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

Can intra-articular daidzein injection reduce oxidative damage and early osteoarthritis in a rabbit temporomandibular joint model?

BACKGROUND

Oxidative damage and inflammatory cytokines in osteoarthritis (OA) exacerbate the disease course. Daidzein (DZ) has antioxidant and anti-inflammatory effects. This study evaluated the early histopathological effects of intra-articular daidzein injection on experimentally induced osteoarthritis in rabbit TMJs.

METHODS

The predictor variable was intra-articular injection of DZ or a saline control. 50 µl of 3 mg/mL MIA solution was injected into the right TMJ of 16 New Zealand rabbits to induce experimental OA. One rabbit was sacrificed after 4 weeks to confirm the formation of the OA model and the OA model was obtained. The remaining 15 rabbits were randomly divided into 2 groups: an experimental group (9 rabbits) and a control group (6 rabbits). On days 1, 7, 14, and 21; 50 µl of saline solution was applied to the right TMJ of the control group and 50 µl daidzein solution (1.8 mg/ml) was applied to the right TMJ to the experimental group. After one week from the date of the last injection, the rabbits were sacrificed, and histopathological and biochemical evaluations were performed. The Shapiro-Wilk test was used to evaluate whether the variables in the study conformed to normal distribution. Mean ± SD (standard deviation) or median (interquartile range (IQR)) was used to show the descriptive statistics of the variables. T-test and Mann Whitney U test were used to compare the control and experimental groups for biochemical changes. The chi-square test was used to show the distribution of histopathological changes variables obtained within the scope of the study based on control and experimental groups. A P-value < 0.05 was considered significant for all evaluations.

RESULTS

There were 8 and 6 animate treated with DZ and saline, respectively. There was no statistically significant difference between groups in articular cartilage (p = 0.3), osteochondral junction (p = 0.3), subchondral bone structure (p = 1.0) or chondrocyte appearance (p = 0.4). The experimental group showed significantly lower mean values for Total Oxidant Status (TOS) (p = 0.002) and Oxidative Stress Index (OSI) (p = 0.007).

CONCLUSIONS

An intra-articular DZ injection appears to show limited reduction of oxidative damage and early OA in the rabbit TMJ. DZ might represent a promising natural compound with beneficial effects in the management of TMJ-OA.

The protective activity of genistein against bone and cartilage diseases

Genistein, a natural isoflavone rich in soybean and leguminous plants, has been shown various biological effects, such as anti-inflammation, anti-oxidation, anti-cancer, and bone/cartilage protection. Due to the structural similarity to estrogen, genistein exhibits estrogen-like activity in protecting against osteoporosis and osteoarthritis. Furthermore, genistein has been considered as an inhibitor of tyrosine kinase, which has been found to be dysregulated in the pathological development of osteoporosis, osteoarthritis, and intervertebral disc degeneration (IDD). Many signaling pathways, such as MAPK, NF-κB, and NRF2/HO-1, are involved in the regulatory activity of genistein in protecting against bone and cartilage diseases. The potential molecular mechanisms of genistein in therapeutic management of bone and cartilage diseases have been investigated, but remain to be fully understood. In this article, we mainly discuss the current knowledge of genistein in protecting against bone and cartilage diseases, such as osteoporosis, osteoarthritis, rheumatoid arthritis (RA), and IDD.

Association of Leptin Gene Polymorphisms with Rheumatoid Arthritis in a Chinese Population

Background

Recently, increasing studies have revealed that leptin is involved in the development of rheumatoid arthritis (RA). This study is aimed at exploring the association of leptin gene single nucleotide polymorphisms (SNPs) with susceptibility to RA in a Chinese population.

Methods

We recruited 600 RA patients and 600 healthy controls from a Chinese population and analyzed their three leptin SNPs (rs10244329, rs2071045, and rs2167270) using the improved Multiplex Ligase Detection Reaction (iMLDR) assays. The associations of these SNPs with clinical manifestations of RA were also analyzed. Enzyme-linked immunosorbent assay (ELISA) was performed for plasma leptin determination.

Results

No significant difference in either allele or genotype frequencies of these three SNPs between RA patients and healthy controls was observed (all P > 0.05). Association between the genotype effects of dominant, recessive models was also not found (all P > 0.05). No significant difference in plasma leptin levels was detected between RA patients and controls (P > 0.05).

Conclusion

Leptin gene (rs10244329, rs2071045, and rs2167270) polymorphisms are not associated with RA genetic susceptibility and its clinical features in the Chinese population.

Phenolic Compounds Impact on Rheumatoid Arthritis, Inflammatory Bowel Disease and Microbiota Modulation

Non-communicable chronic diseases (NCDs) are nowadays the principal cause of death, especially in most industrialized nations. These illnesses have increased exponentially with the consumption of diets very high in fat and sugar, not to mention stress and physical inactivity among other factors. The potential impact of suboptimal diets on NCDs’ morbidity and mortality rates brings to the forefront the necessity for a new way of improving dietary habits. The literature provides extensive scientific work that presents evidence that phenolic compounds from diets have antioxidant, anti-inflammatory and antiproliferative activities that impact human health. Gut microbiota modulation by some phenolic compounds leads to favorable changes in abundance, diversity, and in the immune system. However, polyphenol’s limited bioavailability needs to be overcome, highlighting their application in new delivery systems and providing their health benefits in well-established ways such as health maintenance, treatment or adjuvant to conventional pharmacological treatments. In this context, novel dietary approaches, including new food supplements, have emerged to prevent diseases and preserve health.

Tyrosine Kinase Inhibitors Reduce NMDA NR1 Subunit Expression, Nuclear Translocation, and Behavioral Pain Measures in Experimental Arthritis

In the lumbar spinal cord dorsal horn, release of afferent nerve glutamate activates the neurons that relay information about injury pain. Here, we examined the effects of protein tyrosine kinase (PTK) inhibition on NMDA receptor NR1 subunit protein expression and subcellular localization in an acute experimental arthritis model. PTK inhibitors genistein and lavendustin A reduced cellular histological translocation of NMDA NR1 in the spinal cord occurring after the inflammatory insult and the nociceptive behavioral responses to heat. The PTK inhibitors were administered into lumbar spinal cord by microdialysis, and secondary heat hyperalgesia was determined using the Hargreaves test. NMDA NR1 cellular protein expression and nuclear translocation were determined by immunocytochemical localization with light and electron microscopy, as well as with Western blot analysis utilizing both C- and N-terminal antibodies. Genistein and lavendustin A (but not inactive lavendustin B or diadzein) effectively reduced (i) pain related behavior, (ii) NMDA NR1 subunit expression increases in spinal cord, and (iii) the shift of NR1 from a cell membrane to a nuclear localization. Genistein pre-treatment reduced these events that occur in vivo within 4 h after inflammatory insult to the knee joint with kaolin and carrageenan (k/c). Cycloheximide reduced glutamate activated upregulation of NR1 content confirming synthesis of new protein in response to the inflammatory insult. In addition to this in vivo data, genistein or staurosporin inhibited upregulation of NMDA NR1 protein and nuclear translocation in vitro after treatment of human neuroblastoma clonal cell cultures (SH-SY5Y) with glutamate or NMDA (4 h). These studies provide evidence that inflammatory activation of peripheral nerves initiates increase in NMDA NR1 in the spinal cord coincident with development of pain related behaviors through glutamate non-receptor, PTK dependent cascades.

Investigation of the efficacy of daidzein in experimental knee osteoarthritis-induced with monosodium iodoacetate in rats

BACKGROUND

Osteoarthritis (OA) is a degenerative chronic illness that most frequently occurs in the knee joint. Daidzein (DZ) an isoflavone has anti-inflammatory and antioxidant activity. The aim of this study was to evaluate the effectiveness of DZ as a treatment for experimental knee OA (KOA) in rats.

METHOD

An experimental KOA model was induced by monosodium iodoacetate (MIA) in rats. Thereafter, 49 Wistar albino male rats (250-300 g, 12-16 weeks old) were randomly divided into 7 groups: C (healthy control); DC (KOA + saline); hyaluronic acid (HA); HA+ intraarticular (ia) DZ; oral (po) DZ; ia DZ; HA + po DZ groups. DZ and/or HA were administered intraarticularly to the rats as 50 μL on days 1, 7, 14, and 21. Alternatively, the DZ was administered orally as 0.5 mL twice daily for 21 days. After the treatment, rats were sacrificed by decapitation under general anesthesia. Serum samples were analyzed to determine the total oxidant status (TOS) and total antioxidant status (TAS) and the levels of TNF-α, IL-1β, MMP-13, and DZ. Knee joint samples underwent histopathological examination, and TNF-α, IL-1β, NOS2, and MMP-13 were analyzed with immunohistochemical methods.

RESULTS

HA, DZ, and DZ + HA effectively reduced the levels of TNF-α, IL-1β, and MMP-13 in the serum of the DC group (p < 0.001). In groups that received HA, DZ, or DZ + HA, the serum TAS increased compared with the DC group (p < 0.05). When the DZ + HA combination was used, a more pronounced reduction in the levels of TNFα, NOS2, IL-1β, and MMP-13 was observed in knee joints. In addition, the cracks on the cartilage surface and fibrillation were completely improved in the groups that received HA, DZ, or DZ + HA compared with the DC group.

CONCLUSION

DZ had anti-inflammatory and antioxidant effects in a rat OA model. Therefore, DZ, as monotherapy or especially in combination with HA, may be a promising and beneficial therapy for OA. Key Points •DZ has been shown to reduce TNF-α, IL-1β, and MMP-13 both in serum and in tissue samples taken from the knee-joints. •The cracks on the cartilage surface and fibrillation in KOA were completely improved by using DZ and DZ + HA combination. •DZ may be useful to eliminate/reduce/ameliorate inflammation and oxidative damage in the pathogenesis of KOA. •DZ, alone or in combination with HA, may be a promising natural compound with beneficial effects in the treatment of KOA.

Genistein inhibits angiogenesis developed during rheumatoid arthritis through the IL-6/JAK2/STAT3/VEGF signalling pathway

Background

Angiogenesis plays an important role in the development of rheumatoid arthritis (RA), which increases the supply of nutrients, cytokines, and inflammatory cells to the synovial membrane. Genistein (GEN), a soy-derived isoflavone, has been validated that can effectively inhibit the angiogenesis of several tumours. We thus carried out a study in vitro to investigate the effect of GEN in vascular endothelial growth factor (VEGF) expression and angiogenesis induced by the inflammatory environment of RA.

Methods

MH7A cells were used to verify whether GEN can inhibit the expression of VEGF in MH7A cells under inflammatory conditions and demonstrate the mechanism. EA.hy926 ​cells were used to verify whether GEN can inhibit the migration and tube formation of vascular endothelial cells in inflammatory environment.

Results

GEN dose-dependently inhibited the expression and secretion of interleukin (IL)-6 and VEGF, as well as the nucleus translocation of Signal transducer and activator of transcription 3 (STAT3) in MH7A. Furthermore, GEN inhibited IL-6-induced vascular endothelial cell migration and tube formation in vitro.

Conclusion

GEN inhibits IL-6-induced VEGF expression and angiogenesis partially through the Janus kinase 2 (JAK2)/STAT3 pathway in RA, which has provided a novel insight into the antiangiogenic activity of GEN in RA.

The translational potential of this article

Our study provides scientific guidance for the clinical translational research of GEN in the RA treatment.

Chondroprotective Effects of Genistein against Osteoarthritis Induced Joint Inflammation

Genistein is an isoflavone extracted from soybean (Glycine max). This compound has anti-inflammatory, anti-oxidative, and anti-cancer effects; however, the mechanism underlying the effects of genistein on IL-1β-stimulated human osteoarthritis (OA) chondrocytes remains unknown. Our objectives in this study were to explore the anti-inflammatory effects of genistein on IL-1β-stimulated human OA chondrocytes and to investigate the potential mechanisms which underlie them. Our results from an in-vitro model of osteoarthritis indicate that genistein inhibits the IL-1β-induced expression of the catabolic factors nitric oxide synthase 2 (NOS2), cyclooxygenase 2 (COX-2), and matrix metalloproteinases (MMPs). Genistein was shown to stimulate Ho-1 expression, which has been associated with Nrf-2 pathway activation in human chondrocytes. In a rat model, genistein was also shown to attenuate the progression of traumatic osteoarthritis. Taken together, these results demonstrate the effectiveness of genistein in mediating the inflammation associated with joint disorders. Our results also indicate that genistein could potentially serve as an alternative therapeutic treatment for OA.

Modeling month-season of birth as a risk factor in mouse models of chronic disease: from multiple sclerosis to autoimmune encephalomyelitis

Month-season of birth (M-SOB) is a risk factor in multiple chronic diseases, including multiple sclerosis (MS), where the lowest and greatest risk of developing MS coincide with the lowest and highest birth rates, respectively. To determine whether M-SOB effects in such chronic diseases as MS can be experimentally modeled, we examined the effect of M-SOB on susceptibility of C57BL/6J mice to experimental autoimmune encephalomyelitis (EAE). As in MS, mice that were born during the M-SOB with the lowest birth rate were less susceptible to EAE than mice born during the M-SOB with the highest birth rate. We also show that the M-SOB effect on EAE susceptibility is associated with differential production of multiple cytokines/chemokines by neuroantigen-specific T cells that are known to play a role in EAE pathogenesis. Taken together, these results support the existence of an M-SOB effect that may reflect seasonally dependent developmental differences in adaptive immune responses to self-antigens independent of external stimuli, including exposure to sunlight and vitamin D. Moreover, our documentation of an M-SOB effect on EAE susceptibility in mice allows for modeling and detailed analysis of mechanisms that underlie the M-SOB effect in not only MS but in numerous other diseases in which M-SOB impacts susceptibility.-Reynolds, J. D., Case, L. K., Krementsov, D. N., Raza, A., Bartiss, R., Teuscher, C. Modeling month-season of birth as a risk factor in mouse models of chronic disease: from multiple sclerosis to autoimmune encephalomyelitis.

Emerging role of leptin in rheumatoid arthritis

Numerous studies have suggested the importance of leptin against autoimmune diseases such as systemic lupus erythematosus (SLE), multiple sclerosis (MS) and psoriasis. To summarize our current understanding of the role of leptin in inflammatory responses and rheumatoid arthritis (RA), a systematic review was conducted to assess the discrepancy of leptin in RA and its effect on immunity according to different studies. Recently, emerging data have indicated that leptin is involved in the pathological function of RA, which is common in autoimmune disorders. This review discusses the possible consequences of leptin levels in RA. Blocking the key signal pathways of leptin and inhibiting the leptin activity-like leptin antagonist may be a promising way for potential therapeutic treatment of RA at risk of detrimental effects. However, leptin was increased in patients with RA and may also regulate joint damage. Thus, more understanding of the mechanism of leptin in RA would be advantageous in the future.