Glabridin, a bioactive component of licorice, ameliorates diabetic nephropathy by regulating ferroptosis and the VEGF/Akt/ERK pathways.

BACKGROUND: Glabridin (Glab) is a bioactive component of licorice that can ameliorate diabetes, but its role in diabetic nephropathy (DN) has seldom been reported. Herein, we explored the effect and underlying mechanism of Glab on DN. METHODS: The bioactive component-target network of licorice against DN was by a network pharmacology approach. The protective effect of Glab on the kidney was investigated by a high-fat diet with streptozotocin induced-diabetic rat model. High glucose-induced NRK-52E cells were used for in vitro studies. The effects of Glab on ferroptosis and VEGF/Akt/ERK pathways in DN were investigated in vivo and in vitro using qRT-PCR, WB, and IHC experiments. RESULTS: Bioinformatics analysis constructed a network comprising of 10 bioactive components of licorice and 40 targets for DN. 13 matching targets of Glab were mainly involved in the VEGF signaling pathway. Glab treatment ameliorated general states and reduced FBG, HOMA-ß, and HOMA-insulin index of diabetic rats. The renal pathological changes and the impaired renal function (the increased levels of Scr, BUN, UREA, KIM-1, NGAL, and TIMP-1) were also improved by Glab. Moreover, Glab repressed ferroptosis by increasing SOD and GSH activity, and GPX4, SLC7A11, and SLC3A2 expression, and decreasing MDA and iron concentrations, and TFR1 expression, in vivo and in vitro. Mechanically, Glab significantly suppressed VEGF, p-AKT, p-ERK1/2 expression in both diabetic rats and HG-induced NRK-52E cells. CONCLUSIONS: This study revealed protective effects of Glab on the kidney of diabetic rats, which might exert by suppressing ferroptosis and the VEGF/Akt/ERK pathway.

Cornuside inhibits mast cell-mediated allergic response by down-regulating MAPK and NF-κB signaling pathways.

AIMS: The present study is to investigate the effect of cornuside on mast cell-mediated allergic response, as well as its possible mechanisms of action. METHODS: To test the anti-allergic effects of cornuside in vivo, local extravasation was induced by local injection of anti-dinitrophenyl immunoglobulin E (IgE) followed by intravenous antigenic challenge in passive cutaneous anaphylaxis model rats. Mast cell viability was determined using MTT assay. Histamine content from rat peritoneal mast cells was measured by the radioenzymatic method. To investigate the mechanisms by which cornuside affects the reduction of histamine release, the levels of calcium uptake were measured. To examine whether cornuside affects the expression of pro-inflammatory cytokines, Western blotting and ELISA were carried out. RESULTS: Oral administration of cornuside inhibited passive cutaneous anaphylaxis in rats. Presence of cornuside attenuated IgE-induced histamine release from rat peritoneal mast cells. The inhibitory effect of cornuside on histamine release was mediated by the modulation of intracellular calcium. In addition, cornuside decreased phorbol 12-myristate 13-acetate (PMA) and calcium ionophore A23187-stimulated production and secretion of pro-inflammatory cytokines such as TNF-α and IL-6 in human mast cells. The inhibitory effect of cornuside on pro-inflammatory cytokines was dependent on nuclear factor-κB and p38 mitogen-activated protein kinase. CONCLUSIONS: The present study provides evidence that cornuside inhibits mast cell-derived inflammatory allergic reactions by blocking histamine release and pro-inflammatory cytokine expression. Furthermore, in vivo and in vitro anti-allergic effects of cornuside suggest a possible therapeutic application of this agent in inflammatory allergic diseases.

[Protective effects and mechanism of Inonotus obliquus on asthmatic mice].

OBJECTIVE: To explore the protective effects and mechanism of ethanol extract of Inonotus obliquus (EEIO) injection on asthmatic mice. METHOD: OVA was injected intraperitoneally and inhaled to produce the asthmatic model. Thirty two mice were randomly divided into four groups: control group, asthma group and I. obliquus groups of high and low dose. The concentrations of IL-4, IL-5, IL-13 and IFN-gamma in BALF, the phosphor-p38 MAPK in lung tissues were respectively measured by ELISA and Western blotting. The number of inflammatory cells in BALF and histopathology changes were observed. RESULT: In asthmatic group, the number of inflammatory cells and the concentrations of IL-4, IL-5, IL-13 in BALF and phospho-p38 MAPK in lung tissue were higher, while IFN-gamma were lower than those in normal control mice (P < 0.05). In I. obliquus group, the number of inflammatory cells, the concentrations of IL-4, IL-5, IL-13 in BALF and phosphor-p38 MAPK in lung tissue were lower, but were higher than those in normal control mice (P < 0.05), and histropathology damage was alleviated significantly. There was no significant difference observed among the efficacies in the I. obliquus groups of high and low dose. CONCLUSION: p38 MAPK may play a role in pathological process of asthma. I. obliquus effectively treats asthma by inhibiting the expression of phosphor-p38 MAPK, correcting the unbalance of IFN-gamma/IL-4 and decreasing the number of inflammatory cells.