ABSTRACT
The study is to investigate the effect of glaucocalyxin A (GLA) on mast cell-mediated anaphylaxis. The animal welfare and experimental process of this experiment followed the regulations of the Animal Ethics Committee of Yanbian University. BALB/c mice were used in the animal experiment and randomly divided into five groups, control group, model group, and GLA low, medium, and high dose groups (10, 20, and 40 mg·kg-1). Mice were sensitized by intradermal injection of anti-dinitrophenyl-immunoglobulin E (DNP-IgE) into the ears and challenged with a mixture of DNP-human serum albumin (HSA) and 4% evans blue into the tail veins to prepare an animal skin passive cutaneous anaphylaxis (PCA) model, which was collected from both ears for measurement of dye staining and histology. Rat peritoneal mast cells (RPMCs) were used in the cell experiment and divided into control, IgE + antigen (Ag), and IgE + Ag + GLA groups to determine histamine release as well as calcium influx levels. High-affinity IgE receptor (FcεRI)-mediated signaling pathway proteins and HMGB1/TLR4/NF-κB (high mobility group box 1/toll like receptor 4/nuclear transcription factor kappa B) signaling proteins were detected by Western blot. The results of animal experiments suggest that GLA inhibits PCA, reduces evans blue dye exudation, and reduces ear inflammation and ear thickness in mice. The results of cellular experiments suggested that GLA could reduce histamine release and calcium influx, and inhibit tumor necrosis factor-α (TNF-α), interleukin (IL)-4, IL-13, and IL-1β production; Western blot results showed that GLA inhibited FcεRI-mediated phosphorylation levels of spleen tyrosine kinase (Syk), Lck/Yes novel tyrosine kinase (Lyn), tyrosine kinase Fyn (Fyn), growth-factor receptor-bound protein 2 (Gab2), and phospholipase C (PLC) γ1, while GLA inhibited HMGB1/TLR4 signaling pathway to limit NF-κB p65 nuclear metastasis. The results indicate that GLA inhibits mast cell degranulation and attenuates allergic inflammation through the HMGB1/TLR4/NF-κB signaling pathway.
ABSTRACT
Aim To investigate whether polydatin re-duces airway inflammation in asthmatic mouse model and explore whether this pathway is related to p38 MAPK/Nrf2/HO-1 . Methods After the establish-ment of the OVA-induced asthmatic mouse model, the animals were injected with 30 mg·kg-1 and 45 mg· kg-1 of polydatin diluted in 0. 2 mL normal saline, while the control group was replaced by normal saline. HE, PAS and Masson staining were used to observe the pathological changes of lung tissue. Diff-Quick staining was used to classify and count the number of inflamma-tory cells in BALF. ELISA was used to detect IgE ex-pressions in BALF. The content of ROS in BALF cells was detected by DHR-123 . The activities of antioxidant enzymes SOD, CAT and MDA in BALF were detected by the enzyme-linked immunosorbent assay kit. The expression of HO-1 in lung tissue was detected by im-munohistochemistry. The protein and mRNA expres-sions of Nrf2 and HO-1 in lung tissue of mice were de-tected by Western blot and RT-PCR. Results Poly-datin treatment significantly reduced inflammatory cell infiltration mucosal secretion, goblet cell proliferation and collagen deposition in the lung tissue of mice, and decreased the number of inflammatory cells and the ex-pression of total IgE and ROS in BALF. It also in-creased the levels of antioxidant enzymes such as SOD and CAT, and lowered the level of MDA. Polydatin re-duced the phosphorylation of p38 MAPK in the lung tissue of mice, enhanced the levels of mRNA and pro-tein expressions of Nrf2 and HO-1 and promoted the nuclear transfer of Nrf2 . The above effects of polydatin were dose-dependent. Conclusions Polydatin exerts anti-oxidative effects in OVA-induced asthmatic mouse model via anti-oxidant pathway. The mechanism may be achieved through the p38 MAPK/Nrf2/HO-1 path-way.