koumine and Arthritis--Rheumatoid

The imbalance between M1-and M2-polarized macrophages is one of the major pathophysiological changes in RA. Therefore, targeted macrophage polarization may be an effective therapy for RA. Koumine, an alkaloid monomer with the highest content and low toxicity in Gelsemium elegans Benth., has the effect of treating RA by playing an immunomodulatory role by influencing various immune cells. However, whether koumine affects macrophage polarization in RA and the associated molecular mechanisms remain unknown.. To investigate the mechanism of the anti-RA effect of koumine on macrophage polarization.. The effect of koumine on macrophage polarization was investigated in vivo and in vitro. We first explored the effects of koumine on AIA rats and detected the levels of M1/M2 macrophage polarization markers in the spleen by western blotting. Then, we explored the regulatory effect of koumine on M1/M2 macrophage polarization and the effect on the PI3K/AKT signaling pathway in vitro. Finally, we verified the effects of koumine on macrophage polarization in CIA mice.. We found that koumine alleviated symptoms, including relieving pain, reducing joint redness and swelling in AIA rats and restoring the M1/M2 macrophage balance in vivo. Interestingly, koumine had an inhibitory effect on both M1 and M2 macrophage polarization in vitro, but it had a stronger inhibitory effect on M1 macrophage. In a mixed polarization experiment, koumine mainly inhibited M1 macrophage polarization and had an inhibitory effect on the PI3K/AKT signaling pathway. Finally, we found that koumine had therapeutic effects on CIA mice, regulated macrophage polarization and inhibited the PI3K/AKT signaling pathway.. Our results reveal that koumine regulates macrophage polarization through the PI3K/AKT signaling pathway. This may be one of the important mechanisms of its anti-RA effect, which provides a theoretical and scientific basis for the possible clinical application of koumine.

Topics: Animals; Arthritis, Rheumatoid; Macrophages; Mice; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Rats

Koumine (KME) is the most abundant active ingredient separated from. The composition of the microemulsion was selected by carrying out a solubility study and generating pseudoternary phase diagrams, and further optimized by D-Optimal design. The optimized KME-MEs was evaluated for particle size, viscosity, drug release, storage stability, cytotoxicity, cellular uptake, Caco-2 cell transport and everted gut sac investigations. In vivo fluorescence imaging and the therapeutic effects of KME and KME-MEs on collagen-induced arthritis (CIA) rats were also evaluated.. The KME-MEs improved the solubility and therapeutic efficacy of KME by employing formulation technology. These results provide a promising vehicle for the oral delivery of KME to treat RA and have attractive potential for clinical translation.

Topics: Animals; Arthritis, Experimental; Arthritis, Rheumatoid; Biological Assay; Caco-2 Cells; Humans; Rats

Dysregulated activation of polyclonal B cells and production of pathogenic antibodies are involved in the development of rheumatoid arthritis (RA). Therefore, targeted B cell therapy is effective against RA. Gelsemium elegans (Gardn. & Champ.) Benth., a toxic plant widely distributed in Southeast Asia, has been used for treating rheumatoid pain, neuropathic pain, spasticity, skin ulcers, and cancers for many years in traditional Chinese medicine. Koumine, an alkaloid monomer from Gelsemium elegans Benth., exerts therapeutic effects against RA. However, whether koumine affects B cells remains unknown. In this study, the effect of koumine on B cells under T cell-independent (TI) and T cell-dependent (TD) immune responses is investigated in vitro and in vivo. Mouse primary B cells were obtained by immunomagnetic bead sorting, and immunomodulatory effects of koumine on the activation, proliferation, and differentiation of B cells were determined in TI and TD models induced by lipopolysaccharide (LPS) and anti-CD40 antibodies in vitro, respectively. The humoral immune responses of TI and TD were established using NP-AECM-FICOLL and NP-CGG in C57BL/6J mice, respectively. We found that koumine inhibited B cell differentiation in the TI model and inhibited B cell activation and proliferation in the TD model in vitro. Koumine also inhibited antibody secretion in TI immune response, TD initial immune response, and in TD secondary immune response. Our results reveal that koumine has a direct and indirect immune regulatory effect on B cells, showing that it can directly inhibit the differentiation and secretion of autoantibodies after abnormal activation of B cells, and indirectly inhibit the activation and proliferation of TD B cells to reduce the secretion of antibodies. It may be an important mechanism for its anti-RA effect in mice, providing a rationale and laboratory data support for the application of koumine in anti-human RA therapy.

Topics: Animals; Antibody Formation; Arthritis, Rheumatoid; Autoantibodies; B-Lymphocytes; Cell Differentiation; Drugs, Chinese Herbal; Gelsemium; Immunity, Cellular; Immunomodulating Agents; Indole Alkaloids; Lymphocyte Cooperation; Medicine, Chinese Traditional; Mice; T-Lymphocytes

Koumine, an alkaloid, exerts therapeutic effects against rheumatoid arthritis (RA), and thus may have a potential application in novel treatment strategies against this disease. Herein, we investigated the regulatory effect of koumine on Th cell polarization using a "pyramid" structure model to elucidate the mechanism underlying its therapeutic effect on RA. The third layer of the model comprises the cytokine secretion layer, in which the effects of koumine on the balance of Th-related cytokines were investigated in mice with collagen-induced arthritis (CIA). Koumine showed significant therapeutic effects and reversed the imbalance of Th1/Th2 and Th17/Treg cytokines. In the Th cell polarization layer, the effects of koumine on the relative numbers of Th cell subsets in splenocytes of rats with CIA were examined. Koumine attenuated both of the increased Th1/Th2 and Th17/Treg subset ratios accompanied with its therapeutic effects. Finally, the primary cultured splenocytes from BALB/c mice were used to further investigate the effect of koumine on Th cell activation by evaluating cell proliferation induced by concanavalin A (Con A), lipopolysaccharides (LPS) and phytohemagglutinin (PHA). Koumine inhibited the cell proliferation responses and its effects on proliferation induced by Con A and PHA were greater than those by LPS, showing the relatively selective inhibition on the proliferation of Th cells. Our results suggest that koumine might restore the homeostasis of the network system with Th subsets and cytokines by inhibiting the activation of T cells, subsequently regulating the polarization of Th subsets and the downstream imbalance of pro/anti-inflammatory cytokines in RA.

Topics: Animals; Arthritis, Experimental; Arthritis, Rheumatoid; Cytokines; Lipopolysaccharides; Mice; Rats; T-Lymphocytes, Regulatory; Th17 Cells

Gelsemium elegans Benth. is a toxic plant that has been used as an ancient Chinese herbal remedy for rheumatoid arthritis (RA) and nervous pain, spasticity, skin ulcers, and cancers. Koumine, one of its representative alkaloids, shows numerous promising pharmacological activities, including anti-inflammatory and analgesic activities. Here, we investigated the analgesic effect of koumine on the collagen-induced arthritis (CIA) rat model of RA and explored the potential pharmacological mechanisms underlying the analgesia. In the CIA rats, repeated koumine treatments significantly reduced pain compared to controls and attenuated the collagen-induced increase in levels of glial fibrillary acidic protein (GFAP) and the pro-inflammatory cytokines tumour necrosis factor α (TNF-α) and interleukin 1β (IL-1β). Cultured astrocytes showed reduced astrocyte reactivation and decreased production of both tested cytokines. Based on our results, koumine exerted both analgesic and anti-inflammatory effects on the CIA rat model that were apparently mediated by inhibiting astrocyte reactivation and pro-inflammatory cytokine production.

Topics: Analgesics; Animals; Arthritis, Experimental; Arthritis, Rheumatoid; Collagen; Disease Models, Animal; Drugs, Chinese Herbal; Indole Alkaloids; Inflammation; Male; Rats; Rats, Wistar

To examine the effect of koumine, a Gelsemium alkaloid, on two experimental models of rheumatoid arthritis (RA), rats with adjuvant-induced arthritis (AIA) and collagen-induced arthritis (CIA) were administered koumine (0.6, 3, or 15 mg/kg/day) or vehicle through gastric gavage (i.g.). Clinical evaluation was performed via measurements of hind paw volume, arthritis index (AI) score, mechanical withdrawal threshold, organ weight, and by radiographic and histological examinations. Levels of interleukin (IL)-1β, tumor necrosis factor (TNF)-α, and antitype II collagen (CII) antibody were also examined. In rats with AIA, koumine reduced the AI score and mechanical allodynia of the injected hind paw in a dose-dependent manner and significantly inhibited increase in thymus and liver weights. In rats with CIA, koumine inhibited increase in hind paw volume, AI score, and mechanical allodynia in a dose-dependent manner and reduced joint space narrowing. Furthermore, koumine also attenuated the increase in the expression of IL-1β and TNF-α, as well as the robust increase of serum anti-CII antibodies in response to immunization. These results suggested that koumine effectively attenuated arthritis progression in two rat models of RA and that this therapeutic effect may be associated with its immunoregulatory action.

Topics: Animals; Arthritis, Experimental; Arthritis, Rheumatoid; Collagen; Cytokines; Disease Models, Animal; Dose-Response Relationship, Drug; Edema; Female; Gelsemium; Indole Alkaloids; Interleukin-1beta; Male; Methotrexate; Molecular Structure; Rats; Rats, Inbred Lew; Rats, Wistar; Tumor Necrosis Factor-alpha