Clinical and histopathological evaluation of MDP/collagen induced arthritis rat model (MCIA) after treatment with Urtica dioica, plantago major and Hypericum perforatum L herbal mixture

Adiponectin exerts a potent anti-arthritic effect and insulin resistance in collagen-induced arthritic rats

AIM

Previous research has shown that adiponectin (AD) induces severe insulin resistance (IR) and exhibits pro-inflammatory effect, so it could serve as a useful risk biomarker in rheumatoid arthritis (RA). The present study aims to evaluate the effect of AD on IR and anti-arthritis in collagen-induced arthritic (CIA) rats.

METHOD

After immunization with bovine type II collagen (CII), Wistar rats were administered with AD (60 μg/kg/day) or saline into the ankle joint cavity of the left hind leg for 15 days. The severity of arthritis was clinically and histologically assessed. Arthritis score was recorded every other day for each paw. Paw volume was measured on alternate days to monitor the progression of the disease in the arthritic control group. Tumor necrosis factor (TNF)-α, interleukin (IL)-1, AD, insulin and fasting glucose were measured in sera. Histopathology of joint synovial tissues was also examined.

RESULTS

Treatment with AD resulted in significantly delayed onset of arthritis as well as decreased clinical arthritis and histopathological severity scores. AD reduced both serum fasting glucose, TNF-α, IL-1 and IR. Histological analysis confirmed treatment with AD suppressed joint synovial inflammation and immunohistochemical expression of TNF-α compared to the CIA group. Surprisingly, adiponectin levels measured by enzyme-linked immunosorbent assay in serum were significantly increased in CIA rats compared to the normal group.

CONCLUSIONS

Adiponectin might display anti-inflammatory effects. These results suggest that AD may be a potential immunosuppressant for the treatment of RA linked to metabolic disease.

The globalization of traditional medicine in northern peru: from shamanism to molecules

Northern Peru represents the center of the Andean "health axis," with roots going back to traditional practices of Cupisnique culture (1000 BC). For more than a decade of research, semistructured interviews were conducted with healers, collectors, and sellers of medicinal plants. In addition, bioassays were carried out to evaluate the efficacy and toxicity of plants found. Most of the 510 species encountered were native to Peru (83%). Fifty percent of the plants used in colonial times have disappeared from the pharmacopoeia. Market vendors specialized either on common and exotic plants, plants for common ailments, and plants only used by healers or on plants with magical purposes. Over 974 preparations with up to 29 different ingredients were used to treat 164 health conditions. Almost 65% of the medicinal plants were applied in these mixtures. Antibacterial activity was confirmed in most plants used for infections. Twenty-four percent of the aqueous extracts and 76% of the ethanolic extracts showed toxicity. Traditional preparation methods take this into account when choosing the appropriate solvent for the preparation of a remedy. The increasing demand for medicinal species did not increase the cultivation of medicinal plants. Most species are wild collected, causing doubts about the sustainability of trade.

5,7,3′-Triacetyl Hesperetin Suppresses Adjuvant-Induced Arthritis in Rats through Modulating JAK2/STAT3 Pathway

This work was designed to identify the effect of 5,7,3′-triacetyl hesperetin (TAHP) on rat adjuvant arthritis (AA) and further clarify the possible role of TAHP on modulating Janus kinase signal transducers and activators (JAK/STAT in this process. Freund's complete adjuvant was used to induce AA in rats. TAHP (33, 66, 132 mg/kg) was administered intragastrically. Secondary paw swelling, polyarthritis index, index of immune organs and histopathological assessment were used to evaluate the effects of TAHP on AA in rats. IL-6 in serum and in synovial tissues was examined with ELISA and RT-PCR. In addition, JAK2/STAT3 pathway-related key molecules mRNA expression in synovial tissues of AA rats were detected by RT-PCR and western blot respectively. It was found that TAHP (66, 132 mg/kg) could significantly inhibit secondary paw swelling, restore the index of immune organs and reduce polyarthritis index. Results of histopathological assessment showed that TAHP clearly ameliorated the pathological changes in AA rats. TAHP could downregulate the level of IL-6 in serum and in synovial tissues of AA rats. Besides, treatment with TAHP could decrease mRNA expressions of STAT3 and JAK2, as well as the ratio of p-JAK2/JAK2 protein and p-STAT3/STAT3 protein from synovial tissues. Thus, the paper demonstrated that TAHP had a therapeutic effect on AA in rats and the mechanisms were partly associated with modulating proinflammatory cytokine IL-6 production in serum and in synovial tissues and inhibiting excessive activation of JAK2/STAT3 signaling pathway which might play a crucial role in the pathogenesis of AA.

Comparison of the effects of genistein and daidzein with dexamethasone and soy protein on rheumatoid arthritis in rats

INTRODUCTION

We have already shown the protective effects of soy protein on rheumatoid arthritis in rats. In this study, the effects of genistein and daidzein, two isoflavones from soy on rheumatoid arthritis prognosis and prevention in rats have been investigated.

METHODS

Rheumatoid arthritis was induced in female Sprague-Dawley rats using collagen type II plus adjuvant. Rats were then treated with soy protein (7 g/kg), dexamethasone (1 mg/kg), genistein (20 mg/kg genistein), daidzein (20 mg/kg genistein) and casein (in control groups) by daily gavage feedings for 50 days. Scores of arthritis were recorded every day for each paw of animal. Serum concentrations of TNF-α, IL-6, adiponectin and leptin were characterized. Tibiotarsal tissue was used for histopathologic analyses.

RESULTS

Treatment with genistein and daidzein resulted in not only a reduction in disease symptoms but also a delay in the onset of symptoms. Results from delayed-type hypersensitivity test demonstrated that the ear thickness in treated rats was significantly lower than that in the control group (p<0.05). There was a reduction in TNF-α, IL-6, adiponectin and leptin serum concentrations after treatment with genistein and daidzein. Dexamethasone reduced the serum concentrations of TNF-α, IL-6 and adiponectin but increased leptin serum level. Prevention of the tissue damage and joint inflammation was also observed following treatment with two soy isoflavones.

CONCLUSION

soy isoflavones, daidzein and especially genistein, could significantly improve rheumatoid arthritis symptoms in rats. The structural similarity of isoflavones to estrogen could be the possible underlying mechanism involved in the function.

Protective effect of soy protein on collagen-induced arthritis in rat

To evaluate preventive and therapeutic effects of soy protein on collagen-induced arthritis rats. Sprague-Dawley rats immunized with bovine type II collagen emulsified in adjuvant and treated with soy protein (7 g/kg), dexamethasone (1 mg/kg), and casein (in control groups) by daily gavages feedings for 30 days. Score of arthritis recorded every day for each paws of animal. Tumor necrosis factor-alpha, interleukin6, leptin, and adiponectin were measured in serums. Treatment with soy protein resulted in significant delay in time to onset of arthritis as well as significantly decreased arthritis incidence, clinical arthritis severity score, histopathological arthritis severity score, and in vivo cell-mediated immunity to collagen (P < 0.05). Administration of soy protein significantly suppressed the progression of collagen II-induced arthritis and inhibited the production of tumor necrosis factor-alpha, interleukin6, leptin, and adiponectin. Soy protein appeared to be a potent immunomodulatory inhibitor of collagen II-induced arthritis in rats. It could delay onset of RA and reduced cartilage erosion and synovitis inflammation. Therefore, it may be a useful protein in the prevention and treatment of rheumatoid arthritis patient.

Investigation of the role of tumour necrosis factor-α, interleukin-1β, interleukin-10, nitric oxide and rheumatoid factor-immunoglobulin M in a rat model of arthritis

Collagen-induced arthritis (CIA) in rats is a widely used preclinical animal model of rheumatoid arthritis (RA). However, CIA development in Sprague-Dawley (SD) rats is less severe in terms of inflammatory response compared with other strains. Therefore, a modified CIA model called MCIA, using N-acetylmuramyl dipeptide (MDP), has been developed in the less sensitive SD rat strains. This work was conducted to better understand the immunopathological role and contributions of the pro-inflammatory T-helper type 1 (Th-1) cytokines and inflammatory mediators, interleukin-1 (IL-1 β), tumour necrosis factor-alpha (TNF- α) and nitric oxide (NO); the anti-inflammatory T-helper type 2 (Th-2) cytokine, IL-10 and autoantibodies such as rheumatoid factor (RF)-immunoglobulin M (IgM) in this newly developed RA model. TNF-α, NO and RF-IgM levels were significantly increased, while IL-1 β levels were not affected in this MCIA rat model. The levels of IL-10 were lower than the baseline when compared with controls. In conclusion: (1) the immunological features represented in the MCIA rat model favour the Th-1 cytokine profile over Th-2 and (2) RF-IgM can be used as a diagnostic test in preclinical RA models.