Background. The dry root of Flemingia philippinensis has been widely used in the treatment of rheumatism, arthropathy, and osteoporosis in traditional Chinese medicine; the therapeutic effects of Flemingia philippinensis are associated with antiarthritis in traditional Chinese medicine theory. This study was undertaken to investigate the mechanism of bone erosion protection and anti-inflammatory effect of Flemingia philippinensis flavonoids (FPF) in collagen-induced arthritis (CIA) in mice. Methods. Flavonoids were extracted from the dry root of Flemingia philippinensis. Collagen-induced arthritis in C57BL/6 mice was used as a rheumatoid arthritis model, and the mice were orally fed with FPF prior to induction to mimic clinical prophylactic therapy for a total of 39 days. After treatment, histology and immunohistochemistry staining were performed, and the levels of anti-collagen type II (CII) antibody and inflammatory mediators, as well as the key proteins of nuclear factor kappa-B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways, were detected in the samples taken from ankle joints, plasma, and paws. Results. FPF administration significantly suppressed the paw swelling and arthritic score in CIA mice. FPF reduced inflammatory infiltration and pannus formation, articular cartilage destruction and osteoclast infiltration, and the expression of MMP-9 and cathepsin K in the ankle joint. FPF inhibited plasma anti-CII antibody levels and the production of inflammatory cytokines and chemokines in CIA paws. FPF treatment suppressed the activation of NF-κB as indicated by downregulating the phosphorylation of NF-κB p65 and mitogen-activated protein kinases in CIA paws. Additionally, FPF significantly inhibited inflammation signaling by suppressing the activation of activator protein-1 subset and signal transducers and activators of transcription 3 (STAT3). Conclusions. Our data suggest that FPF might be an active therapeutic agent for rheumatoid arthritis and the preventive effect of FPF on arthritis is attributable to an anti-inflammatory effect on CIA by preventing bone destruction, regulating inflammatory mediators, and suppressing NF-κB and MAPK signaling pathways.

Atopic dermatitis (AD) is a relapsing, acute, and chronic skin disease featured by intractable itching, eczematous skin. Conventional therapies based on immunosuppression such as corticosteroids are associated with multiple adverse reactions. Periploca forrestii Schltr saponin (PFS) was shown to potently inhibit murine arthritis by protecting bone and cartilage injury and suppressing NF-κB activation. However, its therapeutic effect on oxazolone-induced atopic dermatitis (AD) and the underlying mechanisms on macrophage are still unclear. The AD-like dermatitis was induced by repeated oxazolone challenge to the skin of BALB/c mice in vivo. Blood and ears were biochemically or histologically processed. RT-PCR, western blotting, and ELISA were conducted to evaluate the expression of macrophage factors. Mouse bone marrow-derived macrophages (BMDMs) stimulated with lipopolysaccharide (LPS) were used as a model in vitro. PFS treatment inhibited AD-like dermatitis development. PFS downregulated epidermis thickness and cell infiltration, with histological analysis of the skin lesion. PFS alleviated plasma immunoglobulin (Ig) E, IgG2a, and IgG1 levels. PFS downregulated the expression of M1 macrophage factors, tumor necrosis factor- (TNF-) α, interleukin- (IL-) 6, monocyte chemotactic protein-1 (MCP-1), and nitric oxide synthase2 (NOS2), and M2 macrophage factors, IL-4, arginase1 (Arg1) and CD163 in AD-like skin, which were confirmed by western blot and ELISA analysis. In addition, PFS inhibited LPS-induced macrophage polarization via the inhibition of the phosphorylation of signal transducer and activator of transcription 3 (STAT3) and nuclear translocation of NF-κB p65. These results suggest that PFS exerted an antidermatitis effect against oxazolone by modulating macrophage activation. PFS administration might be useful in the treatment of AD and inflammatory skin diseases.

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ObjectivePeriploca forrestii Schltr has been used as a Chinese folk medicine for the treatment of rheumatism, arthralgia and fractures. However, the anti-arthritic activity of Periploca forrestii saponin (PFS) and the active compound has still not been revealed. This study aimed to investigate the protective effects and mechanisms of PFS on collagen type II (CII) collagen-induced arthritis (CIA) mice. We sought to investigate whether PFS and Periplocin could regulate osteoclastogenesis, and if so, further investigation on its mechanism of action.MethodsArthritis was induced in female BALB/c mice by CIA method. PFS was administered at a dose of 50 mg/kg body weight once daily for five weeks. The effects of treatment in mice were assessed by histological and biochemical evaluation in sera and paws. Anti-osteoclastogenic action of PFS and Periplocin was identified using an osteoclast formation model induced by RANKL.ResultsPFS ameliorated paw erythema and swelling, inhibited bone erosion in ankle joint histopathological examination. PFS treatment resulted in decreased IgG2a, and increased IgG1 levels in the serum of CIA mice. Decreased TNF-α, and increased interleukin (IL)-4 and IL-22 levels were also found in PFS-treated mice. PFS inhibited the I-κBα phosphorylation, blocked nuclear factor (NF)-κB/p65 phosphorylation and abrogated AP-1/c-Fos activity. PFS downregulated toll-like receptor (TLR) 4, STAT3 and MMP-9 expression in CIA mice and RANKL-induced osteoclastogenesis. PFS and Periplocin inhibited RANKL-induced osteoclast formation in a dose dependent manner within nongrowth inhibitory concentration, and PFS decreased osteoclastogenesis-related marker expression, including cathepsin K and MMP-9.ConclusionThis study revealed that the protective mechanism of PFS on CIA was associated with regulatory effects on proinflammatory factors and further on the crosstalk between NF-κB and c-Fos/AP-1 in vivo and in vitro. Therefore, PFS is a promising therapeutic alternative for the treatment of RA, evidencing the need to conduct further studies that can identify their active components in treating and preventing RA.