Effect of Dioscorea villosa extract and the phytoestrogen diosgenin on ovariectomized mice with zymosan-induced arthritis

Abstract Humans are exposed to natural compounds such as phytoestrogens primarily through diet and supplements. These compounds promote health by alleviating the symptoms and illnesses associated with menopause and arthritis. Diosgenin (DSG) occurs naturally in plants such as Dioscorea villosa (DV) and binds to estrogen receptors, so it may have similar effects to this hormone, including against arthritis. Thus, we investigated the effect of chronic treatment with dry extract of DV and its phytoestrogen DSG on ovariectomized mice with arthritis. We found that dry extract of Dioscorea villosa (DV) contains the phytoestrogen diosgenin (DSG) in its composition. Furthermore, arthritic mice treated with DV and DSG showed reduced neutrophil accumulation in the articular cartilage. Also, the dry extract of DV administered orally (v.o) did not alter the leukocyte count in the joints or promote changes in the reproductive tract. However, DSG altered these parameters, with possible beneficial effects by reducing symptoms related to reproductive aging. Thus, oral treatment with dry extract of DV and subcutaneous (s.c) treatment with DSG showed promise by acting against inflammation caused by arthritis and reducing symptoms in the reproductive tract due to menopause.

Biochanin A as a modulator of the inflammatory response: An updated overview and therapeutic potential.

Uncontrolled inflammation and failure to resolve the inflammatory response are crucial factors involved in the progress of inflammatory diseases. Current therapeutic strategies aimed at controlling excessive inflammation are effective in some cases, though they may be accompanied by severe side effects, such as immunosuppression. Phytochemicals as a therapeutic alternative can have a fundamental impact on the different stages of inflammation and its resolution. Biochanin A (BCA) is an isoflavone known for its wide range of pharmacological properties, especially its marked anti-inflammatory effects. Recent studies have provided evidence of BCA's abilities to activate events essential for resolving inflammation. In this review, we summarize the most recent findings from pre-clinical studies of the pharmacological effects of BCA on the complex signaling network associated with the onset and resolution of inflammation and BCA's potential protective functionality in several models of inflammatory diseases, such as arthritis, pulmonary disease, neuroinflammation, and metabolic disease.

Biochanin A Regulates Key Steps of Inflammation Resolution in a Model of Antigen-Induced Arthritis via GPR30/PKA-Dependent Mechanism.

Biochanin A (BCA) is a natural organic compound of the class of phytochemicals known as flavonoids and isoflavone subclass predominantly found in red clover (Trifolium pratense). It has anti-inflammatory activity and some pro-resolving actions, such as neutrophil apoptosis. However, the effect of BCA in the resolution of inflammation is still poorly understood. In this study, we investigated the effects of BCA on the neutrophilic inflammatory response and its resolution in a model of antigen-induced arthritis. Male wild-type BALB/c mice were treated with BCA at the peak of the inflammatory process (12 h). BCA decreased the accumulation of migrated neutrophils, and this effect was associated with reduction of myeloperoxidase activity, IL-1ß and CXCL1 levels, and the histological score in periarticular tissues. Joint dysfunction, as seen by mechanical hypernociception, was improved by treatment with BCA. The resolution interval (Ri) was also quantified, defining profiles of acute inflammatory parameters that include the amplitude and duration of the inflammatory response monitored by the neutrophil infiltration. BCA treatment shortened Ri from ∼23 h observed in vehicle-treated mice to ∼5.5 h, associated with an increase in apoptotic events and efferocytosis, both key steps for the resolution of inflammation. These effects of BCA were prevented by H89, an inhibitor of protein kinase A (PKA) and G15, a selective G protein-coupled receptor 30 (GPR30) antagonist. In line with the in vivo data, BCA also increased the efferocytic ability of murine bone marrow-derived macrophages. Collectively, these data indicate for the first time that BCA resolves neutrophilic inflammation acting in key steps of the resolution of inflammation, requiring activation of GPR30 and via stimulation of cAMP-dependent signaling.

Biochanin A attenuates zymosan-induced arthritis in mice similarly to 17-ß estradiol: an alternative to hormone replacement therapy?

OBJECTIVE AND DESIGN: Biochanin A (BCA), a phytoestrogen, has various pharmacological properties. This study was conducted to compare BCA's therapeutic property against 17-ß estradiol replacement therapy in zymosan-induced arthritis (ZIA) in mice. Additionally, we further investigated in vitro the anti-inflammatory action on neutrophils. TREATMENT: Ovariectomized (OVX) and non-OVX mice were pretreated with BCA (1, 3 and 9 mg/kg) or estrogen (50 µg/kg) for 14 days prior to ZIA. Neutrophils were pretreated with BCA (1, 10 and 100 µM) for 1 h prior to phorbol 12-myristate 13-acetate. METHODS: Anti-inflammatory effects of BCA were evaluated by cellular infiltrate, paw edema and cytokine measurement. In vitro, apoptosis was assessed by morphology and flow cytometry. Neutrophil extracellular traps (NET) were determined by fluorescent microscopy and DNA release. Statistical differences were determined by one- or two-way ANOVA. RESULTS: BCA inhibited neutrophil accumulation, paw edema and proinflammatory cytokine (TNF-α and IFN-γ) and increased anti-inflammatory cytokines (IL-4 and IL-10) in OVX and non-OVX mice, similar to 17-ß estradiol replacement therapy. In vitro, BCA increased apoptosis and consequently reduced NETs. CONCLUSION: BCA has a notable anti-inflammatory effect, similar to 17-ß estradiol, and is especially effective for treatment of ZIA. These results suggest that BCA may be promising for the treatment of postmenopausal arthritis.