concanavalin-a and peoniflorin

Paeoniflorin (PF) is one of the main effective components of the total glucosides of peony, which has been reported to have anti-inflammatory ability. However, the effects of paeoniflorin on concanavalin A (Con A)-induced hepatitis have not been carefully examined. The aim of this study was to investigate the protective effect of paeoniflorin and elucidate potential mechanisms of paeoniflorin on Con A-induced hepatitis. C57BL/6 mice were divided randomly into the following four experimental groups: PBS group, PF group, Con A group, and Con A+PF group. Mice received paeoniflorin (50mg/kg) by tail vein before Con A intravenous administration. We found that paeoniflorin pretreatment can significantly reduce the elevated plasma aminotransferase levels and liver necrosis in Con A-induced hepatitis. Also, paeoniflorin pretreatment suppressed the secretion of proinflammatory cytokines (TNF-α, INF-γ, IL-6), compared with Con A group. Meanwhile, paeoniflorin pretreatment decreased CD4(+), CD8(+) and NKT cell infiltration in the liver. Besides, we observed that paeoniflorin pretreatment can decrease the expression level of Toll-like receptor (TLR) 4 mRNA or protein in liver tissues. Further results showed that paeoniflorin pretreatment was capable of suppressing the activation of the NF-κB pathway by inhibiting IκBα kinase and p65 phosphorylation in Con A-induced liver injury. These results suggest that paeoniflorin pretreatment protects mice against Con A-induced liver injury via inhibition of several inflammatory mediators and, at least in part, by suppressing CD4(+), CD8(+) and NKT cell infiltration in liver. The beneficial effect of paeoniflorin may be related to the downregulation of TLR4 expression and the inhibition of NF-κB activation.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Cell Movement; Concanavalin A; Cytokines; Glucosides; Hepatitis; Inflammation Mediators; Liver; Male; Mice; Mice, Inbred C57BL; Monoterpenes; NF-kappa B; Paeonia; Signal Transduction; T-Lymphocytes; Toll-Like Receptor 4; Transaminases

Liver diseases are closely associated with elevated levels of interleukin-8 (IL-8), suggesting the ability to inhibit IL-8 production could enhance the treatment of liver diseases. Paeoniflorin is a major active constituent of dried Paeoniae Radix Alba root (Baishao in Chinese) which is widely used in China to treat liver diseases. We examined the effects and underlying mechanisms of paeoniflorin on IL-8 production in primary human hepatic sinusoidal endothelial cells (HHSECs). Concanavalin A (ConA) at 20 μg/mL produced a 5.2-fold increase in IL-8 mRNA by 8h, and a 14.2-fold rise in IL-8 levels by 16 h. Inhibition of MEK (ERK kinase) and extracellular signal-regulated kinase (ERK) by PD98059 and U0126, or inhibition of phosphatidylinositol 3-kinase (PI3K) by LY294002 blocked both ConA-induced IL-8 mRNA expression and IL-8 secretion. Paeoniflorin reduced ConA-induced IL-8 mRNA expression and IL-8 release by 57.9% and 52.8%, respectively, and also decreased ConA-stimulated phosphorylation of ERK1/2 and Akt, suggesting paeoniflorin inhibits IL-8 expression and release by inhibiting the ERK1/2 and Akt pathways. Combining paeoniflorin with U0126 or LY294002 at low doses showed supra-additive inhibition of not only phospho-ERK1/2 and phospho-Akt by 46.4% and 35.0%, but also IL-8 release by 42.4% and 36.1% and IL-8 mRNA expression by 43.5% and 31.8%, respectively. In conclusion, paeoniflorin most likely contributes to the therapy for liver disease by exerting anti-inflammatory effects on HHSECs through blocking IL-8 secretion via downregulation of ERK1/2 and Akt phosphorylation.

Topics: Anti-Inflammatory Agents; Cells, Cultured; Concanavalin A; Down-Regulation; Endothelial Cells; Extracellular Signal-Regulated MAP Kinases; Glucosides; Humans; Interleukin-8; Liver; MAP Kinase Signaling System; Monoterpenes; Oncogene Protein v-akt; Phosphorylation; Primary Cell Culture

It is well established that macrophage infiltration is involved in concanavalin A (conA)-induced liver injury. However, the role of macrophages in conA-induced renal injury remains unknown. The aims of this study were to investigate macrophage infiltration in conA-induced renal injury and determine whether paeoniflorin (PF) could inhibit macrophage infiltration into the kidney.. BALB/C mice were pre-treated with or without PF 2 h (h) before conA injection. At 8 h after con A injection, all the mice were sacrificed; The liver and kidney histology were studied. The renal CD68 expression was detected by immunohistochemical and real-time PCR analysis. The level of expression of C-X-C chemokine receptor type 3 (CXCR3) was analyzed by western blot, immunohistochemical and real-time PCR. The pathophysiological involvement of CXCR3 in macrophage infiltration were investigated using dual-colour immunofluorescence microscopy.. PF administration significantly reduced the elevated serum levels of alanine transaminase (ALT), blood urea nitrogen (BUN), creatinine (Cr) and the severity of liver and renal damage compared with that in the conA-vehicle group. PF administration inhibited the increase in renal IL1β mRNA expression and concentration. Furthermore, immunohistochemical analysis showed that macrophages secreted CXCR3 in the kidneys of the conA-vehicle mice. Immunofluorescence microscopy demonstrated CXCR3 bound tightly to C-X-C motif ligand 11 (CXCL11) in the kidneys of the conA-vehicle mice and showed that PF treatment could suppress CXCR3/CXCL11 over-activation.. Macrophage infiltration was a notable pathological change in the kidneys of conA-treated mice. PF administration attenuated conA-induced renal damage, at least in part, by inhibiting the over-activated CXCR3/CXCL11 signal axis.

Topics: Acute Kidney Injury; Animals; Anti-Inflammatory Agents, Non-Steroidal; Blotting, Western; Chemical and Drug Induced Liver Injury; Chemokine CXCL11; Concanavalin A; Disease Models, Animal; Female; Glucosides; Immunohistochemistry; Kidney; Macrophages; Mice; Mice, Inbred BALB C; Microscopy, Fluorescence; Monoterpenes; Real-Time Polymerase Chain Reaction; Receptors, CXCR3

Paeoniflorin (Pae), a monoterpene glucoside, is one of the main bioactive components of total glucosides of paeony (TGP) extracted from the root of Paeonia lactiflora. TGP has anti-inflammatory and immunoregulatory effects. In this study, we investigated the effects of Pae on inflammatory and immune responses to the mesenteric lymph node (MLN) lymphocytes and the mechanisms by which Pae regulates beta 2-adrenergic receptor (beta 2-AR) signal transduction in adjuvant arthritis (AA) rats. The onset of secondary arthritis in rats appeared around day 14 after injection of Freund's complete adjuvant (FCA). Remarkable secondary inflammatory response and lymphocytes proliferation were observed in AA rats, along with the decrease of anti-inflammatory cytokines interleukin (IL)-4 and transforming growth factor-beta 1 (TGF-beta 1) of MLN lymphocytes, and the increase of pro-inflammatory cytokine IL-2. The administration of Pae (50, 100 mg kg(-1), days 17-24) significantly diminished the secondary hind paw swelling and arthritis scores, reversed the changes of cytokines as discussed above, and further decreased the lowered proliferation of MLN lymphocytes in AA rats. In vitro, Pae restored the previously increased level of cAMP of MLN lymphocytes at the concentrations of 12.5, 62.5 and 312.5 mg l(-1). Meanwhile, Pae increased protein expressions of beta 2-AR and GRK2, and decreased that of beta-arrestin 1, 2 of MLN lymphocytes in AA rats. These results suggested that Pae might induce the Th1 cells immune tolerance, which then shift to Th2, Th3 cells mediated activities to take effect the anti-inflammatory and immunoregulatory effects. The mechanisms of Pae on beta 2-AR desensitization and beta 2-AR-AC-cAMP transmembrane signal transduction of MLN lymphocytes play crucial roles in pathogenesis of this disease.

Topics: Animals; Arthritis, Experimental; Benzoates; Blotting, Western; Bridged-Ring Compounds; Cell Proliferation; Concanavalin A; Cyclic AMP; Freund's Adjuvant; Glucosides; Immune Tolerance; Interleukin-2; Interleukin-4; Lymph Nodes; Lymphocytes; Male; Mesentery; Mice; Mice, Inbred C57BL; Monoterpenes; Rats; Rats, Sprague-Dawley; Receptors, Adrenergic, beta-2; T-Lymphocytes, Regulatory; Th1 Cells; Th2 Cells; Transforming Growth Factor beta1

Previously, we demonstrated the inhibitory effects of Si-Ni-San, a traditional Chinese prescription, on picryl chloride-induced ear contact sensitivity (PCl-CS). This study aimed to evaluate the role of the four major constituents contained in the prescription (saikosaponins, paeoniflorin, naringin and glycyrrhizin) in the inhibitory effect. When administered during the induction phase, saikosaponin a and glycyrrhizin showed significant inhibitory effects, while paeoniflorin and naringin did not. These components in Si-Ni-San also inhibited the activation and proliferation of T lymphocytes as well as the production of cytokines such as tumour necrosis factor-alpha and interferon-gamma to different extents. Saikosaponin a and paeoniflorin dose-dependently reduced the splenocyte adhesion to type I collagen, while glycyrrhizin only showed a slight tendency. Furthermore, treatment with glycyrrhizin or saikosaponin a, rather than paeoniflorin or naringin, moderately inhibited the matrix metalloproteinase (MMP)-2 activity of the splenocytes from PCl-CS mice, and the combination of all four components showed a strong inhibition against MMP-2. Moreover, the components markedly decreased the serum level of nitric oxide in PCl-sensitized mice. The results indicated that saikosaponin a and glycyrrhizin may be the major contributors in the alleviation effect of Si-Ni-San on contact sensitivity, and paeoniflorin and naringin may exhibit a co-operative effect.

Topics: Animals; Benzoates; Bridged-Ring Compounds; Cell Adhesion; Cells, Cultured; Concanavalin A; Dermatitis, Allergic Contact; Dose-Response Relationship, Drug; Drugs, Chinese Herbal; Female; Flavanones; Glucosides; Glycyrrhizic Acid; Immunosuppressive Agents; Interferon-gamma; Lymphocyte Activation; Lymphocytes; Matrix Metalloproteinase 2; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Inbred ICR; Monoterpenes; Nitric Oxide; Oleanolic Acid; Picryl Chloride; RNA, Messenger; Saponins; Spleen