Tuina Intervention in Sodium Monoiodoacetate Injection-Induced Rat Model of Knee Osteoarthritis.

Knee osteoarthritis (KOA), a common degenerative joint disorder, is characterized by chronic pain and disability, which can progress to irreparable structural damage of the joint. Investigations into the link between articular cartilage, muscles, synovium, and other tissues surrounding the knee joint in KOA are of great importance. Currently, managing KOA includes lifestyle modifications, exercise, medication, and surgical interventions; however, the elucidation of the intricate mechanisms underlying KOA-related pain is still lacking. Consequently, KOA pain remains a key clinical challenge and a therapeutic priority. Tuina has been found to have a regulatory effect on the motor, immune, and endocrine systems, prompting the exploration of whether Tuina could alleviate KOA symptoms, caused by the upregulation of inflammatory factors, and further, if the inflammatory factors in skeletal muscle can augment the progression of KOA. We randomized 32 male Sprague Dawley (SD) rats (180-220 g) into four groups of eight animals each: antiPD-L1+Tuina (group A), model (group B), Tuina (group C), and sham surgery (group D). For groups A, B, and C, we injected 25 µL of sodium monoiodoacetate (MIA) solution (4 mg MIA diluted in 25 µL of sterile saline solution) into the right knee joint cavity, and for group D, the same amount of sterile physiological saline was injected. All the groups were evaluated using the least to most stressful tests (paw mechanical withdrawal threshold, paw withdrawal thermal latency, swelling of the right knee joint, Lequesne MG score, skin temperature) before injection and 2, 9, and 16 days after injection.

Ameliorative Effects of Prolotherapy on Histomorphology of Tibial Articular Cartilage of Chemically Induced Osteoarthritic Knee Joint in a Rat Model.

OBJECTIVE: To determine the ameliorative effects of prolotherapy on monosodium iodoacetate (MIA) induced and histomorphological changes in the articular cartilage of tibial condyles at rat knee joint. STUDY DESIGN: An experimental study. Place and Duration of the Study: Department of Anatomy, Army Medical College Rawalpindi, NUMS, Rawalpindi, from August to November 2021. METHODOLOGY: Thirty adult male Sprague Dawley rats were divided into three groups, each having 10 rats. Group A was control. Group B was injected with single dose of 1mg MIA intraarticularly in the right knee to induce osteoarthritic changes. Group C was injected with single dose of 1mg MIA intraarticularly, in right knee was followed by 0.1ml Prolotherapy (3ml of 25% dextrose, 2ml of 2% xylocaine, 1ml of injection neurobion, and 1ml of injection methecobal) as intra articular injection at week 2, 6 and 10 in right knee. Rats were sacrificed after one month of the last dose of Prolotherapy. Articular cartilage was collected for gross and histological examination and compared among the groups. RESULTS: Articular cartilage belonging to control group A was normal. While group B showed statistically significant deterioration in gross appearance (p = 0.001**), reduction in number of chondrocytes (p = 0.005*) and thickness of articular cartilage (p = 0.001**) in comparison to group A. In group C due to prolotherapy statistically significant improvement in gross appearance (p = 0.034*), increase in number of chondrocytes (p = 0.003*), and thickness of articular cartilage (p = 0.001**) was observed as compared to group B. CONCLUSION: Prolotherapy significantly ameliorates histomorphology of tibial articular cartilage against MIA induced osteoarthritic changes in rat knee joint. KEY WORDS: Articular cartilage, Knee joint, Monosodium iodoacetate, Osteoarthritis, Prolotherapy.

Efficacy of Veronica incana for Treating Osteoarthritis Induced by Monosodium Iodoacetate in Rats.

The aim of this study is to investigate the efficacy and the underlying mechanism of Veronica incana in osteoarthritis (OA) induced by intraarticular injection of monosodium iodoacetate (MIA). The selected major four compounds (A-D) of V. incana were found from fractions 3 and 4. Its structure elucidation was determined by liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) data analysis and nuclear magnetic resonance (NMR) data comparison with literature. MIA (50 µL with 80 mg/mL) for the animal experiment was injected into the right knee joint. The V. incana was administered orally every day to rats for 14 days from 7 days after MIA treatment. Finally, we confirmed the four compounds: (A) verproside; (B) catalposide; (C) 6-vanilloylcatapol; and (D) 6-isovanilloylcatapol. When we evaluated the effect of V. incana on the MIA injection-induced knee OA model, there were a noticeable initial decreased in hind paw weight-bearing distribution compared to the Normal group (P < .001), but V. incana supplementation resulted in a significant increase in the weight-bearing distribution to the treated knee (P < .001). Moreover, the V. incana treatment led to a decrease in the levels of liver function enzymes and tissue malondialdehyde (P < .05 and .01). The V. incana significantly suppressed the inflammatory factors through the nuclear factor-kappa B signaling pathway and downregulated the expression of matrix metalloproteinases, which are involved in the degradation of the extracellular matrix (P < .01 and .001). In addition, we confirmed the alleviation of cartilage degeneration through tissue stains. In conclusion, this study confirmed the major four compounds of V. incana and suggested that V. incana could serve as an anti-inflammatory candidate agent for patients with OA.

Chondroprotective Effects of Grapefruit (Citrus paradisi Macfad.) Juice in a Complete Freund's Adjuvant Rat Model of Knee Osteoarthritis.

Osteoarthritis (OA) is a common disorder that can affect any joint in the human body. This study aimed to examine the anti-arthritic properties of high and low doses of grapefruit juice (GFJ), as grapefruit appears to contain anti-inflammatory biochemicals. Forty male Sprague-Dawley rats weighing 170-180 g were divided into five groups. These groups comprised the untreated control group and osteoarthritic (Osteo) rats administered intra-articular injections of Freund's complete adjuvant (CFA; 0.5 mL; 1 mg/mL) as follows: OA rats administered low doses of GFJ (Osteo+GFJ (low); 5 mL/kg body weight (BW)); OA rats administered high doses of GFJ (Osteo+GFJ (high); 27 mL/kg BW); and OA rats administered diclofenac sodium (Osteo+Diclo) as a reference drug. Injections of CFA induced OA, as indicated by a significant increase in the serum levels of the inflammatory biomarkers C-reactive protein (CRP), interleukin-1ß (IL-1ß), and (prostaglandin (PGE2), as well as matrix metalloproteinases (MMP-1) and cathepsin K. The synovial levels of glycosaminoglycans (GAGs), tumor necrosis factor (TNF-α), and interleukin 6 (IL-6) also increased, with a concomitant reduction in osteocalcin levels. The administration of either high or low doses of GFJ reduced CRP, IL-1ß, PGE2, MMP-1, cathepsin K, and osteocalcin while increasing the synovial levels of GAGs, TNF-α, and IL-6, slowing cartilage degradation and boosting joint function. The results showed comparable histopathological and biochemical responses. A comparison of the treatments showed that high-dose GFJ had a greater chondroprotective effect than low-dose GFJ.

Electroacupuncture ameliorates knee osteoarthritis in rats via inhibiting NLRP3 inflammasome and reducing pyroptosis.

Objective: Knee Osteoarthritis (KOA), is the most common joint disease worldwide. The pathogenesis of KOA is complex and electroacupuncture (EA) is an effective therapy for KOA, but the mechanism remains unclear. In this study, we aim to investigate the potential therapeutic effect of EA on the rat model of KOA induced by monosodium iodoacetate (MIA) and its relationship with NLRP3 inflammasome by immunohistochemistry and western blot. Methods: KOA was induced by intra-articular injection of MIA (3 mg/50 µL) into the right knee joint of rats. Forty-five male rats weighing 250-300 g were randomly divided into 3 groups: control group, KOA group, and KOA + electroacupuncture group (KOA+EA). EA treatment lasted for 2 weeks (6 times a week). Paw withdrawal threshold tests were used to assess mechanical allodynia once a week. Safranin O/Fast Green and hematoxylin and eosin (H&E) staining were used to assess the damage to cartilage, synovium, and subpatellar fat pad (IFP). Immunohistochemistry was used to observe NLRP3 inflammasome-associated protein-positive cells in the same field of view and western blot was used to detect the expression of the associated protein in cartilage tissue. Results: The KOA group showed mechanical hyperalgesia, joint inflammation, and significant cartilage tissue destruction. Safranin O/Fast Green and H&E staining revealed that EA alleviated the joint pathological changes caused by KOA and had a protective effect on cartilage, synovium, and IFP destruction. Mechanical allodynia pain and joint swelling were reduced in KOA rats after EA treatment. Immunohistochemistry and western blot showed significant inhibition of NLRP3 inflammasome-associated protein. Conclusion: The results indicate that EA can inhibit NLRP3 inflammasome and reduce pyroptosis, which results in the protection of cartilage tissue and the treatment of KOA. It provides reliable evidence for the development of EA in the treatment of KOA and the clinical application of acupuncture.

A randomized, double-blind placebo-controlled phase I clinical study on safety and efficacy of the G-Rup® syrup (a mixture of ginger extract and honey) in symptomatic treatment of knee osteoarthritis.

WHAT IS KNOWN AND OBJECTIVES: Present study evaluated the safety profile and efficacy of G-Rup® syrup (100 mg/ml ginger extract plus 150 mg/ml honey) in symptomatic treatment of knee osteoarthritis (OA). METHODS: Patients diagnosed with knee OA were randomly assigned (1:1) to receive either of a 30 ml twice daily regimen of G-Rup® syrup or placebo over a 12-week period. Primary endpoints of the study comprised of an improvement in the joint's stiffness, physical functioning and pain score, assessed by WOMAC questionnaire and the visual analog scale (VAS). Secondary objectives comprised of safety and tolerability of the syrup by patients. RESULTS AND DISCUSSION: The 30 ml twice-daily regimen of G-Rup® syrup was safe and well tolerated by patients. Moreover, in whole studied time points, treatment with G-Rup® syrup could significantly Power the VAS score (p < 0.001) whereas improving WOMAC total score (p < 0.001) and pain (p < 0.001), physical functioning (p < 0.001), and stiffness sub-scores (p = 0.006) compared to the placebo receiving group. WHAT IS NEW AND CONCLUSION: Based on obtained results, the G-Rup® syrup, composed of a combination of honey and ginger, may be a proper supplementary choice, along with routine therapeutic regimens, for improvement of symptomatic treatment of OA.

Intra-articular ozone slows down the process of degeneration of articular cartilage in the knees of rats with osteoarthritis.

BACKGROUND: Osteoarthritis (OA) is a joint disease of multifactorial etiology, affecting mainly the knees. We aimed to evaluate the effects of two different doses of gaseous ozone intra-articularly on the knee cartilage morphology of rats with osteoarthritis (OA). METHODS: The articular lesion was induced by sodium monoiodoacetate (MIA). 40 Wistar rats were divided into 4 groups: G1 control (without lesion and without treatment), G2 articular lesion (AL) (only lesion MIA-induced), G3 AL + treatment with 5 µg/mL of ozone intra-articular, and G4 AL + treatment with 10 µg/mL of ozone intra-articular. The experiment was carried out for 60 days. RESULTS: Both doses of ozone intra-articular demonstrated less reduction in joint space (G3 and G4) compared to the G2, formation of osteophytes, but without subchondral sclerosis. Ozone decreased the volumetric density of the articular lesion (VV(AL)) of tibial. The treatments recovered VV(AL) of the femur similar to G1. Ozone lower dose (G3) showed lower tibia and femur macroscopic scores. CONCLUSION: Intra-articular gaseous ozone can delay the degeneration of articular cartilage and can represents an integrative therapy in the OA treatment of knee after 60 days of treatment. For the first time the role of ozone in articular cartilage degeneration was evaluated helping to understand this therapy.

Niacinamide and undenatured type II collagen modulates the inflammatory response in rats with monoiodoacetate-induced osteoarthritis.

The current work aimed to examine the properties of oral supplementation of niacinamide and undenatured type II collagen (UCII) on the inflammation and joint pain behavior of rats with osteoarthritis (OA). Forty-nine Wistar rats were allocated into seven groups; control (no MIA), MIA as a non-supplemental group with monosodium iodoacetate (MIA)-induced knee osteoarthritis, MIA + undenatured type II collagen (UCII) at 4 mg/kg BW, MIA + Niacinamide at 40 mg/kg BW (NA40), MIA + Niacinamide at 200 mg/kg BW (NA200), MIA + UCII + NA40 and MIA + UCII + NA200. Serum IL-1ß, IL-6, TNF-α, COMP, and CRP increased in rats with OA and decreased in UCII and NA groups (p < 0.05). Rats with osteoarthritis had greater serum MDA and knee joint MMP-3, NF-κB, and TGß protein levels and decreased in treated groups with UCII and NA (p < 0.05). The rats with OA also bore elevated joint diameters with joint pain behavior measured as decreased the stride lengths, the paw areas, and the paw widths, and increased the Kellgren-Lawrence and the Mankin scores (p < 0.05) and decreased in UCII treated groups. These results suggest the combinations with the UCII + NA supplementation as being most effective and reduce the inflammation responses for most OA symptoms in rats.

Cissus quadrangularis (veldt grape) attenuates disease progression and anatomical changes in mono sodium iodoacetate (MIA)-induced knee osteoarthritis in the rat model.

The Cissus quadrangularis (CQ) stem has interesting nutritional and pharmacological properties to promote the health of the skeletal system. It is a well-recognized plant in the conventional system of medicine in India for treating bone and joint-associated complications. This study focuses on identifying the active constituents from the stem and root extracts of CQ and validating its anti-osteoarthritic activity by the in vivo model. Notable levels of phenolics and flavonoids were found in the ethanol extracts of both CQ stem (CQSE) and root (CQRE), among other solvent fractions. UPLC-MS/MS analysis of these selective extracts resulted in different classes of active compounds from both positive and negative ionization modes. By analyzing their mass spectra and fragmentation pattern, 25 active compounds were identified. The CQSE and CQRE extracts, along with the standard drug (naproxen), were further tested in mono-sodium iodoacetate-induced experimental OA animals. The modulatory effects of the test extracts were assessed by haematology, synovial and cartilage marker profiling, radiology and histopathological analysis. The in vivo findings from the biochemical and physiological studies have led to the conclusion that the CQSE extract is a good choice for the management of OA. The results were substantially better than CQ root extract and naproxen drug-treated groups. Thus, CQS has bioactive constituents, which could facilitate recovery from joint tissue damage, cellular metabolism and associated risk factors attributable to dysfunctions in OA incidence and progression.

Chrysin Attenuates the NLRP3 Inflammasome Cascade to Reduce Synovitis and Pain in KOA Rats.

PURPOSE: Our recent reports have revealed that inhibiting NLRP3 activation reduces synovial inflammation and fibrosis in knee osteoarthritis (KOA). Synovial inflammation is involved the entire process of KOA and promotes the progression of KOA. Natural flavonoid Chrysin from Scutellariae Radix, a traditional Chinese medicine, exhibits multifarious biological activities and potentially has protective activity against osteoarthritis. However, the mechanism of Chrysin in the treatment of synovial inflammation remains elusive. The purpose of our research was to explore the anti-inflammatory effects of Chrysin on KOA, which was induced by monoiodoacetic acid (MIA) in rats by targeting the NLRP3 inflammasome in the hopes of identifying an effective drug to treat KOA. METHODS: The MIA-induced KOA model was used to evaluate the cold pain threshold and paw withdrawal threshold (PWT) of joints after MIA (40 mg/mL) injection into the knee joints. Microscopically, we used LPS (5 ug/mL) and ATP (4 mmol/L) to stimulate fibroblast-like synovial cells (FLSs) to explore the underlying mechanisms and effects of Chrysin. Two staining methods, H&E and Sirius Red, were applied to assess histopathological changes in synovial membranes. Cellular signal transduction was determined by qRT-PCR and WB. Cytokine expression (inflammatory cytokines and pain-related cytokines) was detected by ELISA. The degree of chronic inflammatory pain was evaluated by c-Fos immunofluorescence. RESULTS: The results showed that Chrysin not only attenuated synovial inflammation but also reduced the secretion of pain-related factors and increased the PWT and cold pain threshold in rats. Chrysin also inhibited NLRP3 inflammasome activation and increased IL-1ß levels to alleviate the synovitis. CONCLUSION: Chrysin can relieve knee synovial inflammation and improve pain behavior in KOA rats, which may be related to the ability of Chrysin to inhibit NLRP3 inflammasome activation. Therefore, Chrysin may be developed as a new drug for the treatment of KOA.

Huoxuezhitong capsule ameliorates MIA-induced osteoarthritis of rats through suppressing PI3K/ Akt/ NF-κB pathway.

Huoxuezhitong capsule (HXZT, activating blood circulation and relieving pain capsule), has been applied for osteoarthritis since 1974. It consists of Angelica sinensis (Oliv.) Diels, Panax notoginseng (Burkill) F. H. Chen ex C. H., Boswellia sacra, Borneol, Eupolyphaga sinensis Walker, Pyritum. However, the direct effects of HXZT on osteoarthritis and the underlying mechanisms were poorly understood. In this study, we aimed to explore the analgesia effect of HXZT on MIA-induced osteoarthritis rat and the underlying mechanisms. The analgesia and anti-inflammatory effect of HXZT on osteoarthritis in vivo were tested by the arthritis model rats induced by monosodium iodoacetate (MIA).. Mechanistic studies confirmed that HXZT could inhibit the activation of NF-κB and down-regulate the mRNA expression of related inflammatory factors in LPS-induced RAW264.7 and ATDC5 cells. Furtherly, in LPS-induced RAW264.7 cells, HXZT could suppress NF-κB via inhibiting PI3K/Akt pathway. Taken together, HXZT capsule could ameliorate MIA-induced osteoarthritis of rats through suppressing PI3K/ Akt/ NF-κB pathway.

Laser irradiation activates spinal adenosine A1 receptor to alleviate osteoarthritis pain in monosodium iodoacetate injected rats.

The analgesic role of the adenosine A1 receptor is thought to involve the modulation of the spinal N-methyl D-aspartate receptor-mediated nociceptive pathway, which is suggested to be an underlying mechanism in chronic pain. Knee osteoarthritis is a degenerative condition accompanied by chronic pain. We have demonstrated that 10.6-µm laser irradiation has an antinociceptive effect in the monosodium iodoacetate -induced knee osteoarthritis in rats. However, its mechanism of action has yet to be explored. In the present work, we investigate the mechanism of 10.6-µm laser irradiation mediated antinociception in the monosodium iodoacetate -induced knee osteoarthritis. Results showed that the 10.6-µm laser significantly reversed the monosodium iodoacetate -induced nociceptive behaviors for up to 28 days. Moreover, the up-regulation of the A1 receptor and the down-regulated phosphorylation of the N-methyl D-aspartate receptor 1 subunit of the N-methyl D-aspartate receptor were observed in the spinal cord dorsal horn in the monosodium iodoacetate injected rats treated by laser irradiation. Intrathecal injection of 8-cyclopentyl-1,3-dipropylxanthine markedly reversed the effects of laser irradiation, as evidenced both by behavioral pain tests and by levels of spinal phosphorylation of N-methyl D-aspartate receptor 1. These results suggest that the spinal A1 receptor contributes to the antinociceptive effects of 10.6-µm laser, at least in part by inhibiting phosphorylation of N-methyl D-aspartate receptor 1 in the monosodium iodoacetate -induced knee osteoarthritis pain.

A Mixture Containing Fermented Achyranthes japonica Nakai Ameliorates Osteoarthritis in Knee Joints of Monoiodoacetate-Injected Rats.

We demonstrated the effect of a mixture containing fermented Achyranthes japonica Nakai (FS) in the context of a monosodium iodoacetate (MIA)-induced osteoarthritis animal model. The mineralization, anabolic and catabolic factors, and the amount of cytokines within the articular cartilage of rats were measured after administration of MIA. We found that dietary supplementation with methylsulfonylmethane (positive control) and FS (FS 100 mg/kg body weight [b.w.] and FS 300 mg/kg b.w.) effectively suppressed pathological changes in the knee joint and inhibited changes in the architectural and mineralization parameters. In addition, prostaglandin E2 (PGE2) and proinflammatory cytokines in the serum and catabolic factors, including matrix metalloproteinase (MMP)-3 and MMP-7 in articular cartilage, were decreased by dietary supplementation with FS in MIA-induced osteoarthritis. Based on these findings, we suggest that FS can be used for the development of potential therapies for osteoarthritis.

Commiphora Extract Mixture Ameliorates Monosodium Iodoacetate-Induced Osteoarthritis.

Osteoarthritis (OA) is a chronic inflammatory joint disease that affects millions of elderly people around the world. The conventional treatments for OA consisting of nonsteroidal anti-inflammatory drugs and steroid have negative health consequences, such as gastrointestinal, renal, and cardiac diseases. This study has evaluated the Commiphora extract mixture (HT083) on OA progression as an alternative treatment in animal models. The root of P. lactiflora and the gum resin of C. myrrha have been in use as traditional medicines against many health problems including bone disorders since ancient time. The extracts of P. lactiflora root and C. myrrha gum resin were mixed as 3:1 for their optimal effects. Male Sprague-Dawley rats were injected with monosodium iodoacetate (MIA) into the knee joints to induce the symptoms identical to human OA. HT083 substantially prevented the loss of weight-bearing inflicted with MIA in rats. The MIA-induced cartilage erosion as well as the subchondral bone damage in the rats was also reversed. In addition, the increase of serum IL-1ß concentration, a crucial pro-inflammatory cytokine involved in OA progression was countered by HT083. Furthermore, HT083 significantly reduced the acetic acid-induced writhing response in mice. In vitro, HT083 has shown potent anti-inflammatory activities by inhibiting the production of NO and suppressing the interleukin -1ß, interleukin -6, cyclooxygenase-2, and inducible nitric oxide synthase expression in lipopolysaccharide -stimulated RAW 264.7 cells. Given its potent analgesic and anti-inflammatory activities in MIA rats and acetic acid-induced writhing in mice, HT083 should be further studied in order to explain its mechanism of actions in alleviating OA pain and inflammation.

Acid-activatable polymeric curcumin nanoparticles as therapeutic agents for osteoarthritis.

Curcumin, a primary active element of turmeric, has potent antioxidant and anti-inflammatory activity, but its low bioavailability is a major hurdle in its pharmaceutical applications. To enhance the therapeutic efficacy of curcumin, we exploited polymeric prodrug strategy. Here, we report rationally designed acid-activatable curcumin polymer (ACP), as a therapeutic prodrug of curcumin, in which curcumin was covalently incorporated in the backbone of amphiphilic polymer. ACP could self-assemble to form micelles that rapidly release curcumin under the acidic condition. The potential of ACP micelles as therapeutics for osteoarthritis was evaluated using a mouse model of monoidoacetic acid (MIA)-induced knee osteoarthritis. ACP micelles drastically protected the articular structures from arthritis through the suppression of tumor necrosis factor-alpha (TNF-α) and interleukin 1ß (IL-1ß). Given their pathological stimulus-responsiveness and potent antioxidant and anti-inflammatory activities, ACP micelles hold remarkable potential as a therapeutic agent for not only osteoarthritis but also various inflammatory diseases.

Transcutaneous Electrical Nerve Stimulation Reduces Knee Osteoarthritic Pain by Inhibiting Spinal Glial Cells in Rats.

BACKGROUND: Transcutaneous electrical nerve stimulation (TENS) is commonly used for pain control. However, the effects of TENS on osteoarthritis (OA) pain and potential underlying mechanisms remain unclear. OBJECTIVE: The objective of this study was to investigate the effect of TENS on OA pain treatment and underlying mechanisms related to glial cell inhibition. DESIGN: This was an experimental study. METHODS: OA was induced by injection of monosodium iodoacetate into the synovial space of the right knee joint of rats. High-frequency (HF) TENS (100 Hz), low-frequency (LF) TENS (4 Hz), or sham TENS was applied to the ipsilateral knee joint for 20 minutes. Paw withdrawal threshold (PWT), weight bearing, and knee bend score (KBS) were measured. Immunohistochemistry for microglia and astrocytes was performed with L3 to L5 spinal segment samples. To investigate the effects of glial inhibition on OA pain, minocycline, l-α-aminoadipate, or artificial cerebrospinal fluid was injected intrathecally, and PWT and KBS were measured. RESULTS: Compared with sham TENS, both HF TENS and LF TENS significantly increased PWT, decreased KBS, and inhibited activated microglia in the L3 to L5 segments but did not decrease the total number of microglia, except in the L4 segment (HF TENS). Astrocyte expression was significantly decreased in the L3 to L5 segments following LF TENS and in the L3 segment following HF TENS. Compared with artificial cerebrospinal fluid, both minocycline and l-α-aminoadipate increased PWT and decreased KBS. LIMITATIONS: These results cannot be generalized to humans. CONCLUSIONS: TENS alleviates OA pain in rats by inhibiting activated microglia and reducing astrocyte expression in the spinal cord. Although these results may not be generalizable to chronic pain in patients with OA, within the limitation of the experimental animal model used in the present study, they suggest a possible mechanism and preclinical evidence supporting further experimentation or clinical use of TENS in humans.

The influence of probiotic diet and chondroitin sulfate administration on Ptgs2, Tgfb1 and Col2a1 expression in rat knee cartilage during monoiodoacetate-induced osteoarthritis.

BACKGROUND: Osteoarthritis (OA) is a common worldwide disease induced by a wide range of biochemical processes, mainly inflammation and degradation of collagen. The aim of this study, was to describe the effect of a multistrain probiotic (PB) and chondroitin sulfate (CS), administered separately or in combination, on the expression of Ptgs2, Tgfb1 and Col2a1 during monoiodoacetate-induced OA in male rats. METHODS: OA was induced in male rats by injecting monoiodoacetate in right hind knee. Therapeutic groups received 3 mg/kg of CS for 28 days and/or 1.4 g/kg of multistrain PB for 14 days. Knee cartilage were taken 30 days after monoiodoacetate injection. RNA was extracted and the expression of Ptgs2, Tgfb1 and Col2a1 were analyzed using SYBR Green 1-step real-time quantitative polymerase chain reaction. RESULTS: Induction of OA caused an upregulation in Ptgs2, Tgfb1 expression, and downregulation of Col2a1. Separate administration of PB and CS reduced Ptgs2 and Tgfb1 expressions. Their combined administration significantly decreased the expression of these pro-inflammatory cytokines, comparable to controls. Expression of Col2a1 showed similar behavior, with upregulation in therapeutic group with separate administration and the cumulative effects in case of co-administration. CONCLUSIONS: The multistrain PB diet may offer a perspective to improve the standard treatment of OA and, necessitates further investigation with clinical trials.

Curcumin reduces inflammation in knee osteoarthritis rats through blocking TLR4 /MyD88/NF-κB signal pathway.

Preclinical Research & Development Curcumin has been shown to possess a series of beneficial effects, such as antiinflammatory, antioxidant, analgesic, and promoting healing. However, the effect and relative mechanism of curcumin on knee osteoarthritis (OA) have not been elucidated. The aim of this study is to explore the protective effect of curcumin on monosodium iodoacetate (MIA)-induced OA. Forty-eight rats were randomized into four experimental groups: control group, OA group, OA + PBS group, and OA + curcumin group, respectively. A single intraarticular injection of MIA was applied to establish the rat model of knee OA. Hematoxylin-eosin staining was used to evaluate histological changes of knee joint. The paw withdrawal threshold was collected and the expression of synovial fluid cytokine levels was measured by ELISA. The protein expression of TRL-4, MyD88, p-IκBα, NF-κB, TNF-α, IL-1ß, and IL6 was measured by western blot. Treating with curcumin can significantly reduce joint diameter and Mankin's score, and increase the paw withdrawal threshold. The expression of synovial fluid inflammatory biomarkers, IL-6, IL-1ß, and TNF-α in the OA + curcumin group were lower than that in OA and OA + PBS group. The protein expression of the TLR4 receptor was increased in the OA, OA + PBS, and OA + curcumin group compared to the control group. However, curcumin treatment can significantly decrease the expression of MyD88, p-IκBα, NF-κB, TNF-α, IL-1ß, and IL6 in OA + curcumin group. These findings may indicate that curcumin could block TLR4/NF-κB signal pathway, and reduce inflammation level to prevent knee wound in OA rats. Curcumin may be a feasible kind of medicament in the treatment of knee OA.

The effects of particle density in moxa smoke on the ultrastructure of knee cartilage and expressions of TNF-α, IL-1b, BAX, and Bcl-2 mRNA in a rat model for osteoarthritis.

BACKGROUND: The effectiveness of smokeless moxa and other means to reduce exposure are extensively investigated with regards to the health consequences of inhalation of moxa smoke, and clinical studies indicate that classical moxibustion is superior to smokeless moxa. This study aims to quantify the effects of particle density in moxa smoke on the clinical outcome with an established model, demonstrated to be effective for classical moxibustion. OBJECTIVES: The purpose of this study is to explore the effects of particle density in moxa smoke on the ultrastructure of knee cartilage and expression of cytokine, tissue necrosing factor-alpha (TNF-α), interleukin 1 beta (IL-1b), apoptosis regulator, B-cell lymphoma-2 (Bcl-2), and BAX in a rat model for inflammatory joint disease. METHODS: Fifty healthy experimental rats were randomly divided into five groups, including normal control, model control, and moxa exposure groups with low, medium, and high particle density, and n = 10/group. In addition, a knee osteoarthritis model was duplicated in the model control and moxa exposure groups. Finally, the ultrastructure of knee cartilage was observed using transmission electron microscopy, and messenger RNA (mRNA) expressions of TNF-α, IL-1b, BAX, and Bcl-2 were determined with quantitative fluorescence methodology. RESULTS: In the model control and moxa exposure groups, knee cartilage indicated that histologic changes with the degree of injury were inversely proportional to moxa smoke density. The mRNA expressions of TNF-α, IL-1b, and BAX in synovial fluid, as an acute phase reactant, were similarly inversely related to moxa smoke density, but significantly increased. In contrast, Bcl-2, as an antiapoptotic, was substantially decreased in the model, while its levels were directly proportional to moxa smoke density. Besides, the ratio of Bcl-2/BAX mRNA was sharply decreased in the model group, but with levels proportional to moxa smoke density. CONCLUSIONS: A correlation was found between the particle density in moxa smoke and degree of injury to knee cartilage, favoring higher particle densities. This can be partially related to the suppression of the inflammatory effects of TNF-α, IL-1b, enhancement of the antiapoptotic effects of Bcl-2, and, nevertheless, suppression of the apoptotic effects of BAX. Finally, the protective effect of antiapoptotic is one of the key mechanisms for an ambient moxa smoking environment.

Avocado soybean unsaponifiables ameliorates cartilage and subchondral bone degeneration in mono-iodoacetate-induced knee osteoarthritis in rats.

Osteoarthritis (OA), the most common type of arthritis, is a disabling progressive disease mainly affecting the elderly and is becoming a major public health problem. Current therapies for OA provide only palliative pain relief and therapeutic candidates that are able to slow the progression of structural deterioration is a major unmet need for this disorder. Avocado soybean unsaponifiables (ASU) has proven its safety and effectiveness in clinical studies of knee osteoarthritis (OA); however, whether ASU exerts structure-modifying effects is still to be elucidated. There are limited studies that have explored the underlying mechanisms of ASU's beneficial effects in animal models of OA. To this end, this study is the first to evaluate the effects of ASU in a rat model of mono-iodoacetate (MIA)-induced knee OA. OA was induced in rats by knee intra-patellar injection of MIA. Oral administration of ASU (27.5 mg/kg per day for 3 weeks) was initiated 3 weeks after MIA injection. We analysed the knee samples using light and electron microscopy. In addition, we used immunohistochemistry to investigate the expression of inducible nitric oxide synthase (iNOS), tumour necrosis factor-α (TNF-α), and matrix metalloproteinase-13 (MMP-13) in OA cartilage and subchondral bone. ASU significantly attenuated the synovium, cartilage, and subchondral degeneration. In addition, it reduced the expression of TNF-α and MMP-13 in OA cartilage and the expression of iNOS in both OA cartilage and subchondral bone. These results provide evidence of the structure-modifying abilities of ASU via its anti-oxidative and anti-inflammatory properties, in addition to its ability to modulate MMP-13 activity. This work suggests that ASU can be used as a potential disease-modifying treatment for OA.