peoniflorin and Dermatitis--Allergic-Contact

Paeoniflorin (PF) has been demonstrated to have an anti-allergic and anti-inflammatory effect in the treatment of allergic contact dermatitis (ACD). However, its clinical application is hampered by the lacking of comprehensive mechanical explanation. This research aimed to study the effect of PF on the proliferation, apoptosis and cytokines secretion as well as the expression of nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways of T lymphocytes activation in vitro and in vivo. We found that PF depressed human T lymphocytes activation via inhibition ofinterferon-gamma (IFN-γ) production and NF-κB/IκBα and p38 MAPK signaling pathway in vitro, also PF could attenuate such ACD responses by inhibiting the production of IFN-γ and NF-κB/IκBα pathway in T lymphocytes of ACD mouse model, suggesting that PF might be useful for the treatment of T cell-mediated allergic inflammatory disorders such as ACD. This would make PF a promising T cell-targeted drug candidate for further study because of its immunosuppressive and anti-inflammatory effects.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Cells, Cultured; Dermatitis, Allergic Contact; Disease Models, Animal; Glucosides; Humans; Inflammation; Interferon-gamma; Monoterpenes; NF-kappa B; NF-KappaB Inhibitor alpha; Signal Transduction; T-Lymphocytes

Allergic contact dermatitis (ACD) is a classical experimental model of allergic inflammatory skin disease, which is a delayed-type hypersensitivity reaction that is mediated by hapten-specific T lymphocytes. The goal of this study was to investigate the pharmacokinetic profiles of 6'-acetylpaeoniflorin (6-AP) and the effect of 6-AP on the ACD model. 6-AP was synthesized from paeoniflorin (Pae) via acetylation, and the structure was confirmed. There were statistically significant differences in the pharmacokinetic parameters including t 1/2α , t 1/2β , AUC, MRT and C max among the animals that were orally administered Pae and 6-AP. An ACD model was induced using immunization with dinitrochlorobenzene (DNCB) in BALB/c mice. The mice were orally administered 6-AP (35, 70 and 140 mg/kg/d), Pae (70 mg/kg/d) and prednisone (Pre, 5 mg/kg/d) from day 1 to day 7 after immunization. The results indicated that the topical application of DNCB to the skin provoked obvious inflammatory responses. 6-AP significantly inhibited ear swelling and decreased inflammatory cell infiltration and epidermal keratinization. Additionally, 6-AP observably alleviated the hyperplasia of red pulp and germinal center appearance, decreased the spleen index and inhibited splenocyte proliferation in the ACD model compared to that of Pae. Furthermore, the study indicated that 6-AP could increase the IL-10 level, while simultaneously reducing the IL-17 level in splenocytes. In summary, these results suggest that 6-AP has a significantly higher anti-inflammatory effect than Pae and that 6-AP might be a candidate for the treatment of allergic skin diseases.

Topics: Animals; Anti-Inflammatory Agents; Cells, Cultured; Dermatitis, Allergic Contact; Dinitrochlorobenzene; Glucosides; Hypersensitivity, Delayed; Interleukin-10; Interleukin-17; Lymphocyte Activation; Male; Mice; Mice, Inbred BALB C; Monoterpenes; Skin; Spleen

Mounting evidence has suggested that inflammation is associated with IL-6/Stat3 pathway in dendritic cells (DCs) and Th17 cells, which are critical for development of allergic contact dermatitis (ACD). Paeoniflorin (PF) has been clinically proved to be effective in the treatment of inflammatory skin diseases such as ACD. We have previously demonstrated the effect of PF on DCs stimulated with 1-chloro-2,4-dinitrobenze (DNCB) and naïve CD4(+)CD45RA(+) T cells for Th17 cell differentiation. However, whether PF down-regulates IL-6/Stat3 in DCs and Th17 cells remains to be explored. In this study, we show clearly that PF markedly decreases IL-6/Stat3 in DCs stimulated with DNCB at both gene and protein levels compared with control DCs in vitro. Meanwhile, PF up-regulates suppressor of cytokine signaling 3 (Socs3). Such decreased expression of IL-6/Stat3 is abolished in DCs that were transfected with Socs3 short interfering RNA (siRNA). When mice CD4(+)CD45 RA(+) T cells were co-cultured with PF-treated DCs stimulated with/without DNCB, the gene expression of the Th17 cell markers such as retinoic acid-related orphan nuclear hormone receptor γt (RORγt), IL-17A, and IL-23R decreased, in accordance with the less secretions of IL-17 and IL-23 in vitro and in vivo. Finally, the suppressed Th17 differentiation induced by PF can be abolished by additional recombinant mouse IL-6. Our results suggest that the anti-inflammatory mechanisms introduced by depletion of Socs3 expression or inactivation of the negative regulator such as Socs3 may represent a promising strategy for the prevention of ACD.

Topics: Animals; Anti-Inflammatory Agents; Cells, Cultured; Dendritic Cells; Dermatitis, Allergic Contact; Dinitrochlorobenzene; Female; Glucosides; Humans; Interleukin-6; Mice; Mice, Inbred BALB C; Monoterpenes; Nuclear Receptor Subfamily 1, Group F, Member 3; RNA, Small Interfering; Signal Transduction; STAT3 Transcription Factor; Suppressor of Cytokine Signaling 3 Protein; Th17 Cells

Allergic contact dermatitis (ACD) is a hapten-specific CD4(+) T-cells mediated inflammatory response of the skin. Its pathomechanism involves 2 phases, an induction phase and an elicitation phase. Langerhans cells (LCs) and dendritic cells (DCs) in the skin play key roles in presenting low molecular weight chemicals (haptens) to the lymph nodes. Therefore, inhibition of the migration of LCs or DCs and T-cell proliferation is each expected to control ACD disease. To explore the effectiveness of paeoniflorin (PF) on the migration of LCs and T-cell proliferation in vivo, we establish a murine model of ACD, promoted by repeated exposure to an allergen (specifically 1-Chloro-2,4-dinitrobenzene (DNCB)). Administration of PF inhibits DC migration in this DNCB-induced model in the induction phase. As a result, epidermal LC density in the elicitation phase increased in PF-treated mice when compared to PF-untreated mice. At the same time, PF reduced IFN-γ(+)CD4(+) and IL-17(+)CD4(+) T cells proliferation (but not IL-4(+)CD4(+) T cells proliferation), leading to an attenuated cutaneous inflammatory response. Consistent with this T-cell proliferation profile, secretions of IFN-γ and IL-17 were reduced and IL-10 secretion increased in PF-treated mice, but production of IL-4 and IL-5 remained unchanged in the skin and blood samples. These results suggest that oral administration of PF can treat and prevent ACD effectively through inhibition of DC migration, and thus decrease the capacity of DCs to stimulate Th1 and Th17 cell differentiation and cytokine production.

Topics: Administration, Oral; Animals; Cell Differentiation; Cell Movement; Cytokines; Dendritic Cells; Dermatitis, Allergic Contact; Dinitrochlorobenzene; Disease Models, Animal; Female; Glucosides; Lymph Nodes; Mice, Inbred BALB C; Monoterpenes; RNA, Messenger; Skin; Th1 Cells; Th17 Cells

Paeoniflorin (Pae) was previously reported to inhibit inflammation in the skin of mice with allergic contact dermatitis (ACD); however, the mechanism remains unclear. The primary purpose of this study was to investigate the effect of Pae on the regulation of cytokine production in a murine model of ACD.. ACD was induced in the mice by repeated application of dinitrochlorobenzene (DNCB) to their skin. Cutaneous inflammation was evaluated by measuring ear swelling and by histological examination. The cytokine levels were measured by enzyme-linked immunosorbent assays.. The results showed that topical application of DNCB caused obvious swelling and inflammatory cell infiltration. Treatment with Pae (70 or 140 mg/kg/d) significantly inhibited the cutaneous inflammation and decreased thymocyte proliferation in the mice with ACD. Additional data indicated that Pae increased interleukin-4 (IL-4) and IL-10 production but reduced IL-2 and IL-17 levels in the serum as well as in thymocyte and splenocyte culture supernatants. As expected, IL-2 and IL-17 levels in the serum displayed a significant positive correlation with the severity of skin inflammation. In contrast, IL-4 and IL-10 levels were negatively correlated with the inflammation.. The anti-inflammatory action of Pae in the murine model of ACD may be related to its regulation of an imbalanced cytokine production.

Topics: Animals; Animals, Outbred Strains; Anti-Inflammatory Agents; Benzoates; Bridged-Ring Compounds; Cytokines; Dermatitis, Allergic Contact; Dinitrochlorobenzene; Glucosides; Irritants; Male; Mice; Monoterpenes; Skin; Spleen; Thymus Gland

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