Curcumin, a natural polyphenol derived from turmeric, possesses potent antioxidant properties and represents a potential cardioprotective agent capable of mitigating myocardial oxidative stress associated with rheumatoid arthritis (RA). The aim of the study was to examine the cardioprotective effect of curcumin in an experimental model of rheumatoid arthritis. The study included 104 female Wistar albino rats, divided into 8 groups (n = 13 in each group): (1) CTRL (negative control, healthy rats without treatment), (2) CUR (positive control 1, curcumin 200 mg/kg three times a week for 4 weeks orally), (3) MTX (positive control 2, methotrexate 0.75 mg/kg twice a week for 4 weeks intraperitoneally), (4) RA (positive control 3, rats with Complete Freund’s adjuvant (CFA)-induced RA), (5) RA+pCUR (rats with preventive administration of curcumin + CFA-induced RA), (6) RA+tCUR (rats with CFA-induced RA + therapeutic administration of curcumin), (7) RA + MTX+pCUR (rats with preventive administration of curcumin + CFA-induced RA + methotrexate), (8) RA + MTX+tCUR (rats with CFA-induced RA + therapeutic administration of curcumin + methotrexate). Pro-oxidant levels were determined in coronary venous effluent, antioxidant enzyme activities were assessed in heart tissue homogenates, and histopathological analyses of the synovium and myocardium were performed. Curcumin, particularly in the therapeutic regimen and in combination with methotrexate, significantly reduced pro-oxidant levels and lipid peroxidation. Curcumin also increased superoxide dismutase activity and restored reduced glutathione levels, whereas improvement in catalase activity was observed predominantly in the therapeutic regimens. Histopathological analyses demonstrated that curcumin exerted a protective effect on both synovial and myocardial tissues, attenuating RA-induced structural damage, reducing edema, and preserving myocardial architecture. These findings suggest that curcumin improves myocardial redox homeostasis and may contribute to cardioprotection in experimental RA.

Detection of biologically active components, such as ascorbic acid, dopamine, and serotonin, is significant from the perspective of biomedicine, particularly in the process of disease diagnosis and in the quality control of commercial pharmaceutical products. In this work, a novel electrochemical sensor was developed by modifying a glassy carbon electrode with a hydrogel composed of a polyelectrolyte complex of alginate and chitosan, along with the addition of electrochemically reduced graphene oxide. This biocompatible sensor was applied for the simultaneous determination of ascorbic acid, dopamine, and serotonin using adsorptive square wave voltammetry. The modified GCE demonstrated an excellent electrochemical response towards the target analytes, thanks to the enhanced adsorption of the analytes on the surface of the electrode, facilitated by favorable interactions between analytes and the modifiers. This approach increased the electrode's active surface area and ensured excellent electrode response. The sensor exhibited a broad linear range of the anodic current relative to analyte concentration, achieving low detection limits of 0.094 mu M, 4.18 nM and 3.23 nM for ascorbic acid, dopamine and serotonin, respectively. Additionally, the proposed sensor exhibited good stability, reproducibility of results, selectivity, as well as effectiveness, in the determination of target biological compounds in real sample matrices.

The aim of this study was to examine the potential antioxidant activity of curcumin in therapeutic and preventive condition and its potential role as adjuvant to conventional drug methotrexate in treatment of rheumatoid arthritis (RA). The study included 104 female Wistar albino rats, 6 weeks old, body weight of 200–250 g, which were divided into 8 groups (n=13 in each group): 1. CTRL: negative control, 2. CUR: positive control 1 (curcumin 200 mg/kg three times a week for 4 weeks per os), 3. MTX: positive control 2 (methotrexate 0,75 mg/kg i.p. two times a week for 4 weeks), 4. RA: positive control 3 (induced RA), 5. RA+pCUR: rats with induced RA + preventive administration of curcumin (curcumin 200 mg/kg three times a week for 4 weeks per os before the induction of RA), 6. RA+tCUR: rats with induced RA + curcumin therapy, 7. RA+MTX+pCUR; rats with induced RA + preventive administration of curcumin + methotrexate 0.75 mg/kg i.p. twice weekly for 4 weeks, 8. RA+MTX+tCUR: rats with induced RA + therapeutic administration of curcumin + methotrexate 0.75 mg/kg i.p. twice weekly for 4 weeks. Potential therapeutic effect of curcumin (200 mg/kg three times a week for 4 weeks orally) and RA induction were initiated on the same day; for preventive protocol, curcumin was administered 4 weeks before the start of RA induction at a dose of 200 mg/kg orally three times a week. Rheumatoid arthritis was triggered by administering 0.1 ml of Complete Freund’s Adjuvant (CFA) subcutaneously at the base of the rat tail. Rats were sacrificed 28 days after immunization. During the experimental period, we collected data for arthritis score, radiography testing, and blood sample collecting for specific biochemical analysis for prooxidative and antioxidative parameters (superoxide anion radical, hydrogen peroxide, nitric oxide, index of lipid peroxidation, superoxide dismutase, catalase, and reduced glutathione). Our experimental study confirmed that the therapeutic administration of curcumin reduced disease activity and significantly increased the activities of antioxidative enzymes and reduced prooxidants. Also, preventive administration, especially in combination with methotrexate, offers superior protection by limiting the onset and development of oxidative stress. These findings support the claim that curcumin as turmeric can effectively inhibit inflammatory reactions and reduces symptoms through changing the redox status. Future large randomized controlled trials on the effects of turmeric substance are needed.

Dopamine and folic acid are compounds that coexist in biological fluids, essential for metabolic processes and central nervous system function. The fast, sensitive, and accurate detection of these compounds in biological and pharmaceutical samples holds significant importance for human health assessment and the pharmaceutical industry. An innovative and efficacious electrochemical sensor for the simultaneous quantification of dopamine and folic acid was developed. This sensor was based on the glassy carbon electrode modified with chitosan kappa- carrageenan hydrogel, enriched with the addition of a catalytically active component - graphene oxide. This modification procedure significantly improved the adsorption of the analytes onto the electrode surface thanks to the established favorable intermolecular interactions, thereby enhancing the electrical conductivity of the electrode. The sensor demonstrated an extensive linear response range of the cathodic current in relation to the concentration of dopamine and folic acid, both when quantified individually and simultaneously. Key advantages of this sensor include the obtained low detection limits for both analytes (5.65 x 10(-9) mol/L for dopamine, and 1.88 x 10(-7)mol/L- 7 mol/L for folic acid), electrode selectivity, stability, and good reproducibility of results. The results achieved in this study signify the considerable potential of the developed sensor for the determination of dopamine and folic acid in diverse sample types. Additionally, this work presents an effective method for sensitive detection of selected analytes, and also highlights the utilization of nontoxic compounds in the preparation of a biocompatible sensor, given its considerable potential for future practical applications in various fields.

Diclofenac (sodium [o-(2,6-dichloroanilino) phenyl] acetate) belongs to the class of non-steroidal anti-inflammatory drugs and is widely used as a painkiller. In this paper, a new, simple and effective electrochemical sensor for the determination of diclofenac was developed by modifying the carbon paste electrode. The electrode was modified with chitosan, a biopolymer with excellent adsorptive properties, and TiO2 nanoparticles, a catalytically active material. The modification of the electrode provided larger surface area and improved the electrical conductivity, resulting in enhanced electrochemical detection of diclofenac at a pH of 5.0 using adsorptive differential pulse voltammetry. Under optimal working conditions, linear relationship between the oxidation peak current and the diclofenac concentration was obtained in two different ranges, from 0.2 to 10 mu M and from 10 to 100 mu M, with a detection limit of 0.013 mu M. The proposed method was successfully applied for the determination of diclofenac in commercial tablets and synthetic urine samples. The fabricated chitosan/TiO2/ carbon paste electrode, with an optimized voltammetric method, showed excellent analytical performance for diclofenac determination in terms of stability, low detection limit, high sensitivity, selectivity, as well as good reproducibility and repeatability of results. The obtained results suggest the potential for further utilization of the developed sensor for the simultaneous determination of a group of non-steroidal anti-inflammatory drugs.

Films based on carrageenan, alginate and poloxamer 407 have been formulated with the main aim to apply prepared formulations in wound healing process. The formulated films were loaded with diclofenac, an anti-inflammatory drug, as well as diclofenac and curcumin, as multipurpose drug, in order to enhance encapsulation and achieve controlled release of these low-bioavailability compounds. The obtained data demonstrated improved drug bioavailability (encapsulation efficiency higher than 90%), with high, cumulative in vitro release percentages (90.10% for diclofenac, 89.85% for curcumin and 95.61% for diclofenac in mixture-incorporated films). The results obtained using theoretical models suggested that curcumin establishes stronger, primarily dispersion interactions with carrier, in comparison with diclofenac. Curcumin and diclofenac-loaded films showed great antibacterial activity against Gram-positive bacteria strains (Bacillus subtilis and Staphylococcus aureus, inhibition zone 16.67 and 13.67 mm, respectively), and in vitro and in vivo studies indicated that curcumin- and diclofenac-incorporated polymer films have great potential, as a new transdermal dressing, to heal wounds, because diclofenac can target the inflammatory phase and reduce pain, whereas curcumin can enhance and promote the wound healing process.

Polyphenolic compounds are used for treating various diseases due to their antioxidant and anticancer properties. However, utilization of hydrophobic compounds is limited due to their low bioavailability. In order to achieve a greater application of hydrophobic bioactive compounds, hydrogel beads based on biopolymers can be used as carriers for their enhanced incorporation and controlled delivery. In this study, beads based on the biopolymers-κ-carrageenan, sodium alginate and poloxamer 407 were prepared for encapsulation of curcumin. The prepared beads were characterized using IR, SEM, TGA and DSC. The curcumin encapsulation efficiency in the developed beads was 95.74 ± 2.24%. The release kinetics of the curcumin was monitored in systems that simulate the oral delivery (pH 1.2 and 7.4) of curcumin. The drug release profiles of the prepared beads with curcumin indicated that the curcumin release was significantly increased compared with the dissolution of curcumin itself. The cumulative release of curcumin from the beads was achieved within 24 h, with a final release rate of 12.07% (gastric fluid) as well as 81.93% (intestinal fluid). Both the in vitro and in vivo studies showed that new hydrogel beads based on carbohydrates and poloxamer improved curcumin’s bioavailability, and they can be used as powerful carriers for the oral delivery of different hydrophobic nutraceuticals.

Curcumin belongs to a group of multipurpose drugs that can enhance the wound healing process. In this paper, films based on natural polysaccharides -kappa-carrageenan and alginate -were prepared with added synthetic polymer poloxamer 407 to use these carriers for curcumin encapsulation and further apply them in wound healing. The film preparation process (film composition, components ratio, and crosslinking time) has been optimized. Curcumin, as a drug model, has been incorporated into optimal films. Structure, morphology, thermal properties, and the crystallinity degree of optimal films were determined using infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, and X-ray diffraction method. The in vitro release of curcumin from films was monitored for 24 h, achieving its cumulative release with a maximum release rate of 87.64%. The formation of complexes based on carrageenan, alginate, and poloxamer and the interaction of these complexes with curcumin were studied using theoretical models, AIM and NBO analysis. The effect of prepared films on cell viability was also examined. Films with incorporated curcumin were found to accelerate wound healing, both in in vitro and in vivo conditions, indicating their potential as new transdermal wound healing systems.