Anti-inflammatory effects in a mouse osteoarthritis model of a mixture of glucosamine and chitooligosaccharides produced by bi-enzyme single-step hydrolysis

Application of Drug Repurposing Approach for Therapeutic Intervention of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD), represented by Crohn's disease (CD) and ulcerative colitis (UC), is a chronic inflammatory disorder of the gastrointestinal tract (GIT) characterized by chronic relapsing intestinal inflammation, abdominal pain, cramping, loss of appetite, fatigue, diarrhoea, and weight loss. Although the etiology of IBD remains unclear, it is believed to be an interaction between genes, and environmental factors, such as an imbalance of the intestinal microbiota, changing food habits, an ultra-hygiene environment, and an inappropriate immune system. The development of novel effective therapies is stymied by a lack of understanding of the aetiology of IBD. The current therapy involves the use of aminosalicylates, immunosuppressants, and corticosteroids that can effectively manage symptoms, induce and sustain remission, prevent complications, modify the course of the disease, provide diverse treatment options, showcase advancements in biologic therapies, and enhance the overall quality of life. However, the efficacy of current therapy is overshadowed by a plethora of adverse effects, such as loss of weight, mood swings, skin issues, loss of bone density, higher vulnerability to infections, and elevated blood pressure. Biologicals, like anti-tumour necrosis factor agents, can stimulate an autoimmune response in certain individuals that may diminish the effectiveness of the medication over time, necessitating a switch to alternative treatments. The response of IBD patients to current drug therapy is quite varied, which can lead to disease flares that underlines the urgent need to explore alternative treatment option to address the unmet need of developing new treatment strategies for IBD with high efficacy and fewer adverse effects. Drug repurposing is a novel strategy where existing drugs that have already been validated safe in patients for the management of certain diseases are redeployed to treat other, unindicated diseases. The present narrative review focuses on potential drug candidates that could be repurposed for the management of IBD using on-target and off-target strategies. It covers their preclinical, clinical assessment, mechanism of action, and safety profiles, and forecasts their appropriateness in the management of IBD. The review presents useful insights into the most promising candidates for repurposing, like anti-inflammatory and anti-apoptotic troxerutin, which has been found to improve the DSS-induced colitis in rats, an antiosteoarthritic drug diacetylrhein that has been found to have remarkable ameliorating effects on DSS-induced colitis via anti-oxidant and anti- inflammatory properties and by influencing both apoptosis and pyroptosis. Topiramate, an antiepileptic and anticonvulsant drug, has remarkably decreased overall pathophysiological and histopathological events in the experimental model of IBD in rodents by its cytokine inhibitory action.

Physicochemical characterization of chitin extracted by different treatment sequences from an edible insect

Chitin present in the shell of edible insects is a potential source of chitin, lipids, and proteins, and it exerts various biological activities. Thus far, only a few studies have focused on the use of chitin as a source of high-protein-diet oligosaccharides. The use of insect chitin for the production of high-protein-diet oligosaccharides can lessen the reliance on diet crops. Moreover, although chitin composition in Tenebrio molitor larva, pupa, and adult has been extensively investigated, chitin extraction from T. molitor larval whole body and exuvium has received poor attention. The present study compared the effectiveness of two techniques for extracting high-protein-diet chitin oligosaccharide from an edible insect (T. molitor). Two different extraction sequences of chitin from the larval stage (molitor stage larvae) and adult stage (molitor stage adult) of edible T. molitor were investigated. Two processing steps were employed: (a) deproteinization (DEP) and (b) demineralization (DEM) treatments. Differences in the order, conditions, and period of their application resulted in two different chitin extraction procedures. The viscosity, degree of polymerization, and crystallinity index of the chitin extracted using the two procedures were measured, and its chemical components (chitin, ash, protein, fat, and moisture contents) were determined. T. molitor adults and larvae treated sequentially with DEM-DEP demonstrated the greatest yield of approximately 14.62 % ± 0.15 and 6.096 % ± 0.10 %, respectively. By contrast, when treated sequentially with DEP-DEM, the recorded yields were 10.96 % ± 0.18 and 5.31 % ± 0.38, respectively. Differences in the degree of deacetylation between both methods were observed. Additionally, Fourier transform infrared spectroscopy and X-ray diffractometry of the extracted chitin along with a commercial sample revealed consistent chain conformation, mean hydrogen bonding, and crystallinity index. In this way, residues produced by farmed edible insects can be recovered and used as a novel source of chitin.

Pharmatherapeutic Treatment of Osteoarthrosis-Does the Pill against Already Exist? A Narrative Review

The aim of this narrative review is to summarize the current pharmacotherapeutic treatment options for osteoarthritis (OA). Is therapy still mainly symptomatic or does the pill against arthrosis already exist? Causal and non-causal, as well as future therapeutic approaches, are discussed. Various surgical and non-surgical treatment options are available that can help manage symptoms, slow down progression, and improve quality of life. To date, however, therapy is still mainly symptomatic, often using painkilling and anti-inflammatory drugs until the final stage, which is usually joint replacement. These "symptomatic pills against" have side effects and do not alter the progression of OA, which is caused by an imbalance between degenerative and regenerative processes. Next to resolving mechanical issues, the goal must be to gain a better understanding of the cellular and molecular basis of OA. Recently, there has been a lot of interest in cartilage-regenerative medicine and in the current style of treating rheumatoid arthritis, where drug therapy ("the pill against") has been established to slow down or even stop the progression of rheumatoid arthritis and has banned the vast majority of former almost regular severe joint destructions. However, the "causal pill against" OA does not exist so far. First, the early detection of osteoarthritis by means of biomarkers and imaging should therefore gain more focus. Second, future therapeutic approaches have to identify innovative therapeutic approaches influencing inflammatory and metabolic processes. Several pharmacologic, genetic, and even epigenetic attempts are promising, but none have clinically improved causal therapy so far, unfortunately.

Pre-clinical Investigation of Protective Effect of Nutraceutical D-Glucosamine on TNBS-induced Colitis

The level of precursors involved in the biosynthesis of glycosaminoglycan (GAG), glucosamine synthase, and N-acetyl glucosamine (NAG), are significantly reduced in inflammatory bowel disease (IBD). This results in deficient GAG content in mucosa, which eventually disrupts the gut wall integrity, provoking abnormal immunological responses. This is characterized by colossal liberation of inflammatory mediators including tumor necrosis factor-alpha (TNF-α), interleukins (IL), and reactive oxygen species provoking colonic inflammation. D-glucosamine (D-GLU) is reported to suppress oxidative stress, and pro-inflammatory cytokines and acts as a starting material for biosynthesis of NAG. The potential of D-GLU and its combination with mesalamine (5-ASA) was investigated in 2,4,6-trinitrobenzene sulfonic acid (TNBS)-instigated IBD in Wistar rats. Standard and test drugs were given orally for five days to separate groups of rats. Colonic inflammation was evaluated by disease activity score rate (DASR), colon/body weight ratio, colon length, diameter, colon pH, histological injury and score. Inflammatory biomarkers IL-1β, TNF-α, along with reduced glutathione (GSH), and malondialdehyde (MDA) were assessed. Combination of D-GLU +5-ASA significantly ameliorated severity of colonic inflammation by lowering DASR (P < 0.001) and colon/body weight ratio (P < 0.001), restored the colonic architecture and suppressed the histopathological score (P < 0.001), along with the absence of major adverse reactions. The combination suppressed the levels of inflammatory markers (P < 0.001) and MDA (P < 0.001) while enhancing GSH level (P < 0.001). In comparison to individual 5-ASA and D-GLU, combination of drugs significantly diminished colitis severity through their combined anti-inflammatory and antioxidant effects by acting on multiple targets simultaneously. The combination holds remarkable potential in the management of IBD.

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

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

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).

Chitosan and Derivatives: Bioactivities and Application in Foods

Chitosan is a biodegradable, biocompatible, and nontoxic aminopolysaccharide. This review summarizes and discusses the structural modifications, including substitution, grafting copolymerization, cross-linking, and hydrolysis, utilized to improve the physicochemical properties and enhance the bioactivity and functionality of chitosan and related materials. This manuscript also reviews the current progress and potential of chitosan and its derivatives in body-weight management and antihyperlipidemic, antihyperglycemic, antihypertensive, antimicrobial antioxidant, anti-inflammatory, and immunostimulatory activities as well as their ability to interact with gut microbiota. In addition, the potential of chitosan and its derivatives as functional ingredients in food systems, such as film and coating materials, and delivery systems is discussed. This manuscript aims to provide up-to-date information to stimulate future discussion and research to promote the value-added utilization of chitosan in improving the safety, quality, nutritional value and health benefits, and sustainability of our food system while reducing the environmental hazards.

Synthesis and anticholinesterase activities of novel glycosyl benzoxazole derivatives

Eight glycosyl benzoxazole derivatives are synthesized by nucleophilic addition reactions of glycosyl isothiocyanate with o-aminophenol in tetrahydrofuran. The reaction conditions are optimized, and good yields (86%–94%) were obtained. The structures of all new products are confirmed by infrared, 1H nuclear magnetic resonance, and high-resolution mass spectrometry (electrospray ionization). In addition, the in vitro cholinesterase inhibitory activities of these new compounds are tested by Ellman’s method.

The mechanism of medial collateral ligament repair in knee osteoarthritis based on the TLR4/MyD88/NF-κB inflammatory signaling pathway

OBJECTIVES

To explore the role of medial collateral ligament repair in knee osteoarthritis based on TLR4/ MyD88/ NF-κ inflammatory signaling pathway.

METHODS

The modified Hulth method was used to establish models, which were divided into a repair group, a model group, and a sham operation group. The repair group was treated with medial ligament repair technology. Synovium and cartilage morphological changes were evaluated by hematoxylin-eosin staining to determine the degree of reparation. The cartilage was evaluated by the Mankin's score, and inflammatory factors in cartilage tissues were determined by ELISA. The changes in TLR4, MyD88, and NF-κB levels were analyzed using the real-time quantitative PCR and Western blot assays.

RESULTS

The synovial and cartilage damages in the repair group and the sham operation group were significantly alleviated compared to the model group. The Mankin's score of the model group was significantly lower than the other two groups. The expression of inflammatory factors in the repair group and the sham operation group were significantly lower than in the model group. The expressions of those factors in the repair group and the model group were higher than those in the model group.

CONCLUSIONS

Medial ligament repair can improve the cartilage morphology and delay the development and progression of knee osteoarthritis by inhibiting the TLR4/MyD88/NF-κB signaling pathway.

Glucosamine reverses drug resistance in MRP2 overexpressing ovarian cancer cells

Glucosamine (GlcN), a natural amino sugar in human body, was reported to exhibit anticancer activity against some tumors. In the present study, we evaluated the cytotoxicity and multi-drug resistance (MDR) reversal activity of GlcN on resistant MRP2-overexpressing ovarian cancer A2780RCIS cells. The cytotoxicity and MDR reversal activity of GlcN on cancer cells were measured by MTT assay. The effects of GlcN on MRP1 and MRP2 mRNA expression and function were evaluated by qRT-PCR and flow cytometry, respectively. The cell migration capacity of ovarian cancer cells were assessed in the presence or absence of GlcN using wound healing migration assay. Furthermore, the effects of GlcN on the mRNA expression of E-cadherin, vimentin and α-smooth muscle actin as Epithelial-Mesenchymal Transition (EMT)-related markers were evaluated by qRT-PCR. Our results indicated that glucosamine reduced the proliferation of human ovarian cancer cell lines (A2780) and its cisplatin resistant variant (A2780RCIS) in a dose-dependent manner. The IC50 values for A2780RCIS cells treated with cisplatin in the presence of different concentrations of GlcN (0, 1, 2 and 3 mM) for 72 h were 44.463 ± 1.603, 35.17 ± 0.025, 22.25 ± 0.018, 17.78 ± 0.012 μM respectively. Also GlcN decreased the expression of MRP1 and MRP2 mRNA in ovarian cancer cells. Our results further demonstrated that although GlcN had no significant effects on the expression of studied EMT-related markers in invasive A2780RCIS cells, it was able to inhibit their migration in vitro. According to these findings, GlcN could effectively enhance cisplatin cytotoxicity in resistant A2780RCIS cells.

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.

HIF1α inhibition facilitates Leflunomide-AHR-CRP signaling to attenuate bone erosion in CRP-aberrant rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disorder characterized by progressive bone erosion. Leflunomide is originally developed to suppress inflammation via its metabolite A77 1726 to attenuate bone erosion. However, distinctive responsiveness to Leflunomide is observed among RA individuals. Here we show that Leflunomide exerts immunosuppression but limited efficacy in RA individuals distinguished by higher serum C-reactive protein (CRP^Higher, CRP^H), whereas the others with satisfactory responsiveness to Leflunomide show lower CRP (CRP^Lower, CRP^L). CRP inhibition decreases bone erosion in arthritic rats. Besides the immunomodulation via A77 1726, Leflunomide itself induces AHR-ARNT interaction to inhibit hepatic CRP production and attenuate bone erosion in CRP^L arthritic rats. Nevertheless, high CRP in CRP^H rats upregulates HIF1α, which competes with AHR for ARNT association and interferes Leflunomide-AHR-CRP signaling. Hepatocyte-specific HIF1α deletion or a HIF1α inhibitor Acriflavine re-activates Leflunomide-AHR-CRP signaling to inhibit bone erosion. This study presents a precision medicine-based therapeutic strategy for RA.

Leflunomide is used for the treatment of rheumatoid arthritis. Here, the authors show that effectiveness is limited in patients with higher levels of serum c-reactive protein (CRP). Using animal models, they show that higher CRP induces HIF1a expression, which in turn interferes with Leflunomide signalling, and that effectiveness of the drug is restored when HIF1a is pharmacologically inhibited.

Synthesis and bioactivity of novel C2-glycosyl benzofuranylthiazoles derivatives as acetylcholinesterase inhibitors

A new series of C2-glycosyl benzofuranylthiazole derivatives was synthesised by the further cyclization of glycosyl thiourea and 2-(bromoacetyl)-benzofuran via Hantzsch’s method. The corresponding 2-(bromoacetyl)-benzofuran derivatives were obtained by the reaction from various salicylaldehydes, and the glycosyl thiourea was prepared through a series of steps from D-Glucosamine. The acetylcholinesterase-inhibitory activities of the products were tested by Ellman’s method. The most active compounds were subsequently evaluated for the 50% inhibitory concentration values. N-(1,3,4,6-tetra-O-benzyl-2-deoxy-β-D-glucopyranosyl)-4-(5-methoxy-benzofuran-2-yl)-1,3-thiazole-2-amine possessed the best acetylcholinesterase-inhibition activity with a 50% inhibitory concentration of 2.03 ± 0.26 μM.

Rapid and Highly Effective Noninvasive Disinfection by Hybrid Ag/CS@MnO2 Nanosheets Using Near-Infrared Light

A bacterial infection on the surface of medical apparatus and instruments as well as artificial implants is threatening human health greatly. Antibiotics and traditional bacterial-killing agents, even silver nanoparticles, can induce bacterial resistance during long-term interaction with bacteria. Hence, rapid surface sterilization and prevention of bacterial infection in the long term are urgent for biomedical devices, especially for artificial implant materials. Herein, a hybridized chitosan (CS), silver nanoparticles (AgNPs), and MnO₂ nanosheets coating was designed on the surface of titanium plates, which can ensure the implants a rapid and highly effective antibacterial efficacy of 99.00% against Staphylococcus aureus ( S. aureus) and 99.25% against Escherichia coli ( E. coli) within 20 min of 808 nm near-infrared light (NIR) irradiation. The exogenous NIR irradiation can trigger the MnO₂ nanosheets to produce enough hyperthermia within 10 min, which can combine with a low concentration of prereleased Ag⁺ from the coating to achieve superior antimicrobial efficacy through synergistic effects. In contrast, either prereleased Ag ions or a photothermal effect alone can achieve much lower antibacterial efficiency under the same concentration, i.e., 24.00% and 30.01% for the former and 30.00% and 42.54% for the later toward S. aureus and E. coli, respectively. The possible cytotoxicity of coatings could be eliminated owing to the low concentration of AgNPs and chitosan encapsulation. Thus, the novel bifunctional coating Ag/CS@MnO₂ can exhibit great potential in deep site disinfection of Ti implants through the synergy of prereleased Ag ions and a photothermal effect within a short time.

Competitive Biological Activities of Chitosan and Its Derivatives: Antimicrobial, Antioxidant, Anticancer, and Anti-Inflammatory Activities

Chitosan is obtained from alkaline deacetylation of chitin, and acetamide groups are transformed into primary amino groups during the deacetylation. The diverse biological activities of chitosan and its derivatives are extensively studied that allows to widening the application fields in various sectors especially in biomedical science. The biological properties of chitosan are strongly depending on the solubility in water and other solvents. Deacetylation degree (DDA) and molecular weight (MW) are the most decisive parameters on the bioactivities since the primary amino groups are the key functional groups of chitosan where permits to interact with other molecules. Higher DDA and lower MW of chitosan and chitosan derivatives demonstrated higher antimicrobial, antioxidant, and anticancer capacities. Therefore, the chitosan oligosaccharides (COS) with a low polymerization degree are receiving a great attention in medical and pharmaceutical applications as they have higher water solubility and lower viscosity than chitosan. In this review articles, the antimicrobial, antioxidant, anticancer, anti-inflammatory activities of chitosan and its derivatives are highlighted. The influences of physicochemical parameters of chitosan like DDA and MW on bioactivities are also described.