Glucosamine prevents in vitro collagen degradation in chondrocytes by inhibiting advanced lipoxidation reactions and protein oxidation

Risk factor prediction and immune correlation analysis of cuproptosis-related gene in osteoarthritis

Osteoarthritis (OA) is a widespread inflammatory joint disease with significant global disability burden. Cuproptosis, a newly identified mode of cell death, has emerged as a crucial factor in various pathological conditions, including OA. In this context, our study aims to investigate the intrinsic relationship between cuproptosis-related genes (CRGs) and OA, and assess their potential as biomarkers for OA diagnosis and treatment. Datasets from the GEO databases were analysed the differential expression of CRGs, leading to the identification of 10 key CRGs (CDKN2A, DLD, FDX1, GLS, LIAS, LIPT1, MTF1, PDHA1, DLAT and PDHB). A logistic regression analysis and calibration curves were used to show excellent diagnostic accuracy. Consensus clustering revealed two CRG patterns, with Cluster 1 indicating a closer association with OA progression. RT-PCR confirmed a significant increase in the expression levels of these nine key genes in IL-1β-induced C28/i2 cells, and the expression of CDKN2A and FDX1 were also elevated in conditioned monocytes, while the expression of GLS and MTF1 were significantly decreased. In vitro experiments demonstrated that the expression levels of these 7/10 CRGs were significantly increased in chondrocytes induced by IL-1β, and upon stimulation with cuproptosis inducers, chondrocyte apoptosis was exacerbated, accompanied by an increase in the expression of cuproptosis-related proteins. These further substantiated our research findings and indicated that the nine selected cuproptosis genes have high potential for application in the diagnosis of OA.

Identification and verification of a novel signature that combines cuproptosis-related genes with ferroptosis-related genes in osteoarthritis using bioinformatics analysis and experimental validation

BACKGROUND

Exploring the pathogenesis of osteoarthritis (OA) is important for its prevention, diagnosis, and treatment. Therefore, we aimed to construct novel signature genes (c-FRGs) combining cuproptosis-related genes (CRGs) with ferroptosis-related genes (FRGs) to explore the pathogenesis of OA and aid in its treatment.

MATERIALS AND METHODS

Differentially expressed c-FRGs (c-FDEGs) were obtained using R software. Enrichment analysis was performed and a protein-protein interaction (PPI) network was constructed based on these c-FDEGs. Then, seven hub genes were screened. Three machine learning methods and verification experiments were used to identify four signature biomarkers from c-FDEGs, after which gene set enrichment analysis, gene set variation analysis, single-sample gene set enrichment analysis, immune function analysis, drug prediction, and ceRNA network analysis were performed based on these signature biomarkers. Subsequently, a disease model of OA was constructed using these biomarkers and validated on the GSE82107 dataset. Finally, we analyzed the distribution of the expression of these c-FDEGs in various cell populations.

RESULTS

A total of 63 FRGs were found to be closely associated with 11 CRGs, and 40 c-FDEGs were identified. Bioenrichment analysis showed that they were mainly associated with inflammation, external cellular stimulation, and autophagy. CDKN1A, FZD7, GABARAPL2, and SLC39A14 were identified as OA signature biomarkers, and their corresponding miRNAs and lncRNAs were predicted. Finally, scRNA-seq data analysis showed that the differentially expressed c-FRGs had significantly different expression distributions across the cell populations.

CONCLUSION

Four genes, namely CDKN1A, FZD7, GABARAPL2, and SLC39A14, are excellent biomarkers and prospective therapeutic targets for OA.

Circulating Copper Is Associated with Inflammatory Biomarkers in Greek Older Adults with Osteoarthritis

Osteoarthritis (OA) is the most common form of arthritis, that causes a significant decrease in the quality of life of the afflicted and constitutes a great burden for the socioeconomic system. Trace elements and heavy metals are implicated in the pathophysiology of OA, exacerbating inflammatory and oxidative stress responses. The aim of this cross-sectional study was to quantify metals in plasma samples of Greek OA patients and explore their link with disease related parameters, health status or quality of life, as well as epigenetic OA markers. This is the first study on plasma metal levels in Greek knee OA patients. To achieve precision in plasma metal and miRNA measurements, high-quality samples were selected from a subset of 34 participants (NCT04783792). Demographic, quality of life, clinical, biochemical, inflammation, oxidative stress, and anthropometric parameters, as well as microRNA levels were assessed. Significant correlations were found between circulating metals with OA related parameters or with measured microRNAs. Also, significant positive associations between plasma copper (Cu) levels and CRP (p = 0.033) or IL-6 (p = 0.001) occurred when adjusting for age, gender, BMI, physical activity level, smoking, disease severity, total arthroplasty, and dietary intake of the respective metal. Cu's role in OA is bidirectional, and this study confirms the findings that in OA, Cu is positively associated with inflammation. Such relationships between lifestyle, environment and OA enhance our understanding and encourage further study on metals related to OA inflammation.

Meta-analysis of the Relationship Between Zinc and Copper in Patients with Osteoarthritis

This study aims to explore the relationship between osteoarthritis and the trace elements zinc and copper and to provide a theoretical basis for research on the related mechanisms for the prevention, diagnosis, and treatment of osteoarthritis. We searched all the literature indexed in Web Of Science, Embase, and PubMed as of January 10, 2024, summarized the zinc and copper detection indexes in patients with osteoarthritis, obtained clinical data through literature screening, quality assessment, and data extraction, and analyzed the data using Revman 5.4. A total of 13 papers were included in this study, totaling 7983 study subjects. These were divided into osteoarthritis and healthy control groups. The results from the meta-analysis showed that in patients with osteoarthritis, circulating copper levels, but not zinc levels, were significantly higher compared to healthy individuals. The level of copper in the blood of patients with osteoarthritis is significantly higher than that of healthy people.

Protective Effect of Knee Postoperative Fluid on Oxidative-Induced Damage in Human Knee Articular Chondrocytes

The oxidative-stress-elicited deterioration of chondrocyte function is the initial stage of changes leading to the disruption of cartilage homeostasis. These changes entail a series of catabolic damages mediated by proinflammatory cytokines, MMPs, and aggrecanases, which increase ROS generation. Such uncontrolled ROS production, inadequately balanced by the cellular antioxidant capacity, eventually contributes to the development and progression of chondropathies. Several pieces of evidence show that different growth factors, single or combined, as well as anti-inflammatory cytokines and chemokines, can stimulate chondrogenesis and improve cartilage repair and regeneration. In this view, hypothesizing a potential growth-factor-associated action, we investigate the possible protective effect of post-operation knee fluid from patients undergoing prosthesis replacement surgery against ROS-induced damage on normal human knee articular chondrocytes (HKACs). To this end, HKACs were pre-treated with post-operation knee fluid and then exposed to H2O2 to mimic oxidative stress. Intracellular ROS levels were measured by using the molecular probe H2DCFDA; cytosolic and mitochondrial oxidative status were assessed by using HKACs infected with lentiviral particles harboring the redox-sensing green fluorescent protein (roGFP); and cell proliferation was determined by measuring the rate of DNA synthesis with BrdU incorporation. Moreover, superoxide dismutase (SOD), catalase, and glutathione levels from the cell lysates of treated cells were also measured. Postoperative peripheral blood sera from the same patients were used as controls. Our study shows that post-operation knee fluid can counteract H2O2-elicited oxidative stress by decreasing the intracellular ROS levels, preserving the cytosolic and mitochondrial redox status, maintaining the proliferation of oxidatively stressed HKACs, and upregulating chondrocyte antioxidant defense. Overall, our results support and propose an important effect of post-operation knee fluid substances in maintaining HKAC function by mediating cell antioxidative system upregulation and protecting cells from oxidative stress.

Effects of Glucosamine in the Temporomandibular Joint Osteoarthritis: A Review

Osteoarthritis in the temporomandibular joint (TMJ) is a chronic disease characterized by irreversible damage to articular surfaces, including inflammation, loss of articular cartilage, and subchondral bone alterations, which would be radiographically evident only in later stages. Symptomatic slow-acting so-called nutraceutical drugs have been proposed as a treatment for osteoarthritis in comparison to non-steroidal anti-inflammatory drugs (NSAID) because of their appreciable safety profile even in long-term intake. Glucosamine, being one among them, proved highly efficient in knee osteoarthritis. However, its application in TMJ osteoarthritis dates back only to 2001 and is still inconclusive in its efficiency even with systematic reviews, in restoring the structural and functional aspects of damaged TMJ. Glucosamine, being a natural compound and also a contributor to building the matrix of articular cartilage, can be utilized effectively for TMJ osteoarthritis as an adjunct along with other conventional treatment modalities available till now, which also have moderate prognosis in most of the clinical scenarios. This review summarizes data relating to the mechanism of osteoarthritis and its management using glucosamine formulations. The beneficial effects of glucosamine on the pathophysiology of TMJ osteoarthritis are possibly due to its contribution to hyaluronic acid regulation and in establishing a proper balance between anabolism/catabolism in the articular tissues.

Copper(II) Complexes with Carnosine Conjugates of Hyaluronic Acids at Different Dipeptide Loading Percentages Behave as Multiple SOD Mimics and Stimulate Nrf2 Translocation and Antioxidant Response in In Vitro Inflammatory Model

A series of copper(II) complexes with the formula [Cu2+Hy(x)Car%] varying the molecular weight (MW) of Hyaluronic acid (Hy, x = 200 or 700 kDa) conjugated with carnosine (Car) present at different loading were synthesized and characterized via different spectroscopic techniques. The metal complexes behaved as Cu, Zn-superoxide dismutase (SOD1) mimics and showed some of the most efficient reaction rate values produced using a synthetic and water-soluble copper(II)-based SOD mimic reported to date. The increase in the percentage of Car moieties parallels the enhancement of the I50 value determined via the indirect method of Fridovich. The presence of the non-functionalized Hy OH groups favors the scavenger activity of the copper(II) complexes with HyCar, recalling similar behavior previously found for the copper(II) complexes with Car conjugated using β-cyclodextrin or trehalose. In keeping with the new abilities of SOD1 to activate protective agents against oxidative stress in rheumatoid arthritis and osteoarthritis diseases, Cu2+ interaction with HyCar promotes the nuclear translocation of erythroid 2-related factor that regulates the expressions of target genes, including Heme-Oxigenase-1, thus stimulating an antioxidant response in osteoblasts subjected to an inflammatory/oxidative insult.

The Role Played by Ferroptosis in Osteoarthritis: Evidence Based on Iron Dyshomeostasis and Lipid Peroxidation

Ferroptosis, a recently discovered regulated cell death modality, is characterised by iron-dependent accumulation of lipid hydroperoxides, which can reach lethal levels but can be specifically reversed by ferroptosis inhibitors. Osteoarthritis (OA), the most common degenerative joint disease, is characterised by a complex pathogenesis involving mechanical overload, increased inflammatory mediator levels, metabolic alterations, and cell senescence and death. Since iron accumulation and oxidative stress are the universal pathological features of OA, the role played by ferroptosis in OA has been extensively explored. Increasing evidence has shown that iron dyshomeostasis and lipid peroxidation are closely associated with OA pathogenesis. Therefore, in this review, we summarize recent evidence by focusing on ferroptotic mechanisms and the role played by ferroptosis in OA pathogenesis from the perspectives of clinical findings, animal models, and cell research. By summarizing recent research advances that characterize the relationship between ferroptosis and OA, we highlight avenues for further research and potential therapeutic targets.

The Impact of Trace Elements on Osteoarthritis

Osteoarthritis (OA) is a progressive degenerative disease characterized by cartilage degradation, synovial inflammation, subchondral sclerosis and osteophyte formation. It has a multifactorial etiology with potential contributions from heredity, endocrine function, abnormal mechanical load and nutrition. Of particular considerations are trace element status. Several trace elements, such as boron and magnesium are essential for normal development of the bone and joint in human. While cadmium correlates with the severity of OA. The present review focuses on the roles of trace elements (boron, cadmium, copper, iron, magnesium, manganese, selenium, zinc) in OA and explores the mechanisms by which they act.

Nutraceutical Approach to Chronic Osteoarthritis: From Molecular Research to Clinical Evidence

Osteoarthritis (OA) is a degenerative inflammatory condition of the joint cartilage that currently affects approximately 58 million adults in the world. It is characterized by pain, stiffness, and a reduced range of motion with regard to the arthritic joints. These symptoms can cause in the long term a greater risk of overweight/obesity, diabetes mellitus, and falls and fractures. Although the current guidelines for the treatment of OA suggest, as the gold standard for this condition, pharmacological treatment characterized by non-steroidal anti-inflammatory drugs (NSAID), opioids, and cyclooxygenase (COX)-2-specific drugs, a great interest has been applied to nutraceutical supplements, which include a heterogeneous class of molecules with great potential to reduce inflammation, oxidative stress, pain, and joint stiffness and improve cartilage formation. The purpose of this review is to describe the potential application of nutraceuticals in OA, highlighting its molecular mechanisms of actions and data of efficacy and safety (when available).

Novel predictor markers for early differentiation between transient tachypnea of newborn and respiratory distress syndrome in neonates

Neonatal Respiratory Distress Syndrome (RDS) and Transient Tachypnea of newborn (TTN) are common similar neonatal respiratory diseases. Study the early predictor markers in differentiation between TTN and RDS in neonates. A prospective case control study which was done in Neonatal Intensive Care Unit (NICU) of Tanta University Hospital (TUH) from September 2016 to March 2018. Three groups of neonates were included in the study: RDS group (45 neonates), TTN group (45 neonates), and control group (45 healthy neonates). There were statistically significant difference (SSD) between our studied three groups as regard serum Malondialdehyde (MDA), Superoxide dismutase SOD, Lactate dehydrogenase (LDH), and blood PH and P-values were 0.001* for these comparative parameters. The ROC curve of RDS cases revealed that the serum MDA Cut off, sensitivity and specificity were 1.87 mmol/L, 98%, 96%, respectively which had the highest sensitivity and specificity followed by the serum SOD then the serum LDH and lastly the blood PH while in TTN cases, the serum MDA Cut off, sensitivity and specificity were 0.74 mmol/L, 96%, 93%, respectively then the serum SOD then the serum LDH and lastly the blood PH. Serum MDA, SOD, LDH, and PH had a beneficial role as early predictors in differentiation between TTN and RDS in neonates.

Re-appraising the potential of naringin for natural, novel orthopedic biotherapies

Naringin is a naturally occurring flavonoid found in plants of the Citrus genus that has historically been used in traditional Chinese medical regimens for the treatment of osteoporosis. Naringin modulates signaling through numerous molecular pathways critical to musculoskeletal development, cellular differentiation, and inflammation. Administration of naringin increases in vitro expression of bone morphogenetic proteins (BMPs) and activation of the Wnt/β-catenin and extracellular signal-related kinase (Erk) pathways, thereby promoting osteoblastic proliferation and differentiation from stem cell precursors for bone formation. Naringin also inhibits osteoclastogenesis by both modifying RANK/RANKL interactions and inducing apoptosis in osteoclasts in vitro. In addition, naringin acts on the estrogen receptor in bone to mimic the native bone-preserving effects of estrogen, with few systemic side effects on other estrogen-sensitive tissues. The efficacy of naringin therapy in reducing the osteolysis characteristic of common musculoskeletal pathologies such as osteoporosis, degenerative joint disease, and osteomyelitis, as well as inflammatory conditions affecting bone such as diabetes mellitus, has been extensively demonstrated in vitro and in animal models. Naringin thus represents a naturally abundant, cost-efficient agent whose potential for use in novel musculoskeletal biotherapies warrants re-visiting and further exploration through human studies. Here, we review the cellular mechanisms of action that have been elucidated regarding the action of naringin on bone resident cells and the bone microenvironment, in vivo evidence of naringin’s osteostimulative and chondroprotective properties in the setting of osteolytic bone disease, and current limitations in the development of naringin-containing translational therapies for common musculoskeletal conditions.

Anserine and glucosamine supplementation attenuates the levels of inflammatory markers in rats with rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disorder that affects the joint synovium. Anserine is a functional dipeptide containing methylhistidine and β-alanine, and is present in the brain and skeletal muscle of birds and mammals. Glucosamine is an amino sugar used in the synthesis of glycosylated proteins and lipids. We evaluated the effects of anserine and glucosamine on RA. Rats were assigned into the control group, RA group, anserine group (1 mg/kg), glucosamine group (200 mg/kg), or anserine plus glucosamine group (anserine, 1 mg/kg + glucosamine, 200 mg/kg). Treatment was continued for 45 consecutive days and was administered orally. The serum levels of catalase, glutathione peroxidase (Gpx), superoxide dismutase (SOD), reduced glutathione (GSH), lipid peroxidation, uric acid, nitric oxide, ceruloplasmin, zinc, copper, prostaglandin E₂ (PGE₂), matrix metalloproteinase (MMP)-3, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 were assayed. The mRNA and protein levels of nuclear factor (NF)-κB and inducible nitric oxide synthase (iNOS) in synovial tissue were also determined. Anserine plus glucosamine significantly increased the catalase, SOD, Gpx, GSH, and zinc levels compared to the control, anserine, and glucosamine groups. Also, anserine plus glucosamine significantly reduced the PGE₂, MMP-3, TNF-α, IL-1β, and IL-6 levels compared to the control, anserine, and glucosamine groups. Furthermore, anserine plus glucosamine significantly reduced the mRNA and protein levels of NF-κB and iNOS compared to the control, anserine, and glucosamine groups. Therefore, supplementation of anserine plus glucosamine shows therapeutic potential for RA.

Milk-Fat Globule Membrane Plus Glucosamine Improves Joint Function and Physical Performance: A Randomized, Double-Blind, Placebo-Controlled, Parallel-Group Study

Care of the musculoskeletal system, including the muscles, joints, and bones, is important for a healthy life expectancy in today's aging society. The aim of this randomized, double-blind, placebo-controlled study was to investigate the effect of consumption of milk-fat globule membrane (MFGM) and glucosamine on joint function and physical performance. Participants were healthy Japanese men and women, aged 60-74 y, with a history of mild knee or low back pain at rest. They were randomized to receive tablets containing MFGM 1.0 g+glucosamine 1.5 g or placebo tablets for 8 wk. We assessed passive range of motion, active range of motion (self-reported VAS score), JKOM and JLEQ, and physical performance. Data were available for analysis for 25 participants in the active treatment group and 28 in the placebo group. The active group showed significant improvements in passive range of motion at the knee and active range of motion at both the knee and low back. The active group also showed significant improvements in some physical performance, including obstacle walking speed and speed of ascending stairs. The findings of this study suggest that consumption of a combination of MFGM and glucosamine may improve joint function and physical performance.

Multifaceted Protective Role of Glucosamine against Osteoarthritis: Review of Its Molecular Mechanisms

Osteoarthritis (OA) is a joint disease resulting from cartilage degeneration and causing joint pain and stiffness. Glucosamine exerts chondroprotective effects and effectively reduces OA pain and stiffness. This review aims to summarise the mechanism of glucosamine in protecting joint health and preventing OA by conducting a literature search on original articles. Current evidence has revealed that glucosamine exhibits anti-inflammatory effects by reducing the levels of pro-inflammatory factors (such as tumour necrosis factor-alpha, interleukin-1, and interleukin-6) and enhancing the synthesis of proteoglycans that retard cartilage degradation and improve joint function. Additionally, glucosamine improves cellular redox status, reduces OA-mediated oxidative damages, scavenges free radicals, upregulates antioxidant proteins and enzyme levels, inhibits the production of reactive oxygen species, and induces autophagy to delay OA pathogenesis. In conclusion, glucosamine prevents OA and maintains joint health by reducing inflammation, improving the redox status, and inducing autophagy in joints. Further studies are warranted to determine the synergistic effect of glucosamine with other anti-inflammatory and/or antioxidative agents on joint health in humans.

Biomarkers in Stress Related Diseases/Disorders: Diagnostic, Prognostic, and Therapeutic Values

Various internal and external factors negatively affect the homeostatic equilibrium of organisms at the molecular to the whole-body level, inducing the so-called state of stress. Stress affects an organism's welfare status and induces energy-consuming mechanisms to combat the subsequent ill effects; thus, the individual may be immunocompromised, making them vulnerable to pathogens. The information presented here has been extensively reviewed, compiled, and analyzed from authenticated published resources available on Medline, PubMed, PubMed Central, Science Direct, and other scientific databases. Stress levels can be monitored by the quantitative and qualitative measurement of biomarkers. Potential markers of stress include thermal stress markers, such as heat shock proteins (HSPs), innate immune markers, such as Acute Phase Proteins (APPs), oxidative stress markers, and chemical secretions in the saliva and urine. In addition, stress biomarkers also play critical roles in the prognosis of stress-related diseases and disorders, and therapy guidance. Moreover, different components have been identified as potent mediators of cardiovascular, central nervous system, hepatic, and nephrological disorders, which can also be employed to evaluate these conditions precisely, but with stringent validation and specificity. Considerable scientific advances have been made in the detection, quantitation, and application of these biomarkers. The present review describes the current progress of identifying biomarkers, their prognostic, and therapeutic values.

Biomarkers in Stress Related Diseases/Disorders: Diagnostic, Prognostic, and Therapeutic Values

Various internal and external factors negatively affect the homeostatic equilibrium of organisms at the molecular to the whole-body level, inducing the so-called state of stress. Stress affects an organism's welfare status and induces energy-consuming mechanisms to combat the subsequent ill effects; thus, the individual may be immunocompromised, making them vulnerable to pathogens. The information presented here has been extensively reviewed, compiled, and analyzed from authenticated published resources available on Medline, PubMed, PubMed Central, Science Direct, and other scientific databases. Stress levels can be monitored by the quantitative and qualitative measurement of biomarkers. Potential markers of stress include thermal stress markers, such as heat shock proteins (HSPs), innate immune markers, such as Acute Phase Proteins (APPs), oxidative stress markers, and chemical secretions in the saliva and urine. In addition, stress biomarkers also play critical roles in the prognosis of stress-related diseases and disorders, and therapy guidance. Moreover, different components have been identified as potent mediators of cardiovascular, central nervous system, hepatic, and nephrological disorders, which can also be employed to evaluate these conditions precisely, but with stringent validation and specificity. Considerable scientific advances have been made in the detection, quantitation, and application of these biomarkers. The present review describes the current progress of identifying biomarkers, their prognostic, and therapeutic values.

Evaluation of five additives to mitigate toxicity of cryoprotective agents on porcine chondrocytes

Cryoprotective agents (CPAs) are used in cryopreservation protocols to achieve vitrification. However, the high CPA concentrations required to vitrify a tissue such as articular cartilage are a major drawback due to their cellular toxicity. Oxidation is one factor related to CPA toxicity to cells and tissues. Addition of antioxidants has proven to be beneficial to cell survival and cellular functions after cryopreservation. Investigation of additives for mitigating cellular CPA toxicity will aid in developing successful cryopreservation protocols. The current work shows that antioxidant additives can reduce the toxic effect of CPAs on porcine chondrocytes. Our findings showed that chondroitin sulphate, glucosamine, 2,3,5,6-tetramethylpyrazine and ascorbic acid improved chondrocyte cell survival after exposure to high concentrations of CPAs according to a live-dead cell viability assay. In addition, similar results were seen when additives were added during CPA removal and articular cartilage sample incubation post CPA exposure. Furthermore, we found that incubation of articular cartilage in the presence of additives for 2 days improved chondrocyte recovery compared with those incubated for 4 days. The current results indicated that the inclusion of antioxidant additives during exposure to high concentrations of CPAs is beneficial to chondrocyte survival and recovery in porcine articular cartilage and provided knowledge to improve vitrification protocols for tissue banking of articular cartilage.

Comprehensive changes in volatile/nonvolatile compounds and flavor and physicochemical characteristics in Angelica gigas Nakai roots by thermal processing

This study investigated the changes of physicochemical and flavor characteristics of Angelica gigas Nakai roots during roasting. Glutamic acid and arginine were higher in constituent amino acids. In the taste value, glutamic acid was highest in constituent and free amino acids. Total phenol contents were highest in 0 min and lowest in 3 min. Hundred twenty-six volatile compounds were detected by GC/MS during roasting. α-pinene, eudesmol, nonane, and limonene were detected as major volatile compounds. For antioxidant ability, 1,1-diphenyl-2-picrylhydrazyl did not change during roasting, and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid showed the highest value in 3 min. Browning intensity showed a slight decrease over time. In Electronic nose, fragrance increased by roasting, and strength, NH₃ , and H₂ S decreased significantly. In Electronic tongue, sweetness, bitterness, and umami taste increased by roasting, and this was related to amino acid composition. The results provide basic data on the physicochemical and flavor characteristics of A. gigas Nakai according to the roasting process. PRACTICAL APPLICATIONS: Angelica gigas Nakai has been known as a medicinal herb in Asian countries and usually consumed in powder, tea, and snacks. In order to produce the powder, tea, or snacks with A. gigas Nakai, thermal treatment is an essential and critical process. Despite that existing studies reported many physiological benefits and functional properties of A. gigas Nakai, studies have rarely discovered how the nutritional properties and volatile compounds of A. gigas Nakai alter when it undergoes thermal treatment. Therefore, this study will be utilized as basic data to optimize the thermal processing conditions (e.g., roasting time) for the production of food products with A. gigas Nakai such as tea and snacks. This study further provides objective chemical measures of sensory profiles of A. gigas Nakai using electronic tongue and electronic nose during the thermal processing.

Lipoproteins as targets and markers of lipoxidation

Lipoproteins are essential systemic lipid transport particles, composed of apolipoproteins embedded in a phospholipid and cholesterol monolayer surrounding a cargo of diverse lipid species. Many of the lipids present are susceptible to oxidative damage by lipid peroxidation, giving rise to the formation of reactive lipid peroxidation products (rLPPs). In view of the close proximity of the protein and lipid moieties within lipoproteins, the probability of adduct formation between rLPPs and amino acid residues of the proteins, a process called lipoxidation, is high. There has been interest for many years in the biological effects of such modifications, but the field has been limited to some extent by the availability of methods to determine the sites and exact nature of such modification. More recently, the availability of a wide range of antibodies to lipoxidation products, as well as advances in analytical techniques such as liquid chromatography tandem mass spectrometry (LC-MSMS), have increased our knowledge substantially. While most work has focused on LDL, oxidation of which has long been associated with pro-inflammatory responses and atherosclerosis, some studies on HDL, VLDL and Lipoprotein(a) have also been reported. As the broader topic of LDL oxidation has been reviewed previously, this review focuses on lipoxidative modifications of lipoproteins, from the historical background through to recent advances in the field. We consider the main methods of analysis for detecting rLPP adducts on apolipoproteins, including their advantages and disadvantages, as well as the biological effects of lipoxidized lipoproteins and their potential roles in diseases.

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Lipoproteins can be modified by reactive Lipid Peroxidation Products (rLPPs).

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Lipoprotein lipoxidation is known to occur in several inflammatory diseases.

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Biochemical, immunochemical and mass spectrometry methods can detect rLPP adducts.

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Due to higher information output, MS can facilitate localization of modifications.

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Antibodies against some rLPPs have been used to identify lipoxidation in vivo.

Intra-Articular Injections of Polyphenols Protect Articular Cartilage from Inflammation-Induced Degradation: Suggesting a Potential Role in Cartilage Therapeutics

Arthritic diseases, such as osteoarthritis and rheumatoid arthritis, inflict an enormous health care burden on society. Osteoarthritis, a degenerative joint disease with high prevalence among older people, and rheumatoid arthritis, an autoimmune inflammatory disease, both lead to irreversible structural and functional damage to articular cartilage. The aim of this study was to investigate the effect of polyphenols such as catechin, quercetin, epigallocatechin gallate, and tannic acid, on crosslinking type II collagen and the roles of these agents in managing in vivo articular cartilage degradation. The thermal, enzymatic, and physical stability of bovine articular cartilage explants following polyphenolic treatment were assessed for efficiency. Epigallocatechin gallate and tannic acid-treated explants showed >12 °C increase over native cartilage in thermal stability, thereby confirming cartilage crosslinking. Polyphenol-treated cartilage also showed a significant reduction in the percentage of collagen degradation and the release of glycosaminoglycans against collagenase digestion, indicating the increase physical integrity and resistance of polyphenol crosslinked cartilage to enzymatic digestion. To examine the in vivo cartilage protective effects, polyphenols were injected intra-articularly before (prophylactic) and after (therapeutic) the induction of collagen-induced arthritis in rats. The hind paw volume and histomorphological scoring was done for cartilage damage. The intra-articular injection of epigallocatechin gallate and tannic acid did not significantly influence the time of onset or the intensity of joint inflammation. However, histomorphological scoring of the articular cartilage showed a significant reduction in cartilage degradation in prophylactic- and therapeutic-groups, indicating that intra-articular injections of polyphenols bind to articular cartilage and making it resistant to degradation despite ongoing inflammation. These studies establish the value of intra-articular injections of polyphenol in stabilization of cartilage collagen against degradation and indicate the unique beneficial role of injectable polyphenols in protecting the cartilage in arthritic conditions.

Chondroprotective effects of a new glucosamine combination in rats: Gene expression, biochemical and histopathological evaluation

AIMS

This study investigates the effect of a new combination of glucosamine hydrochloride, chondroitin sulfate, methylsulfonylmethane, Harpagophytum procumbens root extract (standardized to 3% harpagoside) and bromelain extract (GCMHB) on formalin-induced damage to cartilage tissue in the rat knee joint and evaluates this combination in comparison with another combination of glucosamine hydrochloride, chondroitin sulfate and methylsulfonylmethane (GKM).

MATERIALS AND METHODS

Animals in the control group were injected with formalin into the knee joint (FCG). Animals in the GCMHB-500 group were given 500mg/kg GCMHB+formalin, and those in the GKM-500 group were given 500mg/kg GKM+formalin. Finally, a healthy group (HG) was also used. GCMHB and GKM were administered to rats orally once a day for 30days. At the end of this period, the rats were sacrificed and the levels of MDA, NO, 8-OH/Gua, and tGSH in the knee joint tissue were measured. Analysis of IL-1β and TNF-α gene expression was done and the tissue was evaluated histopathologically.

KEY FINDINGS

MDA, NO and 8-OH/Gua levels and IL-1β and TNF-α gene expression were significantly lower in the GCMHB-500 group compared to the FCG group, whereas tGSH was significantly higher in the GCMHB-500 group than in the FCG group. No significant difference was found for the IL-1β, TNF-α and oxidant/antioxidant parameters between the GKM and FCG groups. The histopathological analysis showed that GCMHB could prevent damage to the cartilage joint, whereas GKM could not.

SIGNIFICANCE

GCMHB may be used clinically by comparing with GKM in the treatment of osteoarthritis.

Protective effects of glucosamine hydrochloride against free radical-induced erythrocytes damage

Glucosamine (GlcN) is an important precursor in the biochemical synthesis of glycosylated proteins and lipids in human body. It gains importance because of its contribution to human health and its multiple biological and therapeutic effects. In this study, the in vitro oxidative hemolysis of rat erythrocyte was used as a model to study the potential protective effect of glucosamine hydrochloride against free radical-induced damage of biological membranes. Glucosamine hydrochloride exhibited dose-dependent DPPH antioxidant activity. Oxidative hemolysis and lipid/protein peroxidation of erythrocytes induced by a water-soluble free radical initiator 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH) were significantly suppressed by GlcN in a time and dose dependent manner. GlcN also prevented the depletion of cytosolic antioxidant glutathione (GSH) in erythrocytes. These results indicated that glucosamine hydrochloride efficiently protected erythrocytes against free radicals and it could be recommended as a pharmaceutical supplement to alleviate oxidative stress.

Effects of Glucosamine and Chondroitin Sulfate on Cartilage Metabolism in OA: Outlook on Other Nutrient Partners Especially Omega-3 Fatty Acids

Osteoarthritis (OA) is a degenerative joint disease that is characterized by increasing loss of cartilage, remodeling of the periarticular bone, and inflammation of the synovial membrane. Besides the common OA therapy with nonsteroidal anti-inflammatory drugs (NSAIDs), the treatment with chondroprotectives, such as glucosamine sulfate, chondroitin sulfate, hyaluronic acid, collagen hydrolysate, or nutrients, such as antioxidants and omega-3 fatty acids is a promising therapeutic approach. Numerous clinical studies have demonstrated that the targeted administration of selected micronutrients leads to a more effective reduction of OA symptoms, with less adverse events. Their chondroprotective action can be explained by a dual mechanism: (1) as basic components of cartilage and synovial fluid, they stimulate the anabolic process of the cartilage metabolism; (2) their anti-inflammatory action can delay many inflammation-induced catabolic processes in the cartilage. These two mechanisms are able to slow the progression of cartilage destruction and may help to regenerate the joint structure, leading to reduced pain and increased mobility of the affected joint.

High levels of glucosamine-chondroitin sulfate can alter the cyclic preload and acute overload responses of chondral explants

A recent study by our laboratory showed that 14 days of low intensity, intermittent cyclic preloading of chondral explants elevated the concentration of proteoglycans (PGs) to cause a mechanical stiffening of the explants prior to an acute overload and limit the extent of tissue damage. Longer term loading to 21 days resulted in tissue degradation prior to the acute traumatic event and excessive damage from an acute overload. Previous studies by others showed that bathing chondral explants in a supplement of glucosamine-chondroitin sulfate (glcN-CS) upregulated the synthesis of tissue PGs, particularly in stressed tissue, and the supplement served as an anti-inflammatory agent. Our current hypothesis was that the supplementation of culture media with a high concentration of glcN-CS would upregulate the production of tissue PG and limit or mitigate long-term degradation of chondral explants under cyclic preloading and limit tissue damage in an acute overload. We showed that, in the presence of supplement, cyclic preloading significantly increased tissue PG content and matrix modulus by about 65 and 300%, respectively, at 21 days, resulting in a reduction of matrix damage and cell death following an acute overload. These data show a biological action of high concentrations of this supplement and its effect on the mechanical properties in this in vitro model.