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.

Nerolidol-beta-cyclodextrin inclusion complex enhances anti-inflammatory activity in arthritis model and improves gastric protection.

Rheumatoid arthritis is an autoimmune inflammatory disease with progressive degradation of cartilage and joints. Additionally, gastric ulcer affects many patients who make prolonged use of non-steroidal anti-inflammatory drugs widely used in the symptomatic treatment of rheumatoid arthritis. Nerolidol, a natural sesquiterpene, has several biological activities including anti-inflammatory and antiulcerogenic action. This study aims to develop and characterize a nerolidol ß-cyclodextrin inclusion complex and to evaluate its activity in an experimental arthritis model. Inclusion complex was prepared by the lyophilization method and characterized by NMR, term analysis, XRD and SEM. Neutrophil migration assays and histopathological analysis were performed on zymosan-induced arthritis model using Swiss mice. And the gastroprotective effect was evaluated in two models of gastric ulcers: induced by ethanol and indomethacin. Inclusion complex showed no cytotoxicity and free nerolidol at a dose of 100 mg/kg (p.o.) in the arthritis model reduced neutrophil migration in 56% in relation to vehicle, and this inhibition was more expressive in the inclusion complex (67%) at the same dose. Histopathological analysis of the joint tissue confirmed the reduction of inflammatory signs. In the ethanol-induced gastric ulcer model, free nerolidol reduced the relative ulcer area more expressively (4.64%) than the inclusion complex (21.3%). However, in the indomethacin induction model, the inclusion complex showed better results in gastric protection compared to free nerolidol. The action of nerolidol complexed in beta-cyclodextrin in reducing arthritis inflammation combined with its gastroprotective action make it a potential new drug.