Enhancement of anti arthritic effect of quercetin using thioglycolic acid-capped cadmium telluride quantum dots as nanocarrier in adjuvant induced arthritic Wistar rats

Quantum dots for bone tissue engineering

In confronting the global prevalence of bone-related disorders, bone tissue engineering (BTE) has developed into a critical discipline, seeking innovative materials to revolutionize treatment paradigms. Quantum dots (QDs), nanoscale semiconductor particles with tunable optical properties, are at the cutting edge of improving bone regeneration. This comprehensive review delves into the multifaceted roles that QDs play within the realm of BTE, emphasizing their potential to not only revolutionize imaging but also to osteogenesis, drug delivery, antimicrobial strategies and phototherapy. The customizable nature of QDs, attributed to their size-dependent optical and electronic properties, has been leveraged to develop precise imaging modalities, enabling the visualization of bone growth and scaffold integration at an unprecedented resolution. Their nanoscopic scale facilitates targeted drug delivery systems, ensuring the localized release of therapeutics. QDs also possess the potential to combat infections at bone defect sites, preventing and improving bacterial infections. Additionally, they can be used in phototherapy to stimulate important bone repair processes and work well with the immune system to improve the overall healing environment. In combination with current trendy artificial intelligence (AI) technology, the development of bone organoids can also be combined with QDs. While QDs demonstrate considerable promise in BTE, the transition from laboratory research to clinical application is fraught with challenges. Concerns regarding the biocompatibility, long-term stability of QDs within the biological environment, and the cost-effectiveness of their production pose significant hurdles to their clinical adoption. This review summarizes the potential of QDs in BTE and highlights the challenges that lie ahead. By overcoming these obstacles, more effective, efficient, and personalized bone regeneration strategies will emerge, offering new hope for patients suffering from debilitating bone diseases.

Gingerol nanoparticles attenuate complete Freund adjuvant-induced arthritis in rats via targeting the RANKL/OPG signaling pathway

Rheumatoid arthritis (RA) is characterized by inflammatory joint pathology leading to the degradation of articular bone and cartilage, primarily triggered by synovial inflammation, resulting in joint discomfort. The metacarpophalangeal and proximal interphalangeal joints are predominantly affected. Treatment typically involves a combination of biological and synthetic disease-modifying antirheumatic drugs (DAMARDs) alongside steroid therapy. The application of nanomedicine has been instrumental in enhancing treatment efficacy by facilitating controlled release of pharmacologically active compounds, thus augmenting bioavailability and enabling targeted drug delivery. Gingerol, a constituent of ginger, possesses multifaceted properties. including anti-inflammatory, anti-oxidant, antidiabetic, and antipyretic effects. In this study, gingerol-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs), coated with chitosan, were administered orally to rats over a period of 21 days to address RA induced by complete Freund adjuvant (CFA). The rats were segregated into four experimental groups. Upon completion of the treatment regimen, blood samples were collected for the assessment of cyclooxygenase-2 (COX-2), RA factor, interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α). Subsequent gene expression analysis was conducted to evaluate the levels of interleukin-4 (IL-4), interleukin-17a (IL-17a), IL-6, interferon-gamma (INF-γ), TNF-α, interleukin-1 beta (IL-1β), osteoprotegerin (OPG), and receptor activator of nuclear factor kappa-B ligand (RANKL). Statistical analyses utilizing one-way ANOVA followed by Tukey tests were applied to the data. The gene expression profiling revealed significant disparities in mRNA levels of IL-1β, IL-6, IL-4, IL-17a, RANKL, INF-γ, and TNF-α between the CFA-induced arthritis group and the control group. Consequently, it was inferred that gingerol-loaded PLGA NPs coated with chitosan exhibited heightened therapeutic efficacy in addressing CFA-induced arthritis in rats.

Quercetin and ibuprofen combination displayed anti-inflammatory effects and also extenuates the enteric neurons damage of arthritic rats

This study aimed to investigate the antioxidant and anti-inflammatory properties of quercetin on the cellular components of the Enteric Nervous System in the ileum of rats with arthritis. Rats were distributed into five groups: control (C), arthritic (AIA), arthritic treated with ibuprofen (AI), arthritic treated with quercetin (AQ) and arthritic treated with both ibuprofen and quercetin (AIQ). The ileum was processed for immunohistochemical techniques for HuC/D, calcitonin gene-related peptide, and vasoactive intestinal polypeptide. Measurements in histological sections, chemiluminescence assays, and total antioxidant capacity were also performed. Rheumatoid arthritis resulted in a decrease in neuronal density, yet neuroplasticity mechanisms were evident through observed changes in varicosities size and neuronal area compared to the control group. Reduced paw edema and neuroprotective effects were predominantly noted in both plexuses, as evidenced by the increased density preservation of HuC/D-IR neurons in the AIQ group. The increase of lipoperoxidation levels and paw edema volume in the AQ group was observed compared to the arthritic, whereas the AIQ group mainly showed similar results to those observed in the control. The enteropathy associated with arthritis proved to be significant in the field of gastroenterology, and the combination of quercetin and ibuprofen demonstrated promising anti-inflammatory and neuroprotective effects.

Targeting dysregulated intracellular immunometabolism within synovial microenvironment in rheumatoid arthritis with natural products

Immunometabolism has been an emerging hotspot in the fields of tumors, obesity, and atherosclerosis in recent decades, yet few studies have investigated its connection with rheumatoid arthritis (RA). In principle, intracellular metabolic pathways upstream regulated by nutrients and growth factors control the effector functions of immune cells. Dynamic communication and hypermetabolic lesions of immune cells within the inflammatory synovial microenvironment contributes to the development and progression of RA. Hence, targeting metabolic pathways within immune subpopulations and pathological cells may represent novel therapeutic strategies for RA. Natural products constitute a great potential treasury for the research and development of novel drugs targeting RA. Here, we aimed to delineate an atlas of glycolysis, lipid metabolism, amino acid biosynthesis, and nucleotide metabolism in the synovial microenvironment of RA that affect the pathological processes of synovial cells. Meanwhile, therapeutic potentials and pharmacological mechanisms of natural products that are demonstrated to inhibit related key enzymes in the metabolic pathways or reverse the metabolic microenvironment and communication signals were discussed and highlighted.

Plant-Based Approaches for Rheumatoid Arthritis Regulation: Mechanistic Insights on Pathogenesis, Molecular Pathways, and Delivery Systems

Rheumatoid arthritis (RA) is classified as a chronic inflammatory autoimmune disorder, associated with a varied range of immunological changes, synovial hyperplasia, cartilage destructions, as well as bone erosion. The infiltration of immune-modulatory cells and excessive release of proinflammatory chemokines, cytokines, and growth factors into the inflamed regions are key molecules involved in the progression of RA. Even though many conventional drugs are suggested by a medical practitioner such as DMARDs, NSAIDs, glucocorticoids, etc., to treat RA, but have allied with various side effects. Thus, alternative therapeutics in the form of herbal therapy or phytomedicine has been increasingly explored for this inflammatory disorder of joints. Herbal interventions contribute substantial therapeutic benefits including accessibility, less or no toxicity and affordability. But the major challenge with these natural actives is the need of a tailored approach for treating inflamed tissues by delivering these bioactive agentsat an appropriate dose within the treatment regimen for an extended periodof time. Drug incorporated with wide range of delivery systems such as liposomes, nanoparticles, polymeric micelles, and other nano-vehicles have been developed to achieve this goal. Thus, inclinations of modern treatment are persuaded on the way to herbal therapy or phytomedicines in combination with novel carriers is an alternative approach with less adverse effects. The present review further summarizes the significanceof use of phytocompounds, their target molecules/pathways and, toxicity and challenges associated with phytomolecule-based nanoformulations.

Research progress in arthritis treatment with the active components of Herba siegesbeckiae

Arthritis is a group of diseases characterized by joint pain, swelling, stiffness, and limited movement. Osteoarthritis, rheumatoid arthritis, and gouty arthritis are the most common types of arthritis. Arthritis severely affects the quality of life of patients and imposes a heavy financial and medical burden on their families and society at large. As a widely used traditional Chinese medicine, Herba siegesbeckiae has many pharmacological effects such as anti-inflammatory and analgesic, anti-ischemic injury, cardiovascular protection, and hypoglycemic. In addition, it has significant therapeutic effects on arthritis. The rich chemical compositions of H. siegesbeckiae primarily include diterpenoids, sesquiterpenoids, and flavonoids. As one of the main active components of H. siegesbeckiae, kirenol and quercetin play a vital role in reducing arthritis symptoms. In the present study, the research progress in arthritis treatment with the active components of H. siegesbeckiae is reviewed.

Schinus terebinthifolius Raddi (Brazilian pepper) leaves extract: in vitro and in vivo evidence of anti-inflammatory and antioxidant properties

The aim of this work was to evaluate the anti-inflammatory and antioxidant effects of ethyl acetate extract obtained from the leaves of Brazilian peppertree Schinus terebinthifolius Raddi (EAELSt). Total phenols and flavonoids, chemical constituents, in vitro antioxidant activity (DPPH and lipoperoxidation assays), and cytotoxicity in L929 fibroblasts were determined. In vivo anti-inflammatory and antioxidant properties were evaluated using TPA-induced ear inflammation model in mice. Phenol and flavonoid contents were 19.2 ± 0.4 and 93.8 ± 5.2 of gallic acid or quercetin equivalents/g, respectively. LC-MS analysis identified 43 compounds, of which myricetin-O-pentoside and quercetin-O-rhamnoside were major peaks of chromatogram. Incubation with EAELSt decreased the amount of DPPH radical (EC50 of 54.5 ± 2.4 µg/mL) and lipoperoxidation at 200-500 µg/mL. The incubation with EAELSt did not change fibroblast viability up to 100 µg/mL. Topical treatment with EAELSt significantly reduced edema and myeloperoxidase activity at 0.3, 1, and 3 mg/ear when compared to the vehicle-treated group. In addition, EAELSt decreased IL-6 and TNF-α levels and increased IL-10 levels. Besides, it modulated markers of oxidative stress (reduced total hydroperoxides and increased sulfhydryl contents and ferrium reduction potential) and increased the activity of catalase and superoxide dismutase, without altering GPx activity.

Natural anti-inflammatory products for osteoarthritis: From molecular mechanism to drug delivery systems and clinical trials

Osteoarthritis (OA) is a degenerative joint disease that affects millions globally. The present nonsteroidal anti-inflammatory drug treatments have different side effects, leading researchers to focus on natural anti-inflammatory products (NAIPs). To review the effectiveness and mechanisms of NAIPs in the cellular microenvironment, examining their impact on OA cell phenotype and organelles levels. Additionally, we summarize relevant research on drug delivery systems and clinical randomized controlled trials (RCTs), to promote clinical studies and explore natural product delivery options. English-language articles were searched on PubMed using the search terms "natural products," "OA," and so forth. We categorized search results based on PubChem and excluded "natural products" which are mix of ingredients or compounds without the structure message. Then further review was separately conducted for molecular mechanisms, drug delivery systems, and RCTs later. At present, it cannot be considered that NAIPs can thoroughly prevent or cure OA. Further high-quality studies on the anti-inflammatory mechanism and drug delivery systems of NAIPs are needed, to determine the appropriate drug types and regimens for clinical application, and to explore the combined effects of different NAIPs to prevent and treat OA.

Arthritic Microenvironment-Dictated Fate Decisions for Stem Cells in Cartilage Repair

The microenvironment and stem cell fate guidance of post-traumatic articular cartilage regeneration is primarily the focus of cartilage tissue engineering. In articular cartilage, stem cells are characterized by overlapping lineages and uneven effectiveness. Within the first 12 weeks after trauma, the articular inflammatory microenvironment (AIME) plays a decisive role in determining the fate of stem cells and cartilage. The development of fibrocartilage and osteophyte hyperplasia is an adverse outcome of chronic inflammation, which results from an imbalance in the AIME during the cartilage tissue repair process. In this review, the sources for the different types of stem cells and their fate are summarized. The main pathophysiological events that occur within the AIME as well as their protagonists are also discussed. Additionally, regulatory strategies that may guide the fate of stem cells within the AIME are proposed. Finally, strategies that provide insight into AIME pathophysiology are discussed and the design of new materials that match the post-traumatic progress of AIME pathophysiology in a spatial and temporal manner is guided. Thus, by regulating an appropriately modified inflammatory microenvironment, efficient stem cell-mediated tissue repair may be achieved.

Nano-Emulsion Based Gel for Topical Delivery of an Anti-Inflammatory Drug: In vitro and in vivo Evaluation

Introduction

Arthritic disorder is a common disease in elderly patients and the most common cause of joint dysfunction. This study aims to design Piroxicam-loaded nanoemulsion (PXM-NE) formulations to enhance the analgesic and anti-inflammatory activity of the drug for topical use.

Methods

The nanoemulsion preparations were designed based on a high-pressure homogenization technique and were characterized for particle size (PS), poly dispersity index (Pi), zeta potential (ZP), drug content, and the selected formula was investigated for its topical analgesic activity and pharmacokinetic parameters.

Results

The characterizations showed that the PS was 310.20±19.84 nm, Pi was 0.15±0.02, and ZP was -15.74±1.6 mV for the selected formula. A morphology study showed that the PXM-NE droplets were spherical with a uniform size distribution. The in vitro release study showed a biphasic release pattern with a rapid release within the first 2 hours followed by a sustained release pattern. The analgesic activity for optimal formula was 1.66 times higher than the commercial gel with a double duration of analgesic activity. The C_max was 45.73±9.95 and 28.48±6.44 ng/mL for the gel form of the selected formula and the commercial gel respectively. The relevant bioavailability of the selected formula was 2.41 higher than the commercial gel.

Conclusion

The results showed good physicochemical properties, higher bioavailability, and a longer analgesic effect of PXM from nanoemulsion gel, as compared to the commercial product.

Mechanism of action of quercetin in rheumatoid arthritis models: meta-analysis and systematic review of animal studies

Quercetin, a typical flavonoid derived from a common natural plant, has multiple biological activities. Previous research in animal models has demonstrated the effectiveness of quercetin in treating rheumatoid arthritis (RA). The pharmacological effects and probable mechanisms of quercetin were evaluated in this study. Three databases, PubMed, Web of Science, and Embase, were searched for relevant studies from the creation of the databases to November 2022. Methodological quality was assessed using the SYRCLE risk of bias tool. STATA 15.1 was used to perform the statistical analysis. This research included 17 studies involving 251 animals. The results indicated that quercetin was able to reduce arthritis scores, paw swelling, histopathological scores, interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-17 (IL-17), tumor necrosis factor-α (TNF-α), monocyte chemotactic protein-1 (MCP-1), C-reactive protein (CRP), malondialdehyde (MDA), reactive oxygen species (ROS), thiobarbituric acid reactive substances (TBARS), nuclear factor kappa B (NF-kB) and increase interleukin-10 (IL-10), catalase (CAT), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), glutathione (GSH), and heme oxygenase-1 (HO-1). These may be related to quercetin's potential anti-inflammatory, anti-oxidative stress, and osteoprotective properties. However, more high-quality animal studies are needed to assess the effect of quercetin on RA. Additionally, the safety of quercetin requires further confirmation. Given the importance of the active ingredient, dose selection and the improvement of quercetin's bioavailability remain to be explored.

Epimedii Herba: An ancient Chinese herbal medicine in the prevention and treatment of rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic, progressive inflammatory and systemic autoimmune disease resulting in severe joint destruction, lifelong suffering and considerable disability. Diverse prescriptions of traditional Chinese medicine (TCM) containing Epimedii Herba (EH) achieve greatly curative effects against RA. The present review aims to systemically summarize the therapeutic effect, pharmacological mechanism, bioavailability and safety assessment of EH to provide a novel insight for subsequent studies. The search terms included were "Epimedii Herba", "yinyanghuo", "arthritis, rheumatoid" and "Rheumatoid Arthritis", and relevant literatures were collected on the database such as Google Scholar, Pubmed, Web of Science and CNKI. In this review, 15 compounds from EH for the treatment of RA were summarized from the aspects of anti-inflammatory, immunoregulatory, cartilage and bone protective, antiangiogenic and antioxidant activities. Although EH has been frequently used to treat RA in clinical practice, studies on mechanisms of these activities are still scarce. Various compounds of EH have the multifunctional traits in the treatment of RA, so EH may be a great complementary medicine option and it is necessary to pay more attention to further research and development.

Dietary polyphenols for management of rheumatoid arthritis: Pharmacotherapy and novel delivery systems

Rheumatoid arthritis (RA) is a chronic, complex, systemic autoimmune disease causing chronic inflammation, swelling, and pain. It affects pulmonary and ocular physiology, gastrointestinal disturbance, skeletal disorders, and renal malfunctioning. Although conventional and biological drugs available to treat RA are potent and effective, they lead to life-threatening side effects and patient discomfort. Hence, alternative therapies are explored for their treatment which is safe, effective, and economical. Herbal drugs are widely used as an alternative therapy and some medicinal plants, especially dietary polyphenols proved their efficacy in treating RA. Polyphenols are secondary metabolites of plants possessing several pharmacological actions. They exert anti-inflammatory, immunomodulatory and anti-rheumatoid activity by modulating tumor necrosis factor, mitogen-activated protein kinase, nuclear factor kappa-light-chain-enhancer of activated B cells, and c-Jun N-terminal kinases. Thus, polyphenols could be a promising option for the management of RA. Unfortunately, polyphenols suffer from poor bioavailability due to their physicochemical properties and incorporation into novel delivery systems such as liposomes, nanoparticles, nanoemulsions, micelles improved their oral bioavailability. This review article summarizes dietary polyphenols, their pharmacological actions and novel delivery systems for the treatment of RA. Nevertheless, the commercial translation of polyphenols could be only possible after establishing their safety profile and successful clinical trials.

Quercetin-mediated SIRT1 activation attenuates collagen-induced mice arthritis

ETHNOPHARMACOLOGICAL RELEVANCE

Herba taxilli (HT, Sangjisheng in Chinese), which is composed of the dried stems and leaves of Taxillus chinensis (DC.) Danser, has been commonly used to treat inflammation and arthritis in traditional Chinese medicine (TCM). Quercetin (Que) is a major active flavonoid component isolated from HT and is one of the quality control indexes of HT. In the clinical practice of TCM, formulas containing HT are commonly used to treat rheumatoid arthritis (RA). Recent studies have shown that Que exerts antiarthritic effects. However, the mechanism by which Que treatment affects RA is not fully understood.

AIM OF THE STUDY

This study aimed to explore the antiarthritic activity of Que in a collagen-induced arthritis (CIA) mouse model and investigate the underlying mechanisms.

MATERIALS AND METHODS

The antiarthritic activity of Que was evaluated in a CIA mouse model by determining the paw clinical arthritis scores and left ankle thicknesses and by conducting micro-PET imaging and histopathological analysis of ankle joint tissues. The proinflammatory cytokine (IL-6, TNF-α, IL-1β, IL-8, IL-13, IL-17) levels in the serum and ankle joint tissues were measured by ELISA. Mitochondrial oxidative stress was assessed by biochemical methods. Mitochondrial biogenesis was analysed by RT-qPCR. The protein levels of silent information regulator 1 (SIRT1), peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), nuclear respiratory factor 1 (NRF1), mitochondrial transcription factor A (TFAM), high-mobility group box 1 (HMGB1), Toll-like receptor 4 (TLR4), p38, phospho-p38, extracellular signal-regulated kinases (ERK)-1/2, phospho-ERK1/2, p65, and phospho-p65 in ankle joint tissues were detected by Western blot analysis. A total of 30 RA patients were recruited to investigate the relationship between the disease activity score (DAS28) and the SIRT1, PGC-1α, NRF1, and HMGB1 plasma levels.

RESULTS

Que treatment decreased the clinical score and left ankle thickness of CIA mice, attenuated the synovial inflammation and hyperplasia and bone/cartilage destruction in ankle joints, and decreased the secretion of IL-6, TNF-α, IL-1β, IL-8, IL-13, and IL-17. Mechanistically, Que treatment improved impaired mitochondrial biogenesis and mitochondrial function by regulating the SIRT1/PGC-1α/NRF1/TFAM pathway and inhibited inflammation via the HMGB1/TLR4/p38/ERK1/2/NF-κB p65 pathway. Notably, epidemiological data revealed correlations between abnormal circulating levels of SIRT1, PGC-1α, NRF1, HMGB1 and RA disease activity in patients.

CONCLUSIONS

Our data suggested a potential role of Que as a dietary therapeutic drug for RA treatment that may act through SIRT1 to target mitochondrial biogenesis. Additionally, the role of impaired mitochondrial biogenesis in RA was evaluated.

Cissus quadrangularis (veldt grape) attenuates disease progression and anatomical changes in mono sodium iodoacetate (MIA)-induced knee osteoarthritis in the rat model

The Cissus quadrangularis (CQ) stem has interesting nutritional and pharmacological properties to promote the health of the skeletal system. It is a well-recognized plant in the conventional system of medicine in India for treating bone and joint-associated complications. This study focuses on identifying the active constituents from the stem and root extracts of CQ and validating its anti-osteoarthritic activity by the in vivo model. Notable levels of phenolics and flavonoids were found in the ethanol extracts of both CQ stem (CQSE) and root (CQRE), among other solvent fractions. UPLC-MS/MS analysis of these selective extracts resulted in different classes of active compounds from both positive and negative ionization modes. By analyzing their mass spectra and fragmentation pattern, 25 active compounds were identified. The CQSE and CQRE extracts, along with the standard drug (naproxen), were further tested in mono-sodium iodoacetate-induced experimental OA animals. The modulatory effects of the test extracts were assessed by haematology, synovial and cartilage marker profiling, radiology and histopathological analysis. The in vivo findings from the biochemical and physiological studies have led to the conclusion that the CQSE extract is a good choice for the management of OA. The results were substantially better than CQ root extract and naproxen drug-treated groups. Thus, CQS has bioactive constituents, which could facilitate recovery from joint tissue damage, cellular metabolism and associated risk factors attributable to dysfunctions in OA incidence and progression.

Ameliorating quercetin constraints in cancer therapy with pH-responsive agarose-polyvinylpyrrolidone -hydroxyapatite nanocomposite encapsulated in double nanoemulsion

Despite quercetin (QC) promising features for cancer therapy, low solubility, poor permeability, and short biological half-life time significantly confine its application in cancer therapy. In this study, a novel approach is developed to improve loading efficiency and attain quercetin sustained-release concurrently. In this direction, hydrogel nanocomposite of agarose (AG)-polyvinylpyrrolidone (PVP)-hydroxyapatite (HAp) was loaded with QC. Incorporating HAp nanoparticles in the AG-PVP hydrogel improved the loading efficiency up to 61%. Also, the interactions between nanoparticle, drug, and hydrogel polymers rendered the nanocomposite pH-responsive at acidic conditions and controlled the burst release at neutral conditions. Then, QC-loaded hydrogel was encapsulated into the water in oil in water nanoemulsions to further sustain the drug release. As a result, the pH-responsive release of QC with prolonged-release over 96 h was observed. In more detail, according to the Korsmeyer-Peppas mathematical model, the mechanism of release was anomalous (diffusion-controlled) at pH 7.4 and anomalous transport (dissolution-controlled) at pH 5.4. The presence of all nanocomposite components was confirmed with FTIR analysis, and XRD results approved the incorporation of QC in the fabricated nanocomposite. The homogeneous surface of the nanocomposite in FESEM images showed good compatibility between components. The zeta potential analysis confirmed the good stability of the nanocarriers. Besides, the fabricated AG-PVP-HAp-QC platform showed significant cytotoxicity on MCF-7 cells compared to QC as a free drug (p < 0.001) and to quercetin-loaded AG-PVP (AG-PVP-QC) (p < 0.001) with enhanced apoptosis induction after the addition of HAp. Accordingly, this delivery platform ameliorated loading and sustained-release of QC, as well as its anticancer activity by releasing the drug at an effective therapeutic level over a long period to induce apoptosis. Thus, turning this drug delivery system into a potential candidate for further biomedical applications.

Anti-rheumatic effect of quercetin and recent developments in nano formulation

Quercetin is a potential anti-rheumatoid drug. Nano formulation strategies could improve its solubility and efficacy.

Evaluation of the anti-rheumatic properties of thymol using carbon dots as nanocarriers on FCA induced arthritic rats

Rheumatoid Arthritis (RA) is an autoimmune disease that commences as inflammation and progressively destroys the articular joint. In this study, we assess the anti-rheumatic potential of the monoterpenoid class of thymol conjugated with Carbon Dots (CDs). Waste biomass in the form of dried rose petals was chosen as a precursor for the synthesis of CDs via a one-step hydrothermal bottom-up methodology. The prepared CDs exhibited absorption in the near-visible region, and unique excitation-dependent emission behaviour was confirmed from UV-Visible and fluorescence measurements. The surface morphology of CDs was confirmed by SEM and HR-TEM analysis to be quasi-spherical particles with an average size of ∼5-6 nm. The presence of various functional moieties (hydroxyl, carbonyl, and amino) was confirmed via FT-IR measurement. The graphitization of CDs was confirmed by the D and G bands for sp2 and sp3 hybridization, respectively, through Raman analysis. Esterification methodology was adopted to prepare the CDs-thymol conjugate and confirmed via FT-IR analysis. CDs play the role of a nanocarrier for thymol, an anti-arthritic agent. The bioactive compound of thymol showed potent anti-arthritic activity against RA targets through in silico docking studies. Further, the in vivo studies revealed that CDs-thymol conjugates (10 mg per kg body weight) showed a significant reduction in rat paw volume along with reduced levels of RF and CRP (2.23 ± 0.42 IU ml-1 and 16.96 ± 0.22 mg ml-1) when compared to the disease control rats. X-ray radiography and ultrasonic imaging revealed less bone destruction, joint derangement, and swelling in arthritis-induced Wistar rats. They could also potentially improve the Hb (14.14 ± 0.19), RBC (6.01 ± 0.11), PCV (6.01 ± 0.11) levels and elevate the status of antioxidant enzymes (GPx, SOD, MDA), and the activity was comparable to the standard drug, ibuprofen (10 mg kg-1), suggesting that the CDs-thymol conjugate at 10 mg kg-1 could act as a strong anti-arthritic agent. This work is evidence for the utilization of waste biomass as a value-added product such as a nanocarrier for biomedical applications.

Food-Derived Nanoscopic Drug Delivery Systems for Treatment of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a severe systemic inflammatory disease with no cure at present. Recent developments in the understanding of inflammation and nanomaterial science have led to increased applications of nanostructured drug delivery systems in the treatment of RA. The present review summarizes novel fabrications of nanoscale drug carriers using food components as either the delivered drugs or carrier structures, in order to achieve safe, effective and convenient drug administration. Polyphenols and flavonoids are among the most frequently carried anti-RA therapeutics in the nanosystems. Fatty substances, polysaccharides, and peptides/proteins can function as structuring agents of the nanocarriers. Frequently used nanostructures include nanoemulsions, nanocapsules, liposomes, and various nanoparticles. Using these nanostructures has improved drug solubility, absorption, biodistribution, stability, targeted accumulation, and release. Joint vectorization, i.e., using a combination of bioactive molecules, can bring elevated therapeutic outcomes. Utilization of anti-arthritic chemicals that can self-assemble into nanostructures is a promising research orientation in this field.

Antioxidant, hepatoprotective, genoprotective, and cytoprotective effects of quercetin in a murine model of arthritis

Rheumatoid arthritis is a highly debilitating inflammatory autoimmune disease which is characterized by joint destruction. The present study sought to investigate the effect of quercetin in rats with complete Freund's adjuvant-induced arthritis. Animals were divided into control/saline, control/quercetin (5 mg/kg, 25 mg/kg, and 50 mg/kg) arthritis/saline, and arthritis/quercetin (5 mg/kg, 25 mg/kg, and 50 mg/kg); the treatments were administered for 45 days. Biochemical, oxidative stress, genotoxicity, and cytotoxicity parameters were evaluated. All doses of quercetin reduced the levels of aspartate aminotransferase, thiobarbituric acid-reactive substances, and reactive oxygen species; however, only treatment with 25 or 50 mg/kg increased catalase activity. Total thiol and reduced glutathione levels were not significantly affected by the induction nor by the treatments. Genotoxicity assessed by DNA damage, and cytotoxicity through picogreen assay, decreased after treatments with quercetin. Our results present evidence of the antioxidant, cytoprotective, genoprotective and hepatoprotective, and effects of quercetin, demonstrating its potential as a candidate for coadjuvant therapy.

Therapeutic effect of quercetin in collagen-induced arthritis

Quercetin, a bioactive flavonoid with anti-inflammatory, immunosuppressive, and protective properties, is a potential agent for the treatment of rheumatoid arthritis (RA). Collagen-induced arthritis (CIA) is the most commonly used animal model for studying the pathogenesis of RA. This study analysed the therapeutic role of quercetin in collagen-induced arthritis in C57BL/6 mice. The animals were allocated into five groups that were subjected to the following treatments: negative (untreated) control, positive control (arthritis-induced), arthritis+methotrexate, arthritis+quercetin, and arthritis+methotrexate+quercetin. Assessments of weight, oedema, joint damage, and cytokine production were used to determine the therapeutic effect of quercetin. This study demonstrated for the first time the anti-inflammatory and protective effects of quercetin in vivo in CIA. The results also showed that the concurrent administration of quercetin and methotrexate did not offer greater protection than the administration of a single agent. The use of quercetin as a monotherapeutic agent resulted in the lowest degree of joint inflammation and the highest protection. The reduced severity of the disease in animals treated with quercetin was associated with decreased levels of TNF-α, IL-1β, IL-17, and MCP-1. In conclusion, this study determined that quercetin, which was non-toxic, produced better results than methotrexate for the protection of joints from arthritic inflammation in mice. Quercetin may be an alternative treatment for RA because it modulates the main pathogenic pathways of RA.

Study of the interaction of flavonoids with 3-mercaptopropionic acid modified CdTe quantum dots mediated by cetyltrimethyl ammonium bromide in aqueous medium

Flavonoids are polyphenols that help the maintenance of health, aiding the prevention of diseases. In this work, CdTe QDs coated with 3-mercaptopropionic acid (3MPA), with an average size of 2.7nm, were used as photoluminescence probe for flavonoids in different conditions. The interaction between 14 flavonoids and QDs was evaluated in aqueous dispersions in the absence and in the presence of cetyltrimethylammonium bromide (CTAB). To establish a relationship between photoluminescence quenching and the concentration of flavonoids, the Stern-Volmer model was used. In the absence of CTAB, the linear ranges for quercetin, morin and rutin were from 5.0×10^-6molL^-1 to 6.0×10^-5molL^-1 and from 1.0×10^-5molL^-1 to 6.0×10^-4molL^-1 for kaempferol. The sensibility of the Stern-Volmer curves (K_s) indicated that quercetin interacts more strongly with the probe: K_{s quercetin}>K_{s kaempferol}>K_{s rutin}>K_{s morin}. The conjugation extension in the 3 rings, and the acidic hydroxyl groups (positions 3'and 4') in the B-ring enhanced the interaction with 3MPA-CdTe QDs. The other flavonoids do not interact with the probe at 10^-5molL^-1 level. In CTAB organized dispersions, K_{s 3-hydroxyflavone}>K_{s 7-hydroxyflavone}>K_{s flavona}>K_{s rutin} in the range from 1.0×10^-6molL^-1 to 1.2×10^-5molL^-1 for flavones and of 1.0×10^-6molL^-1 to 1.0×10^-5molL^-1 for rutin. Dynamic light scattering, conductometric measurements and microenvironment polarity studies were employed to elucidate the QDs-flavonoids interaction in systems containing CTAB. The quenching can be attributed to the preferential solubility of hydrophobic flavonoid in the palisade layer of the CTAB aggregates adsorbed on the surface of the 3MPA CdTe QDs.

Advancement in contemporary diagnostic and therapeutic approaches for rheumatoid arthritis

This review is intended to provide a summary of the pathogenesis, diagnosis and therapies for rheumatoid arthritis. Rheumatoid arthritis (RA) is a common form of inflammatory autoimmune disease with unknown aetiology. Bone degradation, cartilage and synovial destruction are three major pathways of RA pathology. Sentinel cells includes dendritic cells, macrophages and mast cells bound with the auto antigens and initiate the inflammation of the joints. Those cells further activates the immune cells on synovial membrane by releasing inflammatory cytokines Interleukin 1, 6, 17, etc., Diagnosis of this disease is a combinational approach comprises radiological imaging, blood and serology markers assessment. The treatment of RA still remain inadequate due to the lack of knowledge in disease development. Non-steroidal anti-inflammatory drugs, disease modifying anti rheumatic drugs and corticosteroid are the commercial drugs to reduce pain, swelling and suppressing several disease factors. Arthroscopy will be an useful method while severe degradation of joint tissues. Gene therapy is a major advancement in RA. Suppressor gene locus of inflammatory mediators and matrix degrading enzymes were inserted into the affected area to reduce the disease progression. To overcome the issues aroused from those therapies like side effects and expenses, phytocompounds have been investigated and certain compounds are proved for their anti-arthritic potential. Furthermore certain complementary alternative therapies like yoga, acupuncture, massage therapy and tai chi have also been proved for their capability in RA treatment.

Neutrophils and arthritis: Role in disease and pharmacological perspectives

The inflammatory response in the joint can induce an intense accumulation of leukocytes in the tissue that frequently results in severe local damage and loss of function. Neutrophils are essential cells to combat many pathogens, but their arsenal can contribute or aggravate articular inflammation. Here we summarized some aspects of neutrophil biology, their role in inflammation and indicated how the modulation of neutrophil functions could be useful for the treatment of different forms of arthritis.

Metal chalcogenide quantum dots: biotechnological synthesis and applications

Metal chalcogenide (metal sulfide, selenide and telluride) quantum dots (QDs) have attracted considerable attention due to their quantum confinement and size-dependent photoemission characteristics.

An update on dietary phenolic compounds in the prevention and management of rheumatoid arthritis

Certain nutritional components influence the cellular metabolism and interfere in the pathological inflammatory process, so that they may act as a coadjuvant in the treatment of many chronic inflammatory diseases, including rheumatoid arthritis (RA).

In vivo study of immunogenicity and kinetic characteristics of a quantum dot-labelled baculovirus

Nanomaterials conjugated with biomacromolecules, including viruses, have great potential for in vivo applications. Therefore, it is important to evaluate the safety of nanoparticle-conjugated macromolecule biomaterials (Nano-mbio). Although a number of studies have assessed the risks of nanoparticles and macromolecule biomaterials in living bodies, only a few of them investigated Nano-mbios. Here we evaluated the in vivo safety profile of a quantum dot-conjugated baculovirus (Bq), a promising new Nano-mbio, in mice. Each animal was injected twice intraperitoneally with 50 μg virus protein labelled with around 3*10(-5)nmol conjugated qds. Control animals were injected with PBS, quantum dots, baculovirus, or a mixture of quantum dots and baculovirus. Blood, tissues and body weight were analysed at a series of time points following both the first and the second injections. It turned out that the appearance and behaviour of the mice injected with Bq were similar to those injected with baculovirus alone. However, combination of baculovirus and quantum dot (conjugated or simply mixed) significantly induced stronger adaptive immune responses, and lead to a faster accumulation and longer existence of Cd in the kidneys. Thus, despite the fact that both quantum dot and baculovirus have been claimed to be safe in vivo, applications of Bq in vivo should be cautious. To our knowledge, this is the first study examining the interaction between a nanoparticle-conjugated virus and a living body from a safety perspective, providing a basis for in vivo application of other Nano-mbios.