Evaluation of different substance combinations in a multiple-session mesotherapy protocol for the management of osteoarthritis in dogs: a retrospective study.

OBJECTIVE: To describe the effect of different substance combinations administered through mesotherapy in dogs with hip osteoarthritis. ANIMALS: 104 dogs. METHODS: In this retrospective study, 4 groups (dogs treated with a combination of lidocaine, piroxicam, and thiocolchicoside [MG]; dogs treated with lidocaine, piroxicam, and Traumeel [TG]; dogs treated with lidocaine, piroxicam, and glucosamine [GG]; and dogs treated with the same combination as in MG combined with a photobiomodulation session [MPG]) were set. For all groups, the same treatment frequency was followed. Response to treatment was measured with the Canine Brief Pain Inventory (divided into pain interference score and pain severity score), Liverpool Osteoarthritis in Dogs (LOAD), and Canine Orthopedic Index (divided into function, gait, stiffness, and quality of life) before treatment and 15, 30, 60, 90, and 120 days after treatment. Cox proportional hazard regression analysis was used to investigate the influence of treatment, age, sex, body weight, breed, and Orthopedic Foundation for Animals score. RESULTS: Dogs had a mean age of 7.6 ± 3.1 years and body weight of 28.6 ± 5.5 kg. Hip osteoarthritis was classified as mild (4), moderate (70), or severe (30). Greater improvements were observed in MG and MPG. Kaplan-Meier estimators showed MG and MPG had longer periods with clinically significant results. Treatment was the covariable that contributed more frequently to the outcomes observed. CLINICAL RELEVANCE: The combination used in MG, particularly combined with photobiomodulation, produced longer-lasting clinically significant results.

Open, Observational, Single-Arm, Multicenter Study Assessing the Effectiveness of a Dietary Supplement Containing Hydrolyzed Collagen, Chondroitin Sulfate, and Glucosamine for Osteoarthritis Pain Reduction.

Osteoarthritis (OA) is an age-related degenerative joint disease with a great impact on patients' well-being and quality of life. This is an observational, open, single-arm multicenter study aimed to evaluate the effectiveness of a nutritional supplement in patients with knee and/or hip OA. A total of 186 patients were recruited from Spanish centers and received a supplement containing hydrolyzed collagen (3000 mg), chondroitin sulfate (800 mg), glucosamine sulfate (700 mg), turmeric extract (250 mg) and devil's claw (150 mg), once daily during 6 months. The primary outcome was the patients' self-perceived pain in the affected joints measured with a visual analogue scale (VAS). Secondary outcome was the patient's functioning, measured with the Lequesne Functional Index and the Western Ontario and McMaster Universities Arthritis Index (WOMAC). Participants showed a significant reduction in self-perceived pain after 3 (mean reduction ± standard deviation, 1.99 ± 1.05) and 6 months (3.57 ± 1.39) of treatment (p < 0.0001 in both comparisons). Lequesne Functional Index score was significantly reduced at 3 months (3.86 ± 2.94) and at 6 months (6.73 ± 4.30) of treatment (p < 0.0001 in both comparisons). The WOMAC index was also significantly reduced after 3 (14.24 ± 10.04) and 6 months (26.43 ± 17.35) of treatment (p < 0.0001 in both comparisons). Significant reductions in WOMAC subdomains (p < 0.0001 in all comparisons) were observed. No severe adverse events were reported during the study. The main results arising from this study show that this nutritional supplementation can improve OA-related symptoms and physical function with a good safety profile in patients with hip and/or knee OA.

No Associations Between Glucosamine Supplementation and Dementia or Parkinson's Disease: Findings From a Large Prospective Cohort Study.

BACKGROUND: We investigated the associations between habitual use of glucosamine and incident dementia and Parkinson's disease in a population-based cohort. METHODS: Using the UK Biobank data, we included around 0.29 million middle- to old-aged participants free of dementia or Parkinson's disease at baseline. Glucosamine supplementation was measured by questionnaire at baseline. Some participants additionally answered 1-5 rounds of 24-hour dietary recalls afterwards, particularly 112 243 participants (for dementia) and 112 084 (for Parkinson's disease). Incident cases of dementia and Parkinson's disease were identified through linkage to health administrative data sets. We examined the associations of glucosamine supplementation with incident dementia and Parkinson's disease using Cox proportional-hazards regression models with adjustment for various covariates. RESULTS: During the study period (median follow-up: 9.1-10.9 years), 4 404 and 1 637 participants developed dementia and Parkinson's disease, respectively. Glucosamine intake was not associated with incident dementia or Parkinson's disease. In fully adjusted models, the hazard ratios associated with glucosamine intake were 1.06 [95% confidence interval (CI): 0.99, 1.14] for dementia and 0.97(95% CI: 0.86, 1.09) for Parkinson's disease. In the subsample, similar results were found as the frequency of reported glucosamine use over multiple dietary surveys was associated with neither of the 2 conditions. CONCLUSIONS: Habitual supplementation of glucosamine was not associated with incident dementia or Parkinson's disease.

Habitual glucosamine use, APOE genotypes, and risk of incident cause-specific dementia in the older population.

BACKGROUND: The relationship of glucosamine use with incident dementia in the older population remains uncertain. We aimed to evaluate the longitudinal association between habitual glucosamine supplement and the risk of cause-specific dementia and examine the possible effect modifiers on this association. METHODS: The study included 214,945 participants over the age of 60 who had available information on glucosamine use and did not have dementia at baseline in the UK Biobank. The APOE genotypes were determined by a combination variant of rs429358 and rs7412. The primary outcome was incident vascular dementia, incident Alzheimer's disease, and incident frontotemporal dementia, respectively. RESULTS: Over a median follow-up duration of 12 years, 1039, 1774, and 122 participants developed vascular dementia, Alzheimer's disease, and frontotemporal dementia, respectively. Overall, habitual glucosamine use was significantly associated with a lower risk of incident vascular dementia (adjusted HR, 0.82; 95%CI, 0.70-0.96), but not significantly associated with incident Alzheimer's disease (adjusted HR, 1.02; 95%CI, 0.92-1.14) and incident frontotemporal dementia (adjusted HR, 0.95; 95%CI, 0.63-1.43). Moreover, the inverse association between habitual glucosamine use and incident vascular dementia was more pronounced in participants with concomitant supplement of calcium (P-interaction = 0.011), and those without concomitant supplement of zinc (P-interaction = 0.018). However, APOE ε4 dosage and baseline cognitive function did not significantly modify the relationships of glucosamine use with incident vascular dementia or Alzheimer's disease (All P-interactions > 0.05). CONCLUSIONS: Regardless of APOE genotypes and baseline cognitive function, habitual glucosamine use was significantly inversely associated with incident vascular dementia in the older population.

Randomized, double-blind, four-arm pilot study on the effects of chicken essence and type II collagen hydrolysate on joint, bone, and muscle functions.

BACKGROUND: Knee osteoarthritis (OA) is a leading cause of disability among older adults. Medical and surgical treatments are costly and associated with side effects. A natural nutraceutical, collagen hydrolysate, has received considerable attention due to its relieving effects on OA-associated symptoms. This study investigated the effects of hydrolyzed collagen type II (HC-II) and essence of chicken (BRAND'S Essence of Chicken) with added HC-II (EC-HC-II) on joint, muscle, and bone functions among older adults with OA. METHODS: Patients (n = 160) with grade 1-3 knee OA according to the Kellgren-Lawrence classification system, joint pain for ≥ 3 months, and a Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score of > 6 were randomly assigned with equal probability to consume EC-HC-II, HC-II, glucosamine HCl, or a placebo for 24 weeks in combination with resistance training. Outcome measurements were WOMAC score, visual analogue scale (VAS) pain score, grip strength, fat-free mass (FFM), and bone mass. RESULTS: All groups exhibited similar levels of improvement in WOMAC index scores after 24 weeks. HC-II significantly reduced VAS pain score by 0.9 ± 1.89 (p = 0.034) after 14 days. A repeated-measures analysis of variance showed that HC-II reduced pain levels more than the placebo did (mean ± standard error: - 1.3 ± 0.45, p = 0.021) after 14 days; the EC-HC-II group also had significantly higher FFM than the glucosamine HCl (p = 0.02) and placebo (p = 0.017) groups and significantly higher grip strength than the glucosamine HCl group (p = 0.002) at 24 weeks. CONCLUSION: HC-II reduces pain, and EC-HC-II may improve FFM and muscle strength. This suggests that EC-HC-II may be a novel holistic solution for mobility by improving joint, muscle, and bone health among older adults. Large-scale studies should be conducted to validate these findings. TRIAL REGISTRATION: This trial was retrospectively registered at ClinicalTrials.gov (NCT04483024).

Glucosamine and Chondroitin Use and Mortality Among Adults in the United States from 1999 to 2014.

Introduction: Glucosamine and chondroitin are supplements that are often, but not always, used in combination for arthritis and joint pain. Multiple studies have suggested that glucosamine and chondroitin may be associated with reduced risk of several diseases, as well as all-cause, cancer- and respiratory disease-specific mortality. Methods: Nationally representative data from the National Health and Nutrition Examination Survey (NHANES) were used to further evaluate the association between glucosamine and chondroitin with mortality. Participants include 38,021 adults, ages 20+ years and older, who completed the detailed NHANES between 1999 and 2014. Participants were followed for death through linkage with the National Death Index through the end of 2015, over which time 4905 deaths occurred. Adjusted hazard ratios (HRs) for overall and cause-specific mortality were estimated using Cox regression models. Results: Despite glucosamine and chondroitin use appearing to be inversely associated with mortality in the minimally adjusted models, no association was observed in multivariable models (glucosamine: HR = 1.02; 95% confidence interval [CI]: 0.86-1.21, chondroitin: HR = 1.04, 95% CI: 0.87-1.25). No association with cancer mortality or other mortality rate was observed after multivariable adjustment. There was a suggestive, nonsignificant inverse association for cardiovascular-specific mortality (glucosamine HR = 0.72; 95% CI: 0.46-1.15, chondroitin: HR = 0.76; 95% CI: 0.47-1.21). Conclusion: The lack of significant relationship between glucosamine and chondroitin use and all-cause or cause-specific mortality after adjusting extensively for multiple covariates in this nationally representative adult population was in contrast to prior literature. Given the limited power to explore the cause-specific mortality, future well-powered studies will be needed to better understand the potential association with cardiovascular-specific mortality.

Association of regular glucosamine use with incident dementia: evidence from a longitudinal cohort and Mendelian randomization study.

BACKGROUND: Emerging data suggests the neuroprotective and anti-neuroinflammatory effects of glucosamine. We aimed to examine the association between regular glucosamine use and risk of incident dementia, including dementia subtypes. METHODS: We conducted large-scale observational and two-sample Mendelian randomization (MR) analyses. Participants in UK Biobank having accessible data for dementia incidence and who did not have dementia at baseline were included in the prospective cohort. Through the Cox proportional hazard model, we examined the risks of incident all-cause dementia, Alzheimer's disease (AD), and vascular dementia among glucosamine users and non-users. To further test the causal association between glucosamine use and dementia, we conducted a 2-sample MR utilizing summary statistics from genome-wide association studies (GWAS). The GWAS data were obtained from observational cohort participants of mostly European ancestry. RESULTS: During a median follow-up of 8.9 years, there were 2458 cases of all-cause dementia, 924 cases of AD, and 491 cases of vascular dementia. In multivariable analysis, the hazard ratios (HR) of glucosamine users for all-cause dementia, AD, and vascular dementia were 0.84 (95% CI 0.75-0.93), 0.83 (95% CI 0.71-0.98), and 0.74 (95% CI 0.58-0.95), respectively. The inverse associations between glucosamine use and AD appeared to be stronger among participants aged below 60 years than those aged above 60 years (p = 0.04 for interaction). The APOE genotype did not modify this association (p > 0.05 for interaction). Single-variable MR suggested a causal relationship between glucosamine use and lower dementia risk. Multivariable MR showed that taking glucosamine continued to protect against dementia after controlling for vitamin, chondroitin supplement use and osteoarthritis (all-cause dementia HR 0.88, 95% CI 0.81-0.95; AD HR 0.78, 95% CI 0.72-0.85; vascular dementia HR 0.73, 95% CI 0.57-0.94). Single and multivariable inverse variance weighted (MV-IVW) and MR-Egger sensitivity analyses produced similar results for these estimations. CONCLUSIONS: The findings of this large-scale cohort and MR analysis provide evidence for potential causal associations between the glucosamine use and lower risk for dementia. These findings require further validation through randomized controlled trials.

The efficacy and safety of hydrotherapy in patients with knee osteoarthritis: A protocol for systematic review and meta-analysis.

BACKGROUND: Knee osteoarthritis (OA) is a common clinical degenerative disease of the joints, which is prone to occur in middle-aged and elderly people. At present, the disease cannot be cured, it is mostly treated with drugs to relieve symptoms, improve joint function, protect cartilage, such as glucosamine, anti-inflammatory and analgesic drugs, and but the efficacy is not lasting and the recurrence rate is high. Hydrotherapy has become a long-term alternative therapy in China and is receiving increasing attention. We perform a protocol for systematic review and meta-analysis to determine the efficacy and safety of a hydrotherapy program in individuals living with knee OA. METHODS: This protocol will be designed in accordance with the preferred reporting items for systematic reviews and meta-analysis protocols. It is registered on the international prospective register of systematic reviews (No. CRD42022365564). We will search the following databases: The Cochrane Skin Group Trials Register, MEDLINE, EMBASE, The Cochrane central register of controlled trials, Chinese biomedical literature database, Chinese medical current content and China national knowledge infrastructure. The risk of bias of the included studies will be appraised using the Cochrane collaboration tool. Statistical analysis will be performed using IBM SPSS Statistics (Armonk, NY). RESULTS: This systematic review will summarize the short- and long-term clinical outcomes of hydrotherapy for knee OA. CONCLUSION: The findings from this review will establish the quality of currently available evidence, which will determine the need for further studies to establish the true effect size of hydrotherapy in knee OA.

Regular Glucosamine Use May Have Different Roles in the Risk of Site-Specific Cancers: Findings from a Large Prospective Cohort.

BACKGROUND: Previous studies indicated that glucosamine supplements may have a general anticancer effect. This study aimed to assess whether the potential effect differs across different types of cancers in a large prospective cohort study. METHODS: All participants from the UK Biobank who were free of cancers and had complete information on glucosamine use at baseline were included and followed up from 2006 until 2021. Cox proportional hazards models were used to assess the associations between regular glucosamine use and different site-specific cancers. Subgroup analyses were performed to explore potential interactions. Several sensitivity analyses were conducted to assess the robustness of the main findings. RESULTS: A total of 450,207 eligible participants (mean age: 56.2 years; females: 53.3%) were included, of whom 84,895 (18.9%) reported regular glucosamine use at baseline. During a median of 12.5 years follow-up, glucosamine use was significantly associated with an increased risk of overall cancer [HR, 1.04; 95% confidence interval (CI), 1.01-1.06], skin cancer (HR, 1.11; 95% CI, 1.07-1.15), and prostate cancer (HR, 1.07; 95% CI, 1.01-1.13), and with a reduced risk of lung cancer (HR, 0.88; 95% CI, 0.79-0.97) after adjusting for potential confounders. Statistical interaction was observed for gender, age, and education for the association of glucosamine use with overall cancer risk (all Pinteraction < 0.027). These results remained unchanged in the sensitivity analyses. CONCLUSIONS: Regular glucosamine use was associated with lower risk of lung cancer but higher risk of skin cancer, prostate cancer, and overall cancer. IMPACT: The roles of glucosamine use potentially differ in the development of different site-specific cancers.

The role of type 2 diabetes in the association between habitual glucosamine use and dementia: a prospective cohort study.

BACKGROUND: Growing evidence has showed an association between habitual glucosamine use and type 2 diabetes (T2D). However, the effect of habitual glucosamine use on risk of dementia remains poorly understood. Our study aimed to examine the association between glucosamine use and risk of dementia and further to identify the mediating role of T2D in the association. METHODS: A total of 495,942 participants from UK Biobank who completed a questionnaire on habitual glucosamine use were included at baseline (2006-2010) and then followed up for incidence of dementia until 2020. Cox proportional hazard regressions were performed to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for incident dementia. Markov multi-state models were used to explore the role of incidence of T2D during the follow-up in the association. RESULTS: Overall, 18.80% of the participants reported habitual use of glucosamine at baseline. A total of 6831 dementia events were recorded during a median follow-up of 11 years. In fully adjusted models, habitual glucosamine use was associated with a significantly lower risk of dementia (HR = 0.87, 95% CI: 0.82-0.93). Multi-state models showed that the association between glucosamine use and dementia was mediated by the incidence of T2D during the follow-up (HR of dementia without T2D: 0.92, 95% CI: 0.86-0.99; HR of post-T2D dementia: 0.79, 95% CI: 0.67-0.93). CONCLUSIONS: Our findings reveal that habitual use of glucosamine supplement is associated with a lower risk of dementia, which might be explained by incidence of T2D.

Associations of habitual glucosamine supplementation with incident gout: a large population based cohort study.

OBJECTIVES: The association between habitual glucosamine use and incident gout has not been examined in previous studies. We aimed to evaluate the association of habitual use of glucosamine with the risk of gout in general population. METHODS: A total of 436,594 participants (55.4% female) without prior gout at baseline who completed a questionnaire on supplementation use, which included glucosamine, in the UK Biobank were enrolled. Incident gout was recorded from self-report, death register, primary care, and hospital admission data. RESULTS: At baseline, 53,433 (22.1%) females and 30,685 (15.8%) males reported habitual glucosamine use. During a median follow-up period of 12.1 years, 1718 (0.7%) females and 5685 (2.9%) males developed gout. After multivariable adjustment for major risk factors, glucosamine use was associated with a significantly lower risk of incident gout in females (hazard ratio [HR], 0.81, 95% confidence interval [CI], 0.71-0.92), but not in males (HR, 1.05, 95% CI, 0.97-1.13), compared with non-use (P-interaction < 0.001). Among females, the inverse association between glucosamine use and gout was stronger in participants with diuretics use (HR, 0.64, 95% CI, 0.50-0.81) than those without diuretics use (HR, 0.89, 95% CI, 0.77-1.03) (P-interaction = 0.015). Moreover, gout genetic risk scores did not significantly modify the association between glucosamine use and the risk of incident gout in males (P-interaction = 0.548) or females (P-interaction = 0.183). CONCLUSIONS: Habitual glucosamine use to relieve osteoarthritis pain was related to lower risk of gout in females, but not in males.

Effects of glucosamine and chondroitin sulfate supplementation in addition to resistance exercise training and manual therapy in patients with knee osteoarthritis: A randomized controlled trial.

OBJECTIVE: To determine the added benefits of short-term glucosamine and chondroitin sulfate supplementation in combination with manual therapy and resistance exercise training in the management of knee osteoarthritis. METHODS: A parallel-design, double-blind randomised controlled trial was conducted from January to September 2020 at the Foundation University Institute of Rehabilitation Sciences and Fauji Foundation Hospital, Rawalpindi, Pakistan, and comprised of knee osteoarthritis patients of either gender having radiological evidence of grade III or less on Kellgren classification. The subjects were randomly allocated to active comparator group A and experimental group B. Both the groups received manual therapy and resistance exercise training, while group B additionally received glucosamine and chondroitin sulfate supplementation for 4 weeks. Study outcomes included pain, function, quality of life, range of motion, strength, fall risk, skeletal muscle mass, visceral fat area, body fat, intracellular water ratio, and segmental lean and fat mass. Data was analysed using SPSS 21. RESULTS: Of the 24 subjects, there were 12(50%) in each of the two groups. Each groups had 9(75%) males and 3(25%) females. In terms knee osteoarthritis grade, there was no significant difference between the groups (p=1.00). No significant differences were observed in any of the outcome measures neither at 2 weeks, nor at 4 weeks post-intervention between the groups (p>0.05) except for percentage change in segmental lean mass of the right leg at 2nd week and of the left leg at 4th week (p<0.05). CONCLUSIONS: Manual therapy and resistance exercise training are effective in the management of knee osteoarthritis, however, glucosamine and chondroitin sulfate supplementation for 4 weeks showed no additional benefits. Clinical Trial Number: NCT04654871. https://www.clinicaltrials.gov/ct2/show/NCT04654871.

A 2022 Systematic Review and Meta-Analysis of Enriched Therapeutic Diets and Nutraceuticals in Canine and Feline Osteoarthritis.

With osteoarthritis being the most common degenerative disease in pet animals, a very broad panel of natural health products is available on the market for its management. The aim of this systematic review and meta-analysis, registered on PROSPERO (CRD42021279368), was to test for the evidence of clinical analgesia efficacy of fortified foods and nutraceuticals administered in dogs and cats affected by osteoarthritis. In four electronic bibliographic databases, 1578 publications were retrieved plus 20 additional publications from internal sources. Fifty-seven articles were included, comprising 72 trials divided into nine different categories of natural health compound. The efficacy assessment, associated to the level of quality of each trial, presented an evident clinical analgesic efficacy for omega-3-enriched diets, omega-3 supplements and cannabidiol (to a lesser degree). Our analyses showed a weak efficacy of collagen and a very marked non-effect of chondroitin-glucosamine nutraceuticals, which leads us to recommend that the latter products should no longer be recommended for pain management in canine and feline osteoarthritis.

Glucosamine and lower mortality and cancer incidence: Selection bias in the observational studies.

BACKGROUND: Glucosamine is a widely used supplement to treat joint pain and osteoarthritis despite inconclusive randomized trial results on its effectiveness. In contrast, observational studies associate glucosamine with significant reductions in mortality and cancer incidence. We evaluated the extent of bias, particularly selection bias, to explain these surprising beneficial effects. METHODS: We searched the literature to identify all observational studies reporting on the effect of glucosamine use on major outcomes. RESULTS: We identified 11 observational studies, reporting a mean 16% reduction in all-cause mortality (hazard ratio [HR] 0.84, 95% CI: 0.81-0.87) with glucosamine use, as well as significant reductions in cancer incidence and other major diseases including cardiovascular, respiratory and diabetes. We show that these significant effects can result from selection bias due to collider stratification, as all studies used "prevalent" cohorts, where glucosamine use started before cohort entry, and where subjects agreed to join the cohorts. Our illustration of the bias using the UK Biobank publication involving a half-million subjects shows how a true rate ratio of mortality of 1.0 in the population can result in a biased rate ratio of 0.82 in the prevalent cohort. CONCLUSIONS: The observational studies reporting significant reductions in mortality, cancer incidence and other outcomes with glucosamine were affected by selection bias from collider stratification. In the absence of properly conducted observational studies that circumvent this bias by considering "new users", the studies to date cannot support the prescription of this supplement as a preventive measure for mortality, cancer, and other chronic diseases.

The comparison of curcuminoid formulations or its combination with conventional therapies versus conventional therapies alone for knee osteoarthritis.

BACKGROUND: Presently, curcuminoid formulations or its combination with conventional therapies has been used for the treatment of knee osteoarthritis (KOA). Nevertheless, evidence is limited due to small-sized clinical trials. This study aims to evaluate the efficacy of curcuminoid formulations or its combination with conventional therapies for KOA. METHODS: Randomized controlled trials comparing curcuminoid formulations or its combination with conventional therapies versus conventional therapies, such as non-steroidal antiinflammatory drugs (NSAIDs) and chondroitin sulfate/glucosamine, were searched from databases. RESULTS: In total, 14 studies involving 1533 patients were included. Curcuminoid formulations were comparative to NSAIDs in reducing Visual Analogue Scale (VAS), total Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, and WOMAC score for pain/stiffness/physical function. No significant difference was seen between the two groups in terms of patients' satisfaction index, patients' global assessment, reduction of several inflammatory factor, rate of drug compliance, and rescue medication. Notably, curcuminoid formulations combined with NSAIDs significantly reduced VAS and WOMAC/Knee injury and OA Outcome Score (KOOS) pain score more than NSAIDs did. In addition, the curcuminoid formulations were superior to chondroitin sulfate/glucosamine in reducing VAS, total WOMAC score, and WOMAC score for stiffness/difficulty in physical function, while no significant difference was seen in reducing WOMAC pain score and Karnofsky Performance Scale score. CONCLUSIONS: Curcuminoid formulations may be considered a promising alternative for treating KOA. Key points • Curcuminoid formulations are comparative to NSAIDs for KOA. • Curcuminoid formulations are superior to chondroitin sulfate/glucosamine for KOA. • Curcuminoid formulations could provide additional benefits in alleviating pain and some adverse events caused by NSAIDs.

Antinociceptive effect of N-acetyl glucosamine in a rat model of neuropathic pain.

OBJECTIVE: This study was aimed at evaluating the efficacy of glucosamine and potential mechanisms of actions in a neuropathic pain model in rats. METHODS: Glucosamine (500, 1000 and 2000 mg/kg) was administered via gavage route, 1 day before the chronic constriction injury (CCI) of sciatic nerve and daily for 14 days (prophylactic regimen), or from days 5 to 14 post-injury (therapeutic regimen), as the indicators of neuropathic pain, mechanical allodynia, cold allodynia and thermal hyperalgesia were assessed on days 0, 3, 5, 7, 10 and 14 after ligation. Inducible nitric oxide synthase (iNOS) and tumour necrosis factor alpha (TNF-α) gene expressions were measured by real-time polymerase chain reaction. TNF-α protein content was measured using the enzyme-linked immunosorbent assay method. RESULTS: Three days after nerve injury, the threshold of pain was declined among animals subjected to neuropathic pain. Mechanical and cold allodynia, as well as thermal hyperalgesia were attenuated by glucosamine (500, 1000, 2000 mg/kg) in the prophylactic regimen. However, existing pain was not decreased by this drug. Increased mRNA expression of iNOS and TNF-α was significantly reduced in the spinal cord of CCI animals by glucosamine (500, 1000, 2000 mg/kg) in the prophylactic regimen. The overall expression of spinal TNF-α was increased by CCI, but this increase was reduced in animals receiving glucosamine prophylactic treatment. CONCLUSION: Findings suggest that glucosamine as a safe supplement may be a useful candidate in preventing neuropathic pain following nerve injury. Antioxidant and anti-inflammatory effects may be at least in part responsible for the antinociceptive effects of this drug.

Evaluation of a nutritional supplement for the alleviation of pain associated with feline degenerative joint disease: a prospective, randomized, stratified, double-blind, placebo-controlled clinical trial.

OBJECTIVES: The purpose of this study was to evaluate the pain-alleviating and activity-enhancing effects of glucosamine/chondroitin sulfate (Dasuquin) in cats that had degenerative joint disease (DJD) and owner-noted mobility/activity impairment. We hypothesized that the nutritional supplement would produce pain-relieving and activity-enhancing effects in cats with painful DJD. METHODS: In this prospective, randomized, stratified, double-blind, placebo-controlled clinical trial, 59 cats with DJD pain were assigned to receive a placebo (n = 30) or supplement (n = 29) for 6 weeks after 2 weeks of placebo. Outcome measures (at-home accelerometry and client-specific outcome measures [feline (CSOMf); Feline Musculoskeletal Pain Index (FMPI); quality of life (QoL)]; and veterinarian examination) were collected at days 14, 28, 42 and 56. RESULTS: Twenty-seven cats in the treatment group and 30 in the placebo group completed the trial. Within the first 2 weeks (placebo administration to all cats), 78% of all cats had an improvement in CSOMf scores. Both groups showed significant improvement at most time points in CSOMf, FMPI, QoL and pain scores, with the placebo group showing greater improvement than the supplement group (significant for CSOMf [P = 0.01]). Overall, no differences in activity were seen between the groups. Cumulative distribution function analysis indicated that for most levels of activity, the placebo-treated cats were more active; however, the least active cats were more active on the supplement (P = 0.013). CONCLUSIONS AND RELEVANCE: This study showed a strong placebo effect. The glucosamine/chondroitin sulfate supplement did not show pain-relieving effects when compared with placebo.

EFFICACY OF HERBAL AND NATURALLY-DERIVED DIETARY SUPPLEMENTS FOR THE MANAGEMENT OF KNEE OSTEOARTHRITIS: A MINI-REVIEW.

Knee osteoarthritis (OA) accounts for approximately 85% of the burden of OA worldwide. Knee OA is a whole joint disorder involving structural alterations in the hyaline articular cartilage, subchondral bone, ligaments, capsule, synovium, and periarticular muscles. The complex knee OA pathogenesis includes mechanical, inflammatory, and metabolic factors, eventually leading to the synovial joint's structural destruction and failure. This review aims to present an overview of current knowledge on dietary supplements, such as glucosamine, chondroitin, methylsulfonylmethane, diacerein, avocado-soybean unsaponifiables, curcuminoids, as well as boswellic acids. Results originating from several small studies with natural products in managing knee OA are encouraging. However, additional well-designed placebo-controlled clinical trials are required.

Repeated hypoxia exposure induces cognitive dysfunction, brain inflammation, and amyloidß/p-Tau accumulation through reduced brain O-GlcNAcylation in zebrafish.

Repetitive hypoxia (RH) exposure affects the initiation and progression of cognitive dysfunction, but little is known about the mechanisms of hypoxic brain damage. In this study, we show that sublethal RH increased anxiety, impaired learning and memory (L/M), and triggered downregulation of brain levels of glucose and several glucose metabolites in zebrafish, and that supplementation of glucose or glucosamine (GlcN) restored RH-induced L/M impairment. Fear conditioning (FC)-induced brain activation of and PKA/CREB signaling was abrogated by RH, and this effect was reversed by GlcN supplementation. RH was associated with decreased brain O-GlcNAcylation and an increased O-GlcNAcase (OGA) level. RH increased brain inflammation and p-Tau and amyloid ß accumulation, and these effects were suppressed by GlcN. Our observations collectively suggest that changes in O-GlcNAc flux during hypoxic exposure could be an important causal factor for neurodegeneration, and that supplementation of the HBP/O-GlcNAc flux may be a potential novel therapeutic or preventive target for addressing hypoxic brain damage.