Decreased production of inflammatory mediators in human osteoarthritic chondrocytes by conjugated linoleic acids

Omega-3 Supplementation and Its Effects on Osteoarthritis

Osteoarthritis (OA) is a degenerative joint disease characterized by the destruction of the articular cartilage, resulting in a pro-inflammatory response. The progression of OA is multifactorial and is influenced by the underlying cause of inflammation, which includes but is not limited to trauma, metabolism, biology, comorbidities, and biomechanics. Although articular cartilage is the main tissue affected in osteoarthritis, the chronic inflammatory environment negatively influences the surrounding synovium, ligaments, and subchondral bone, further limiting their functional abilities and enhancing symptoms of OA. Treatment for osteoarthritis remains inconsistent due to the inability to determine the underlying mechanism of disease onset, severity of symptoms, and complicating comorbidities. In recent years, diet and nutritional supplements have gained interest regarding slowing the disease process, prevention, and treatment of OA. This is due to their anti-inflammatory properties, which result in a positive influence on pain, joint mobility, and cartilage formation. More specifically, omega-3 polyunsaturated fatty acids (PUFA) have demonstrated an influential role in the progression of OA, resulting in the reduction of cartilage destruction, inhibition of pro-inflammatory cytokine cascades, and production of oxylipins that promote anti-inflammatory pathways. The present review is focused on the assessment of evidence explaining the inflammatory processes of osteoarthritis and the influence of omega-3 supplementation to modulate the progression of osteoarthritis.

Risk of metabolic abnormalities in osteoarthritis: a new perspective to understand its pathological mechanisms

Although aging has traditionally been viewed as the most important risk factor for osteoarthritis (OA), an increasing amount of epidemiological evidence has highlighted the association between metabolic abnormalities and OA, particularly in younger individuals. Metabolic abnormalities, such as obesity and type II diabetes, are strongly linked to OA, and they affect both weight-bearing and non-weight-bearing joints, thus suggesting that the pathogenesis of OA is more complicated than the mechanical stress induced by overweight. This review aims to explore the recent advances in research on the relationship between metabolic abnormalities and OA risk, including the impact of abnormal glucose and lipid metabolism, the potential pathogenesis and targeted therapeutic strategies.

Targeting the Inflammatory Hallmarks of Obesity-Associated Osteoarthritis: Towards Nutraceutical-Oriented Preventive and Complementary Therapeutic Strategies Based on n-3 Polyunsaturated Fatty Acids

Obesity (Ob), which has dramatically increased in the last decade, is one of the main risk factors that contribute to the incidence and progression of osteoarthritis (OA). Targeting the characteristics of obesity-associated osteoarthritis (ObOA) may offer new chances for precision medicine strategies in this patient cohort. First, this review outlines how the medical perspective of ObOA has shifted from a focus on biomechanics to the significant contribution of inflammation, mainly mediated by changes in the adipose tissue metabolism through the release of adipokines and the modification of fatty acid (FA) compositions in joint tissues. Preclinical and clinical studies on n-3 polyunsaturated FAs (PUFAs) are critically reviewed to outline the strengths and weaknesses of n-3 PUFAs' role in alleviating inflammatory, catabolic and painful processes. Emphasis is placed on potential preventive and therapeutic nutritional strategies based on n-3 PUFAs, with a focus on ObOA patients who could specifically benefit from reformulating the dietary composition of FAs towards a protective phenotype. Finally, tissue engineering approaches that involve the delivery of n-3 PUFAs directly into the joint are explored to address the perspectives and current limitations, such as safety and stability issues, for implementing preventive and therapeutic strategies based on dietary compounds in ObOA patients.

Adiponectin, May Be a Potential Protective Factor for Obesity-Related Osteoarthritis

Osteoarthritis (OA) is the most common joint disease in elderly individuals and seriously affects quality of life. OA has often been thought to be caused by body weight load, but studies have increasingly shown that OA is an inflammation-mediated metabolic disease. The current existing evidence suggests that OA is associated with obesity-related chronic inflammation as well as abnormal lipid metabolism in obesity, such as fatty acids (FA) and triglycerides. Adiponectin, a cytokine secreted by adipose tissue, can affect the progression of OA by regulating obesity-related inflammatory factors. However, the specific molecular mechanism has not been fully elucidated. According to previous research, adiponectin can promote the metabolism of FA and triglycerides, which indicates that it is a potential protective factor for OA through many mechanisms. This article aims to review the mechanisms of chronic inflammation, FA and triglycerides in OA, as well as the potential mechanisms of adiponectin in regulating chronic inflammation and promoting FA and triglyceride metabolism. Therefore, adiponectin may have a protective effect on obesity-related OA, which could provide new insight into adiponectin and the related mechanisms in OA.

Osteoarthritis complications and the recent therapeutic approaches

The accelerated prevalence of osteoarthritis (OA) disease worldwide and the lack of convenient management led to the frequent search for unprecedented and specific treatment approaches. OA patients usually suffer from many annoying complications that negatively influence their quality of life, especially in the elderly. Articular erosions may lead eventually to the loss of joint function as a whole which occurs over time according to the risk factors presented in each case and the grade of the disease. Conventional therapies are advancing, showing most appropriate results but still greatly associated with many adverse effects and have restricted curative actions as well. Hence, novel management tools are usually required. In this review, we summarized the recent approaches in OA treatment and the role of natural products, dietary supplements and nanogold application in OA treatment to provide new research tracks for more therapeutic opportunities to those who are in care in this field.

Fatty Acids and Oxylipins in Osteoarthritis and Rheumatoid Arthritis-a Complex Field with Significant Potential for Future Treatments

Purpose of Review

Osteoarthritis (OA) and rheumatoid arthritis (RA) are characterized by abnormal lipid metabolism manifested as altered fatty acid (FA) profiles of synovial fluid and tissues and in the way dietary FA supplements can influence the symptoms of especially RA. In addition to classic eicosanoids, the potential roles of polyunsaturated FA (PUFA)-derived specialized pro-resolving lipid mediators (SPM) have become the focus of intensive research. Here, we summarize the current state of knowledge of the roles of FA and oxylipins in the degradation or protection of synovial joints.

Recent Findings

There exists discordance between the large body of literature from cell culture and animal experiments on the adverse and beneficial effects of individual FA and the lack of effective treatments for joint destruction in OA and RA patients. Saturated 16:0 and 18:0 induce mostly deleterious effects, while long-chain n-3 PUFA, especially 20:5n-3, have positive influence on joint health. The situation can be more complex for n-6 PUFA, such as 18:2n-6, 20:4n-6, and its derivative prostaglandin E₂, with a combination of potentially adverse and beneficial effects. SPM analogs have future potential as analgesics for arthritic pain.

Summary

Alterations in FA profiles and their potential implications in SPM production may affect joint lubrication, synovial inflammation, pannus formation, as well as cartilage and bone degradation and contribute to the pathogeneses of inflammatory joint diseases. Further research directions include high-quality randomized controlled trials on dietary FA supplements and investigations on the significance of lipid composition of microvesicle membrane and cargo in joint diseases.

Fatty acids and osteoarthritis: different types, different effects

While the association between obesity and osteoarthritis used to be solely regarded as a result of increased mechanical loading, systemic factors also likely play a role in the pathophysiology of osteoarthritis. Nutrient excess leading to obesity may result in lipotoxicity, which might be involved in the development of osteoarthritis. The different fatty acid types have distinct effects on inflammation. This review focusses on the currently available studies, summarizing the effects of the different fatty acid types on osteoarthritis and involved joint tissues. In animal studies omega-3 polyunsaturated fatty acids reduced the expression of inflammatory markers, cartilage degradation and oxidative stress in chondrocytes. In contrast, these markers were increased upon omega-6 polyunsaturated fatty acid and saturated fatty acid stimulation. Additionally, a decrease in pain and dysfunction was observed upon omega-3 supplementation in cats and dogs. In line, most human in vitro studies show pro-apoptotic and pro-inflammatory actions of saturated fatty acids. While all polyunsaturated fatty acids reduced markers of oxidative stress, omega-3 polyunsaturated fatty acids additionally decreased prostaglandin production. Human intervention studies with omega-3 polyunsaturated fatty acid supplementation may indicate a beneficial effect on pain and function and might be associated with less structural damage. In contrast, an adverse effect of saturated fatty acids on osteoarthritis has been observed. Monounsaturated fatty acids have been infrequently studied and findings are inconclusive. Existing studies indicate a promising effect of especially omega-3 polyunsaturated fatty acids on osteoarthritis signs and symptoms. However, more human intervention studies are warranted to draw robust conclusions.

CLA Has a Useful Effect on Bone Markers in Patients with Rheumatoid Arthritis

Rheumatoid arthritis is a systemic, chronic disease which may increase the risk of osteoporosis. This study was carried out in order to examine the effect of conjugated linoleic acid (CLA) on bone markers in rheumatoid arthritis disease which is the most common autoimmune disease. The present study is a randomized double-blind clinical trial. Subjects included 52 patients with active rheumatoid arthritis who were divided into two groups. Group I received standard treatment plus 2 daily 1.25 g capsules (Containing about 2 g of 9-cis 11-trans isomer and 10-cis 12-trans isomer in ratio of 50 -50 CLA in glycerinated form), Group II received standard treatment plus 2 Placebo 1.25 g capsules containing sunflower oil with high oleic acid. Telopeptides C, osteocalcin, and MMP3 were analyzed by ELISA method, PGE₂ was done by competitive enzymatic immunoassay method, and IGF-1 was analyzed by the IRMA method based on the sandwich method and ALK-P of bone. Before and after the intervention, the questionnaires about general information, nutrition assessment and medical history were filled out by the subjects. Nutritional assessment was done by a 24-h record questionnaire for the three-day diet. The results were analyzed using SPSS software (version 18).

FINDINGS

There was no significant difference between the groups in enzyme activity of ALK-P of bone, PGE₂ and MMP3 variables. However, differences between the two groups in terms of activity of telopeptides C, Osteocalcin, and IGF1 were significant (P < 0.05). CLA has a potentially beneficial effect on bone markers in patients with rheumatoid arthritis. Therefore, in order to study the effect of CLA on bone health in patients with RA and all patients with autoimmune and bone diseases more studies with longer duration and evaluation of bone mass density are required.

Resveratrol and Omega-3 Fatty Acid: Its Implications in Cardiovascular Diseases

The present review aims at summarizing the major therapeutic roles of resveratrol and omega-3 fatty acids (O3FAs) along with their related pathways. This article reviews some of the key studies involving the health benefits of resveratrol and O3FAs. Oxidative stress has been considered as one of the most important pathophysiological factors associated with various cardiovascular disease conditions. Resveratrol, with the potent antioxidant and free radical scavenging properties, has been proven to be a significantly protective compound in restoring the normal cardiac health. A plethora of research also demonstrated the reduction of the risk of coronary heart disease, hypertension, and stroke, and their complications by O3FAs derived from fish and fish oils. This review describes the potential cardioprotective role of resveratrol and O3FAs in ameliorating the endoplasmic reticulum stress.

ω-3 PUFAs and Resveratrol Differently Modulate Acute and Chronic Inflammatory Processes

ω-3 PUFAs and polyphenols have multiple effects on inflammation in vivo and in vitro. The effects of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and resveratrol (RV) were investigated in LPS-stimulated peripheral blood leukocytes (PBLs) (i.e., acute inflammation) and IL-1β activated human chondrocytes (i.e., chronic inflammation). Inflammatory mediators including chemokines, cytokines, interleukins, and PGE₂ were measured by multiplex analysis and gene expression was quantified by RT-PCR. In PBLs, RV decreased the secretion of PGE₂, CCL5/RANTES, and CXCL8/IL-8 but increased IL-1β, IL-6, and IL-10. In contrast to RV, ω-3 PUFAs augmented the production of PGE₂ and CXCL8/IL-8. EPA and DHA similarly affected the pattern of inflammatory mediators. Combination of RV and ω-3 PUFAs exerted synergistic effects on CCL5/RANTES and had additive effects on IL-6 or CXCL8/IL-8. Both ω-3 PUFAs and RV reduced catabolic gene expression (e.g., MMPs, ADAMTS-4, IL-1β, and IL-6) in activated chondrocytes. The data suggest that ω-3 PUFAs and RV differ in the regulation of acute inflammation of peripheral blood leukocytes but have common properties in modulating features related to chronic inflammation of chondrocytes.

Developments in intervertebral disc disease research: pathophysiology, mechanobiology, and therapeutics

Low back pain is a leading cause of disability worldwide and the second most common cause of physician visits. There are many causes of back pain, and among them, disc herniation and intervertebral disc degeneration are the most common diagnoses and targets for intervention. Currently, clinical treatment outcomes are not strongly correlated with diagnoses, emphasizing the importance for characterizing more completely the mechanisms of degeneration and their relationships with symptoms. This review covers recent studies elucidating cellular and molecular changes associated with disc mechanobiology, as it relates to degeneration and regeneration. Specifically, we review findings on the biochemical changes in disc diseases, including cytokines, chemokines, and proteases; advancements in disc disease diagnostics using imaging modalities; updates on studies examining the response of the intervertebral disc to injury; and recent developments in repair strategies, including cell-based repair, biomaterials, and tissue engineering. Findings on the effects of the omega-6 fatty acid, linoleic acid, on nucleus pulposus tissue engineering are presented. Studies described in this review provide greater insights into the pathogenesis of disc degeneration and may define new paradigms for early or differential diagnostics of degeneration using new techniques such as systemic biomarkers. In addition, research on the mechanobiology of disease enriches the development of therapeutics for disc repair, with potential to diminish pain and disability associated with disc degeneration.

Synergism of α-linolenic acid, conjugated linoleic acid and calcium in decreasing adipocyte and increasing osteoblast cell growth

Whole fat milk and dairy products (although providing more energy compared to low- or non-fat products), are good sources of α-linolenic acid (ALA), conjugated linoleic acid (CLA) and calcium, which may be favorable in modulating bone and adipose tissue metabolism. We examined individual and/or synergistic effects of ALA, CLA and calcium (at levels similar to those in whole milk/dairy products) in regulating bone and adipose cell growth. ST2 stromal, MC3T3-L1 adipocyte-like and MC3T3-E1 osteoblast-like cells were treated with: (a) linoleic acid (LNA):ALA ratios = 1-5:1; (b) individual/combined 80-90 % c9, t11 (9,11) and 5-10 % t10, c12 (10,12) CLA isomers; (c) 0.5-3.0 mM calcium; (d) combinations of (a), (b), (c); and (e) control. Local mediators, including eicosanoids and growth factors, were measured. (a) The optimal effect was found at the 4:1 LNA:ALA ratio where insulin-like growth factor-1 (IGF-1) and IGF binding protein-3 (IGFBP-3) production was the lowest in MC3T3-L1 cells. (b) All CLA isomer blends decreased MC3T3-L1 and increased MC3T3-E1 cell differentiation. (c) 1.5-2.5 mM calcium increased ST2 and MC3T3-E1, and decreased MC3T3-L1 cell proliferation. (d) Combination of 4:1 LNA:ALA + 90:10 % CLA + 2.0 mM calcium lowered MC3T3-L1 and increased MC3T3-E1 cell differentiation. Overall, the optimal LNA:ALA ratio to enhance osteoblastogenesis and inhibit adipogenesis was 4:1. This effect was enhanced by 90:10 % CLA + 2.0 mM calcium, indicating possible synergism of these dietary factors in promoting osteoblast and inhibiting adipocyte differentiation in cell cultures.

Osteoarthritis: another component of metabolic syndrome?

Osteoarthritis (OA) has become a major public health problem not only because of its increasing prevalence worldwide but also because of its frequent association with cardiovascular disease, the leading cause of death in industrialized countries. There is growing evidence that OA is not simply a disease related to aging or mechanical stress of joints but rather a "metabolic disorder" in which various interrelated lipid, metabolic, and humoral mediators contribute to the initiation and progression of the disease process. Indeed, OA has been linked not only to obesity but also to other cardiovascular risk factors, namely, diabetes, dyslipidemia, hypertension, and insulin resistance.

Interleukin-6 and Cyclooxygenase-2 downregulation by fatty-acid fractions of Ranunculus constantinopolitanus

Background

Medicinal plants represent alternative means for the treatment of several chronic diseases, including inflammation. The genus Ranunculus, a representative of the Ranunculaceae family, has been reported to possess anti-inflammatory, analgesic, antiviral, antibacterial, antiparasitic and antifungal activities, possibly due to the presence of anemonin and other. Different studies have shown the occurrence of unusual fatty acids (FAs) in Ranunculaceae; however, their therapeutic role has not been investigated. The purpose of this study is to characterize potential anti-inflammatory bioactivities in Ranunculus constantinopolitanus D'Urv., traditionally used in Eastern Mediterranean folk medicine.

Methods

The aerial part of R. constantinopolitanus was subjected to methanol (MeOH) extraction and solvent fractionation. The bioactive fraction (I.2) was further fractionated using column chromatography, and the biologically active subfraction (Y₂₊₃) was identified using infrared (IR) spectroscopy, nuclear magnetic resonance (NMR) and gas chromatography-mass spectrometry (GC-MS). The effects of I.2 and Y₂₊₃ on cell viability were studied in mouse mammary epithelial SCp2 cells using trypan blue exclusion method. To study the anti-inflammatory activities of I.2 and Y₂₊₃, their ability to reduce interleukin (IL)-6 levels was assessed in endotoxin (ET)-stimulated SCp2 cells using enzyme-linked immunosorbent assay (ELISA). In addition, the ability of Y₂₊₃ to reduce cyclooxygenase (COX)-2 expression was studied in IL-1-treated mouse intestinal epithelial Mode-K cells via western blotting. Data were analyzed by one-way analysis of variance (ANOVA), Student-Newman-Keuls (SNK), Tukey HSD, two-sample t-test and Dunnett t-tests for multiple comparisons.

Results

The chloroform fraction (I.2) derived from crude MeOH extract of the plant, in addition to Y₂₊₃, a FA mix isolated from this fraction and containing palmitic acid, C18:2 and C18:1 isomers and stearic acid (1:5:8:1 ratio), reduced ET-induced IL-6 levels in SCp2 cells without affecting cell viability or morphology. When compared to fish oil, conjugated linoleic acid (CLA) and to individual FAs as palmitic, linoleic, oleic and stearic acid or to a mix of these FAs (1:5:8:1 ratio), Y₂₊₃ exhibited higher potency in reducing ET-induced IL-6 levels within a shorter period of time. Y₂₊₃ also reduced COX-2 expression in IL-1-treated Mode-K cells.

Conclusion

Our studies demonstrate the existence of potential anti-inflammatory bioactivities in R. constantinopolitanus and attribute them to a FA mix in this plant.

Conjugated linoleic acid modulation of risk factors associated with atherosclerosis

Conjugated linoleic acid (CLA) has been the subject of extensive investigation regarding its possible benefits on a variety of human diseases. In some animal studies, CLA has been shown to have a beneficial effect on sclerotic lesions associated with atherosclerosis, be a possible anti-carcinogen, increase feed efficiency, and act as a lean body mass supplement. However, the results have been inconsistent, and the effects of CLA on atherogenesis appear to be dose-, isomer-, tissue-, and species-specific. Similarly, CLA trials in humans have resulted in conflicting findings. Both the human and animal study results may be attributed to contrasting doses of CLA, isomers, the coexistence of other dietary fatty acids, length of study, and inter-and/or intra-species diversities. Recent research advances have suggested the importance of CLA isomers in modulating gene expression involved in oxidative damage, fatty acid metabolism, immune/inflammatory responses, and ultimately atherosclerosis. Although the possible mechanisms of action of CLA have been suggested, they have yet to be determined.

Conjugated linoleic acid modulation of risk factors associated with atherosclerosis

Conjugated linoleic acid (CLA) has been the subject of extensive investigation regarding its possible benefits on a variety of human diseases. In some animal studies, CLA has been shown to have a beneficial effect on sclerotic lesions associated with atherosclerosis, be a possible anti-carcinogen, increase feed efficiency, and act as a lean body mass supplement. However, the results have been inconsistent, and the effects of CLA on atherogenesis appear to be dose-, isomer-, tissue-, and species-specific. Similarly, CLA trials in humans have resulted in conflicting findings. Both the human and animal study results may be attributed to contrasting doses of CLA, isomers, the coexistence of other dietary fatty acids, length of study, and inter-and/or intra-species diversities. Recent research advances have suggested the importance of CLA isomers in modulating gene expression involved in oxidative damage, fatty acid metabolism, immune/inflammatory responses, and ultimately atherosclerosis. Although the possible mechanisms of action of CLA have been suggested, they have yet to be determined.

Impact of PUFA on early immune and fetal development

It has recently been reported that the increased prevalence in childhood allergy may be linked to deviations in fetal immune development. One reason may be impaired nutrient supply. Hence, a well-differentiated placenta together with an optimal fetal nutrition via the mother are important prerequisites for the establishment of a functional immune system with normal immune responses. Fatty acids and their derivatives can influence both the early immune development and immune maturation by regulating numerous metabolic processes and the gene expression of important proteins such as enzymes and cytokines. The present review summarises the impact of nutritional fatty acids on the development of the immune system as well as the fetal development. It describes the mechanisms of action of PUFA, trans fatty acids and conjugated linoleic acids in programming the fetus with regard to its risk of acquiring atopic diseases in childhood.

Using nutrition for intervention and prevention against environmental chemical toxicity and associated diseases

BACKGROUND

Nutrition and lifestyle are well-defined modulators of chronic diseases. Poor dietary habits (such as high intake of processed foods rich in fat and low intake of fruits and vegetables), as well as a sedentary lifestyle clearly contribute to today's compromised quality of life in the United States. It is becoming increasingly clear that nutrition can modulate the toxicity of environmental pollutants.

OBJECTIVES

Our goal in this commentary is to discuss the recommendation that nutrition should be considered a necessary variable in the study of human disease associated with exposure to environmental pollutants.

DISCUSSION

Certain diets can contribute to compromised health by being a source of exposure to environmental toxic pollutants. Many of these pollutants are fat soluble, and thus fatty foods often contain higher levels of persistent organics than does vegetable matter. Nutrition can dictate the lipid milieu, oxidative stress, and antioxidant status within cells. The modulation of these parameters by an individual's nutritional status may have profound affects on biological processes, and in turn influence the effects of environmental pollutants to cause disease or dysfunction. For example, potential adverse health effects associated with exposure to polychlorinated biphenyls may increase as a result of ingestion of certain dietary fats, whereas ingestion of fruits and vegetables, rich in antioxidant and anti-inflammatory nutrients or bioactive compounds, may provide protection.

CONCLUSIONS

We recommend that future directions in environmental health research explore this nutritional paradigm that incorporates a consideration of the relationships between nutrition and lifestyle, exposure to environmental toxicants, and disease. Nutritional interventions may provide the most sensible means to develop primary prevention strategies of diseases associated with many environmental toxic insults.

Protective effect of dietary long-chain n-3 polyunsaturated fatty acids on bone loss in gonad-intact middle-aged male rats

This study evaluated the effect of a fat blend containing long-chain (LC) n-3 PUFA on bone mineral density (BMD) and bone metabolism in gonad-intact middle-aged male rats (12 months old, n 28). Seven rats were killed on day 0 of dietary intervention to determine the baseline BMD. The remaining rats (seven per group) were fed a diet with one of the following dietary lipid treatments (g/kg diet): 167 g safflower oil + 33 g menhaden oil (N6 + N3 diet, control), 200 g safflower oil (N6 diet, almost devoid of LC n-3 PUFA), or 190 g menhaden oil + 10 g corn oil (N3 diet, rich in LC n-3 PUFA) for 20 weeks. After 20 weeks, all dietary treatment groups had a lower BMD compared with the baseline reference. However, rats fed the N3 diet had the highest bone mineral content and cortical + subcortical BMD compared with those fed the N6 and control N6 + N3 diet. Compared with the control (N6 + N3) group, rats fed the N3 diet had higher values for serum insulin-like growth factor-I, parathyroid hormone, 1,25-(OH)2 vitamin D3 and bone-specific alkaline phosphatase activity, but lower bone NO production and urinary Ca, whereas rats fed the N6 diet had higher bone prostaglandin E2 production and serum pyridinoline. These findings indicate a protective action of LC n-3 PUFA on ageing-induced bone loss in gonad-intact middle-aged male rats through a modulation of local factors and systemic calcitrophic hormones.

Biological effects of conjugated linoleic acids in health and disease

Conjugated linoleic acid (CLA) is a mixture of positional and geometric isomers of octadecadienoic acid [linoleic acid (LA), 18:2n-6] commonly found in beef, lamb and dairy products. The most abundant isomer of CLA in nature is the cis-9, trans-11 (c9t11) isomer. Commercially available CLA is usually a 1:1 mixture of c9t11 and trans-10, cis-12 (t10c12) isomers with other isomers as minor components. Conjugated LA isomer mixture and c9t11 and t10c12 isomers alone have been attributed to provide several health benefits that are largely based on animal and in vitro studies. Conjugated LA has been attributed many beneficial effects in prevention of atherosclerosis, different types of cancer, hypertension and also known to improve immune function. More recent literature with availability of purified c9t11 and t10c12 isomers suggests that t10c12 is the sole isomer involved in antiadipogenic role of CLA. Other studies in animals and cell lines suggest that the two isomers may act similarly or antagonistically to alter cellular function and metabolism, and may also act through different signaling pathways. The effect of CLA and individual isomers shows considerable variation between different strains (BALB/C mice vs. C57BL/6 mice) and species (e.g., rats vs. mice). The dramatic effects seen in animal studies have not been reflected in some clinical studies. This review comprehensively discusses the recent studies on the effects of CLA and individual isomers on body composition, cardiovascular disease, bone health, insulin resistance, mediators of inflammatory response and different types of cancer, obtained from both in vitro and animal studies. This review also discusses the latest available information from clinical studies in these areas of research.

Comparative effects of ginger root (Zingiber officinale Rosc.) on the production of inflammatory mediators in normal and osteoarthrotic sow chondrocytes

Ginger root was previously demonstrated to exert anti-arthritic effects in sow cartilage explants. This study further investigated the comparative effects of ginger root extract (GRE) on the production of inflammatory mediators, including nitric oxide (NO) and prostaglandin E2 (PGE2), in normal chondrocytes (NC) and osteoarthrotic chondrocytes (OC) isolated from sow cartilage explants. The sow chondrocyte cells were isolated and grown in Ham's F-12/Dulbecco's modified Eagle's medium supplemented with 10% fetal bovine serum and 1% antibiotics. GRE was then added at different concentrations (0-2,000 microg/mL), and the cells were allowed to grow for 24 hours in the presence of cytokine inducer. The culture media were collected and assayed for NO by the Griess reaction and for PGE2 by radioimmunoassay. When GRE was not used, the NC had lower PGE2 and NO than the OC. With GRE treatment, both PGE2 and NO decreased linearly in both the NC and the OC. As GRE concentrations increased, the rate of PGE(2) decrease was the same in the NC and the OC, whereas the rate of NO decrease was greater for the OC than for the NC. Collectively, OC produce more inflammatory mediators than do NC, and the production of inflammatory mediators was reduced when GRE was added to both the OC and the NC. The inhibitory effects of GRE on NO and PGE2 production by sow OC observed in this study suggest an important role for GRE as an anti-arthritic agent.