Eupatilin Exerts Antinociceptive and Chondroprotective Properties in a Rat Model of Osteoarthritis by Downregulating Oxidative Damage and Catabolic Activity in Chondrocytes.

Increases in oxidative stress are thought to be associated with the development of osteoarthritis (OA). Eupatilin, one of the major compounds present in artemisia species, was shown to have both anti-oxidative and anti-inflammatory properties. Here, we investigated the in vivo effects of eupatilin on pain severity and cartilage degradation in an experimental rat model of OA, along with the mechanisms of action underlying these effects. Experimental OA was induced via an intra-articular injection of monosodium iodoacetate (MIA), with oral administration of eupatilin initiated on the day of MIA injection. Pain was assessed by measuring the paw withdrawal latency and threshold. Cartilage destruction was analyzed macroscopically and histomorphologically. The effects of eupatilin on mRNA expression were investigated in interleukin-1β (IL-1β)-stimulated human OA chondrocytes. Eupatilin treatment exhibited clear antinociceptive effects, along with an attenuation of cartilage degradation in OA rats. Additionally, the number of osteoclasts present in the subchondral bone region was significantly decreased following eupatilin treatment. Eupatilin reduced the expression of interleukin-1β (IL-1β), interleukin-6 (IL-6), nitrotyrosine and inducible nitric oxide synthase (iNOS) in cartilage. mRNA levels of matrix metalloproteinase-3 (MMP-3), MMP13, and a disintegrin and metalloproteinase with thrombospondin motifs-5 (ADAMTS-5) were reduced in IL-1β-stimulated human OA chondrocytes, while tissue inhibitor of metalloproteinases-1 (TIMP-1) was induced. Phosphorylated protein levels of the c-jun N-terminal kinase (JNK) was reduced by eupatilin. Taken together, these results suggest that eupatilin suppresses oxidative damage and reciprocally enhances extracellular matrix production in articular chondrocytes, making eupatilin a promising therapeutic option for the treatment of OA

Immunological benefits by ginseng through reciprocal regulation of Th17 and Treg cells during cyclosporine-induced immunosuppression

Background: It is not clear whether ginseng affects cyclosporine A (CsA)-induced desirable immunosuppressive action. In this study, we evaluated the immunological influence of combined treatment of ginseng with CsA. Methods: Using CD4+ T cells from mouse spleens stimulated with the T cell receptor (TCR) or allogeneic antigen-presenting cells (APCs), we examined the differentiation of naïve T cells into T helper 1 (Th1), Th2, Th17, and regulatory T cells (Tregs), and their cytokine production during treatment by Korean Red Ginseng extract (KRGE) and/or CsA. The influence of KRGE on the allogeneic T cell response was evaluated by mixed lymphocyte reaction (MLR). We also evaluated whether signal transducer and activator of transcription 3 (STAT3) and STAT5 are implicated in this regulation. Results: Under TCR stimulation, KRGE treatment did not affect the population of CD4+interferon gamma (IFNγ)+ and CD4+interleukin (IL)-4+ cells and their cytokine production compared with CsA alone. Under the Th17-polarizing condition, KRGE significantly reduced the number of CD4+IL-17+ cells and CD4+/phosphorylated STAT3 (p-STAT3)+ cells, but increased the number of CD4+CD25+forkhead box P3 (Foxp3)+ cells and CD4+/p-STAT5+ cells compared with CsA alone. In allogeneic APCs-stimulated CD4+ T cells, KRGE significantly decreased total allogeneic T cell proliferation. Consistent with the effects of TCR stimulation, KRGE reduced the number of CD4+IL-17+ cells and increased the number of CD4+CD25+Foxp3+ cells under the Th17-polarizing condition. Conclusion: KRGE has immunological benefits through the reciprocal regulation of Th17 and Treg cells during CsA-induced immunosuppression

Increased Th17 differentiation in aged mice is significantly associated with high IL-1β level and low IL-2 expression

AbstractObjectiveAging has been reported to be associated with changes in immune function. Although frequent infection and the development of malignancy suggest the decline of immune function with aging, changes toward proinflammatory conditions also develop at the same time. Th17 cells are well known CD4+ T cell subpopulation closely linked to chronic inflammation and autoimmunity. In this study, changes in the Th17 population were investigated to elucidate a possible mechanism for this response with aging.MethodsSplenocytes were isolated from 2-month-old (young) and 20-month-old (aged) mice. CD4+CD44+ memory T cells and CD4+CD62L+ naïve T cells were isolated and sorted using magnetic beads and flow cytometry. The frequency of IL-17-producing cells was measured using flow cytometry. The expression of IL-17 and Th17-related factors at the mRNA level was measured with RT-PCR. IL-17 and Il-1β expression in spleen tissues was additionally assessed using confocal microscopy.ResultsThe proportion of IL-17-producing CD4+ T cells was higher in the splenocytes among the old mice than those of the young mice. When splenocytes were cultured in Th17 polarizing conditions, the proportion of IL-17 producing CD4+ T cells was higher in aged mice as well. This was consistently observed when naïve and memory cells were isolated and differentiated into Th17 respectively. In addition, the expression of retinoic acid receptor-related orphan nuclear receptor gamma t (RORγt) and other Th17-related factors (AhR, CCR6, and CCL20) increased in the splenocytes of aged mice compared to the young mice. The expression of IL-1β, showing to promote Th17 differentiation, was higher in the aged mice. Likewise, CD4+ T cell expression of IL-1R was higher in the aged mice, suggesting that the CD4+ T cells of the aged mice are readily prepared to differentiate into Th17 cells in response to IL-1β. Confocal microscopy showed that cells positive for IL-1R or IL-1β were more frequent in the spleens of the aged mice. When an anti-IL-2 antibody was applied, the proportion of IL-17-producing cells increased more prominently in the young mice. We observed that IL-2 production and IL-2R expression were reduced in the aged mice, respectively, explaining the blunted response to the anti-IL-2 antibody treatment and the consequent minimal change in the Th17 population.ConclusionWe demonstrated that the proportion of Th17 cells increased in the aged mice both in naïve and memory cell populations. Elevation of IL-1R and IL-1β expression and the reduction in IL-2 and IL-2R expression in aged mice seemed to promote Th17 differentiation. Our results suggest that enhanced Th17 differentiation in aging may have a pathogenic role in the development of Th17-mediated autoimmune diseases

Coenzyme Q10 ameliorates pain and cartilage degradation in a rat model of osteoarthritis by regulating nitric oxide and inflammatory cytokines.

OBJECTIVE: To investigate the effect of CoenzymeQ10 (CoQ10) on pain severity and cartilage degeneration in an experimental model of rat osteoarthritis (OA). MATERIALS AND METHODS: OA was induced in rats by intra-articular injection of monosodium iodoacetate (MIA) to the knee. Oral administration of CoQ10 was initiated on day 4 after MIA injection. Pain severity was assessed by measuring secondary tactile allodynia using the von Frey assessment test. The degree of cartilage degradation was determined by measuring cartilage thickness and the amount of proteoglycan. The mankin scoring system was also used. Expressions of matrix metalloproteinase-13 (MMP-13), interleukin-1β (IL-1β), IL-6, IL-15, inducible nitric oxide synthase (iNOS), nitrotyrosine and receptor for advanced glycation end products (RAGE) were analyzed using immunohistochemistry. RESULTS: Treatment with CoQ10 demonstrated an antinociceptive effect in the OA animal model. The reduction in secondary tactile allodynia was shown by an increased pain withdrawal latency and pain withdrawal threshold. CoQ10 also attenuated cartilage degeneration in the osteoarthritic joints. MMP-13, IL-1β, IL-6, IL-15, iNOS, nitrotyrosine and RAGE expressions were upregulated in OA joints and significantly reduced with CoQ10 treatment. CONCLUSION: CoQ10 exerts a therapeutic effect on OA via pain suppression and cartilage degeneration by inhibiting inflammatory mediators, which play a vital role in OA pathogenesis

Recovery of anabolic and catabolic activities in human OA chondrocytes following the treatment with eupatilin.

<p>Human articular chondrocytes from OA patients were cultured with IL-1β in the presence or absence of eupatilin for 48 h following 24 h in serum-free medium. The mRNA expression of catabolic (MMP-3, and MMP-13, and ADAMTS5) (A) and anabolic (TIMP-1) factor (B) were measured by quantitative real-time PCR; β-actin was used as the internal control. (C) Cell viability was determined by MTT assay. The data are expressed as a mean of three independent experiments per group. **<i>P</i> < 0.01 and ***<i>P</i> < 0.001 compared with IL-1β-stimulated chondrocytes.</p

Effects of eupatilin on the expression of MMP-13, IL-1β, IL-6, iNOS, nitrotyrosine in OA joints.

<p>Rats were injected with 3 mg of monosodium iodoacetate (MIA) in the right knee. Eupatilin was administered orally daily for 7 days after MIA injection. Immunohistochemical staining was used to identify the expression of MMP13, IL-1β, IL-6 (A), iNOS, and nitrotyrosine (B) in the articular cartilage. The data are expressed as means ± SEM for six animals per group. **<i>P</i> < 0.01 ***<i>P</i> < 0.001 compared with the MIA-induced OA group.</p

Macroscopic photographs of the damaged articular cartilage after treatment with eupatilin in MIA-induced OA rats.

<p>Rats were injected with 3 mg of MIA in the right knee. Eupatilin was administered orally daily for 14 days after MIA injection. The gross morphological changes of the femoral condyles and tibial plateau were photographed using a microscope.</p