Use of glucosamine and chondroitin and lung cancer risk in the VITamins And Lifestyle (VITAL) cohort

Targeting Breast Cancer with N-Acetyl-D-Glucosamine: Integrating Machine Learning and Cellular Assays for Promising Results

BACKGROUND

Breast cancer is a common cancer with high mortality rates. Early diagnosis is crucial for reducing the prognosis and mortality rates. Therefore, the development of alternative treatment options is necessary.

OBJECTIVE

This study aimed to investigate the inhibitory effect of N-acetyl-D-glucosamine (D-GlcNAc) on breast cancer using a machine learning method. The findings were further confirmed through assays on breast cancer cell lines.

METHODS

MCF-7 and 4T1 cell lines (ATCC) were cultured in the presence and absence of varying concentrations of D-GlcNAc (0.5 mM, 1 mM, 2 mM, and 4 mM) for 72 hours. A xenograft mouse model for breast cancer was established by injecting 4T1 cells into mammary glands. D-GlcNAc (2 mM) was administered intraperitoneally to mice daily for 28 days, and histopathological effects were evaluated at pre-tumoral and post-tumoral stages.

RESULTS

Treatment with 2 mM and 4 mM D-GlcNAc significantly decreased cell proliferation rates in MCF-7 and 4T1 cell lines and increased Fas expression. The number of apoptotic cells was significantly higher than untreated cell cultures (p < 0.01 - p < 0.0001). D-GlcNAc administration also considerably reduced tumour size, mitosis, and angiogenesis in the post-treatment group compared to the control breast cancer group (p < 0.01 - p < 0.0001). Additionally, molecular docking/dynamic analysis revealed a high binding affinity of D-GlcNAc to the marker protein HER2, which is involved in tumour progression and cell signalling.

CONCLUSION

Our study demonstrated the positive effect of D-GlcNAc administration on breast cancer cells, leading to increased apoptosis and Fas expression in the malignant phenotype. The binding affinity of D-GlcNAc to HER2 suggests a potential mechanism of action. These findings contribute to understanding D-GlcNAc as a potential anti-tumour agent for breast cancer treatment.

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.

Glucose transporter 4: Insulin response mastermind, glycolysis catalyst and treatment direction for cancer progression

The glucose transporter family (GLUT) consists of fourteen members. It is responsible for glucose homeostasis and glucose transport from the extracellular space to the cell cytoplasm to further cascade catalysis. GLUT proteins are encoded by the solute carrier family 2 (SLC2) genes and are members of the major facilitator superfamily of membrane transporters. Moreover, different GLUTs also have their transporter kinetics and distribution, so each GLUT member has its uniqueness and importance to play essential roles in human physiology. Evidence from many studies in the field of diabetes showed that GLUT4 travels between the plasma membrane and intracellular vesicles (GLUT4-storage vesicles, GSVs) and that the PI3K/Akt pathway regulates this activity in an insulin-dependent manner or by the AMPK pathway in response to muscle contraction. Moreover, some published results also pointed out that GLUT4 mediates insulin-dependent glucose uptake. Thus, dysfunction of GLUT4 can induce insulin resistance, metabolic reprogramming in diverse chronic diseases, inflammation, and cancer. In addition to the relationship between GLUT4 and insulin response, recent studies also referred to the potential upstream transcription factors that can bind to the promoter region of GLUT4 to regulating downstream signals. Combined all of the evidence, we conclude that GLUT4 has shown valuable unknown functions and is of clinical significance in cancers, which deserves our in-depth discussion and design compounds by structure basis to achieve therapeutic effects. Thus, we intend to write up a most updated review manuscript to include the most recent and critical research findings elucidating how and why GLUT4 plays an essential role in carcinogenesis, which may have broad interests and impacts on this field.

Role of Glucosamine and Chondroitin in the Prevention of Cancer: A Meta-Analysis

The anti-inflammatory properties of glucosamine and chondroitin suggest that they may have potential effects in cancer prevention. We performed this meta-analysis to assess the protective function of glucosamine and/or chondroitin intake against cancer risk. We searched the PubMed, Embase, Web of Science, and China National Knowledge Infrastructure (CNKI) databases. The odds ratio (OR), corresponding to the 95% confidence interval (95% CI), was used to assess the association between chondroitin and/or glucosamine intake and cancer risk. Thirteen studies met the inclusion criteria, with 1,690,918 participants and 55,045 cancer cases. Overall, chondroitin and/or glucosamine intake was associated with a lower risk of colorectal cancer (OR = 0.91, 95% CI, 0.87-0.94) and lung cancer (OR = 0.84, 95% CI, 0.79-0.89). Subgroup analysis supported the protective effect of different SYSADOAs (chondroitin and/or glucosamine) intake. However, the protective effect was not observed in the only chondroitin intake group and in the NSAIDs group. Our meta-analysis found that the intake of glucosamine and/or chondroitin decreased the risk of colorectal and lung cancers. Moreover, NSAIDs use may have a synergistic protective effect.

Identification of natural products and FDA-approved drugs for targeting cancer stem cell (CSC) propagation

Here, we report the identification of key compounds that effectively inhibit the anchorage-independent growth and propagation of cancer stem cells (CSCs), as determined via screening using MCF7 cells, a human breast adenocarcinoma cell line. More specifically, we employed the mammosphere assay as an experimental format, which involves the generation of 3D spheroid cultures, using low-attachment plates. These positive hit compounds can be divided into 5 categories: 1) dietary supplements (quercetin and glucosamine); 2) FDA-approved drugs (carvedilol and ciprofloxacin); 3) natural products (aloe emodin, aloin, tannic acid, chlorophyllin copper salt, azelaic acid and adipic acid); 4) flavours (citral and limonene); and 5) vitamins (nicotinamide and nicotinic acid). In addition, for the compounds quercetin, glucosamine and carvedilol, we further assessed their metabolic action, using the Seahorse to conduct metabolic flux analysis. Our results indicate that these treatments can affect glycolytic flux and suppress oxidative mitochondrial metabolism (OXPHOS). Therefore, quercetin, glucosamine and carvedilol can reprogram the metabolic phenotype of breast cancer cells. Despite having diverse chemical structures, these compounds all interfere with mitochondrial metabolism. As these compounds halt CSCs propagation, ultimately, they may have therapeutic potential.

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.

Association between glucosamine use and cancer mortality: A large prospective cohort study

Objective

Previous studies have shown anti-cancer and anti-inflammatory benefits of glucosamine. This study was performed to prospectively evaluate the association between glucosamine supplementation and the mortality of multiple cancers based on the UK Biobank cohort study.

Materials and methods

A total of 453,645 participants aged 38-73 who had no cancer at baseline were recruited between 2006 and 2010 and followed until March 2021. We used cox and poission proportional hazards models to explore the association between habitual use of glucosamine and cancer mortality. Subgroup analyses were conducted to understand the potential effect modifications of demographics, lifestyle factors, and health outcomes. Sensitivity analyses were performed to determine the robustness of the results.

Results

Of the participants, 88,224 (19.4%) reported habitual glucosamine use at baseline. There were 9,366 cancer deaths during a median follow-up of 12.1 years, and we observed a significant association between the use of glucosamine and lower overall cancer mortality (HR = 0.95, 95% CI = 0.90-1.00, p < 0.05), kidney cancer (IRR = 0.68, 95% CI = 0.49-0.95, p < 0.05), lung cancer mortality (IRR = 0.84, 95% CI = 0.74-0.95, p < 0.05), and rectum cancer (IRR = 0.76, 95% CI = 0.59-0.98, p < 0.05). Subgroup analysis showed that habitual glucosamine supplementation was correlated with lower overall cancer mortality among participants who were aged ≥ 60 years, male, current smoker, without high cholesterol and not obese. Sensitivity analysis showed that the results were stable.

Conclusion

Habitual glucosamine use was significantly related to decreased overall cancer, kidney cancer, lung cancer, and rectum cancer mortality, based on data from the large-scale, nationwide, prospective UK Biobank cohort study.

Glucosamine use, smoking and risk of incident chronic obstructive pulmonary disease: a large prospective cohort study

Chronic inflammation exerts pleiotropic effects in the aetiology and progression of chronic obstructive pulmonary disease (COPD). Glucosamine is widely used in many countries and may have anti-inflammatory properties. We aimed to prospectively evaluate the association of regular glucosamine use with incident COPD risk and explore whether such association could be modified by smoking in the UK Biobank cohort, which recruited more than half a million participants aged 40-69 years from across the UK between 2006 and 2010. Cox proportional hazards models with adjustment for potential confounding factors were used to calculate hazard ratios (HR) as well as 95 % CI for the risk of incident COPD. During a median follow-up of 8·96 years (interquartile range 8·29-9·53 years), 9016 new-onset events of COPD were documented. We found that the regular use of glucosamine was associated with a significantly lower risk of incident COPD with multivariable adjusted HR of 0·80 (95 % CI, 0·75, 0·85; P < 0·001). When subgroup analyses were performed by smoking status, the adjusted HR for the association of regular glucosamine use with incident COPD were 0·84 (0·73, 0·96), 0·84 (0·77, 0·92) and 0·71 (0·62, 0·80) among never smokers, former smokers and current smokers, respectively. No significant interaction was observed between glucosamine use and smoking status (P_{for interaction} = 0·078). Incident COPD could be reduced by 14 % to 84 % through a combination of regular glucosamine use and smoking cessation.

Relationship between glucosamine use and the risk of lung cancer: data from a nationwide prospective cohort study

BACKGROUND

Research on glucosamine shows anti-inflammatory and anti-cancer benefits with a minimal adverse effects. We aimed to explore the relationship between use of glucosamine and risk of lung cancer and lung cancer mortality based on data from the large-scale nationwide prospective UK Biobank cohort study.

METHODS

Participants were enrolled between the year 2006 and 2010 and followed up to 2020. Cox proportion hazards model were used to assess the relationship between glucosamine use and risk of lung cancer and lung cancer mortality. Subgroup analyses and sensitivity analyses were performed to explore the potential effect modifications and the robustness of main findings.

RESULTS

A total of 439,393 participants (mean age: 56 years; 53% females) with a mean follow-up of 11 years were included for analyses. There were 82,603 (18.80%) participants reporting regular use of glucosamine at baseline. During follow-up, there were 1,971 (0.45%) lung cancer events documented. Glucosamine use was significantly associated with a decreased risk of lung cancer (hazard ratio=0.84, 95% CI: 0.75-0.92, p<0.001) and lung cancer mortality (hazard ratio=0.88, 95% CI: 0.81-0.96, p=0.002) in fully-adjusted models. A stronger association between glucosamine use and decreased lung cancer risk was observed in participants with a family history of lung cancer when compared to those without a family history.

CONCLUSION

Regular use of glucosamine was significantly related with decreased risk of lung cancer and lung cancer mortality, based on data from this nationwide prospective cohort study.

Recent advances in the field of caloric restriction mimetics and anti-aging molecules

Caloric restriction (CR) mimetics are molecules that produce beneficial effects on health and longevity in model organisms and humans, without the challenges of maintaining a CR diet. Conventional CR mimetics such as metformin, rapamycin and spermidine activate autophagy, leading to recycling of cellular components and improvement of physiological function. We review here novel CR mimetics and anti-aging compounds, such as 4,4'-dimethoxychalcone, fungal polysaccharides, inorganic nitrate, and trientine, highlighting their possible molecular targets and mechanisms of action. The activity of these compounds can be understood within the context of hormesis, a biphasic dose response that involves beneficial effects at low or moderate doses and toxic effects at high doses. The concept of hormesis has widespread implications for the identification of CR mimetics in experimental assays, testing in clinical trials, and use in healthy humans. We also discuss the promises and limitations of CR mimetics and anti-aging molecules for delaying aging and treating chronic diseases.

Glucosamine and Chondroitin Use in Relation to C-Reactive Protein Concentration: Results by Supplement Form, Formulation, and Dose

Objectives: Glucosamine and chondroitin supplements have been associated with reduced inflammation, as measured by C-reactive protein (CRP). It is unclear if associations vary by formulation (glucosamine alone vs. glucosamine+chondroitin), form (glucosamine hydrochloride vs. glucosamine sulfate), or dose. Design, Subjects, Setting, Location: The authors evaluated these questions using cross-sectional data collected between 1999 and 2010 on 21,917 US adults, surveyed as part of the National Health and Nutrition Examination Survey (NHANES). Exposures: Glucosamine and chondroitin use was assessed during an in-home interview; exposures include supplement formulation, form, and dose. Outcome/Analysis: CRP was measured using blood collected at interview. Survey-weighted linear regression was used to evaluate the multivariable-adjusted association between exposures and log-transformed CRP. Results: In early years (1999-2004), use of glucosamine (ratio = 0.87; 95% confidence interval [CI] = 0.79-0.96) and chondroitin (ratio = 0.83; 95% CI = 0.72-0.95) was associated with reduced CRP. However, associations significantly varied by calendar time (p-interaction = 0.04 and p-interaction = 0.01, respectively), with associations nonsignificant in later years (ratio = 1.09; 95% CI = 0.94-1.28 and ratio = 1.16; 95% CI = 0.99-1.35, respectively). Consequently, all analyses have been stratified by calendar time. Associations did not significantly differ by formulation in either set of years; however, significant associations were observed for combined use of glucosamine+chondroitin (ratio_early = 0.82; 95% CI = 0.72-0.95; ratio_late = 1.16; 1.00-1.35), but not glucosamine alone. Associations also did not significantly differ by supplement form. Even so, a significant inverse association was observed only for glucosamine sulfate in the early years (ratio = 0.78; 95% CI = 0.64-0.95); no significant association was observed for glucosamine hydrochloride. No significant trends were observed by dose. Conclusions: Although a significant inverse association was observed for glucosamine and chondroitin and CRP in early years, this association did not hold in later years. This pattern held for combined use of glucosamine+chondroitin as well as glucosamine sulfate, although associations did not significantly vary by supplement form, formulation, or dose. Further study is needed to better understand these associations in the context of calendar time.

Azithromycin and glucosamine may amplify the type 1 interferon response to RNA viruses in a complementary fashion

Previous research demonstrates that, in clinically relevant concentrations, azithromycin can boost the ability of RNA viruses to induce type 1 interferon by amplifying the expression and virally-mediated activation of MDA5. O-GlcNAcylation of MAVS, a down-stream target of MDA5, renders it more effective for type 1 interferon induction. High-dose glucosamine administration up-regulates O-GlcNAcylation by increasing the cellular pool of UDP-N-acetylglucosamine. Hence, it is proposed that joint administration of azithromycin and high-dose glucosamine, early in the course of RNA virus infections, may interact in a complementary fashion to aid their control by enhancing type 1 interferon induction.

Antitumoral Properties of the Nutritional Supplement Ocoxin Oral Solution: A Comprehensive Review

Ocoxin Oral Solution (OOS) is a nutritional supplement whose formulation includes several plant extracts and natural products with demonstrated antitumoral properties. This review summarizes the antitumoral action of the different constituents of OOS. The action of this formulation on different preclinical models as well as clinical trials is reviewed, paying special attention to the mechanism of action and quality of life improvement properties of this nutritional supplement. Molecularly, its mode of action includes a double edge role on tumor biology, that involves a slowdown in cell proliferation accompanied by cell death induction. Given the safety and good tolerability of OOS, and its potentiation of the antitumoral effect of other standard of care drugs, OOS may be used in the oncology clinic in combination with conventional therapies.

Associations of regular glucosamine use with all-cause and cause-specific mortality: a large prospective cohort study

Objectives

To evaluate the associations of regular glucosamine use with all-cause and cause-specific mortality in a large prospective cohort.

Methods

This population-based prospective cohort study included 495 077 women and men (mean (SD) age, 56.6 (8.1) years) from the UK Biobank study. Participants were recruited from 2006 to 2010 and were followed up through 2018. We evaluated all-cause mortality and mortality due to cardiovascular disease (CVD), cancer, respiratory and digestive disease. HRs and 95% CIs for all-cause and cause-specific mortality were calculated using Cox proportional hazards models with adjustment for potential confounding variables.

Results

At baseline, 19.1% of the participants reported regular use of glucosamine supplements. During a median follow-up of 8.9 years (IQR 8.3–9.7 years), 19 882 all-cause deaths were recorded, including 3802 CVD deaths, 8090 cancer deaths, 3380 respiratory disease deaths and 1061 digestive disease deaths. In multivariable adjusted analyses, the HRs associated with glucosamine use were 0.85 (95% CI 0.82 to 0.89) for all-cause mortality, 0.82 (95% CI 0.74 to 0.90) for CVD mortality, 0.94 (95% CI 0.88 to 0.99) for cancer mortality, 0.73 (95% CI 0.66 to 0.81) for respiratory mortality and 0.74 (95% CI 0.62 to 0.90) for digestive mortality. The inverse associations of glucosamine use with all-cause mortality seemed to be somewhat stronger among current than non-current smokers (p for interaction=0.00080).

Conclusions

Regular glucosamine supplementation was associated with lower mortality due to all causes, cancer, CVD, respiratory and digestive diseases.

Aging Fits the Disease Criteria of the International Classification of Diseases

The disease criteria used by the World Health Organization (WHO) were applied to human biological aging in order to assess whether aging can be classified as a disease. These criteria were developed for the 11th revision of the International Classification of Diseases (ICD) and included disease diagnostics, mechanisms, course and outcomes, known interventions, and linkage to genetic and environmental factors. RESULTS: Biological aging can be diagnosed with frailty indices, functional, blood-based biomarkers. A number of major causal mechanisms of human aging involved in various organs have been described, such as inflammation, replicative cellular senescence, immune senescence, proteostasis failures, mitochondrial dysfunctions, fibrotic propensity, hormonal aging, body composition changes, etc. We identified a number of clinically proven interventions, as well as genetic and environmental factors of aging. Therefore, aging fits the ICD-11 criteria and can be considered a disease. Our proposal was submitted to the ICD-11 Joint Task force, and this led to the inclusion of the extension code for "Ageing-related" (XT9T) into the "Causality" section of the ICD-11. This might lead to greater focus on biological aging in global health policy and might provide for more opportunities for the new therapy developers.

Glucosamine for the Treatment of Osteoarthritis: The Time Has Come for Higher-Dose Trials

Although clinical trials with glucosamine in osteoarthritis have yielded mixed results, leading to doubts about its efficacy, the utility of glucosamine for preventing joint destruction and inflammation is well documented in rodent models of arthritis, including models of spontaneous osteoarthritis. The benefit of oral glucosamine in adjuvant arthritis is markedly dose dependent, likely reflecting a modulation of tissue levels of UDP-N-acetylglucosamine that in turn influences mucopolysaccharide synthesis and the extent of protein O-GlcNAcylation. Importantly, the minimal oral dose of glucosamine that exerts a detectible benefit in adjuvant arthritis achieves plasma glucosamine levels similar to those achieved when the standard clinical dose of glucosamine, 1.5 g daily, is administered as a bolus. The response of plasma glucosamine levels to an increase in glucosamine intake is nearly linear. Remarkably, every published clinical trial with glucosamine has employed the same 1.5 g dose that Rottapharm recommended for its proprietary glucosamine sulfate product decades ago, yet there has never been any published evidence that this dose is optimal with respect to efficacy and side effects. If this dose is on the edge of demonstrable clinical efficacy when experimental design is ideal, then variations in the patient populations targeted, the assessment vehicles employed, and the potency of glucosamine preparations tested could be expected to yield some null results. Failure to employ bolus dosing may also be a factor in the null results observed in the GAIT study and other trials. Clinical studies evaluating the dose dependency of glucosamine's influence on osteoarthritis are long overdue.

Glucosamine use and risk of colorectal cancer: results from the Cancer Prevention Study II Nutrition Cohort

PURPOSE

Use of glucosamine supplements has been associated with reduced risk of colorectal cancer (CRC) in previous studies; however, information on this association remains limited.

METHODS

We examined the association between glucosamine use and CRC risk among 113,067 men and women in the Cancer Prevention Study II Nutrition Cohort. Glucosamine use was first reported in 2001 and updated every 2 years thereafter. Participants were followed from 2001 through June of 2011, during which time 1440 cases of CRC occurred.

RESULTS

As has been observed in prior studies, current use of glucosamine, modeled using a time-varying exposure, was associated with lower risk of CRC (HR 0.83; 95% CI 0.71-0.97) compared to never use. However, for reasons that are unclear, this reduction in risk was observed for shorter-duration use (HR 0.68; 95% CI 0.52-0.87 for current users with ≤ 2 years use) rather than longer-duration use (HR 0.90; 95% CI 0.72-1.13 for current users with 3 to < 6 years of use; HR 0.99; 95% CI 0.76-1.29 for current users with ≥ 6 years of use).

CONCLUSIONS

Further research is needed to better understand the association between glucosamine use and risk of CRC, and how this association may vary by duration of use.

Molecular mechanisms of anticancer effects of Glucosamine

Glucosamine is an amino sugar that is produced naturally in human body. It is an essential carbohydrate component of many cellular glycoproteins, glycolipids, and glycosaminoglycans (GAGs). This popular over-the-counter supplement is also found in the exoskeleton of crustaceans. Glucosamine and its derivatives have a long history in medicine for inflammatory conditions specially to relieve arthritis. This dietary supplement has numerous biological and pharmacological properties, including anti-inflammatory, antioxidant, anti-aging, anti-fibrotic, neuroprotective and cardioprotective activities. Many studies have shown that glucosamine has anti-cancer activity through influence on biological pathways involved in cell death, apoptosis, cell proliferation, and angiogenesis. Accordingly, this comprehensive review summarizes anti-cancer molecular mechanisms of glucosamine in details.

Anti‑lung cancer effect of glucosamine by suppressing the phosphorylation of FOXO

Lung cancer is the most common cause of cancer‑associated mortality worldwide, and glucosamine has the potential to exhibit antitumor activity. To reveal its anti‑lung cancer mechanism, the present study investigated the effect of glucosamine on the transcriptional activity of forkhead box O (FOXO)1 and FOXO3, and associated signal transduction pathways in A549 cells. An MTT assay was performed to investigate cell viability and immunoblotting was performed to detect protein levels of FOXO1/3, phosphorylated (p)‑FOXO1/3, AKT, p‑AKT, extracellular signal‑regulated kinase (ERK) and p‑ERK, and the levels of β‑O‑linked N‑acetylglucosamine (O‑GlcNAc)‑modified FOXO1 protein. Immunoprecipitation was performed to purify O‑GlcNAc‑modified protein prior to immunoblotting. Glucosamine inhibited FOXO1‑ and FOXO3‑specific amino acid phosphorylation, which was correlated with its translocation from the nucleus to cytoplasm, indicating a possible anti‑lung cancer mechanism of glucosamine. The present study also examined the phosphoinositide 3‑kinase (PI3K)/AKT and mitogen‑activated protein kinase (MAPK)/ERK pathways, which induce FOXO1‑ and FOXO3‑specific site phosphorylation. The data showed that glucosamine suppressed the translocation of FOXO from the cytoplasm to the nucleus via glucosamine‑induced O‑GlcNAc modification. These observations suggested that glucosamine modulated A549 cell proliferation, possibly via O‑GlcNAc modification‑induced downregulation of the PI3K/AKT and MAPK/ERK pathways and their downstream signaling molecules, FOXO1 and FOXO3.

Developing criteria for evaluation of geroprotectors as a key stage toward translation to the clinic

In the coming decades, a massive shift in the aging segment of the population will have major social and economic consequences around the world. One way to offset this increase is to expedite the development of geroprotectors, substances that slow aging, repair age‐associated damage and extend healthy lifespan, or healthspan. While over 200 geroprotectors are now reported in model organisms and some are in human use for specific disease indications, the path toward determining whether they affect aging in humans remains obscure. Translation to the clinic is hampered by multiple issues including absence of a common set of criteria to define, select, and classify these substances, given the complexity of the aging process and their enormous diversity in mechanism of action. Translational research efforts would benefit from the formation of a scientific consensus on the following: the definition of ‘geroprotector’, the selection criteria for geroprotectors, a comprehensive classification system, and an analytical model. Here, we review current approaches to selection and put forth our own suggested selection criteria. Standardizing selection of geroprotectors will streamline discovery and analysis of new candidates, saving time and cost involved in translation to clinic.

Molecular mechanisms and biomedical applications of glucosamine as a potential multifunctional therapeutic agent

Glucosamine and its acetylated derivative, N-acetyl glucosamine, are naturally occurring amino sugars found in human body. They are important components of glycoproteins, proteoglycans and glycosaminoglycans. Scientific studies have supported that glucosamine has the beneficial pharmacological effects to relieve osteoarthritis symptoms. Glucosamine can also be as a promising candidate for the prevention and/or treatment of some other diseases due to its anti-oxidant and anti-inflammatory activities. Most of its function is exerted by modulation of inflammatory responses especially through Nuclear Factor-κB (NF-κB) that can control inflammatory cytokine production and cell survival. In this review, we present a concise update on additional new therapeutic applications of glucosamine including treatment of cardiovascular disease, neurological deficits, skin disorders, cancer and the molecular mechanistic rationale for these uses. This article will also examine safety profile and adverse effects of glucosamine in human.

[An antinociceptive effect of chondroprotectors: a myth or a reality?]

Authors reviewed the literature on the efficacy of chondroprotectors in the treatment of chronic pain syndromes in comparison with placebo and other analgesics to discover the own antinociceptive effect of these drugs and mechanisms by which it occurs. Authors evaluated the results of various clinical studies on the effect of symptomatic slow-acting drugs for osteoarthritis (SYSADOA) on chronic pain syndrome in osteoarthritis and low back pain. We compared their effects with those of NSAIDs, celecoxib, or placebo. Assessment of pain and functional status was performed using WOMAC, VASandLeken's index as well as the Roland--Morrisquality of life questionnaire. The review of a number of clinical studies revealed a definite antinociceptive and anti-inflammatory effect of SYSADOA comparable with NSAIDs not only in the treatment of osteoarthritis, but also in chronic back pain, which is characterized by early onset and gradual development with a long-term retention of the result even after discontinuation of therapy. It has been shown that SYSADOA are able to reduce the level of inflammatory cytokines in the blood (IL-6, C-reactive protein) and to activate the production of anti-inflammatory cytokine IL-10 in the synovial membrane. It is shown that blocking of the effects of interleukin 1-beta and thereby inhibition of inflammatory enzymes like nitric oxide synthase and cyclooxygenase-2 is one of the points of glucosamine chondrocytes application. The data obtained in numerous studies that confirm the ability of SYSADOA to inhibit proinflammatory cytokines open the new perspectives for their use in the treatment of not only joint pain but also other chronic pain syndromes.

Associations between glucosamine and chondroitin supplement use and biomarkers of systemic inflammation

OBJECTIVES

Glucosamine and chondroitin supplements have been shown to have anti-inflammatory properties in both in vitro studies and animal models; however, little is known about these relationships in humans. The VITamins and Lifestyle (VITAL) biomarker study evaluated the associations between use of these supplements and a panel of circulating inflammatory biomarkers.

DESIGN

Study participants included 217 men and women age 50-75 years living in the Seattle metropolitan area. Use of glucosamine and chondroitin supplements was ascertained by home interview/supplement inventory. Inflammation was assessed by using blood and urine collected at the time of home interview. Measures of systemic inflammation included plasma high-sensitivity C-reactive protein (hsCRP), interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor (TNF)-α, soluble TNF receptors I and II, and urinary prostaglandin E2-metabolite (PGE-M). Multivariate-adjusted linear regression was used to evaluate the associations between supplement use and biomarkers of inflammation.

RESULTS

High users (14 or more pills/week) of chondroitin had 36% lower hsCRP (ratio, 0.64; 95% confidence interval [CI], 0.39-1.04; p for trend=.03) and 27% lower PGE-M (ratio, 0.73; 95% CI, 0.5-0.98; p for trend=.07) than nonusers. Compared with nonusers, high users of glucosamine had 28% lower hsCRP (ratio, 0.72; 95% CI, 0.47-1.08; p for trend=.09) and 24% lower PGE-M (ratio, 0.76; 95% CI, 0.59-0.97; p for trend=0.10). Use of glucosamine and chondroitin supplements was not associated with the other markers of inflammation.

CONCLUSIONS

These results support prior research suggesting that use of glucosamine and chondroitin is associated with reduced hsCRP and PGE2, but further work is needed to more definitively evaluate the anti-inflammatory potential of these supplements.

Glucosamine, a naturally occurring amino monosaccharide, inhibits A549 and H446 cell proliferation by blocking G1/S transition

Uncontrolled proliferation is important in tumorigenesis. In the present study, the effects of glucosamine on lung cancer cell proliferation were investigated. The expression of cyclin E, one of the key cyclins in the G1/S transition, and Skp2, the ubiquitin ligase subunit that targets the negative cell cycle regulator, p27Kip1, were also assessed. Moreover, the underlying mechanisms of action of glucosamine were investigated in lung cancer cells. A549 and H446 cells were synchronized using thymidine in the presence or absence of glucosamine. The effect of glucosamine on lung cancer cell proliferation was determined by MTT assay. Cyclin E and p27Kip1 proteins and their phosphorylation levels were detected by western blot analysis. Furthermore, the effect of glucosamine on the cell cycle was evaluated by flow cytometry. Glucosamine was found to inhibit lung cancer cell proliferation and to suppress Skp2 and cyclin E expression. Notably, the phosphorylation levels of cyclin E (Thr62) and p27Kip1 (Thr187) were downregulated by glucosamine, and negatively correlated with degradation. Glucosamine was also found to arrest lung cancer cells in the G1/S phase. Thus, glucosamine may inhibit lung cancer cell proliferation by blocking G1/S transition through the inhibition of cyclin E and Skp2 protein expression.

Use of glucosamine and chondroitin supplements and risk of colorectal cancer

PURPOSE

Glucosamine and chondroitin are non-vitamin, non-mineral supplements which have anti-inflammatory properties. These supplements are typically used for joint pain and osteoarthritis and are commonly taken as either glucosamine alone or glucosamine plus chondroitin. An exploratory analysis conducted within the VITamins And Lifestyle (VITAL) study observed any use of glucosamine and chondroitin to be associated with reduced risk of colorectal cancer (CRC) after 5 years of follow-up.

METHODS

With two additional years of follow-up, we have studied these associations in greater depth, including associations by frequency/duration of use and by formulation, and have evaluated whether observed associations are modified by factors associated with inflammation. Participants include 75,137 western Washington residents aged 50-76 who completed the mailed VITAL questionnaire between 2000 and 2002. Use of glucosamine and chondroitin was ascertained by questions about supplement use during the 10-year period prior to baseline, and participants were followed for CRC through 2008 (n = 557). Cox regression was used to estimate hazard ratios (HRs) and 95 % confidence intervals (CIs).

RESULTS

Persons reporting use of glucosamine + chondroitin on 4+ days/week for 3+ years had a non-statistically significant 45 % lower CRC risk than non-users (HR: 0.55; 95 % CI 0.30-1.01; p-trend: 0.16). This association varied by body mass index (p-interaction: 0.006), with inverse association observed among the overweight/obese (p-trend: 0.02), but not among the underweight/normal weight. Use of glucosamine alone was not significantly associated with CRC risk.

CONCLUSIONS

There is great need to identify safe and effective cancer preventive strategies, suggesting that glucosamine and chondroitin may merit further attention as a potential chemopreventive agent.

Chemoprevention of lung cancer: prospects and disappointments in human clinical trials

Decreasing the risk of lung cancer, or preventing its development in high-risk individuals, would have a huge impact on public health. The most effective means to decrease lung cancer incidence is to eliminate exposure to carcinogens. However, with recent advances in the understanding of pulmonary carcinogenesis and the identification of intermediate biomarkers, the prospects for the field of chemoprevention research have improved dramatically. Here we review the most recent research in lung cancer chemoprevention-focusing on those agents that have been investigated in human clinical trials. These agents fall into three major categories. First, oxidative stress plays an important role in pulmonary carcinogenesis; and therefore, antioxidants (including vitamins, selenium, green tea extracts, and isothiocyanates) may be particularly effective in preventing the development of lung cancer. Second, inflammation is increasingly accepted as a crucial factor in carcinogenesis, and many investigators have focused on anti-inflammatory agents, such as glucocorticoids, NSAIDs, statins, and PPARγ agonists. Finally, the PI3K/AKT/mTOR pathway is recognized to play a central role in tobacco-induced carcinogenesis, and inhibitors of this pathway, including myoinositol and metformin, are promising agents for lung cancer prevention. Successful chemoprevention will likely require targeting of multiple pathways to carcinogenesis-both to minimize toxicity and maximize efficacy.

Association between use of specialty dietary supplements and C-reactive protein concentrations

Laboratory evidence suggests that certain specialty dietary supplements have antiinflammatory properties, though evidence in humans remains limited. Data on a nationally representative sample of 9,947 adults from the 1999-2004 cycles of the National Health and Nutrition Examination Survey were used to assess the associations between specialty supplement use and inflammation, as measured by serum high-sensitivity C-reactive protein (hs-CRP) concentration. Using survey-weighted multivariate linear regression, significant reductions in hs-CRP concentrations were associated with regular use of glucosamine (17%, 95% confidence interval (CI): 7, 26), chondroitin (22%, 95% CI: 8, 33), and fish oil (16%, 95% CI: 0.3, 29). No associations were observed between hs-CRP concentration and regular use of supplements containing methylsulfonylmethane, garlic, ginkgo biloba, saw palmetto, or pycnogenol. These results suggest that glucosamine and chondroitin supplements are associated with reduced inflammation in humans and provide further evidence to support an inverse association between use of fish oil supplements and inflammation. It is important to further investigate the potential antiinflammatory role of these supplements, as there is a need to identify safe and effective ways to reduce inflammation and the burden of inflammation-related diseases such as cancer and cardiovascular disease.

Use of glucosamine and chondroitin in relation to mortality

Glucosamine and chondroitin are products commonly used by older adults in the US and Europe. There is limited evidence that they have anti-inflammatory properties, which could provide risk reduction of several diseases. However, data on their long-term health effects is lacking. To evaluate whether use of glucosamine and chondroitin are associated with cause-specific and total mortality. Participants (n = 77,510) were members of a cohort study of Washington State (US) residents aged 50-76 years who entered the cohort in 2000-2002 by completing a baseline questionnaire that included questions on glucosamine and chondroitin use. Participants were followed for mortality through 2008 (n = 5,362 deaths). Hazard ratios (HR) for death adjusted for multiple covariates were estimated using Cox models. Current (baseline) glucosamine and chondroitin use were associated with a decreased risk of total mortality compared to never use. The adjusted HR associated with current use of glucosamine (with or without chondroitin) was 0.82 (95 % CI 0.75-0.90) and 0.86 (95 % CI 0.78-0.96) for chondroitin (included in two-thirds of glucosamine supplements). Current use of glucosamine was associated with a significant decreased risk of death from cancer (HR 0.87 95 % CI 0.76-0.98) and with a large risk reduction for death from respiratory diseases (HR 0.59 95 % CI 0.41-0.83). Use of glucosamine with or without chondroitin was associated with reduced total mortality and with reductions of several broad causes of death. Although bias cannot be ruled out, these results suggest that glucosamine may provide some mortality benefit.