Effects of single or combined administration of salmon calcitonin and omega-3 fatty acids vs. diclofenac sodium in sodium monoiodoacetate-induced knee osteoarthritis in male Wistar rats

A synoptic literature review of animal models for investigating the biomechanics of knee osteoarthritis

Osteoarthritis (OA) is a common chronic disease largely driven by mechanical factors, causing significant health and economic burdens worldwide. Early detection is challenging, making animal models a key tool for studying its onset and mechanically-relevant pathogenesis. This review evaluate current use of preclinical in vivo models and progressive measurement techniques for analysing biomechanical factors in the specific context of the clinical OA phenotypes. It categorizes preclinical in vivo models into naturally occurring, genetically modified, chemically-induced, surgically-induced, and non-invasive types, linking each to clinical phenotypes like chronic pain, inflammation, and mechanical overload. Specifically, we discriminate between mechanical and biological factors, give a new explanation of the mechanical overload OA phenotype and propose that it should be further subcategorized into two subtypes, post-traumatic and chronic overloading OA. This review then summarises the representative models and tools in biomechanical studies of OA. We highlight and identify how to develop a mechanical model without inflammatory sequelae and how to induce OA without significant experimental trauma and so enable the detection of changes indicative of early-stage OA in the absence of such sequelae. We propose that the most popular post-traumatic OA biomechanical models are not representative of all types of mechanical overloading OA and, in particular, identify a deficiency of current rodent models to represent the chronic overloading OA phenotype without requiring intraarticular surgery. We therefore pinpoint well standardized and reproducible chronic overloading models that are being developed to enable the study of early OA changes in non-trauma related, slowly-progressive OA. In particular, non-invasive models (repetitive small compression loading model and exercise model) and an extra-articular surgical model (osteotomy) are attractive ways to present the chronic natural course of primary OA. Use of these models and quantitative mechanical behaviour tools such as gait analysis and non-invasive imaging techniques show great promise in understanding the mechanical aspects of the onset and progression of OA in the context of chronic knee joint overloading. Further development of these models and the advanced characterisation tools will enable better replication of the human chronic overloading OA phenotype and thus facilitate mechanically-driven clinical questions to be answered.

Food-derived bioactive peptides potentiating therapeutic intervention in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease that affects the joints of the human body and is projected to have a prevalence age-standardized rate of 1.5 million new cases worldwide by 2030. Several conventional and non-conventional preventive and therapeutic interventions have been suggested but they have their side effects including nausea, abdominal pain, liver damage, ulcers, heightened blood pressure, coagulation, and bleeding. Interestingly, several food-derived peptides (FDPs) from both plant and animal sources are increasingly gaining a reputation for their potential in the management or therapy of RA with little or no side effects. In this review, the concept of inflammation, its major types (acute and chronic), and RA identified as a chronic type were discussed based on its pathogenesis and pathophysiology. The conventional treatment options for RA were briefly outlined as the backdrop of introducing the FDPs that potentiate therapeutic effects in the management of RA.

Effects of Different Nonsteroidal Anti-Inflammatory Drugs Combined with Platelet-Rich Plasma on Inflammatory Factor Levels in Patients with Osteoarthritis

Objective. To investigate the effects of different nonsteroidal anti-inflammatory drugs combined with platelet-rich plasma on inflammatory factor levels in patients with osteoarthritis. Methods. The clinic data of 120 patients with osteoarthritis who were treated in our hospital (June 2019-June 2021) were retrospectively reviewed. All the patients were given platelet-rich plasma. According to the different nonsteroidal anti-inflammatory drugs the patients received, they were equalized into diclofenac sodium group, celecoxib group, and iguratimod group, with 40 cases in each group. After treatment, the patients’ clinical efficacy was compared and analyzed. Results. After treatment, the pain degrees of the patients in the three groups were gradually reduced. After 4 weeks and 8 weeks of treatment, the statistical differences in the scores of Visual Analogue Scale (VAS) were found among the three groups. Specifically, compared with the other two groups, the iguratimod group had remarkably lower VAS scores ( $P<0.05$ ) and the celecoxib group had signally lower VAS scores compared with the diclofenac sodium group ( $P<0.05$ ). After treatment, the inflammatory factor levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and high-sensitivity C-reactive protein (hs-CRP) in the diclofenac sodium group were observably higher compared with the celecoxib group ( $P<0.05$ ), and the inflammatory factor levels in the celecoxib group were remarkably higher compared with the iguratimod group ( $P<0.05$ ). Before treatment, no notable difference in the Lysholm scores was found among the three groups, and the patients’ knee joint function was gradually improved after treatment. To be specific, after 4 and 8 weeks of treatment, the iguratimod group had observably higher Lysholm scores compared with the other two groups ( $P<0.05$ ), and the celecoxib group had signally higher Lysholm scores compared with the diclofenac sodium group ( $P<0.05$ ). The iguratimod group got markedly lower Western Ontario and McMaster Universities (WOMAC) score compared with the celecoxib group ( $P<0.05$ ); Compared with the diclofenac sodium group, the celecoxib group got remarkably lower WOMAC score ( $P<0.05$ ). During treatment, few patients suffered from mild gastrointestinal discomfort and hepatic dysfunction in the three groups, and no other severe adverse reactions were found. No statistical difference in the total incidence of adverse reactions among the three groups was observed ( $P>0.05$ ). Conclusion. The combination of nonsteroidal anti-inflammatory drugs with platelet-rich plasma can further reduce the inflammatory reactions of the patients with osteoarthritis and improve their knee joint function. Significantly, the iguratimod, with high safety, has observably better effects on inhibiting inflammatory factors and improving knee joint function compared with diclofenac sodium and celecoxib.

Knee osteoarthritis in young growing rats is associated with widespread osteopenia and impaired bone mineralization

Osteoarthritis (OA) leads to joint pain from intraarticular inflammation with articular cartilage erosion, deterioration of joint function and abnormal subchondral bone structure. Besides aging, chronic repetitive joint injury is a common risk factor in young individuals. Nevertheless, whether OA is associated with bone loss at other skeletal sites is unclear. Since OA-associated proinflammatory cytokines-some of which are osteoclastogenic factors-are often detected in the circulation, we hypothesized that the injury-induced knee OA could result in widespread osteopenia at bone sites distant to the injured knee. Here we performed anterior cruciate ligament transection (ACLT) to induce knee OA in one limb of female Sprague-Dawley rats and determined bone changes post-OA induction by micro-computed tomography and computer-assisted bone histomorphometry. We found that although OA modestly altered bone density, histomorphometric analyses revealed increases in bone resorption and osteoid production with impaired mineralization. The bone formation rate was also reduced in OA rats. In conclusions, ACLT in young growing rats induced microstructural defects in the trabecular portion of weight-bearing (tibia) and non-weight-bearing bones (L5 vertebra), in part by enhancing bone resorption and suppressing bone formation. This finding supports the increasing concern regarding the repetitive sport-related ACL injuries and the consequent bone loss.

Effect of antioxidants, mitochondrial cofactors and omega-3 fatty acids on telomere length and kinematic joint mobility in young and old shepherd dogs - A randomized, blinded and placebo-controlled study

In dogs, decreasing telomere length is a biomarker for cellular aging. On a systemic level, aging affects the locomotor system in particular, leading to restricted joint mobility. As aging is thought to be related to oxidative stress, it may be counteracted by a diet enriched with antioxidants, mitochondrial cofactors and omega-3 fatty acids. This randomized, blinded and placebo-controlled study examined the influence of an accordingly enriched diet compared to a control diet on 36 young and 38 old shepherd dogs. At the outset, after 3 and after 6 months, mean and minimum telomere lengths were measured. Furthermore, minimum and maximum joint angles and range of motion of the shoulder, elbow, carpal, hip, stifle and tarsal joints were measured by computer-assisted gait analysis. A positive influence of the enriched diet on old dogs could be verified for minimum telomere length and all three parameters of the shoulder joint on the side with the higher vertical ground reaction force after 6 months. In the other joints there were less significant differences; in some cases they indicated a contrary influence of the enriched diet on young dogs, probably due to its reduced protein content. The greater effect of the enriched diet on minimum than on mean telomere length may be due to the higher preference of telomerase for short telomeres. The greater effect on shoulder joint mobility is explained by the greater influence of musculature and connective tissue in this joint. For elderly dogs it is advisable to feed these nutritional supplements.

Co-administration of omega-3 fatty acids and metformin showed more desirable effects than the single therapy on indices of bone mineralisation but not gluco-regulatory and antioxidant markers in diabetic rats

Although metformin (Met) is the most recommended anti-diabetogenic drug in type 2 diabetic state, the drug is known to compromise bone integrity. Like metformin, omega-3 fatty acids (ω-3) have gluco-regulatory action; however, it aids bone health. Therefore, the present study investigated the effects of ω-3 and/or metformin in diabetic rats. Fifty rats of ten animals per group were divided into the following: Control; Diabetic untreated; Diabetic + ω-3; Diabetic + metformin (metfm) and Diabetic + ω-3 + metf groups. Diabetes was induced by the administration of streptozotocin (65 mg/kg b.w., i.p.), 15 min after the administration of nicotinamide (110 mg/kg b.w., i.p.). Five days afterwards, treatments started and they lasted for 28 days. ω-3 and metformin were administered at 200 and 180 mg/kg b.w., p.o. respectively. The results showed that the induced diabetes was characterised by significant increases in calcium to phosphorus ratio, tartrate resistant acid phosphatase (TRAP), glucose and insulin resistance; but significant decreases in parathyroid hormone(PTH), phosphorus, TAC and hepatic glycogen. Relative to the diabetic control, treatments with ω-3 or metformin caused significant elevations in hepatic glycogen, total alkaline phosphatase (TALP), osteocalcin, PTH, estradiol, and calcium; however, significant decreases in TRAP and glucose. Co-administration of ω-3 and metformin caused more desirable effects on TALP, c-terminal telopeptide of type 1 collagen, estradiol and calcium to phosphorus ratio compared to the single administration. Relative to ω-3, melatonin showed a more favourable effect on calcium to phosphorus ratio; however, the former proved to have more desirable actions on insulin and TAC. Hence, it was concluded that the combined but not the single administration of ω-3 and metformin could be preferably used in the management of bone health in diabetic state.

The GLP-1 agonist, liraglutide, ameliorates inflammation through the activation of the PKA/CREB pathway in a rat model of knee osteoarthritis

Background

Inflammation is a common pathological phenomenon of osteoarthritis (OA). Accumulated evidence indicates that ameliorating or suppressing inflammation might be a promising and effective therapeutic strategy for the treatment of OA. Notably, glucagon-like peptide-1 (GLP-1)-based drugs are being successfully used to control glucose levels in patients with diabetes mellitus. In addition, recent findings have indicated that GLP-1 agonists, such as liraglutide have therapeutic potential in preventing inflammation-related disorders through the regulation of protein kinase A (PKA)/ cyclic adenosine monophosphate (cAMP) response element-binding protein (CREB) signals. Intra-articular injection of monoiodoacetate (MIA) has been widely used to induce OA. Thus, the present study aimed to investigate whether liraglutide has anti-inflammatory effects on MIA-induced OA rats and uncover its underlying molecular mechanisms.

Methods

Intra-articular injection of MIA was used to induce knee OA in a rat model. Subcutaneous injection of liraglutide was used to upregulate the expression of GLP-1 receptor (GLP-1R). Western blot analysis was utilized to measure the expression of GLP-1R, PKA/CREB pathway components and inflammation-related proteins, such as tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), and IL-6. Immunoprecipitation techniques were used to detect the interactions between GLP-1R and the PKA/CREB pathway.

Results

The levels of GLP-1R decreased significantly in the knees of OA rats, accompanied by the downregulation of PKA /CREB signals and upregulation of inflammation-related proteins. We also found that GLP-1R interacted with the PKA/CREB pathway and that liraglutide could activate PKA/CREB signals, thereby inhibiting the expression of inflammation-related proteins.

Conclusions

Together our results suggest that liraglutide exhibits anti-inflammatory activity through the activation of the PKA/CREB pathway in an OA rat model.

The Oxidative Stress in Knee Osteoarthritis Patients. An Attempt of Evaluation of Possible Compensatory Effects Occurring in the Disease Development

Background and Objective: Osteoarthritis (OA) is a disorder of the musculoskeletal system resulting in worsening of life condition. The research revealed the involvement of oxidative stress into both OA pathogenesis and the effects of therapeutic agents applied in OA cases. The activities of the most important antioxidant enzymes, namely superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and total antioxidant status (TAS), in blood of the knee OA patients were studied, with the aim of clarifying which enzymatic antioxidants are involved into osteoarthritis (OA)-related oxidative stress and whether any compensatory effects occur. The results were additionally analyzed with regard to gender. Methods: Whole blood SOD (U/mL), plasma GPx (U/L) and CAT (U/mL) activities as well as plasma TAS (mmol/L)) in knee OA patients were investigated. Sixty-seven patients (49 females and 18 males) with primary knee OA were enrolled. The control comprised 21 subjects (10 females and 11 males) free of osteoarthritis or inflammation. Results: TAS was decreased in OA subjects (4.39 ± 0.53 vs. 4.70 ± 0.60), with this effect being more significant in OA females (4.31 ± 0.51 vs. 5.02 ± 0.54). GPx was depressed in all OA patients (518 ± 176 vs. 675 ± 149). In both genders, GPx was decreased, significantly in males (482 ± 185 vs. 715 ± 105). SOD was decreased in all OA patients (109 ± 32 vs. 127 ± 42). CAT showed no difference in all OA subjects vs. control, while in OA females it was depleted (20.2 (11.6–31.6) vs. 38.5 (27.9–46.6)) and in OA men it increased (26.9 (23.3–46.5) vs. 14.0 (7.0–18.6)). Conclusions: The obtained results suggest that in men some compensatory mechanisms towards OA-related oxidative stress occurred. Based on the obtained data, the introduction of antioxidant supplements into OA therapy could be suggested with further research concerning the choice of agents.

Diabetes escalates knee osteoarthritis in rats: Evidence of adaptive mechanism

Clinical reports on the coexistence of diabetes mellitus (DM) and osteoarthritis (OA) dated back to the 1960 s. Therefore, the study investigated the effects of induced DM and/or knee osteoarthritis (KOA) on known biomarkers in male Wistar rats. Twenty rats of five animals per group were induced with DM and/or knee OA using streptozotocin plus nicotinamide and sodium monoiodoacetate. Afterwards, they were left untreated for four weeks.The results showed that pro-inflammatory and pro-oxidative events were most significantly expressed in D + OA group and least in OA group. In contrast to the other experimental groups, there was a decreased bone formation in DM group.Unexpectedly, there were significant increases in bone and cartilage degradation markers in diabetic group, relative to D + OA group. In conclusion, diabetic-osteoarthritic state is characterised by more altered biochemical profile, relative to what is probable in either disease condition. Nevertheless, this situation remains subject to the influence of endogenous homeostatic mechanisms.

Synergistic and non-synergistic effects of salmon calcitonin and omega - 3 fatty acids on antioxidant, anti-inflammatory, and haematological indices in diabetic rats

The optimum therapy for the management of diabetes mellitus (DM) has been a controversial issue. Therefore, the study investigated the effects of salmon calcitonin (Sct) and/or omega-3 fatty acids {eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA); EPA/DHA ratio?=?3/2} relative to metformin in diabetic male Wistar rats. Forty rats were used for this study. They were randomly divided into 8 groups of five (5) rats each, which were treated with single or combined administration of salmon calcitonin, N-3 and metformin. DM was induced by the administration of streptozotocin (65?mg/kg b.w., i.p.), 15?min after the administration of nicotinamide (110?mg/kg b.w., i.p.). Nine days afterwards, treatments started, and they lasted for 28 days. Sct was administered at 2.5 and 5.0 IU/kg b.w./day (i.m.), while, N-3 and metformin were administered at 200 and 180?mg/kg b.w./day (p.o.) respectively. The results showed that the induced DM significantly increased pro-inflammatory markers, and significantly altered antioxidant and haematological indices. The combined administration of Sct and N-3 had synergistic effects on total bilirubin and total antioxidant capacity, but, non-synergistic actions on malondialdehyde, uric acid, interleukin-6, lactate dehydrogenase, superoxide dismutase, catalase, glutathione peroxidase, and the haematological parameters. These effects were comparable to that of metformin which showed a more or less therapeutic action than N-3. The study concluded that the antioxidant, anti-inflammatory, and haematological effects of the combined administration of Sct and N-3 is comparable to that of metformin. Nevertheless, the latter showed more or less therapeutic effects relative to N-3.

Calcitonin and Omega-3 Fatty Acids Exhibit Antagonistic and Non-Additive Effects in Experimental Diabetes

Because optimising therapy for the management of diabetes mellitus remains challenging, the study investigated the effects of salmon calcitonin (Sct) and/or omega-3 fatty acids (N-3 - eicosapentaenoic acid and docosahexaenoic acid-3:2), compared to metformin, on selected biochemical parameters in male Wistar rats, in an experimental model of diabetes. Forty rats were used for this study. They were divided into eight groups of five rats each, which included: Normal control; Diabetic (D) control; D + N-3; D + low dose Sct (Sct. Lw); D + high dose Sct (Sct. Hi); D + N-3 + Sct.Lw; D + N-3 + Sct.Hi; and D + metformin. Diabetes was induced in overnight fasted rats by the administration of streptozotocin (65 mg/kg b.w., i.p.), 15 min after the administration of nicotinamide (110 mg/kg b.w., i.p.). Nine days later, Sct was administered at 2.5 and 5.0 IU/kg b.w./day (i.m.), while N-3 and metformin were administered at 200 and 180 mg/kg b.w./day (p.o.) respectively, for four weeks. Sct, N-3, and metformin significantly reduced total cholesterol, LDL-C, cortisol, c-telopeptide of type 1 collagen, and collagen type 2 alpha-1. The combined administration of Sct and N-3 had more favorable effects on triglyceride and HDL-C than either monotherapy. Unlike metformin and Sct. Hi, N-3 significantly reduced alkaline phosphatase activity. Moreover, N-3 significantly suppressed the hypocalcaemic, hyperglycaemic, and insulin resistance provoking actions of Sct. Furthermore, N-3 contradicted the hepatic glycogen depletion and inhibition of nitric oxide synthesis brought about by Sct. In conclusion, N-3 demonstrated antagonistic and non-additive actions with Sct. Moreover, the effects of the combined administration of Sct and N-3 were comparable to that of metformin; therefore, they might be considered as therapeutic alternatives in diabetes.

Diclofenac - induced hepatotoxicity: Low dose of omega-3 fatty acids have more protective effects

•

Diclofenac sodium instigates pro-oxidative and pro-inflammatory responses.

•

Dietary supplementation with omega-3 fatty acids (N-3) boost the antioxidant system.

•

Low dose of N-3 has more hepatoprotective effects than the high.

The global embrace of the Western dietary style has necessitated the need for supplementation with omega-3 fatty acids (N-3) to redress the imbalance in omega-6/omega-3 fatty acids ratio. Therefore, the study investigated the effects of pre-treatment with N-3 in adult male Wistar rats exposed to diclofenac sodium (DF). Twenty adult male Wistar rats were used for this study. They were divided into 4 groups of 5 rats each, which included: Group 1 - Normal control; Group 2 - DF control; Group 3 - Low N-3 + DF; and, Group 4 - High N-3 + DF. The rats in group 2 were administered DF (10 mg/kg b.w./day, im) during the last 7 days of the experiment, while the rats in groups 3 and 4 were pre-treated with N-3 at 100 and 300 mg/kg b.w./day, po respectively for 21 days, afterwards, they received DF at 10 mg/kg b.w./day (im) for 7 days. The result showed that DF significantly increased malondialdehyde, lactate dehydrogenase, and pro-inflammatory markers (total white blood cell count, uric acid, platelet/lymphocyte and neutrophil/lymphocyte ratios). Moreover, DF significantly elevated the activities of alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase, but, significant reduced the total antioxidant capacity and the activities of superoxide dismutase, catalase, and glutathione peroxidase. The histological results were parallel to the biochemical and haematological findings. Pre-treatment with N-3 significantly prevented the manifestation of the abnormalities brought about by DF. Although there were indications of the dose-dependent effects of N-3, the low dose was found to be more effective. In conclusion, the pre-administration of N-3, preferably at a low dose, could reduce hepatotoxicity that could result from subsequent exposure to DF.