Micellar solubilisation enhances the antiinflammatory activities of curcumin and boswellic acids in rats with adjuvant-induced arthritis

Rheumatoid arthritis-recent advances in pathogenesis and the anti-inflammatory effect of plant-derived COX inhibitors

The majority of people with autoimmune disorders, including those with rheumatoid arthritis, osteoarthritis, and tendonitis report pain, stiffness, and inflammation as major contributors to their worse quality of life in terms of overall health. Of all the available treatment options, COX inhibitors are the ones that are utilized most frequently to ease the symptoms. Various signaling cascades have been reported to be involved in the pathogenesis of rheumatoid arthritis which includes JAK/STAT, MAPK, and NF-kB signaling pathways, and several allopathic inhibitors (tofacitinib and baricitinib) have been reported to target the components of these cascades and have received approval for RA treatment. However, the prolonged use of these COX inhibitors and other allopathic drugs can pose serious health challenges due to their significant side effects. Therefore, searching for a more effective and side effect-free treatment for rheumatoid arthritis has unveiled phytochemicals as both productive and promising. Their therapeutic ability helps develop potent and safe drugs targeting immune-inflammatory diseases including RA. Various scientific databases were used for searching articles such as NCBI, SpringerLink, BioMed Central, ResearchGate, Google Scholar, Scopus, Nature, Wiley Online Library, and ScienceDirect. This review lists various phytochemicals and discusses their potential molecular targets in RA treatment, as demonstrated by various in vitro, in vivo (pre-clinical), and clinical studies. Several pre-clinical and clinical studies suggest that various phytochemicals can be an alternative promising intervention for attenuating and managing inflammation-associated pathogenesis of rheumatoid arthritis.

Comparative Pharmacokinetic Study of Standard Astaxanthin and its Micellar Formulation in Healthy Male Volunteers

BACKGROUND AND OBJECTIVE

Astaxanthin is a naturally occurring carotenoid with high anti-oxidant properties, but it is a very lipophilic compound with low oral bioavailability. This study was conducted to compare the pharmacokinetic parameters of a novel astaxanthin preparation based on micellar solubilization technology, NovaSOL® 400-mg capsules (Test product), and those of astaxanthin 400-mg capsules (reference product), after single oral dose administration to healthy male adults.

METHODS

A single oral dose (400 mg equivalent to 8 mg astaxanthin) of test and reference astaxanthin were administered with 240 mL of water to 12 volunteers according to crossover design, in two phases, with a washout period of 1 week in between. Blood samples were collected at hourly intervals for the first 12 h, then at 24.0, 48.0, and 72.0 h after administration. Aliquots of plasma were centrifuged and the clear supernatant was injected into the high performance liquid chromatography-diode array detection (HPLC-DAD) system. Plasma concentration of astaxanthin versus time profiles were constructed, and the primary pharmacokinetic parameters, maximum concentration (Cmax), area under concentration time curve from time of administration (0) to time (t) [AUC0-t] or to infinity ∞, [AUC0-∞],  half-life (T½) and time to reach Cmax (Tmax) were calculated.

RESULTS

The test micellar astaxanthin reached a Cmax of 7.21 µg/ml after 3.67 h compared to only 3.86 µg/ml after 8.5 h for the reference native astaxanthin.

CONCLUSION

Micellar formulation of astaxanthin is capable of producing a high concentration of astaxanthin in plasma in a shorter time, thereby expected to provide faster potential therapeutic efficacy.

Curcumin-Loaded RH60/F127 Mixed Micelles: Characterization, Biopharmaceutical Characters and Anti-Inflammatory Modulation of Airway Inflammation

Curcumin's ability to impact chronic inflammatory conditions, such as metabolic syndrome and arthritis, has been widely researched; however, its poor bioavailability limits its clinical application. The present study is focused on the development of curcumin-loaded polymeric nanomicelles as a drug delivery system with anti-inflammatory effects. Curcumin was loaded in PEG-60 hydrogenated castor oil and puronic F127 mixed nanomicelles (Cur-RH60/F127-MMs). Cur-RH60/F127-MMs was prepared using the thin film dispersion method. The morphology and releasing characteristics of nanomicelles were evaluated. The uptake and permeability of Cur-RH60/F127-MMs were investigated using RAW264.7 and Caco-2 cells, and their bioavailability and in vivo/vitro anti-inflammatory activity were also evaluated. The results showed that Cur-RH60/F127-MMs have regular sphericity, possess an average diameter smaller than 20 nm, and high encapsulation efficiency for curcumin (89.43%). Cur-RH60/F127-MMs significantly increased the cumulative release of curcumin in vitro and uptake by cells (p < 0.01). The oral bioavailability of Cur-RH60/F127-MMs was much higher than that of curcumin-active pharmaceutical ingredients (Cur-API) (about 9.24-fold). The treatment of cell lines with Cur-RH60/F127-MMs exerted a significantly stronger anti-inflammatory effect compared to Cur-API. In addition, Cur-RH60/F127-MMs significantly reduced OVA-induced airway hyperresponsiveness and inflammation in an in vivo experimental asthma model. In conclusion, this study reveals the possibility of formulating a new drug delivery system for curcumin, in particular nanosized micellar aqueous dispersion, which could be considered a perspective platform for the application of curcumin in inflammatory diseases of the airways.

Impacts of Curcumin Treatment on Experimental Sepsis: A Systematic Review

Background and Aims

Sepsis is defined as a life-threatening organ dysfunction due to a dysregulated host immune response to an infection. Curcumin is a yellow polyphenol derived from the rhizome of Curcuma longa with anti-inflammatory and antioxidant properties scientifically proven, a condition that allowed its use as a tool in the treatment of sepsis. Thus, the purpose of this article was to systematically review the evidence on the impact of curcumin's anti-inflammatory effect on experimental sepsis.

Methods

For this, the PubMed, MEDLINE, EMBASE, Scopus, Web of Science, and LILACS databases were used, and the research was not limited to a specific publication period. Only original articles in English using in vivo experimental models (rats or mice) of sepsis induction performed by administration of lipopolysaccharide (LPS) or cecal ligation and perforation surgery (CLP) were included in the study. Studies using curcumin in dry extract or with a high degree of purity were included. At initial screening, 546 articles were selected, and of these, 223 were eligible for primary evaluation. Finally, 12 articles with full text met all inclusion criteria. Our results showed that curcumin may inhibit sepsis-induced complications such as brain, heart, liver, lungs, and kidney damage. Curcumin can inhibit inflammatory factors, prevent oxidative stress, and regulate immune responses in sepsis. Additionally, curcumin increased significantly the survival rates after experimental sepsis in several studies. The modulation of the immune response and mortality by curcumin reinforces its protective effect on sepsis and indicates a potential therapeutic tool for the treatment of sepsis.

The Anti-Inflammatory and Immunomodulatory Activities of Natural Products to Control Autoimmune Inflammation

Inflammation is an integral part of autoimmune diseases, which are caused by dysregulation of the immune system. This dysregulation involves an imbalance between pro-inflammatory versus anti-inflammatory mediators. These mediators include various cytokines and chemokines; defined subsets of T helper/T regulatory cells, M1/M2 macrophages, activating/tolerogenic dendritic cells, and antibody-producing/regulatory B cells. Despite the availability of many anti-inflammatory/immunomodulatory drugs, the severe adverse reactions associated with their long-term use and often their high costs are impediments in effectively controlling the disease process. Accordingly, suitable alternatives are being sought for these conventional drugs. Natural products offer promising adjuncts/alternatives in this regard. The availability of specific compounds isolated from dietary/medicinal plant extracts have permitted rigorous studies on their disease-modulating activities and the mechanisms involved therein. Here, we describe the basic characteristics, mechanisms of action, and preventive/therapeutic applications of 5 well-characterized natural product compounds (Resveratrol, Curcumin, Boswellic acids, Epigallocatechin-3-gallate, and Triptolide). These compounds have been tested extensively in animal models of autoimmunity as well as in limited clinical trials in patients having the corresponding diseases. We have focused our description on predominantly T cell-mediated diseases, such as rheumatoid arthritis, multiple sclerosis, Type 1 diabetes, ulcerative colitis, and psoriasis.

Micellar Curcumin: Pharmacokinetics and Effects on Inflammation Markers and PCSK-9 Concentrations in Healthy Subjects in a Double-Blind, Randomized, Active-Controlled, Crossover Trial

SCOPE

Preclinical models have demonstrated the anti-inflammatory and lipid-lowering effects of curcumin. Innovative formulations have been developed to overcome the poor bioavailability of native curcumin. The study hypothesizes that the bioavailability of micellar curcumin is superior to native curcumin and investigates the potential anti-inflammatory and proprotein convertase subtilisin/kexin type 9 (PCSK9) concentration lowering effects.

METHODS AND RESULTS

In this double-blind, randomized, crossover trial, 15 healthy volunteers receive micellar or native curcumin (105 mg day-1 ) for 7 days with a ≥7 days washout period. Curcumin and metabolite concentrations are quantified by high-performance liquid chromatography with fluorescence detection (HPLC-FD), and pharmacokinetics are calculated. To analyze anti-inflammatory effects, blood samples (baseline, 2 h, 7 days) are stimulated with 50 ng mL-1 lipopolysaccharides (LPS). Interleukin (IL)-6, tumor-necrosis factor (TNF-α), and PCSK9 concentrations are quantified. Micellar curcumin demonstrates improved bioavailability (≈39-fold higher maximum concentrations, ≈14-fold higher area-under-the-time-concentration curve, p < 0.001) but does not reduce pro-inflammatory cytokines in the chosen model. Subjects receiving micellar curcumin have significantly lower PCSK9 concentrations (≈10% reduction) after 7 days compared to baseline (p = 0.038).

CONCLUSION

Micellar curcumin demonstrates an improved oral bioavailability but does not show anti-inflammatory effects in this model. Potential effects on PCSK9 concentrations warrant further investigation.

Potential complementary and/or synergistic effects of curcumin and boswellic acids for management of osteoarthritis

For several thousand years (~4000) Boswellia serrata and Curcuma longa have been used in Aryuvedic medicine for treatment of various illnesses, including asthma, peptic ulcers, and rheumatoid arthritis, all of which are mediated through pathways associated with inflammation and pain. Although the in vivo pharmacology of both these natural ingredients is difficult to study because of poor bioavailability, in vitro data suggest that both influence gene expression mediated through nuclear factor kappa B (NF-κB). Therefore, the activity of pathways associated with inflammation (including NF-κB and lipoxygenase- and cyclooxygenase-mediated reduction in leukotrienes/prostaglandins) and those involved in matrix degradation and apoptosis are reduced, resulting in a reduction in pain. Additive activity of boswellic acids and curcumin was observed in preclinical models and synergism was suggested in clinical trials for the management of osteoarthritis (OA) pain. Overall, studies of these natural ingredients, alone or in combination, revealed that these extracts relieved pain from OA and other inflammatory conditions. This may present an opportunity to improve patient care by offering alternatives for patients and physicians, and potentially reducing nonsteroidal anti-inflammatory or other pharmacologic agent use. Additional research is needed on the effects of curcumin on the microbiome and the influence of intestinal metabolism on the activity of curcuminoids to further enhance formulations to ensure sufficient anti-inflammatory and antinociceptive activity. This narrative review includes evidence from in vitro and preclinical studies, and clinical trials that have evaluated the mechanism of action, pharmacokinetics, efficacy, and safety of curcumin and boswellic acids individually and in combination for the management of OA pain.

Technologies for Solubility, Dissolution and Permeation Enhancement of Natural Compounds

The current review is based on the advancements in the field of natural therapeutic agents which could be utilized for a variety of biomedical applications and against various diseases and ailments. In addition, several obstacles have to be circumvented to achieve the desired therapeutic effectiveness, among which limited dissolution and/or solubility and permeability are included. To counteract these issues, several advancements in the field of natural therapeutic substances needed to be addressed. Therefore, in this review, the possible techniques for the dissolution/solubility and permeability improvements have been addressed which could enhance the dissolution and permeability up to several times. In addition, the conventional and modern isolation and purification techniques have been emphasized to achieve the isolation and purification of single or multiple therapeutic constituents with convenience and smarter approaches. Moreover, a brief overview of advanced natural compounds with multiple therapeutic effectiveness have also been anticipated. In brief, enough advancements have been carried out to achieve safe, effective and economic use of natural medicinal agents with improved stability, handling and storage.

Curcumin: Useful add-on for Rheumatic Diseases?

Plant-derived nutraceuticals are proposed as new key instruments to represent a profound "back to basics" shift in medical treatment. Data accumulated over the past ten years suggest that curcumin, the major active compound of the turmeric plant, has anti-inflammatory properties. It has yet to be determined whether the anti-inflammatory profile of curcumin is potent enough to justify the application of this substance as a nutritional supplement for patients with rheumatic diseases. To address this question, the most relevant in vitro studies that investigate the mechanism of action of curcumin were reviewed in this article. In addition, a total of 18 animal and human trials were evaluated. The pleiotropic, anti-inflammatory and immunomodulatory effects of curcumin were observed in animal studies. In addition, human trials demonstrated promising findings. In these studies, curcumin was able to reduce the expression of proinflammatory cytokines, lower the level of the C-reactive protein and improve clinical parameters. A limiting factor of the application of curcumin is the inconsistent bioavailability of the substance. Therefore, new formulations have been developed to improve the pharmacodynamic profile of curcumin. The future acceptance of the substance is dependent on new controlled clinical trials with a standardised formulation of curcumin administered as well as standard of care.

Benefits of Curcumin in the Vasculature: A Therapeutic Candidate for Vascular Remodeling in Arterial Hypertension and Pulmonary Arterial Hypertension?

Growing evidence suggests that hypertension is one of the leading causes of cardiovascular morbidity and mortality since uncontrolled high blood pressure increases the risk of myocardial infarction, aortic dissection, hemorrhagic stroke, and chronic kidney disease. Impaired vascular homeostasis plays a critical role in the development of hypertension-induced vascular remodeling. Abnormal behaviors of vascular cells are not only a pathological hallmark of hypertensive vascular remodeling, but also an important pathological basis for maintaining reduced vascular compliance in hypertension. Targeting vascular remodeling represents a novel therapeutic approach in hypertension and its cardiovascular complications. Phytochemicals are emerging as candidates with therapeutic effects on numerous pathologies, including hypertension. An increasing number of studies have found that curcumin, a polyphenolic compound derived from dietary spice turmeric, holds a broad spectrum of pharmacological actions, such as antiplatelet, anticancer, anti-inflammatory, antioxidant, and antiangiogenic effects. Curcumin has been shown to prevent or treat vascular remodeling in hypertensive rodents by modulating various signaling pathways. In the present review, we attempt to focus on the current findings and molecular mechanisms of curcumin in the treatment of hypertensive vascular remodeling. In particular, adverse and inconsistent effects of curcumin, as well as some favorable pharmacokinetics or pharmacodynamics profiles in arterial hypertension will be discussed. Moreover, the recent progress in the preparation of nano-curcumins and their therapeutic potential in hypertension will be briefly recapped. The future research directions and challenges of curcumin in hypertension-related vascular remodeling are also proposed. It is foreseeable that curcumin is likely to be a therapeutic agent for hypertension and vascular remodeling going forwards.

Multilayered Curcumin-Loaded Hydrogel Microcarriers with Antimicrobial Function

The design of multifunctional microcarriers has attracted significant attention because they combine various functions within a single system. In this study, we developed a set of multilayered hydrogel microcarriers, which were first loaded with chemotherapeutic curcumin (CUR), then, using the layer-by-layer (LbL) technique, coated through a polyelectrolyte shell consisting of chitosan (CHIT) or poly(allylamine hydrochloride) (PAH). As an outer layer with antimicrobial function, newly synthesised alkylene quaternary ammonium salt functionalised polyelectrolytes (A-QAS-PEs) were applied. For this purpose, poly(acrylic acid) (PAA) was decorated with different hydrophobic side chains (n-hexane and n-dodecane side entities) and different degrees of substitution (m) of quaternary ammonium groups (abbreviated as PAA-C(O)O-(CH2)n-N+(CH3)3(m); n = 6, 12; m = 8–14%). The grafting approach of PAA with the alkylene quaternary ammonium salt moiety was performed under mild reaction conditions using Steglich esterification followed by quaternisation. The structure of antimicrobial decorated PAA was confirmed by 1H NMR and FTIR, and the mean diameter of all multifunctional microparticles was characterised by SEM. The viscoelastic properties of the functional layers were studied using quartz crystal microbalance with a dissipation (QCM-D). The release of CUR from the microcarriers was described using a hybrid model, i.e., a combination of first-order kinetics and the Korsmeyer-Peppas model. The antimicrobial activity of functionalised PAA and multilayered CUR-loaded hydrogel microcarriers with quaternary ammonium function was assessed against Staphylococcus aureus and Serratia marcescens by the agar diffusion assay method. Only a limited inhibition zone of PAA was observed, but in the case of both antimicrobial decorated PAA and the corresponding multilayered nanocarriers, the inhibitory activity increase was achieved against both strains of bacteria.

Botanical Drug Extracts Combined With Biomaterial Carriers for Osteoarthritis Cartilage Degeneration Treatment: A Review of 10 Years of Research

Osteoarthritis (OA) is a long-term chronic arthrosis disease which is usually characterized by pain, swelling, joint stiffness, reduced range of motion, and other clinical manifestations and even results in disability in severe cases. The main pathological manifestation of OA is the degeneration of cartilage. However, due to the special physiological structure of the cartilage, once damaged, it is unable to repair itself, which is one of the challenges of treating OA clinically. Abundant studies have reported the application of cartilage tissue engineering in OA cartilage repair. Among them, cell combined with biological carrier implantation has unique advantages. However, cell senescence, death and dedifferentiation are some problems when cultured in vitro. Botanical drug remedies for OA have a long history in many countries in Asia. In fact, botanical drug extracts (BDEs) have great potential in anti-inflammatory, antioxidant, antiaging, and other properties, and many studies have confirmed their effects. BDEs combined with cartilage tissue engineering has attracted increasing attention in recent years. In this review, we will explain in detail how cartilage tissue engineering materials and BDEs play a role in cartilage repair, as well as the current research status.

Novel approaches of the nanotechnology-based drug delivery systems for knee joint injuries: A review

The knee joint is one of the largest, most complex, and frequently utilized organs in the body. It is very vulnerable to injuries due to activities, diseases, or accidents, which lead to or cause knee joint injuries in people of all ages. There are several types of knee joint injuries such as contusions, sprains, and strains to the ligament, tendon injuries, cartilage injuries, meniscus injuries, and inflammation of synovial membrane. To date, many drug delivery systems, e.g. nanoparticles, dendrimers, liposomes, micelles, and exosomes, have been used for the treatment of knee joint injuries. They aim to alleviate or reverse the symptoms with an improvement of the function of the knee joint by restoring or curing it. The nanosized structures show good biodegradability, biocompatibility, precise site-specific delivery, prolonged drug release, and enhanced efficacy. They regulate cell proliferation and differentiation, ECM synthesis, proinflammatory factor secretion, etc. to promote repair of injuries. The goal of this review is to outline the finding and studies of the novel strategies of nanotechnology-based drug delivery systems and provide future perspectives to combat the challenges of knee joint injuries by using nanotechnology.

Curcumin and rheumatoid arthritis: A systematic review of literature

BACKGROUND

Curcumin is a natural polyphenol and the main compound from the rhizome of Turmeric (Curcuma longa) and other Curcuma species. It has been widely used for different medical purposes, such as improvement of pain and inflammatory conditions in various diseases.

PURPOSE

This systematic review was aimed to assess all studies regarding the efficacy of the pure form of curcumin (unformulated curcumin) on rheumatoid arthritis (RA).

METHODS

The comprehensive search of the literature was done until September 2020 on the MEDLINE, Embase, Scopus and Web of Knowledge databases. Out of 2079 initial records, 51 articles (13 in vitro and 37 animal and one human) were met our inclusion criteria.

RESULTS

Most studies have shown the curative effects of curcumin on clinical and inflammatory parameters of RA and reported different mechanisms; inhibition of mitogen-activated protein kinase family, extracellular signal-regulated protein kinase, activator protein-1 and nuclear factor kappa B are the main mechanisms associated with the anti-inflammatory function of curcumin in RA. The results of the only human study showed that curcumin significantly improved morning stiffness, walking time and joint swelling.

CONCLUSION

In conclusion, curcumin seems to be useful, and it is recommended that more human studies be performed to approve the cellular and animal results and determine the effective and optimal doses of curcumin on RA patients.

Cytotoxic, Genotoxic and Senolytic Potential of Native and Micellar Curcumin

BACKGROUND

Curcumin, a natural polyphenol and the principal bioactive compound in Curcuma longa, was reported to have anti-inflammatory, anti-cancer, anti-diabetic and anti-rheumatic activity. Curcumin is not only considered for preventive, but also for therapeutic, purposes in cancer therapy, which requires a killing effect on cancer cells. A drawback, however, is the low bioavailability of curcumin due to its insolubility in water. To circumvent this limitation, curcumin was administered in different water-soluble formulations, including liposomes or embedded into nanoscaled micelles. The high uptake rate of micellar curcumin makes it attractive also for cancer therapeutic strategies. Native curcumin solubilised in organic solvent was previously shown to be cytotoxic and bears a genotoxic potential. Corresponding studies with micellar curcumin are lacking.

METHODS

We compared the cytotoxic and genotoxic activity of native curcumin solubilised in ethanol (Cur-E) with curcumin embedded in micells (Cur-M). We measured cell death by MTT assays, apoptosis, necrosis by flow cytometry, senolysis by MTT and C12FDG and genotoxicity by FPG-alkaline and neutral singe-cell gel electrophoresis (comet assay).

RESULTS

Using a variety of primary and established cell lines, we show that Cur-E and Cur-M reduce the viability in all cell types in the same dose range. Cur-E and Cur-M induced dose-dependently apoptosis, but did not exhibit senolytic activity. In the cytotoxic dose range, Cur-E and Cur-M were positive in the alkaline and the neutral comet assay. Genotoxic effects vanished upon removal of curcumin, indicating efficient and complete repair of DNA damage. For inducing cell death, which was measured 48 h after the onset of treatment, permanent exposure was required while 60 min pulse-treatment was ineffective. In all assays, Cur-E and Cur-M were equally active, and the concentration above which significant cytotoxic and genotoxic effects were observed was 10 µM. Micelles not containing curcumin were completely inactive.

CONCLUSIONS

The data show that micellar curcumin has the same cytotoxicity and genotoxicity profile as native curcumin. The effective concentration on different cell lines, including primary cells, was far above the curcumin concentration that can be achieved systemically in vivo, which leads us to conclude that native curcumin and curcumin administered as food supplement in a micellar formulation at the ADI level are not cytotoxic/genotoxic, indicating a wide margin of safety.

The Effect of Curcumin Nanoparticles on Cisplatin-Induced Cardiotoxicity in Male Wistar Albino Rats

The cardiotoxicity of chemotherapeutic drugs as cisplatin has become a major issue in recent years. The present study investigates the efficacy of curcumin nanoparticles against the cardiotoxic effects of cisplatin by assessment of oxidative stress parameters, Na+,K+-ATPase, acetylcholinesterase (AchE) and tumor necrosis factor-alpha (TNF-α) in cardiac tissue in addition to serum lactate dehydrogenase (LDH). Rats were divided into three groups: control rats that received saline for 14 days; cisplatin-treated rats that received a single intraperitoneal (i.p.) injection of cisplatin (12 mg/kg) followed by a daily oral administration of saline (0.9%) for 14 days and rats treated with a single i.p. injection of cisplatin (12 mg/kg) followed by a daily oral administration of curcumin nanoparticles (50 mg/kg) for 14 days. Cisplatin resulted in a significant increase in lipid peroxidation, nitric oxide (NO), and TNF-α and a significant decrease in reduced glutathione (GSH) levels and Na+, K+- ATPase activity. Moreover, significant increases in cardiac AchE and serum lactate dehydrogenase activities were recorded. Treatment of cisplatin-injected animals with curcumin nanoparticles ameliorated all the alterations induced by cisplatin in the heart of rats. This suggests that curcumin nanoparticles can be used as an important therapeutic adjuvant in chemotherapeutic and other toxicities mediated by oxidative stress and inflammation.

A family of chitosan-peptide conjugates provides broad HLB values, enhancing emulsion's stability, antioxidant and drug release capacity

Strong hydrophilicity of polysaccharide and physicochemical instability of peptides limit application of polysaccharide-peptide mixtures in food industry. In this study, a natural resource platform of polysaccharide-peptide conjugates was constructed through Maillard reaction from chitosan and casein hydrophobic peptide. By choosing the molecular weight and deacetylation degree of chitosan and other reaction parameters, the conjugated chitosan-peptides possess extensive HLB values from 6 to 14 were obtained with grafting degree of 3.10%-15.08%. The conjugates have gained dramatically improved emulsifying ability, and endowed the emulsion higher antioxidant capacity than the peptide, chitosan and the mixture of peptide-chitosan has. Emulsions prepared with all conjugates exhibited long-term stability and strengthened tolerance towards temperature and electrolyte stimuli. This stable emulsion system also provided an effective encapsulation, protection and controlled release of curcumin, which may provide a method for transfer polysaccharides to stable emulsifiers with broader HLB values and application.

Near-infrared light II - assisted rapid biofilm elimination platform for bone implants at mild temperature

Light-triggered therapy is a prospective method to combat implant-associated infection but near-infrared I (NIR-I) light has insufficient penetrating ability in tissues and local hyperthermia induced by the photothermal treatment may destroy surrounding healthy tissues. Herein, a near-infrared II (NIR-II) phototherapy system composed of upconversion elements doped titanium dioxide nanorods (TiO₂ NRs)/curcumin (Cur)/hyaluronic acid (HA)/bone morphogenetic protein-2 (BMP-2) is designed for biomedical titanium and demonstrated to overcome the above hurdles simultaneously. Incorporation of F, Yb, and Ho not only improves the photocatalytic ability, but also renders the implants with the upconversion capability, so that the NRs can generate enough reactive oxygen species (ROS) when irradiated by the NIR-II laser. Furthermore, the combined actions of quorum sensing inhibitors, ROS, and physical puncture by NRs eliminate Staphylococcus aureus biofilms on titanium rapidly at a mild temperature of 45 °C by only requiring irradiation with the 1060 nm laser for only 15 min in vitro and in vivo. The presence of Cur mitigates the immune response and BMP-2 improves osteogenic differentiation, thus accelerating new bone formation. This low-temperature NIR-II light-triggered antibacterial platform has large potential in combating deep-tissue infection in clinical applications.

Folate-Targeted Curcumin-Encapsulated Micellar Nanosystem for Chemotherapy and Curcumin-Mediated Photodynamic Therapy

Curcumin (CUR) is a natural phenolic product used as a high-efficiency and low-toxicity anticancer drug and photosensitizer. However, it has a poor aqueous solubility and a lack of target specificity, which limits its clinical applications. Hence, we developed a folate-conjugated polymeric micelle to enhance the efficient delivery of CUR for effective cancer cell targeting and anticancer efficiency. A series of biocompatible folate-conjugated poly(2-(methacryloyloxy)ethylphosphoryl- choline)-b-poly(ε-caprolactone) (FPM) was synthesized with different hydrophobic lengths and folate contents. The prepared CUR-loaded micelles (CUR-FPM) possessed several superior properties, including an excellent drug loading capacity (6.3 ± 1.2%), improved CUR aqueous stability, fast-sustained CUR release in an acidic environment, and efficient intracellular production of reactive oxygen species. The in vitro cytotoxicity demonstrated that the CUR-FPM micelles efficiently suppressed the growth of HeLa cells (folate-receptor overexpression) compared to that of HT-29 cells, and a competition study showed less cytotoxic effect when free folic acid blocked the folate receptor, indicating the folate conjugation played the role of targeting the specific cells well. Moreover, the CUR-mediated photodynamic therapy (PDT) by CUR-FPM micelles under irradiation further inhibited the proliferation of cancer cells. All these results indicate that the CUR-FPM micelles could be a promising delivery system for folate-overexpressing cancer cells, complementary chemotherapy, and CUR-mediated photodynamic therapy.

Antioxidant Activity of Encapsulated Extracts and Bioactives from Natural Sources

The low water solubility and low bioavailability of natural bioactive substances such as polyphenols and flavonoids, either in pure form or extracts, are a major concern in the pharmaceutical field and even on the food development sector. Although encapsulation has demonstrated success in addressing these drawbacks, it is important to evaluate the antioxidant activity of the encapsulated compounds. This article reviews the encapsulation of bioactive compounds from natural sources focusing their antioxidant activity after encapsulation. Attention is given to the methods and wall materials used, and the antioxidant activity methodologies (classical in vitro techniques such as DPPH, ORAC, FRAP and others, as well as in vivo/ex vivo tests to evaluate endogenous antioxidant enzymes or oxidative stress) applied to assess the antioxidant capacity are also comprehensively summarized.

Micellar solubilization enhances the anti-inflammatory effect of xanthohumol

BACKGROUND

Xanthohumol is known to exert anti-inflammatory properties but has poor oral bioavailability. Using advanced micellization technology, it has been possible to markedly enhance its bioavailability.

PURPOSE

In the present study, we compared the chronic anti-inflammatory activities of native and micellar xanthohumol in the rat adjuvant arthritis model, using diclofenac as a reference drug.

METHODS

Adjuvant arthritis was induced by injecting Freund's complete adjuvant into the right hind paw of rats and monitoring paw volume over 3 weeks. The drugs were given daily for 3 weeks, starting from the day of adjuvant inoculation. Serum was collected at the end of the experiment to measure inflammatory and oxidative stress parameters. Statistical comparisons between different groups were carried out by one-way analysis of variance followed by Tukey-Kramer multiple comparison test.

RESULTS

Micellar solubilized xanthohumol showed a better anti-inflammatory activity than its native form. The reduction in paw volume was reflected in corresponding changes in relevant mediators of inflammation like tumor necrosis factor-α, interleukin-6 and C-reactive protein, myloperoxidase and lipid peroxidation markers.

CONCLUSION

The findings confirm that micellar solubilization of xanthohumol enhances its anti-inflammatory activity, probably as a result of improving its bioavailabilty. The solubilized xanthohumol may prove to be a promising adjuvant tool for anti-inflammatory treatment and a potential anti-inflammatory alternative to synthetic drugs.

Modulatory effects of curcumin on the atherogenic activities of inflammatory monocytes: Evidence from in vitro and animal models of human atherosclerosis

Atherosclerosis is a complex and long-lasting disorder characterized by chronic inflammation of arteries that leads to the initiation and progression of lipid-rich plaques, in which monocytes/macrophages play the central role in endothelial inflammation and taking up these lipids. Circulating monocytes can adopt a long-term proinflammatory phenotype leading to their atherogenic activities. During atherogenic condition, inflammatory monocytes adhere to the surface of the activated endothelial cells and then transmigrate across the endothelial monolayer into the intima, where they proliferate and differentiate into macrophages and take up the lipoproteins, forming foam cells that derive atherosclerosis progression. Therefore, modulating the atherogenic activities of inflammatory monocytes can provide a valuable therapeutic approach for atherosclerosis prevention and treatment. Curcumin is a naturally occurring polyphenolic compound with numerous pharmacological activities and shows protective effects against atherosclerosis; however, underlying mechanisms are not clearly known yet. In the present review, on the basis of a growing body of evidence, we show that curcumin can exert antiatherosclerotic effect through inhibiting the atherogenic properties of monocytes, including inflammatory cytokine production, adhesion, and transendothelial migration, as well as intracellular cholesterol accumulation.

Therapeutic effects of curcumin on sepsis and mechanisms of action: A systematic review of preclinical studies

Sepsis is a complex disease that begins with an infectious disorder and causes excessive immune responses. Curcumin is considered as an active component of turmeric that can improve the condition in sepsis due to its anti-inflammatory and antioxidant properties. PubMed, Embase, Google Scholar, Web of Science, and Scopus databases were searched. Searching was not limited to a specific publication period. Only English-language original articles, which had examined the effect of curcumin on sepsis, were included. At first, 1,098 articles were totally found, and 209 articles were selected after excluding duplicated data; 46 articles were remained due to the curcumin effects on sepsis. These included 23 in vitro studies and 23 animal studies. Our results showed that curcumin and various analogs of curcumin can have an inhibitory effect on sepsis-induced complications. Curcumin has the ability to inhibit the inflammatory, oxidative coagulation factors, and regulation of immune responses in sepsis. Despite the promising evidence of the therapeutic effects of curcumin on the sepsis complication, further studies seem necessary to investigate its effect and possible mechanisms of action in human studies.

Mechanistic insights of hepatoprotective effects of curcumin: Therapeutic updates and future prospects

The liver is the most essential organ of the body performing vital functions. Hepatic disorders affect the physiological and biochemical functions of the body. These disorders include hepatitis B, hepatitis C, alcoholic liver disease (ALD), nonalcoholic fatty liver disease (NAFLD), liver cirrhosis, hepatic failure and hepatocellular carcinoma (HCC). Drugs related hepatotoxicity is one of the major challenges facing by clinicians as it is a leading cause of liver failure. During post-marketing surveillance studies, detection and reporting of drug-induced hepatotoxicity may lead to drug withdrawal or warnings. Several mechanisms are involved in hepatotoxicity such as cell membrane disruption, initiating an immune response, alteration of cellular pathways of drug metabolism, accumulation of reactive oxygen species (ROS), lipid peroxidation and cell death. Curcumin, the active ingredient of turmeric and exhibits therapeutic potential for the treatment of diabetes, cardiovascular disorders and various types of cancers. Curcumin is strong anti-oxidant and anti-inflammatory effects and thus it possesses hepatoprotective properties. Despite its low bioavailability, its hepatoprotective effects have been studied in various protocols of hepatotoxicity including acetaminophen, alcohol, lindane, carbon tetrachloride (CCL₄), diethylnitrosamine and heavy metals induced hepatotoxicities. This report reviews the hepatoprotective effects of curcumin with a focus on its mechanistic insights in various hepatotoxic protocols.

Bioactivity, Health Benefits, and Related Molecular Mechanisms of Curcumin: Current Progress, Challenges, and Perspectives

Curcumin is a principal curcuminoid of turmeric (Curcuma longa), which is commonly used as a spice in cooking and a yellow pigment in the food processing industry. Recent studies have demonstrated that curcumin has a variety of biological activities and pharmacological performances, providing protection and promotion of human health. In addition to presenting an overview of the gut metabolism of curcumin, this paper reviews the current research progress on its versatile bioactivity, such as antioxidant, anti-inflammatory, and immune-regulatory activities, and also intensively discusses its health benefits, including the protective or preventive effects on cancers and diabetes, as well as the liver, nervous system, and cardiovascular systems, highlighting the potential molecular mechanisms. Besides, the beneficial effects of curcumin on human are further stated based on clinical trials. Considering that there is still a debate on the beneficial effects of curcumin, we also discuss related challenges and prospects. Overall, curcumin is a promising ingredient of novel functional foods, with protective efficacy in preventing certain diseases. We hope this comprehensive and updated review will be helpful for promoting human-based studies to facilitate its use in human health and diseases in the future.

Dual antibacterial behavior of a curcumin–upconversion photodynamic nanosystem for efficient eradication of drug-resistant bacteria in a deep joint infection

The curcumin–upconversion photodynamic nanosystem exhibits dual antibacterial behavior for MRSA-induced periprosthetic joint infection under NIR irradiation.