflammation. In this study, we assessed the inhibitory effect of nothofagin on allergic inflammation using cultured/isolated mast cells and an anaphylaxis mouse model. Nothofagin treatment prevented histamine and β-hexosaminidase release by reducing the influx of calcium into the cytosol in a concentration-dependent manner. Nothofagin also inhibited the gene expression and secretion of pro-inflammatory cytokines such as tumor necrosis factor-α and interleukin-4 by downregulating the phosphorylation of Lyn, Syk, Akt and nuclear translocation of nuclear factor-κB. To confirm these effects of nothofagin in vivo, we used a passive cutaneous anaphylaxis mouse model. Topical administration of nothofagin suppressed local pigmentation and ear thickness. Taken together, these results suggest nothofagin as a potential candidate for the treatment of mast cell-involved allergic inflammatory diseases.

Topics: Anaphylaxis; Animals; Calcium; Cell Degranulation; Chalcones; Cytokines; Disease Models, Animal; Gene Expression Regulation; Hypersensitivity; Inflammation; Male; Mast Cells; Mice, Inbred ICR; NF-kappa B; Rats, Sprague-Dawley

Vascular inflammation plays a key role in the initiation and progression of atherosclerosis, a major complication of diabetes mellitus. Aspalathin (Asp) and nothofagin (Not) are two major active dihydrochalcones found in green rooibos, which have been reported for their antioxidant activity. In this study, we assessed whether Asp or Not can suppress vascular inflammation induced by high glucose (HG) in human umbilical vein endothelial cells (HUVECs) and mice. We monitored the effects of Asp or Not on HG-induced vascular hyperpermeability, expression of cell adhesion molecules (CAMs), formation of reactive oxygen species (ROS), and activation of nuclear factor (NF)-κB in vitro and in vivo. Our data indicate that HG markedly increased vascular permeability, monocyte adhesion, expression of CAMs, formation of ROS, and activation of NF-κB. Remarkably, treatment of Asp or Not inhibited HG-mediated vascular hyperpermeability, adhesion of monocytes toward HUVECs, and expression of CAMs. In addition, Asp or Not suppressed the formation of ROS and the activation of NF-κB. Since vascular inflammation induced by HG is critical in the development of diabetic complications, our results suggest that Asp or Not may have significant benefits in the treatment of diabetic complications.

Topics: Animals; Aspalathus; Cell Survival; Chalcones; Dose-Response Relationship, Drug; Glucose; Human Umbilical Vein Endothelial Cells; Humans; Inflammation; Male; Mice; Mice, Inbred C57BL; Plant Extracts