Prophylactic role of acetyl-l-carnitine on knee lesions and associated pain in a rat model of osteoarthritis

Ski ameliorates synovial cell inflammation in monosodium iodoacetate-induced knee osteoarthritis

Knee osteoarthritis (KOA) is one of the most common degenerative diseases and is characterized by cartilage degeneration, synovial inflammation, joint stiffness and even loss of motor function. In the clinical treatment of arthritis, conventional analgesic and anti-inflammatory drugs have great side effects. We have evaluated the possibility of the endogenous transcription regulator Ski as an anti-inflammatory alternative in OA through experimental studies in animal models and in vivo and in vitro. Male Sprague‒Dawley rats were injected with monosodium iodoacetate (MIA) into the knee joints to induce symptoms identical to those of human OA. We isolated knee synovial tissue under sterile conditions and cultured primary synovial cells. In vitro, Ski inhibits the proinflammatory factors IL-1β, IL-6 and TNF-α mRNA and protein expression in lipopolysaccharide (LPS)-stimulated fibroblast-like synoviocytes (FLSs) and U-937 cells. In addition, Ski attenuates or inhibits OA-induced synovial inflammation by upregulating the protein expression of the anti-inflammatory factor IL-4 and downregulating the protein expression of downstream molecules related to the NF-κB inflammatory signaling pathway. In vivo, Ski downregulated proinflammatory factors and p-NF-κB p65 in KOA synovial tissue and alleviated pain-related behaviors in KOA rats. These experimental data show that Ski has strong anti-inflammatory activity. Ski is an endogenous factor, and if used in the clinical treatment of OA, the side effects are small. However, the anti-inflammatory mechanism of Ski must be further studied.

Anti-Hyperalgesic Efficacy of Acetyl L-Carnitine (ALCAR) Against Visceral Pain Induced by Colitis: Involvement of Glia in the Enteric and Central Nervous System

The management of abdominal pain in patients affected by inflammatory bowel diseases (IBDs) still represents a problem because of the lack of effective treatments. Acetyl L-carnitine (ALCAR) has proved useful in the treatment of different types of chronic pain with excellent tolerability. The present work aimed at evaluating the anti-hyperalgesic efficacy of ALCAR in a model of persistent visceral pain associated with colitis induced by 2,4-dinitrobenzene sulfonic acid (DNBS) injection. Two different protocols were applied. In the preventive protocol, ALCAR was administered daily starting 14 days to 24 h before the delivery of DNBS. In the interventive protocol, ALCAR was daily administered starting the same day of DNBS injection, and the treatment was continued for 14 days. In both cases, ALCAR significantly reduced the establishment of visceral hyperalgesia in DNBS-treated animals, though the interventive protocol showed a greater efficacy than the preventive one. The interventive protocol partially reduced colon damage in rats, counteracting enteric glia and spinal astrocyte activation resulting from colitis, as analyzed by immunofluorescence. On the other hand, the preventive protocol effectively protected enteric neurons from the inflammatory insult. These findings suggest the putative usefulness of ALCAR as a food supplement for patients suffering from IBDs.

Acetyl-L-carnitine in chronic pain: A narrative review

Acetyl-L-carnitine (ALC) is an endogenous molecule that not only plays a role in energy metabolism, but also has antioxidant properties, protects from oxidative stress, modulates brain neurotransmitters such as acetylcholine, serotonin and dopamine, and acts on neurotrophic factors such as nerve growth factor (NGF) and metabotropic glutamate (mGlu) receptors by means of epigenetic mechanisms. Importantly, it induces mGlu2 expression at nerve terminals, thus giving rise to analgesia and preventing spinal sensitisation. It has also been found to have even long-term neurotrophic and analgesic activity in experimental models of chronic inflammatory and neuropathic pain. The aim of this narrative review is to summarise the current evidence regarding the use of ALC in patients with chronic pain, and cognitive and mood disorders, and investigate the rationale underlying its use in patients with fibromyalgia syndrome, which is characterised by nociplastic changes that increase the sensitivity of the nervous system to pain.

The effect of L-Carnitine supplementation on clinical symptoms, C-reactive protein and malondialdehyde in obese women with knee osteoarthritis: a double blind randomized controlled trial

BACKGROUNDS

L-carnitine decreases oxidation and inflammation by reducing the fatty acid in plasma and using oxygen in ATP synthesis. As such, knee osteoarthritis (KOA) can be improved by reducing apoptotic chondrocytes. This study was designed to compare the effect of L-carnitine supplementation and low-calorie diet on improving KOA among obese women. We further investigated the effect of L- carnitine on improvement of KOA in obese women on low calorie diet.

METHODS

To conduct the study, 76 obese women with KOA were randomly assigned into two low-calorie diet groups: the first received 1000 mg of LCG and the second took the placebo (PLG) (n = 38). Anthropometry indices, body composition, lipid profile, C-reactive Protein (CRP), Malondialdehyde (MDA), and the Western Ontario and McMaster Universities Arthritis Index (WOMAC) were assessed at the baseline condition and after 12 weeks.

RESULTS

The mean change of body mass index (BMI) (- 1.21 ± 0.84 vs. -0.79 ± 0.70; P = 0.02) and weight (- 2.76 ± 1.69 vs. -1.95 ± 1.73; P = 0.05) were significant in the LCG compared with the PLG. Likewise, LCG compared to the PLG showed insignificant improvement in waist circumference (WC) (- 5.65 ± 5.85 vs. -3.64 ± 3.37; P = 0.08). Total cholesterol (P = 0.02), MDA (P = 0.03), fat mass (P = 0.03) and visceral fat (P = 0.001) only showed decreased levels in LCG in comparison to the baseline condition. There was no significant difference between LCG and PLG, in the mean changes of hip circumference, visceral fat, free fat mass, fat mass, lipid profiles, CRP, MDA as well as stiffness, physical function, decrease of pain and total scores (P > 0.05).

CONCLUSION

The 12-week L-carnitine supplementation could improve BMI, but had no significant effect on other anthropometric and body composition measures as well as clinical symptoms, CRP, MDA, and lipid profile in women with KOA. Further trials with higher doses and longer durations are required. IRCT registration number: IRCT2017011932026N2. Registration date: 2017-04-27.

L-Carnitine potentiates the anti-inflammatory and antinociceptive effects of diclofenac sodium in an experimentally-induced knee osteoarthritis rat model

OBJECTIVES

The aim of the present research is to investigate the efficacy of L-carnitine (LC) as a complementary therapy to diclofenac sodium (Dic) treatment in a mono-iodoacetate (MIA) induced knee osteoarthritis (OA) rat model, with respect to pain relief and the underlying pathology.

MATERIALS AND METHODS

Fifty adult male albino rats were randomly divided into five groups (n=10): Control, OA, OA/Dic, OA/LC, and OA/Dic+LC. Knee diameter and pain assessment tests were done weekly. After four weeks, serum malondialdehyde, reduced glutathione, interleukin 1-β, tumor necrosis factor-alpha, prostaglandin E2, and bone-specific alkaline phosphatase were measured. The injected knees were removed and processed for the histological and immunohistological study of matrix metalloproteinase-13 (MMP-13) and cyclooxygenase 2 (COX-2). Also, histological examination of dorsal root ganglia and calcitonin gene-related peptide (CGRP) expression in the spinal cord were assessed.

RESULTS

Treatment with Dic and/or LC significantly reduced knee swelling, improved pain-related behaviors, inflammatory and oxidative stress markers, attenuated the MIA-mediated histopathological alteration in the knee joint, and down-regulated expression of MMP-13 and COX-2 in the knee joint. It, also, significantly reduced CGRP expression, compared with the OA group. Dic+LC showed a better effect in improving some parameters than each treatment alone.

CONCLUSION

LC plus Dic is a more effective therapy than Dic alone for OA treatment.

Protective effects of Erdosteine on interleukin-1β-stimulated inflammation via inhibiting the activation of MAPK, NF-κB, and Wnt/β-catenin signaling pathways in rat osteoarthritis

Osteoarthritis (OA), a degenerative arthropathy, is featured with progressive degradation of cartilage and a chondrocyte inflammatory response. Erdosteine (ER) showed the anti-oxidant properties and various anti-inflammatory effects in various diseases. However, whether it protects against OA remains unknown. In this study, we explore the potential therapeutic properties of ER on IL-1β-stimulated rat chondrocytes and its underlying mechanism in vitro and vivo. Cell viability, pro-inflammatory cytokines and the degradation of ECM biomarkers were tested to determine the effects of ER at 10, 20, and 40 μM doses on IL-1β-induced rat chondrocytes for 24 h in virto. In vivo, intra-articular injections of 50 μl of 100 mg/ml ER twice a week for 8 weeks. The results showed ER significantly suppressed the expressions of IL-1β-induced the production of inflammatory factors in a dose-dependent pattern (4.30-fold decrease in COX-2, p < 0.05; 4.77-fold decrease in iNOS, p < 0.05 at 40 μM in protein levels). Moreover, ER could attenuate the degradation of ECM in IL-1β-induced rat chondrocytes by repressing the expression of OA-related factors (2.40-fold decrease in ADAMTS-5, p < 0.05; 3.12-fold decrease in MMP1, p < 0.05; 3.97-fold decrease in MMP3, p < 0.05; and 2.62-fold decrease in MMP-13, p < 0.05 at 40 μM in protein levels). Furthermore, our study revealed that ER could inhibit the activations of IL-1β-induced MAPK and Wnt/β-catenin. Besides, ER could suppress the process of IL-1β-induced P65 from the cytoplasm into the nucleus. In vivo, ER delaied the osteoarthritis progression in rat OA models. Collectively, ER might become a new therapeutic agent for OA.

Inhibition of early response genes prevents changes in global joint metabolomic profiles in mouse post-traumatic osteoarthritis

OBJECTIVE

Although joint injury itself damages joint tissues, a substantial amount of secondary damage is mediated by the cellular responses to the injury. Cellular responses include the production and activation of proteases (MMPs, ADAMTSs, Cathepsins), and the production of inflammatory cytokines. The trajectory of cellular responses is driven by the transcriptional activation of early response genes, which requires Cdk9-dependent RNA Polymerase II phosphorylation. Our objective was to determine whether inhibition of cdk9-dependent early response gene activation affects changes in the joint metabolome.

DESIGN

To model post-traumatic osteoarthritis, we subjected mice to non-invasive Anterior Cruciate Ligament (ACL)-rupture joint injury. Following injury, mice were treated with flavopiridol - a potent and selective inhibitor of Cdk9 kinase activity - to inhibit Cdk9-dependent transcriptional activation, or vehicle control. Global joint metabolomics were analyzed 1 h after injury.

RESULTS

We found that injury induced metabolomic changes, including increases in Vitamin D3 metabolism, anandamide, and others. Inhibition of primary response gene activation immediately after injury largely prevented the global changes in the metabolomics profiles. Cluster analysis of joint metabolomes identified groups of injury-induced and drug-responsive metabolites.

CONCLUSIONS

Metabolomic profiling provides an instantaneous snapshot of biochemical activity representing cellular responses. We identified two sets of metabolites that change acutely after joint injury: those that require transcription of primary response genes, and those that do not. These data demonstrate the potential for inhibition of early response genes to alter the trajectory of cell-mediated degenerative changes following joint injury, which may offer novel targets for cell-mediated secondary joint damage.

Alteration of Metabolic Pathways in Osteoarthritis

Sir Archibald Edward Garrod, who pioneered the field of inborn errors of metabolism and first elucidated the biochemical basis of alkaptonuria over 100 years ago, suggested that inborn errors of metabolism were "merely extreme examples of variations of chemical behavior which are probably everywhere present in minor degrees, just as no two individuals of a species are absolutely identical in bodily structure neither are their chemical processes carried out on exactly the same lines", and that this "chemical individuality [confers] predisposition to and immunities from various mishaps which are spoken of as diseases". Indeed, with advances in analytical biochemistry, especially the development of metabolomics in the post-genomic era, emerging data have been demonstrating that the levels of many metabolites do show substantial interindividual variation, and some of which are likely to be associated with common diseases, such as osteoarthritis (OA). Much work has been reported in the literature on the metabolomics of OA in recent years. In this narrative review, we provided an overview of the identified alteration of metabolic pathways in OA and discussed the role of those identified metabolites and related pathways in OA diagnosis, prognosis, and treatment.

A putative Chondroprotective role for IL-1β and MPO in herbal treatment of experimental osteoarthritis

BACKGROUND

Herbal treatment may have a chondroprotective and therapeutic effect on Osteoarthritis (OA). We investigated the mechanism of action of ginger and curcumin rhizomes cultivated in Egypt in treatment of OA in rat model.

METHODS

Thirty-five albino rats were intra-articularly injected with Monosodium Iodoacetate in the knee joint. Ginger and curcumin was orally administered at doses of 200 and 400 mg/kg (F200 and F400). Serum levels of cartilage oligomeric matrix protein (COMP), hyaluronic acid (HA), malondialdehyde (MDA), myeloperoxidase (MPO), Interleukin-1 beta (IL-1β) and superoxide dismutase activity (SOD) were measured using ELISA. The composition of the herbal formula hydro-ethanolic extract was characterized using UPLC-ESI-MS. Histopathological changes in injected joints was examined using routine histopathology. Statistical analysis was performed using one-way ANOVA.

RESULTS

Serum levels of COMP, HA, MPO, MDA, and IL-1β were significantly decreased in F 200, F 400 and V groups when compared to OA group (P value <0.0001). On the other hand SOD levels were significantly elevated in treated groups compared to OA groups (P value <0.0001).

CONCLUSIONS

The ginger/curcumin at 1:1 had chondroprotective effect via anti-inflammatory and antioxidant effect in rat OA model. Further pharmacological and clinical studies are needed to evaluate this effect.

Widespread pain reliever profile of a flower extract of Tanacetum parthenium

BACKGROUND

Tanacetum parthenium L., commonly called Feverfew, is known for anti-inflammatory and anti-migraine properties.

PURPOSE

Aimed to individuate new therapeutical strategies to control acute and persistent pain induced by different origins we tested two hydroalcoholic extracts obtained from Feverfew flowers and leaves, respectively.

STUDY DESIGN

Extracts were characterized according to the European Pharmacopoeia monograph. Both the extracts were tested after acute per os administration in the dose range 30-1000 mg kg(-1). The anti-nociceptive properties were evaluated by the Writhing test in mice.

RESULTS

The number of abdominal contractions was dose dependently reduced by the flower extract. It reduced mechanical hypersensitivity (Paw pressure test) related to the acute inflammatory phase induced by carrageenan similarly to diclofenac and ibuprofen. In the osteoarthritis model induced by intra articular injection of monoiodoacetate (MIA) the flower extract significantly increased the pain threshold peaking 30 min after treatment. Moreover, it was effective in the chronic constriction injury model of neuropathic pain showing activity similar to the anti-epileptic drug gabapentin. The flower extract activity was confirmed in rat models of chemotherapy-induced neuropathic pain. The mechanical hypersensitivity induced by repeated treatments with the anticancer drug oxaliplatin and with the antiviral dideoxycytidine was significantly reduced after a single injection of Feverfew flower extract. The leaf extract showed lesser efficacy and potency and it was devoid of any effect in carrageenan-, MIA- and chemotherapy-induced pain.

CONCLUSION

The present Feverfew flower extract behaves as a potent pain reliever in acute, inflammatory, articular and neuropathic pain. It appears as a natural strategy potentially suitable for the treatment of different kinds of pain.