Huo-luo-xiao-ling dan (HLXL) is an herbal mixture that has long been used in traditional Chinese medicine for the treatment of rheumatoid arthritis (RA) and other inflammatory disorders. Despite the availability of potent conventionally used drugs for RA, their limited efficacy in a proportion of patients coupled with their high cost and severe adverse effects has necessitated the search for novel therapeutics for this debilitating disease. Further, the control of both inflammation and bone damage is essential for effective management of arthritis. The aim of our study was to evaluate the efficacy of HLXL against arthritic bone damage in adjuvant arthritis (AA) model of RA. Our results show that HLXL treatment suppressed inflammatory arthritis and reduced bone and cartilage damage in the joints of arthritic Lewis rats. HLXL-induced protection against bone damage was mediated primarily via inhibition of mediators of osteoclastic bone remodeling (e.g., receptor activator of nuclear factor kappa-B ligand; RANKL), skewing of RANKL/osteoprotegerin (OPG) ratio in favor of antiosteoclastic activity, reduction in the number of osteoclasts in the arthrodial joint's bone, and inhibition of cytokine production and MMP activity. Our results suggest that HLXL might offer a promising alternative/adjunct treatment for both inflammation and bone damage in RA.
Rheumatoid arthritis (RA) is a chronic inflammatory disease of autoimmune origin. Huo-luo-xiao-ling dan (HLXL) is an herbal mixture that has been used in traditional Chinese medicine over several decades to treat chronic inflammatory diseases including RA. However, the mechanism of the anti-arthritic action of this herbal remedy is poorly understood at the molecular level. In this study, we determined by microarray analysis the effects of HLXL on the global gene expression profile of the draining lymph node cells (LNC) in the rat adjuvant arthritis (AA) model of human RA. In LNC restimulated in vitro with the disease-related antigen mycobacterial heat-shock protein 65 (Bhsp65), 84 differentially expressed genes (DEG) (64 upregulated and 20 downregulated) versus 120 DEG (94 upregulated and 26 downregulated) were identified in HLXL-treated versus vehicle (Water)-treated rats, respectively, and 62 DEG (45 upregulated and 17 downregulated) were shared between the two groups. The most affected pathways in response to HLXL treatment included immune response, inflammation, cellular proliferation and apoptosis, and metabolic processes, many of which are directly relevant to arthritis pathogenesis. These results would advance our understanding of the mechanisms underlying the anti-arthritic activity of HLXL.
The herbal formula Huo Luo Xiao Ling Dan (HLXL) and its modifications have been used in traditional Chinese medicine for about one hundred years to alleviate pain and inflammation.
To investigate the effects of HLXL on complete Freund’s adjuvant (CFA)-induced multiple-joint arthritis in rats.
Materials and Methods
Male Lewis rats, 190–210g, were immunized subcutaneously at the base of the tail with 200 µl of heat-killed M. tuberculosis in mineral oil (5 mg/ml). HLXL (2.30g/kg and 4.60g/kg) or vehicle control (n=8 per group) was administered orally (i.g.) once a day between days 16–25 post-CFA injection. The rats were observed for signs of arthritis with arthritic changes (erythema, edema, induration) being scored on a scale of 0 to 4 of increasing severity using a standard scoring system. The maximum arthritis score per rat was 16. A plethysmometer was used to measure edema volume in each paw. Adverse effects of HLXL were monitored by closely observing the animals for unusual behavioral changes. Levels of tumor necrosis factor alpha (TNF-α) and interleukin 1 beta (IL-1β) in local tissue were measured by enzyme-linked immunosorbent assay on day 25 post-CFA.
HLXL significantly decreased arthritis scores between days 23–25 in the 2.30g/kg group and 21–25 in the 4.60g/kg group (p<0.05). It reduced paw edema on days 22 and 24 in the 2.30g/kg group and on days 20, 22 and 24 in the 4.60g/kg group compared to control (p<0.05). Local tissue TNF-α and IL-1β levels on day 25 post-CFA injection were significantly (p<0.05) lower in rats treated with HLXL than in control rats. No observable adverse effects were found.
The data suggest that HLXL produces significant anti-arthritic effects that may be mediated by suppressing pro-inflammatory cytokines, and it appears to be safe.
Arthritis; Chinese Herbs; IL-1β; TNF-α; Rats
Rheumatoid arthritis (RA) is one of the major autoimmune diseases of global prevalence. The use of the anti-inflammatory drugs for the treatment of RA is associated with severe adverse reactions and toxicity. This limitation has necessitated the search for novel therapeutic products. We report here a traditional Chinese medicine-based herbal formula, Huo luo xiao ling dan (HLXL), which has potent antiarthritic activity as validated in the rat adjuvant-induced arthritis (AA) model. HLXL (2.3 g/Kg) was fed to Lewis (RT.11) rats daily by gavage beginning at the onset of arthritis and then continued through the observation period. HLXL inhibited the severity of ongoing AA. This suppression of arthritis was associated with significant alterations in the T cell proliferative and cytokine responses as well as the antibody response against the disease-related antigen, mycobacterial heat-shock protein 65 (Bhsp65). There was a reduction in the level of the proinflammatory cytokines IL-17 and IL-1β but enhancement of the anti-inflammatory cytokine IL-10 level. In addition, there was inhibition of both the anti-Bhsp65 antibody response and the serum level of nitric oxide. Thus, HLXL is a promising CAM modality for further testing in RA patients.
Proving the efficacy and corresponding mode of action of herbal supplements is a difficult challenge for evidence-based herbal therapy. A major hurdle is the complexity of herbal preparations, many of which combine multiple herbs, particularly when the combination is assumed to be vitally important to the effectiveness of the herbal therapy. This issue may be addressed through the use of contemporary methodology and validated animal models.
Methods and Principal Findings
In this study, two commonly used traditional herbal formulas, Shi Quan Da Bu Tang (SQDB) and Huo Luo Xiao Ling Dan (HLXL) were evaluated using a survival assay and oxidative stress biomarkers in a well-established C. elegans model of aging. HLXL is an eleven herb formula modified from a top-selling traditional herbal formula for the treatment of arthritic joint pain. SQDB consists of ten herbs often used for fatigue and energy, particularly in the aged. We demonstrate here that SQDB significantly extend life span in a C. elegans model of aging. Among all individual herbs tested, two herbs Cinnamomum cassia bark (Chinese pharmaceutical name: Cinnamomi Cortex, CIN) and Panax ginseng root (Chinese pharmaceutical name: Ginseng Radix, GS) significantly extended life span in C. elegans. CIN in both SQDB and HLXL formula extended life span via modulation of multiple longevity assurance genes, including genes involved in insulin signaling and stress response pathways. All the life-span-extending herbs (SQDB, CIN and GS) also attenuated levels of H2O2 and enhanced small heat shock protein expression. Furthermore, the life span-extending herbs significantly delayed human amyloid beta (Aβ)-induced toxicity in transgenic C. elegans expressing human Aβ.
These results validate an invertebrate model for rapid, systematic evaluation of commonly used Chinese herbal formulations and may provide insight for designing future evidence-based herbal therapy(s).
HLXL is a traditional Chinese medicine that has long been used in folk medicine for the treatment of chronic inflammatory diseases. However, the precise immunological mechanisms by which HLXL mediates its anti-inflammatory activity are not fully defined.
Aim of the study
To determine the effects of HLXL on antigen-specific immune parameters in adjuvant-induced inflammation model in the Lewis rat.
Materials and Methods
Rats were fed daily with either HLXL (2.3 g/kg) or vehicle (water) beginning 3 d before subcutaneous injection of heat-killed M. tuberculosis H37Ra (Mtb), and then continued for another 6 d. After 9 d of Mtb injection, the draining lymph node cells were tested for T cell proliferative and cytokine responses against mycobacterial heat-shock protein 65 (Bhsp65). Moreover, sera were tested for anti-Bhsp65 antibodies and nitric oxide (NO).
HLXL-treated rats showed reduced T cell proliferative response to Bhsp65 compared to control rats. Furthermore, HLXL suppressed IL-17 response but enhanced IL-10 response without much effect on IFN-γ. HLXL treatment also reduced the levels of anti-Bhsp65 antibodies but not that of NO.
HLXL feeding modulated both the cellular and the humoral immune response to Bhsp65 favoring an anti-inflammatory milieu for suppression of adjuvant-induced inflammation.
Huo-Luo-Xiao-Ling Dan; Immune modulation; Cytokines; Antibodies; T cells; Inflammation
To investigate the safety of oral administration of Modified Huo Luo Xiao Ling Dan (HLXLD), a compound traditional Chinese herbal medicine.
The toxicological information of HLXLD and its individual constituent herbs was searched in cintcm or TCMlars (www.cintcm.com), PubMed (MEDLINE), Chinese Herbal Medicine (1999) and WHO Monographs on Selected Medicinal Plants (Vol. I—III). Single-dose acute toxicity was assessed by using the highest possible dosage. Motor function test was used to determine whether the herbal formula might cause motor impairment. Nine-day HLXLD repeat-dose sub-chronic toxicity/adverse effects, and 42-day chronic toxicity/adverse effects in rats were also assessed.
The literature searches showed that HLXLD and its eleven ingredient herbs had no side/adverse effects listed in the traditional Chinese medicine literature. Under the dosages proposed in the formula, the HLXLD formula had no side/adverse effects according to MEDLINE, Chinese Herbal Medicine and WHO Monographs on Selected Medicinal Plants. The studies in rats showed: (1) in single-dose acute toxicity assessment, the maximal feasible single oral dose, 9.20 g/kg HLXLD, showed no significant effect on clinical signs, or body weight and mortality over a 14-day period in rats; (2) during motor function test, nine-day repeat-dose of daily HLXLD treatment at 4.60 g/kg did not cause motor impairment; (3) in nine-day HLXLD repeat-dose sub-chronic toxicity/adverse effects assessment, there were no noticeable abnormal behavioral changes or obvious adverse reactions and signs in complete Freund's adjuvant inflamed rats (highest observed dosage: 4.60 g/kg), and no noticeable adverse effects were observed during, or 14 days after nine-day treatment at 4.60 g/kg in non-inflamed rats; (4) during 42-day chronic toxicity/adverse effects assessments, no noticeable abnormal behavioral changes, no obvious adverse reactions and signs were observed in normal rats administered with HLXLD at a dose of 2.30 g/kg and the values of serum biochemistry and histopathology were in normal range.
Both existing information and animal data support that Modified HLXLD is a safe herbal product for clinical application.
Chinese herb formula; Modified Huo Luo Xiao Ling Dan; Safety; Literature investigation; Acute toxicity tests; Motor function; Sub-acute toxicity; Chronic toxicity tests; Rats
Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic inflammation of the synovial joints, deformities, and disability. The prolonged use of conventional anti-inflammatory drugs is associated with severe adverse effects. Therefore, there is an urgent need for safer and less expensive therapeutic products. Celastrol is a bioactive component of Celastrus, a traditional Chinese medicine, and it possesses anti-arthritic activity. However, the mechanism of action of Celastrol remains to be fully defined. In this study based on the rat adjuvant-induced arthritis (AA) model of RA, we examined the effect of Celastrol on two of the key mediators of arthritic inflammation, namely chemokines and their receptors, and related pro-inflammatory cytokines. We treated arthritic Lewis rats with Celastrol (200 μg/rat) or its vehicle by daily intraperitoneal (i.p.) injection beginning at the onset of AA. At the peak phase of AA, the sera, the draining lymph node cells, spleen adherent cells, and synovial-infiltrating cells of these rats were harvested and tested. Celastrol-treated rats showed a significant reduction in the levels of chemokines (RANTES, MCP-1, MIP-1α, and GRO/KC) as well as cytokines (TNF-α and IL-1β) that induce them, compared to the vehicle-treated rats. However, Celastrol did not have much effect on cellular expression of chemokine receptors except for an increase in CCR1. Further, Celastrol inhibited the migration of spleen adherent cells in vitro. Thus, Celastrol-induced suppression of various chemokines that mediate cellular infiltration into the joints might contribute to its anti-arthritic activity. Our results suggest that Celastrol might offer a promising alternative/adjunct treatment for RA
Inflammation; arthritis; chemokines; cytokines; traditional Chinese medicine; natural plant products; animal model
We have recently found that matrix metalloproteinases (MMPs) are targets for T-cell and B-cell reactivity in experimental arthritis. In the present article, we investigate whether modulation of MMP-specific T-cell responses could influence the course of adjuvant arthritis (AA). Lewis rats were treated nasally with MMP peptides prior to or after AA induction. Administration of the MMP-10 or the MMP-16 peptide prior to AA induction reduced the arthritic symptoms. In contrast, administration of the MMP-10 peptide after AA induction aggravated the arthritic symptoms. The present study shows the possible usefulness of MMP peptides for immunotherapy. However, a clear understanding of proper timing of peptide administration is crucial for the development of such therapies.
adjuvant arthritis; immunotherapy; matrix metalloproteinase; nasal treatment; peptides
Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic inflammation of the joints. The prolonged use of anti-inflammatory drugs and other newer drugs is associated with severe adverse reactions. Therefore, there is a need for newer anti-arthritic agents. Celastrol, a bioactive component of the Chinese herb Celastrus, possesses anti-arthritic activity as tested in the adjuvant arthritis (AA) model of rheumatoid arthritis (RA). However, the mechanism of action of Celastrol has not been fully defined. We reasoned that microarray analysis of the lymphoid cells of Celastrol-treated arthritic animals might provide vital clues in this regard. We isolated total RNA of the draining lymph node cells (LNC) of Celastrol-treated (Tc) and vehicle-treated (Tp) arthritic Lewis rats, restimulated them in vitro with the disease-related antigen, mycobacterial heat-shock protein 65 (Bhsp65), and tested it using microarray gene chips. Also tested were control arthritic rats just before any treatment (T0). Seventy six genes involved in various biological functions were differentially regulated by Bhsp65 in LNC of Tp group, and 19 genes among them were shared by the Tc group. Furthermore, a group of 14 genes was unique to Tc, indicating that Celastrol modulated not only arthritis-related genes but also those involved in other defined pathways. When Tc and Tp were compared, many of the Bhsp65-induced genes were related to the immune cells, cellular proliferation and inflammatory responses. Our results revealed 10 differentially expressed genes and 14 pathways that constituted the “Celastrol Signature”. Our results would help identify novel targets for therapeutic purposes.
Arthritis; Celastrus; Celastrol; Inflammation; Gene expression; Microarray
This study was aimed at examining the effect of an ointment containing essential oils (EO) on the severity of adjuvant arthritis (AA), an experimental model of human rheumatoid arthritis (RA), in Lewis rats and to define the underlying mechanisms. At the onset of AA, rats received topical application twice daily of ointment containing 20% EO or placebo ointment. The synovial fluid (SF) and synovium-infiltrating cells (SIC) of rats were tested for pro-inflammatory cytokines TNF-α and IL-1β. The hind paws and skin were examined histologically. The activity/level of matrix metalloproteinases (MMPs) and anti-mycobacterial heat-shock protein 65 (Bhsp65) antibodies was tested. Arthritic rats treated with ointment containing EO developed less severe clinical arthritis compared to the controls, and this activity was attributable to EO and not the carrier oil. The levels of TNF-α and IL-1β, and the activity of MMPs in SF and SIC-lysate were significantly (p<0.05) reduced in EO-treated arthritic rats compared to the controls. However, the levels of anti-Bhsp65 antibodies were unaffected by treatment. Thus, topical dermal delivery of EO-containing ointment downmodulates the severity of AA in Lewis rats by inhibiting defined mediators of inflammation. Such ointments should be tested in patients with RA and other arthritic conditions.
Essential oils; Arthritis; Cytokines; Topical application; MMPs; Inflammation
Eleven authenticated botanicals used in the traditional Chinese medicine Huo-Luo-Xiao-Ling Dan were screened for ligands to cyclooxygenase (COX) using pulsed ultrafiltration liquid chromatography-mass spectrometry, and a mass spectrometry-based enzyme assay was used to determine the concentration of each of 17 ligands that inhibited COX-1 or COX-2 by 50% (IC50). Acetyl-11-keto-β-boswellic -boswellic acid, acid, acetyl-α-boswellic acid, acetyl-β-boswellic acid, and betulinic acid were COX-1 selective inhibitors with IC50 values of approximately 10 μM. Senkyunolide O and cryptotanshinone were COX-2 selective inhibitors with IC50 values of 5 and 22 μM, respectively. Roburic acid and phenethyl-trans-ferulate inhibited COX-1 and COX-2 equally. COX inhibition and the IC50 values of most of these natural product ligands have not been reported previously.
Cyclooxygenase; COX-2; drug discovery; botanical dietary supplements; senkyunolide O; cryptotanshinone
Chronic inflammation induces skeletal muscle wasting and cachexia. In arthritic rats, fenofibrate, a peroxisome proliferator-activated receptor α (PPARα (PPARA)) agonist, reduces wasting of gastrocnemius, a predominantly glycolytic muscle, by decreasing atrogenes and myostatin. Considering that fenofibrate increases fatty acid oxidation, the aim of this study was to elucidate whether fenofibrate is able to prevent the effect of arthritis on serum adipokines and on soleus, a type I muscle in which oxidative metabolism is the dominant source of energy. Arthritis was induced by injection of Freund's adjuvant. Four days after the injection, control and arthritic rats were gavaged daily with fenofibrate (300 mg/kg bw) or vehicle over 12 days. Arthritis decreased serum leptin, adiponectin, and insulin (P<0.01) but not resistin levels. In arthritic rats, fenofibrate administration increased serum concentrations of leptin and adiponectin. Arthritis decreased soleus weight, cross-sectional area, fiber size, and its Ppar
α mRNA expression. In arthritic rats, fenofibrate increased soleus weight, fiber size, and Ppar
α expression and prevented the increase in Murf1 mRNA. Fenofibrate decreased myostatin, whereas it increased MyoD (Myod1) and myogenin expressions in the soleus of control and arthritic rats. These data suggest that in oxidative muscle, fenofibrate treatment is able to prevent arthritis-induced muscle wasting by decreasing Murf1 and myostatin expression and also by increasing the myogenic regulatory factors, MyoD and myogenin. Taking into account the beneficial action of adiponectin on muscle wasting and the correlation between adiponectin and soleus mass, part of the anticachectic action of fenofibrate may be mediated through stimulation of adiponectin secretion.
adjuvant-induced arthritis; oxidative muscle; adiponectin; leptin; PPAR alpha; fenofibrate; MyoD; myogenin; myostatin; Murf1; Insulin
Fibroblast-like synoviocytes (FLS) play an important role in the pathologic processes of destructive arthritis by producing a number of catabolic cytokines and metalloproteinases (MMPs). The expression of these mediators is controlled at the transcriptional level. The purposes of this study were to evaluate the anti-arthritic effects of magnolol (5,5′-Diallyl-biphenyl-2,2′-diol), the major bioactive component of the bark of Magnolia officinalis, by examining its inhibitory effects on inflammatory mediator secretion and the NF-κB and AP-1 activation pathways and to investigate its therapeutic effects on the development of arthritis in a rat model. The in vitro anti-arthritic activity of magnolol was tested on interleukin (IL)-1β-stimulated FLS by measuring levels of IL-6, cyclooxygenase-2, prostaglandin E2, and matrix metalloproteinases (MMPs) by ELISA and RT-PCR. Further studies on how magnolol inhibits IL-1β-stimulated cytokine expression were performed using Western blots, reporter gene assay, electrophoretic mobility shift assay, and confocal microscope analysis. The in vivo anti-arthritic effects of magnolol were evaluated in a Mycobacterium butyricum-induced arthritis model in rats. Magnolol markedly inhibited IL-1β (10 ng/mL)-induced cytokine expression in a concentration-dependent manner (2.5–25 µg/mL). In clarifying the mechanisms involved, magnolol was found to inhibit the IL-1β-induced activation of the IKK/IκB/NF-κB and MAPKs pathways by suppressing the nuclear translocation and DNA binding activity of both transcription factors. In the animal model, magnolol (100 mg/kg) significantly inhibited paw swelling and reduced serum cytokine levels. Our results demonstrate that magnolol inhibits the development of arthritis, suggesting that it might provide a new therapeutic approach to inflammatory arthritis diseases.
To study the relative contribution of various matrix degrading enzymes in the pathogenesis of arthritis, changes in the levels of various matrix metalloprtoteinases (MMPs) during the progression of collagen induced arthritis was studied in experimental animals. Arthritis was induced in male wistar rats by injecting an emulsion containing collagen type II and Freund’s complete adjuvant. The duration of the experiment was 35 days. Synovial effusate was collected at regular intervals after induction. At the end of the experiment serum and cartilage were collected and analysed. Synovial fluid of osteoarthritic patients was also analyzed. Levels of MMP-2, MMP-3, MMP-9 and MT1-MMP were found to be high in synovial effusate and cartilage of experimental animals. In synovial effusate of arthritic animals the expression of MMP-3 was found to be high during the early stages while increase in MMP-2 and MMP-9 occurred at later stages. Synovial fluid of osteoarthritic patients also showed elevated levels of MMP-2, MMP-3 and MMP-9. Our results indicated that sequential action of MMPs such as MMP-3, MMP-2 and MMP-9 can cause degradation of articular cartilage extracellular matrix.
Matrix metalloproteinases; Osteoarthritis; Synovial effusate; Synovial fluid
Our previous studies showed that arthritic Lewis (LEW) rats produced the highest levels of tumour necrosis factor (TNF)α in the recovery phase of adjuvant arthritis (AA), suggesting a correlation between high TNFα levels and reduced severity of arthritis. To further explore this correlation, we compared the TNFα secretion profile of the AA-resistant Wistar Kyoto (WKY) rats with that of LEW rats, determined the effect of exogenous TNFα on the course of AA in LEW rats, and examined various mechanisms involved in TNFα-induced disease modulation.
A cohort each of LEW and WKY rats was immunised subcutaneously with heat-killed Mycobacterium tuberculosis H37Ra (Mtb). At different time points thereafter, subgroups of rats were killed and their draining lymph node cells were tested for cytokine production. Another group of LEW rats was injected with TNFα intraperitoneally daily for a total of 10 injections, 3 before and 6 after Mtb challenge, and then observed for signs of AA. In parallel, TNFα-treated rats were examined for changes in other cytokines, in CD4+CD25+ T cell frequency, and in indoleamine 2,3-dioxygenase (IDO) mRNA expression levels.
LEW rats displayed a TNFα secretion profile that was opposite to that of the WKY rats. Furthermore, TNFα treatment significantly downmodulated the severity of AA in LEW rats, and decreased the interferon (IFN)-γ secretion in response to the pathogenic determinant of the disease-related antigen. No significant alterations were observed in other parameters tested.
The role of endogenous TNFα in the induction and propagation of arthritis is well established. However, exogenous TNFα can downmodulate the course of AA, displaying an immunoregulatory functional attribute of this cytokine.
Hypoxia is a feature of the inflamed synovium in rheumatoid arthritis (RA). Intra-articular injection of hyaluronan (HA) may be considered a potential way to treat RA. However, the exact molecular mechanism of HA on decreased cellular responses to hypoxic environment is unclear. The present study has been designed to use the adjuvant-induced arthritis model to examine the effects of HA on the changes of immunohistochemical expressions of hypoxia-inducible factor-1alpha (HIF-1alpha), inducible nitric oxide synthase (iNOS), and matrix metalloproteinase-3 (MMP3) in the synovial tissues at the early phase of arthritic inflammation.
Monoarthritis was induced in adult male Sprague-Dawley (250-300 g) via intraarticular injection of complete Freund's adjuvant (CFA) into the tibiotarsal joint. The CFA-induction arthritis animals were divided into three groups: treatment (intraarticular injection of HA), placebo (intraarticular injection of saline) and controls (no treatments). Functional evaluations of edema and pain behavior, histology, and HIF-1alpha, iNOS, and MMP3 immunohistochemistry were performed before, after the first injection, three injections, and on the follow-up injection of the treatments.
Intra-articular injection of HA also significantly suppressed the mechanical allodynia (p < 0.001) and overexpressions of HIF-1alpha (p < 0.001), iNOS (p = 0.004) and MMP3 (p < 0.001) immunoreactivity in synovium.
This study demonstrated that early intervention of HA is an effective protection against accumulation of inflammation-induced HIF-1alpha, iNOS, and MMP3 to limit erosive damage in CFA-induced model of arthritis.
Dexamethasone (DEX) is often given for the treatment of rheumatoid arthritis and clinical dosing regimens of DEX have often been based empirically. This study tests whether the inflammation processes in a rat model of rheumatoid arthritis alters the clearance and volume of distribution of DEX when compared with healthy controls. Groups of healthy and arthritic male Lewis rats received either a low (0.225 mg/kg) or high (2.25 mg/kg) intramuscular dose of DEX. Arthritis was induced by intradermal injection of type II porcine collagen in incomplete Freund's adjuvant emulsion at the base of the tail. DEX was dosed in the arthritic animals 22 days post arthritis induction. Plasma DEX concentrations were determined by HPLC. Plasma concentration versus time data were analysed by non-compartmental analysis and pharmacokinetic model fitting using the population pharmacokinetic software NONMEM V. A linear bi-exponential pharmacokinetic model with extravascular input described the data for both healthy and arthritic animals. Clearance was the only parameter determined statistically different between both groups (healthy=1.05 l/h/kg, arthritic=1.19 l/h/kg). The steady-state volume of distribution for both groups was 4.85 l/kg. The slight difference in clearance was visibly undetectable and unlikely to produce meaningful changes in DEX disposition in arthritic rats.
dexamethasone; pharmacokinetics; arthritis; collagen
Rheumatoid arthritis (RA) is a debilitating autoimmune disease of global prevalence and the disease process primarily targets the synovial joints. Despite improvements in the treatment of RA over the past decade, there still is a need for new therapeutic agents that are efficacious, less expensive, and free of severe adverse reactions. Celastrus has been used in China for centuries for the treatment of rheumatic diseases. Further, we reported previously that ethanol extract of Celastrus aculeatus Merr. (Celastrus) attenuates adjuvant-induced arthritis (AA) in rats. However, the mechanisms underlying the anti-arthritic activity of Celastrus have not yet been fully defined. We reasoned that microarray analysis might offer useful insights into the pathways and molecules targeted by Celastrus. We compared the gene expression profiles of the draining lymph node cells (LNC) of Celastrus-treated (Tc) versus water-treated (Tw) rats, and each group with untreated arthritic rats before starting any treatment (To). LNC were restimulated with mycobaterial heat shock protein-65 (Bhsp65). We identified 104 differentially expressed genes (DEG) (8 upregulated, 96 downregulated) when comparing Tc with T0 rats, in contrast to 28 (12 upregulated, 16 downregulated) when comparing Tw and T0 rats. Further, 20 genes (6 upregulated, 14 downregulated) were shared by both Tw and Tc groups. Thus, Celastrus treatment (Tc) significantly downregulated a large proportion of genes compared to controls (Tw). The DEG were mainly associated with the processes of immune response, cell proliferation and apoptosis, and signaling regulation and signaling transduction. These results provide novel insights into the mechanism of anti-arthritic activity Celastrus, and unravel potential therapeutic targets for arthritis.
Celastrus; microarray; gene expression profile; adjuvant-induced arthritis
Auranofin, a member of a class of compounds with disease modifying activity, was given to arthritic rats to determine if it could reverse the abnormal plasma concentrations of fibronectin (Fn), C reactive protein (CRP), and albumin, which were unaffected by treatment with non-steroidal anti-inflammatory drugs (NSAIDs). When auranofin was orally administered for two weeks to adjuvant induced arthritic rats it significantly inhibited swelling of the injected and non-injected paws at doses of 3 and 10 mg/kg. Rocket electroimmunoassay measurement of plasma proteins in normal, arthritic, and auranofin treated arthritic rats indicated that auranofin at 10 mg/kg significantly decreased (by 77%) the abnormally high concentration of arthritic rat plasma Fn, though it had no effect on Fn concentrations when administered to normal rats. CRP, which was raised approximately twofold above normal in arthritic rats, was reduced by 56% after treatment of arthritic rats with auranofin at 10 mg/kg, though CRP concentrations in normal rats were unaffected by auranofin treatment. Depressed albumin concentrations in arthritic rats were significantly enhanced (by 30%) by dosing with 10 mg/kg of auranofin. At the 3 mg/kg dose, auranofin did not significantly change plasma concentrations of Fn, CRP, and albumin in arthritic rats. At a dose of 10 mg/kg, however, auranofin, in addition to inhibiting chronic systemic paw inflammation, also altered abnormal concentrations of plasma Fn, CRP, and albumin in the adjuvant arthritic rat, thus distinguishing auranofin from standard NSAIDs we have previously tested.
Excessive matrix metalloproteinase (MMP) activity has been implicated in the pathogenesis of acute and chronic liver injury. CTS-1027 is a MMP inhibitor, which has previously been studied in humans as an anti-arthritic agent. Thus, our aim was to assess if CTS-1027 is hepato-protective and anti-fibrogenic during cholestatic liver injury. C57/BL6 mice were subjected to bile duct ligation (BDL) for 14 days. Either CTS-1027 or vehicle was administered by gavage. BDL mice treated with CTS-1027 demonstrated a 3-fold reduction in hepatocyte apoptosis as assessed by the TUNEL assay or immunohistochemistry for caspase 3/7-positive cells as compared to vehicle treated BDL animals (p<0.01). A 70% reduction in bile infarcts, a histologic indicator of liver injury, was also observed in CTS-1027 treated BDL animals. These differences could not be ascribed to differences in cholestasis as serum total bilirubin concentrations were nearly identical in the BDL groups of animals. Markers for stellate cell activation (α-smooth muscle actin) and hepatic fibrogenesis (collagen 1) were reduced in CTS-1027 versus vehicle-treated BDL animals (p<0.05). Overall animal survival following 14 days of BDL was also improved in the group receiving the active drug (p<0.05). In conclusion, in the BDL mouse, liver injury and hepatic fibrosis are attenuated by treatment with the MMP inhibitor CTS-1027. This drug warrants further evaluation as an anti-fibrogenic drug in hepatic injury.
apoptosis; cholestasis; liver fibrosis; matrix metalloproteinase
Green tea, a product of the dried leaves of Camellia sinensis, is the most widely consumed beverage in the world. The polyphenolic compounds from green tea (PGT) possess anti- inflammatory properties. We investigated whether PGT can afford protection against autoimmune arthritis, and also examined the immunological basis of this effect using the rat adjuvant arthritis (AA) model of human rheumatoid arthritis (RA). AA can be induced in the Lewis rat (RT.1l) by immunization with heat-killed Mycobacterium tuberculosis H37Ra (Mtb), and arthritic rats raise T cell response to the mycobacterial heat-shock protein 65 (Bhsp65). PGT (2-12 g/L, w/v) was fed to rats in drinking water for 1-3 wk followed by disease induction by Mtb injection. Thereafter, these rats were observed regularly and graded for signs of arthritis. Sub-groups of these rats were killed at defined time points, and their draining lymph node cells (LNC) were harvested and tested for T cell proliferative and cytokine responses. Furthermore, the sera collected from these rats were tested for anti-Bhsp65 antibodies. We observed that feeding 8 g/L PGT to Lewis rats for 9 d significantly reduced the severity of arthritis compared to the water-fed controls. Interestingly, PGT-fed rats had lower concentrations of the pro-inflammatory cytokine interleukin-17 (IL-17), but greater concentration of the immunoregulatory cytokine IL-10 than controls. PGT feeding also suppressed the anti-Bhsp65 antibody response. Thus, green tea induced changes in arthritis related immune response. We suggest further systematic exploration of dietary supplementation with PGT as an adjunct nutritional strategy for the management of RA.
Matrix metalloproteinase (MMP)-1, MMP-8 and MMP-13 are interstitial collagenases that degrade type II collagen in cartilage; this is a committed step in the progression of rheumatoid arthritis and osteoarthritis. Of these enzymes, the expression of MMP-1 and MMP-13 is substantially increased in response to IL-1 and tumor necrosis factor-α, and elevated levels of these collagenases are observed in arthritic tissues. Therefore, cytokine-mediated MMP-1 and MMP-13 gene regulation is an important issue in arthritis research. In this review, we discuss current models of MMP-1 and MMP-13 transcriptional regulation, with a focus on signaling intermediates and transcription factors that may be future targets for the development of new arthritis drugs.
arthritis; matrix metalloproteinases; mitogen-activated protein kinases; nuclear factor κB; transcription
Anti-tumour necrosis factor (TNF)α therapy is highly effective in rheumatoid arthritis and it is surprising, therefore, that a recent study showed that intraperitoneal administration of recombinant TNFα reduced the severity of adjuvant-induced arthritis and decreased IFNγ expression in cultured draining lymph node cells. Furthermore, in untreated arthritic rats, maximal TNFα expression in draining lymph node cells coincided with spontaneous disease remission, suggesting a role for endogenous TNFα in recovery from arthritis. If confirmed in further studies, these findings suggest that, in addition to its well-established pro-inflammatory properties, TNFα may also play a disease-limiting role in this model of rheumatoid arthritis by suppressing effector T cell responses.
To assess the potential use of hyaluronic acid (HA) as adjuvant therapy in rheumatoid arthritis, the anti-inflammatory and chondroprotective effects of HA were analysed in experimental rat antigen-induced arthritis (AIA). Lewis rats with AIA were subjected to short-term (days 1 and 8, n = 10) or long-term (days 1, 8, 15 and 22, n = 10) intra-articular treatment with microbially manufactured, high-molecular-weight HA (molecular weight, 1.7 × 106 Da; 0.5 mg/dose). In both tests, 10 buffer-treated AIA rats served as arthritic controls and six healthy animals served as normal controls. Arthritis was monitored by weekly assessment of joint swelling and histological evaluation in the short-term test (day 8) and in the long-term test (day 29). Safranin O staining was employed to detect proteoglycan loss from the epiphyseal growth plate and the articular cartilage of the arthritic knee joint. Serum levels of IL-6, tumour necrosis factor alpha and glycosaminoglycans were measured by ELISA/kit systems (days 8 and 29). HA treatment did not significantly influence AIA in the short-term test (days 1 and 8) but did suppress early chronic AIA (day 15, P < 0.05); however, HA treatment tended to aggravate chronic AIA in the long-term test (day 29). HA completely prevented proteoglycan loss from the epiphyseal growth plate and articular cartilage on day 8, but induced proteoglycan loss from the epiphyseal growth plate on day 29. Similarly, HA inhibited the histological signs of acute inflammation and cartilage damage in the short-term test, but augmented acute and chronic inflammation as well as cartilage damage in the long-term test. Serum levels of IL-6, tumour necrosis factor alpha, and glycosaminoglycans were not influenced by HA. Local therapeutic effects of HA in AIA are clearly biphasic, with inhibition of inflammation and cartilage damage in the early chronic phase but with promotion of joint swelling, inflammation and cartilage damage in the late chronic phase.