Curcumin inhibits LPS-induced inflammation in rat vascular smooth muscle cells in vitro via ROS-relative TLR4-MAPK/NF-κB pathways

Sequential management of burn wound healing stages through biointelligence-inspired platelet extracellular vesicle-encapsulated photodynamic diferuloylmethane

The process of wound healing is a complex, multi-phase phenomenon crucial for optimal tissue regeneration. Traditional drug delivery systems often target specific phases of wound repair, neglecting the dynamic interplay among the stages. This limitation highlights the need for comprehensive delivery systems that cater to the holistic needs of wound healing, enhancing tissue regeneration efficiency. Herein, we explored the utility of platelet-derived extracellular vesicles (pEVs) as carriers for the phototherapeutic diferuloylmethane (DIF), resulting in a formulation termed DIF@pEVs, which is designed to sequentially address the distinct phases of wound healing. Initially, upon exposure to light, administered DIF@pEVs generate photodynamic therapy-derived reactive oxygen species during the early inflammatory phase. This generation of ROS aims to modulate the inflammatory response, induce the protective mechanisms of heat shock proteins, and kickstart the tissue regeneration process. Following this initial phase, the remaining DIF and pEVs persist in promoting tissue repair and regeneration. Ultimately, it reduces inflammation, speeds up the healing process, and promotes vascular and follicular formation in a model of burn wound skin damage, thereby supporting skin regeneration. The deployment of DIF@pEVs represents an advancement in regenerative medicine, providing a precise, versatile approach to fostering regeneration across a wide range of clinical scenarios.

The emerging role of oxidative stress in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic immune-mediated condition that affects the digestive system and includes Crohn's disease (CD) and ulcerative colitis (UC). Although the exact etiology of IBD remains uncertain, dysfunctional immunoregulation of the gut is believed to be the main culprit. Amongst the immunoregulatory factors, reactive oxygen species (ROS) and reactive nitrogen species (RNS), components of the oxidative stress event, are produced at abnormally high levels in IBD. Their destructive effects may contribute to the disease's initiation and propagation, as they damage the gut lining and activate inflammatory signaling pathways, further exacerbating the inflammation. Oxidative stress markers, such as malondialdehyde (MDA), 8-hydroxy-2'-deoxyguanosine (8-OHdG), and serum-free thiols (R-SH), can be measured in the blood and stool of patients with IBD. These markers are elevated in patients with IBD, and their levels correlate with the severity of the disease. Thus, oxidative stress markers can be used not only in IBD diagnosis but also in monitoring the response to treatment. It can also be targeted in IBD treatment through the use of antioxidants, including vitamin C, vitamin E, glutathione, and N-acetylcysteine. In this review, we summarize the role of oxidative stress in the pathophysiology of IBD, its diagnostic targets, and the potential application of antioxidant therapies to manage and treat IBD.

The Modulatory Effects of Curcumin on the Gut Microbiota: A Potential Strategy for Disease Treatment and Health Promotion

Curcumin (CUR) is a lipophilic natural polyphenol that can be isolated from the rhizome of turmeric. Studies have proposed that CUR possesses a variety of biological activities. Due to its anti-inflammatory and antioxidant properties, CUR shows promise in the treatment of inflammatory bowel disease, while its anti-obesity effects make it a potential therapeutic agent in the management of obesity. In addition, curcumin's ability to prevent atherosclerosis and its cardiovascular benefits further expand its potential application in the treatment of cardiovascular disease. Nevertheless, owing to the limited bioavailability of CUR, it is difficult to validate its specific mechanism of action in the treatment of diseases. However, the restricted bioavailability of CUR makes it challenging to confirm its precise mode of action in disease treatment. Recent research indicates that the oral intake of curcumin may lead to elevated levels of residual curcumin in the gastrointestinal system, hinting at curcumin's potential to directly influence gut microbiota. Furthermore, the ecological dysregulation of the gut microbiota has been shown to be critical in the pathogenesis of human diseases. This review summarizes the impact of gut dysbiosis on host health and the various ways in which curcumin modulates dysbiosis and ameliorates various diseases caused by it through the administration of curcumin.

Promotion of transcription factor EB-dependent autophagic process by curcumin alleviates arsenic-caused lung oxidative stress and inflammation in mice

Arsenic is a human carcinogen widely distributed in the environment, and arsenic exposure from drinking water has received widespread attention as a global public health problem. Curcumin is a natural bioactive substance with high efficiency and low toxicity extracted from turmeric, which has a variety of biological properties such as antioxidation, anti-inflammation, anticancer, and immuno-modulatory activities. Curcumin is widely used in daily life as a food additive and dietary supplement. However, its protective effects in lung injuries by chronic arsenic exposure orally remain unexplored. In this study, curcumin treatment not only significantly accelerated arsenic elimination and improved lung tissue morphology, but also decreased arsenic-generated ROS by activating Nrf2 and its down-stream antioxidants. Further, curcumin alleviated inflammatory changes in mice exposed to arsenic for 6 and 12 weeks, as manifested by lung MPO levels, total protein and cellular levels in bronchoalveolar lavage fluid (BALF), serum IL-4 levels, and MAPK/NF-κB expression in lung tissue. Notably, our study also confirmed that curcumin could promote the expression and nuclear translocation of the transcription factor EB (TFEB), as well as activate TFEB-regulated autophagy in lung tissue of arsenic-treated mice, accompanied by inhibition of the AKT-mTOR signaling pathway. Overall, our study here suggests that natural bioactive compound curcumin could alleviate arsenic-induced pulmonary oxidative stress and inflammation in vivo, which is closely related to enhanced TFEB activity and induction of the autophagic process.

Effect of reactive oxygen, nitrogen, and sulfur species on signaling pathways in atherosclerosis

Atherosclerosis is a chronic inflammatory disease in which fats, lipids, cholesterol, calcium, proliferating smooth muscle cells, and immune cells accumulate in the intima of the large arteries, forming atherosclerotic plaques. A complex interplay of various vascular and immune cells takes place during the initiation and progression of atherosclerosis. Multiple reports indicate that tight control of reactive oxygen species (ROS), reactive nitrogen species (RNS), and reactive sulfur species (RSS) production is critical for maintaining vascular health. Unrestricted ROS and RNS generation may lead to activation of various inflammatory signaling pathways, facilitating atherosclerosis. Given these deleterious consequences, it is important to understand how ROS and RNS affect the signaling processes involved in atherogenesis. Conversely, RSS appears to exhibit an atheroprotective potential and can alleviate the deleterious effects of ROS and RNS. Herein, we review the literature describing the effects of ROS, RNS, and RSS on vascular smooth muscle cells, endothelial cells, and macrophages and focus on how changes in their production affect the initiation and progression of atherosclerosis. This review also discusses the contribution of ROS, RNS, and RSS in mediating various post-translational modifications, such as oxidation, nitrosylation, and sulfation, of the molecules involved in inflammatory signaling.

Role of Nutraceuticals in Counteracting Inflammation in In Vitro Macrophages Obtained from Childhood Cancer Survivors

The advancement of anti-cancer therapies has markedly improved the survival rate of children with cancer, making them long-term childhood cancer survivors (CCS). Nevertheless, these treatments cause a low-grade inflammatory state, determining inflamm-aging and, thus, favoring the early onset of chronic diseases normally associated with old age. Identification of novel and safer therapeutic strategies is needed to counteract and prevent inflamm-aging. Macrophages are cells involved in immune and inflammatory responses, with a pivotal role in iron metabolism, which is related to inflammation. We obtained macrophages from CCS patients and evaluated their phenotype markers, inflammatory states, and iron metabolism by Western blotting, ELISA, and iron assays. We observed a strong increase in classically activated phenotype markers (M1) and iron metabolism alteration in CCS, with an increase in intracellular iron concentration and inflammatory markers. These results suggest that the prevalence of M1 macrophages and alteration of iron metabolism could be involved in the worsening of inflammation in CCS. Therefore, we propose macrophages and iron metabolism as novel therapeutic targets to counteract inflamm-aging. To avoid toxic regimens, we tested some nutraceuticals (resveratrol, curcumin, and oil-enriched lycopene), which are already known to exert anti-inflammatory properties. After their administration, we observed a macrophage switch towards the anti-inflammatory phenotype M2, as well as reductions in pro-inflammatory cytokines and the intracellular iron concentration. Therefore, we suggest-for the first time-that nutraceuticals reduce inflammation in CCS macrophages through a novel anti-inflammatory mechanism of action, modulating iron metabolism.

Review of the Protective Mechanism of Curcumin on Cardiovascular Disease

Cardiovascular diseases (CVDs) are the most common cause of death worldwide and has been the focus of research in the medical community. Curcumin is a polyphenolic compound extracted from the root of turmeric. Curcumin has been shown to have a variety of pharmacological properties over the past decades. Curcumin can significantly protect cardiomyocyte injury after ischemia and hypoxia, inhibit myocardial hypertrophy and fibrosis, improve ventricular remodeling, reduce drug-induced myocardial injury, improve diabetic cardiomyopathy(DCM), alleviate vascular endothelial dysfunction, inhibit foam cell formation, and reduce vascular smooth muscle cells(VSMCs) proliferation. Clinical studies have shown that curcumin has a protective effect on blood vessels. Toxicological studies have shown that curcumin is safe. But high doses of curcumin also have some side effects, such as liver damage and defects in embryonic heart development. This article reviews the mechanism of curcumin intervention on CVDs in recent years, in order to provide reference for the development of new drugs in the future.

Cardioprotective effects of arjunolic acid in LPS-stimulated H9C2 and C2C12 myotubes via the My88-dependent TLR4 signaling pathway

CONTEXT

Arjunolic acid (AA) is a triterpenoid saponin found in Terminalia arjuna (Roxb.) Wight & Arn. (Combretaceae). It exerts cardiovascular protective effects as a phytomedicine. However, it is unclear how AA exerts the effects at the molecular level.

OBJECTIVE

This study investigates the cardioprotective effects of arjunolic acid (AA) via MyD88-dependant TLR4 downstream signaling marker expression.

MATERIALS AND METHODS

The MTT viability assay was used to assess the cytotoxicity of AA. LPS induced in vitro cardiovascular disease model was developed in H9C2 and C2C12 myotubes. The treatment groups were designed such as control (untreated), LPS control, positive control (LPS + pyrrolidine dithiocarbamate (PDTC)-25 µM), and treatment groups were co-treated with LPS and three concentrations of AA (50, 75, and 100 µM) for 24 h. The changes in the expression of TLR4 downstream signaling markers were evaluated through High Content Screening (HCS) and Western Blot (WB) analysis.

RESULTS

After 24 h of co-treatment, the expression of TLR4, MyD88, MAPK, JNK, and NF-κB markers were upregulated significantly (2-6 times) in the LPS-treated groups compared to the untreated control in both HCS and WB experiments. Evidently, the HCS analysis revealed that MyD88, NF-κB, p38, and JNK were significantly downregulated in the H9C2 myotube in the AA treated groups. In HCS, the expression of NF-κB was downregulated in C2C12. Additionally, TLR4 expression was downregulated in both H9C2 and C2C12 myotubes in the WB experiment.

DISCUSSION AND CONCLUSIONS

TLR4 marker expression in H9C2 and C2C12 myotubes was subsequently decreased by AA treatment, suggesting possible cardioprotective effects of AA.

Targeting endothelial cells with golden spice curcumin: A promising therapy for cardiometabolic multimorbidity

Cardiometabolic multimorbidity (CMM) is an increasingly significant global public health concern. It encompasses the coexistence of multiple cardiometabolic diseases, including hypertension, stroke, heart disease, atherosclerosis, and T2DM. A crucial component to the development of CMM is the disruption of endothelial homeostasis. Therefore, therapies targeting endothelial cells through multi-targeted and multi-pathway approaches hold promise for preventing and treatment of CMM. Curcumin, a widely used dietary supplement derived from the golden spice Carcuma longa, has demonstrated remarkable potential in treatment of CMM through its interaction with endothelial cells. Numerous studies have identified various molecular targets of curcumin (such as NF-κB/PI3K/AKT, MAPK/NF-κB/IL-1β, HO-1, NOs, VEGF, ICAM-1 and ROS). These findings highlight the efficacy of curcumin as a therapeutic agent against CMM through the regulation of endothelial function. It is worth noting that there is a close relationship between the progression of CMM and endothelial damage, characterized by oxidative stress, inflammation, abnormal NO bioavailability and cell adhesion. This paper provides a comprehensive review of curcumin, including its availability, pharmacokinetics, pharmaceutics, and therapeutic application in treatment of CMM, as well as the challenges and future prospects for its clinical translation. In summary, curcumin shows promise as a potential treatment option for CMM, particularly due to its ability to target endothelial cells. It represents a novel and natural lead compound that may offer significant therapeutic benefits in the management of CMM.

Beyond Glucose: The Dual Assault of Oxidative and ER Stress in Diabetic Disorders

Diabetes mellitus, a prevalent global health concern, is characterized by hyperglycemia. However, recent research reveals a more intricate landscape where oxidative stress and endoplasmic reticulum (ER) stress orchestrate a dual assault, profoundly impacting diabetic disorders. This review elucidates the interplay between these two stress pathways and their collective consequences on diabetes. Oxidative stress emanates from mitochondria, where reactive oxygen species (ROS) production spirals out of control, leading to cellular damage. We explore ROS-mediated signaling pathways, which trigger β-cell dysfunction, insulin resistance, and endothelial dysfunction the quintessential features of diabetes. Simultaneously, ER stress unravels, unveiling how protein folding disturbances activate the unfolded protein response (UPR). We dissect the UPR's dual role, oscillating between cellular adaptation and apoptosis, significantly influencing pancreatic β-cells and peripheral insulin-sensitive tissues. Crucially, this review exposes the synergy between oxidative and ER stress pathways. ROS-induced UPR activation and ER stress-induced oxidative stress create a detrimental feedback loop, exacerbating diabetic complications. Moreover, we spotlight promising therapeutic strategies that target both stress pathways. Antioxidants, molecular chaperones, and novel pharmacological agents offer potential avenues for diabetes management. As the global diabetes burden escalates, comprehending the dual assault of oxidative and ER stress is paramount. This review not only unveils the intricate molecular mechanisms governing diabetic pathophysiology but also advocates a holistic therapeutic approach. By addressing both stress pathways concurrently, we may forge innovative solutions for diabetic disorders, ultimately alleviating the burden of this pervasive health issue.

Oxidative stress, hormones, and effects of natural antioxidants on intestinal inflammation in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic, relapsing gastrointestinal (GI) disorder characterized by intestinal inflammation. The etiology of IBD is multifactorial and results from a complex interplay between mucosal immunity, environmental factors, and host genetics. Future therapeutics for GI disorders, including IBD, that are driven by oxidative stress require a greater understanding of the cellular and molecular mechanisms mediated by reactive oxygen species (ROS). In the GI tract, oxidative stressors include infections and pro-inflammatory responses, which boost ROS generation by promoting the production of pro-inflammatory cytokines. Nuclear factor kappa B (NF-κB) and nuclear factor erythroid 2-related factor 2 (Nrf2) represent two important signaling pathways in intestinal immune cells that regulate numerous physiological processes, including anti-inflammatory and antioxidant activities. Natural antioxidant compounds exhibit ROS scavenging and increase antioxidant defense capacity to inhibit pro-oxidative enzymes, which may be useful in IBD treatment. In this review, we discuss various polyphenolic substances (such as resveratrol, curcumin, quercetin, green tea flavonoids, caffeic acid phenethyl ester, luteolin, xanthohumol, genistein, alpinetin, proanthocyanidins, anthocyanins, silymarin), phenolic compounds including thymol, alkaloids such as berberine, storage polysaccharides such as tamarind xyloglucan, and other phytochemicals represented by isothiocyanate sulforaphane and food/spices (such as ginger, flaxseed oil), as well as antioxidant hormones like melatonin that target cellular signaling pathways to reduce intestinal inflammation occurring with IBD.

Isolated Fraction of Gastric-Digested Camel Milk Yogurt with Carao (Cassia grandis) Pulp Fortification Enhances the Anti-Inflammatory Properties of HT-29 Human Intestinal Epithelial Cells

Functional foods have recently generated a lot of attention among consumers looking for healthy options. Studies have examined yogurt with carao to increase health benefits and probiotic characteristics. It has been determined that carao fruit and camel milk have high phenolic compound and antioxidant activity concentrations. The objective of this study was to examine if carao (0, 1.3, 2.65, and 5.3 g/L) incorporated into yogurt enhances anti-inflammatory stimulus and antioxidant activity and impacts the physio-chemical and sensory properties of camel milk yogurt. HT-29 cells were used as a model of anti-inflammatory response, including cytokine responses of IL-8 and mRNA production of IL-1β and TNF-α in gastric digested isolated fraction. In addition, pH, titratable acidity, Streptococcus thermophilus counts and Lactobacillus bulgaricus counts of camel yogurts were examined during the fermentation process in 0, 2.5, 5, and 7 h whereas viscosity, syneresis, and radical scavenging assay evaluations were determined at hour 7. Furthermore, a consumer study was performed. Compared to control samples, the incorporation of carao into yogurts did not lead to a significant (ρ > 0.05) difference in the pH. In contrast, titratable acidity (TA), viscosity, syneresis, and antioxidant capacity significantly increased with the inclusion of 2.65 and 5.3 g/L carao, while 5.3 g/L carao significantly (ρ < 0.05) increased the counts of both bacteria. The inflammatory response of IL-8 and the level of mRNA production of IL-1β and TNF-α was significantly (ρ < 0.05) lower with 2.65 and 5.3 g/L carao yogurt compared to control camel yogurt. Sensory attributes were not impacted by the addition of 1.3 and 2.65 g/L carao. Carao could be a possible ingredient to consider when improving the nutrition value of yogurt.

Micro-algal astaxanthin improves lambda-cyhalothrin-induced necroptosis and inflammatory responses via the ROS-mediated NF-κB signaling in lymphocytes of carp (Cyprinus carpio L.)

Lambda-cyhalothrin (LCY) is a widely used toxic pesticide that causes harmful effects on the immune organs of fish and aquatic species. Micro-algal astaxanthin (MAA), a heme pigment found in haematococcus pluvialis, has been shown to benefit antioxidants and immunity in aquaculture. To investigate how MAA protects carp lymphocytes from LCY-induced immunotoxicity, a model of fish lymphocytes treated with LCY and/or MAA was established. Lymphocytes from carp (Cyprinus carpio L.) were given LCY (80 μM) and/or MAA (50 μM) as a treatment for a period of 24 h. Firstly, LCY exposure resulted in excessive ROS and malondialdehyde production and reduces antioxidant enzymes (SOD and CAT), indicating a reduced capacity of the antioxidant system. Secondly, the results of flow cytometry and AO/EB labeling proved that lymphocytes treated with LCY have a larger ratio of necroptosis. In addition, LCY upregulated the levels of necroptosis-related regulatory factors (RIP1, RIP3 and MLKL) via the ROS-mediated NF-κB signaling pathway in lymphocytes. Thirdly, LCY treatment caused increased secretion of inflammatory genes (IL-6, INF-γ, IL-4, IL-1β and TNF-α), leading to immune dysfunction in lymphocytes. Surprisingly, LCY-induced immunotoxicity was inhibited by MAA treatment, indicating that it effectively attenuated the LCY-induced changes described above. Overall, we concluded that MAA treatment could ameliorate LCY-induced necroptosis and immune dysfunction by inhibiting the ROS-mediated NF-κB signaling in lymphocytes. It provides insights into the protection of farmed fish from agrobiological threats in fish under LCY and the value of MAA applications in aquaculture.

Polysaccharides-based nanocarriers enhance the anti-inflammatory effect of curcumin

Curcumin (CUR) has been discovered to have many biological activities, including anti-inflammatory, anti-cancer, anti-oxygenation, anti-human immunodeficiency virus, anti-microbial and exhibits a good effect on the prevention and treatment of many diseases. However, the limited properties of CUR, including the poor solubility, bioavailability and instability caused by enzymes, light, metal irons, and oxygen, have compelled researchers to turn their attention to drug carrier application to overcome these drawbacks. Encapsulation may provide potential protective effects to the embedding materials and/or have a synergistic effect with them. Therefore, nanocarriers, especially polysaccharides-based nanocarriers, have been developed in many studies to enhance the anti-inflammatory capacity of CUR. Consequently, it's critical to review current advancements in the encapsulation of CUR using polysaccharides-based nanocarriers, as well as further study the potential mechanisms of action where polysaccharides-based CUR nanoparticles (the complex nanoparticles/Nano CUR-delivery systems) exhibit their anti-inflammatory effects. This work suggests that polysaccharides-based nanocarriers will be a thriving field in the treatment of inflammation and inflammation-related diseases.

Phenolic metabolites as therapeutic in inflammation and neoplasms: molecular pathways explaining their efficacy

Polyphenols, also known as phenolic compounds, are chemical substances containing aromatic rings as well as at least two hydroxyl groups. Natural phenolic compounds exist widely in plants, which protect plants from ultraviolet radiation and other insults. Phenolic compounds have superior pharmacological and nutritional properties (antimicrobial, antibacterial, antiviral, anti-sclerosis, antioxidant, and anti-inflammatory activities), which have been paid more and more attention by the scientific community. Phenols can protect key cellular components from reactive free radical damage, which is mainly due to their property to activate antioxidant enzymes and alleviate oxidative stress and inflammation. It can also inhibit or isolate reactive oxygen species and transfer electrons to free radicals, thereby avoiding cell damage. It has a regulatory role in glucose metabolism, which has a promising prospect in the prevention and intervention of diabetes. It also prevents cardiovascular disease by regulating blood pressure and blood lipids. Polyphenols can inhibit cell proliferation by affecting Erk1/2, CDK, and PI3K/Akt signaling pathways. Polyphenols can function as enhancers of intrinsic defense systems, including superoxide dismutase (SOD) and glutathione peroxidase (GPX). Simultaneously, they can modulate multiple proteins and transcription factors, making them promising candidates in the investigation of anti-cancer medications. This review focuses on multiple aspects of phenolic substances, including their natural origins, production process, disinfection activity, oxidative and anti-inflammatory functions, and the effects of different phenolic substances on tumors.

PCSK9 attenuates efferocytosis in endothelial cells and promotes vascular aging

Aims: Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a serine protease that binds to low-density lipoprotein receptors. Efferocytosis is the process by which phagocytes remove apoptotic cells. Both PCSK9 and efferocytosis play important roles in regulating redox biology and inflammation, the key factors contributing to vascular aging. This study was designed to investigate the impact of PCSK9 on efferocytosis in endothelial cells (ECs) and its implications in vascular aging. Methods and Results: Studies were performed in primary human aortic ECs (HAECs) and primary mouse aortic ECs (MAECs) isolated from male wild-type (WT) and PCSK9-/- mice, and in young and aged mice treated with saline or the PCSK9 inhibitor Pep2-8. Our findings include that recombinant PCSK9 protein induces defective efferocytosis and aging marker senescence-associated-β-galactosidase (SA-β-gal) expression in ECs, while PCSK9-/- restores efferocytosis and inhibits SA-β-gal activity. Further studies in aged mice showed that endothelial deficiency of MerTK, a critical receptor for efferocytosis that allows phagocytes to detect the presence of apoptotic cells, may be an indicator of vascular dysfunction in the aortic arch. Pep2-8 treatment markedly restored efferocytosis in endothelium from the aged mice. A proteomics study in the aortic arch from aged mice revealed that Pep2-8 administration significantly downregulates expression of NOX4, MAPK subunits, NF-κB, and secretion of pro-inflammatory cytokines, all known to promote vascular aging. Immunofluorescent staining showed that Pep2-8 administration upregulates expression of eNOS and downregulates expression of pro-IL-1β, NF-κB and p22phox compared to saline treated group. Conclusions: These findings provide initial evidence for the ability of aortic ECs to accomplish efferocytosis and argue for a role of PCSK9 in attenuating EC efferocytosis, thereby leading to vascular dysfunction and acceleration in vascular aging.

Curcumin and chemokines: mechanism of action and therapeutic potential in inflammatory diseases

Chemokines belong to the family of cytokines with chemoattractant properties that regulate chemotaxis and leukocyte migration, as well as the induction of angiogenesis and maintenance of hemostasis. Curcumin, the major component of the Curcuma longa rhizome, has various pharmacological actions, including anti-inflammatory, immune-regulatory, anti-oxidative, and lipid-modifying properties. Chemokines and chemokine receptors are influenced/modulated by curcumin. Thus, the current review focuses on the molecular mechanisms associated with curcumin's effects on chemoattractant cytokines, as well as putting into context the many studies that have reported curcumin-mediated regulatory effects on inflammatory conditions in the organs/systems of the body (e.g., the central nervous system, liver, and cardiovascular system). Curcumin's effects on viral and bacterial infections, cancer, and adverse pregnancy outcomes are also reviewed.

Curcumin interferes with sepsis-induced cardiomyocyte apoptosis via TLR1 inhibition

OBJECTIVE

Sepsis-induced cardiomyopathy is the leading cause of death in sepsis and is characterized by reversible myocardial depression. However, the specific mechanisms responsible for myocardial injury in sepsis are not known. The present study used bioinformatic analysis to explore the possible mechanisms of sepsis-induced myocardial injury and the therapeutic potential of curcumin.

METHODS

The GSE125042 microarray gene expression matrix was obtained from the Gene Expression Omnibus database, which includes 10 septic cardiomyocyte samples from cecum ligation perforation constructs and 10 sham-operated groups cardiomyocyte samples. Background correction and matrix data normalization were performed using the robust multiarray average algorithm. Differentially expressed genes (DEGs) screening was performed using the Limma R package expression matrix, and whole gene analysis was performed using the weighted gene co-expression network analysis R package to construct gene networks and identify modules. Enrichment analysis and gene set enrichment analysis was performed on the genes to be selected. Construct cellular and animal models of myocardial injury in sepsis were assessed and the effects of curcumin on a rat or cardiac myocytes were observed.

RESULTS

A total of 2876 DEGs were screened based on the GSE125042 chip, of which 1424 genes were upregulated and 1452 genes were down regulated. WGCNA analysis of the whole genes was also performed and a total of 20 gene modules were generated. Among them, the selected TLR1 gene was present in the most strongly correlated Brown module. Enrichment analysis of the upregulated DEGs with the Brown module showed that they were significantly enriched in biological processes related to ribosomal protein complex generation, cellular components related to phagocytic vesicles and molecular functions related to Toll-like receptor binding, affecting cardiomyocyte survival as a target for molecular intervention in septic cardiomyopathy. Animal experiments showed that curcumin reduced inflammation levels, improved cardiac function and increased survival in rats with septic myocardial injury. Cellular experiments showed that curcumin increased the survival rate of lipopolysaccharide-treated cardiomyocytes and down regulated TLR1 expression and inhibited NF-κB phosphorylation in cells in a dose-dependent manner. Molecular docking analysis revealed that curcumin interacted with TLR1 by hydrogen bonding and could be stably bound to inhibit the biological function of TLR1.

CONCLUSION

Our study shows that curcumin attenuates myocardial injury in sepsis by inhibiting TLR1 expression, which provides a molecular theoretical basis for clinical treatment.

Anti-Inflammatory Therapeutic Mechanisms of Natural Products: Insight from Rosemary Diterpenes, Carnosic Acid and Carnosol

Carnosic acid (CA) and carnosol (CAR) are two major diterpenes of the rosemary plant (Rosmarinus officinalis). They possess a phenolic structural moiety and are endowed with the power to remove cellular reactive oxygen species (ROS) either through direct scavenging reaction or indirectly through upregulation of antioxidant defences. Hand in hand with these activities are their multiple biological effects and therapeutic potential orchestrated through modulating various signalling pathways of inflammation, including the NF-κB, MAPK, Nrf2, SIRT1, STAT3 and NLRP3 inflammasomes, among others. Consequently, they ameliorate the expression of pro-inflammatory cytokines (e.g., TNF-α, IL-1 and IL-6), adhesion molecules, chemokines and prostaglandins. These anti-inflammatory mechanisms of action as a therapeutic link to various effects of these compounds, as in many other natural products, are scrutinised.

Natural Bioactive Compounds Targeting NADPH Oxidase Pathway in Cardiovascular Diseases

Cardiovascular disease (CVD) is the leading cause of death worldwide, in both developed and developing countries. According to the WHO report, the morbidity and mortality caused by CVD will continue to rise with the estimation of death going up to 22.2 million in 2030. NADPH oxidase (NOX)-derived reactive oxygen species (ROS) production induces endothelial nitric oxide synthase (eNOS) uncoupling and mitochondrial dysfunction, resulting in sustained oxidative stress and the development of cardiovascular diseases. Seven distinct members of the family have been identified of which four (namely, NOX1, 2, 4 and 5) may have cardiovascular functions. Currently, the treatment and management plan for patients with CVDs mainly depends on the drugs. However, prolonged use of prescribed drugs may cause adverse drug reactions. Therefore, it is crucial to find alternative treatment options with lesser adverse effects. Natural products have been gaining interest as complementary therapy for CVDs over the past decade due to their wide range of medicinal properties, including antioxidants. These might be due to their potent active ingredients, such as flavonoid and phenolic compounds. Numerous natural compounds have been demonstrated to have advantageous effects on cardiovascular disease via NADPH cascade. This review highlights the potential of natural products targeting NOX-derived ROS generation in treating CVDs. Emphasis is put on the activation of the oxidases, including upstream or downstream signalling events.

Curcumin ameliorates oxidized low-density lipoprotein (ox-LDL)-caused damage in human umbilical vein endothelial cells (HUVECs) through the miR-599/MYD88/NF-κB axis

BACKGROUND

The role of curcumin in multiple human diseases was widely reported, including arteriosclerosis (AS). We aimed to investigate the correlation between curcumin and AS-related microRNAs (miRNAs) to find out more underlying mechanism of curcumin used in AS.

METHODS

Cell proliferation and apoptosis were determined using CCK-8 assay, EdU staining assay, flow cytometry, and western blot for the detection of PCNA and Bax protein expression in human umbilical vein endothelial cells (HUVECs). Inflammation response was evaluated using ELISA kits, and oxidative stress was evaluated by detecting SOD activity and MDA level using the matched commercial kits. RT-qPCR analysis was applied for miR-599 and MYD88 mRNA level measurement.

RESULTS

Curcumin treatment and miR-599 overexpression could promote cell proliferation, and inhibit cell apoptosis, inflammation response and oxidative stress, thereby alleviating ox-LDL-induced cell damage in HUVECs. Mir-599 was lowly expressed and MYD88 was highly expressed in AS patients and AS cell model. Curcumin could modulate miR-599 to exert the protective effect on ox-LDL-caused cell damage, and miR-599 directly targeted MYD88 to alleviate ox-LDL-caused cell damage in HUVECs. Curcumin targeted miR-599 to regulate MYD88 expression, thereby inactivating the NF-κB pathway in AS cell model.

CONCLUSION

Our findings illustrated that curcumin exhibited anti-AS effect through the miR-599/MYD88 axis and thereby inhibiting the NF-κB pathway.

5-Methoxyflavone alleviates LPS-mediated lung injury by promoting Nrf2-mediated the suppression of NOX4/TLR4 axis in bronchial epithelial cells and M1 polarization in macrophages

BACKGROUND

Acute lung injury (ALI) arises from sepsis or bacterial infection, which are life-threatening respiratory disorders that cause the leading cause of death worldwide. 5-Methoxyflavone, a methylated flavonoid, is gaining increased attention for its various health benefits. In the current study, we investigated the potential effects of 5-methoxyflavone against LPS-mediated ALI and elucidated the corresponding possible mechanism.

METHODS

A mouse model with ALI was established by intratracheal instillation of LPS, and lung pathological changes, signaling pathway related proteins and apoptosis in lung tissues were estimated by H&E staining, immunofluorescence and TUNEL assay, respectively. Cell viability was evaluated by MTT assay; protein levels of pro-inflammatory mediators were measured by ELISA assay; levels of ROS and M1 macrophage polarization were assayed by flow cytometry; the expression of Nrf2 signaling, NOX4/TLR4 axis and P-STAT1 were detected by western blotting.

RESULTS

Our results showed that 5-methoxyflavone treatment inhibited LPS-induced expression of NOX4 and TLR4 as well as the activation of downstream signaling (NF-κB and P38 MAPK), which was accompanied by markedly decreased ROS levels and pro-inflammatory cytokines (IL-6, TNF-α, MCP-1, and IL-8) in BEAS-2B cells. Moreover, we revealed that these effects of 5-methoxyflavone were related to its Nrf2 activating property, and blockade of Nrf2 prevented its inhibitory effects on NOX4/TLR4/NF-κB/P38 MAPK signaling, thus abrogating the anti-inflammatory effects of 5-methoxyflavone. Besides, the Nrf2 activating property of 5-methoxyflavone in RAW264.7 cells led to inhibition of LPS/IFN-γ-mediated STAT1 signaling, resulting in suppression of LPS/IFN-γ-induced M1 macrophage polarization and the repolarization of M2 macrophages to M1. In a mouse model of LPS-induced ALI, 5-methoxyflavone administration ameliorated LPS-mediated lung pathological changes, the increased lung index (lung/body weight ratio), and epithelial cell apoptosis. Meanwhile, we found 5-methoxyflavone effectively suppressed the hyperactive signaling pathways and the production of excessive pro-inflammatory mediators. Moreover, 5-methoxyflavone reduced LPS-mediated M1 macrophage polarization associated with elevated P-STAT1 activation in the lung tissues. In addition, 5-methoxyflavone improved the survival of LPS-challenged mice.

CONCLUSION

These results indicated that 5-methoxyflavone might be suitable for the development of a novel drug for ALI therapeutic.

Apigenin and apigenin-7, 4'-O-dioctanoate protect against acrolein-aggravated inflammation via inhibiting the activation of NLRP3 inflammasome and HMGB1/MYD88/NF-κB signaling pathway in Human umbilical vein endothelial cells (HUVEC)

Exposure to acrolein, one environmental and dietary pollutant, has been shown to cause inflammation. Here, we reported for the first time that acrolein aggravated lipopolysaccharide (LPS)-induced inflammation in Human umbilical vein endothelial cells (HUVEC) as evidenced by the further increased mRNA expression of three pro-inflammatory cytokines, including interleukin 1β (IL-1β), interleukin 6 (IL-6), and tumor necrosis factor-alpha (TNF-α). Acrolein also further increased the generation of reactive oxygen species (ROS) and decreased the activity of glutathione peroxidase (GSH-Px) in LPS-pretreated HUVEC. Moreover, acrolein treatment further increased the nucleotide oligomerization domain-like receptor protein 3 (NLRP3) and apoptosis-associated speck-like protein containing a caspase-recruitment domain (ASC) expression, caspase-1 cleavage, and downstream matures interleukin 18 (IL-18) and IL-1β level in LPS-pretreated HUVEC. Acrolein treatment also further increased the expressions of high-mobility group box 1 (HMGB1), toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), and phospho-NF-κB P65 (P-P65) in the LPS pre-treated HUVEC. Thus, acrolein aggravated LPS-induced HUVEC inflammation through induction of oxidative stress, and activation of NLRP3 inflammasome and HMGB1/MYD88/NF-κB signaling pathway. In addition, apigenin and apigenin-7, 4'-O-dioctanoate attenuated acrolein-aggravated inflammation by targeting the above signaling pathways. Our findings could help to develop potential therapeutic strategies against acrolein-enhanced inflammation.

Isoflavones daidzin and daidzein inhibit lipopolysaccharide-induced inflammation in RAW264.7 macrophages

Background

Inflammation contributes to various diseases and soybeans and legumes are shown to reduce inflammation. However, the bioactive ingredients involved and mechanisms are not completely known. We hypothesized that soy isoflavones daidzin and daidzein exhibit anti-inflammatory effect in lipopolysaccharides (LPS)-stimulated RAW264.7 macrophage cell model and that activation mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB) signaling pathways may mediate the effect.

Methods

Cell viability and nitric oxide (NO) level were determined by 3-(4,5)-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and Griess reagent respectively. ELISA kits and Western blotting respectively assessed the generations of pro-inflammatory cytokines and protein expressions of signaling molecules. p65 nuclear translocation was determined by immunofluorescence assay.

Results

The in vitro results showed that both isoflavones did not affect cell viability at the concentrations being tested and significantly reduced levels of NO, pro-inflammatory cytokines such as interleukin (IL)-6 and tumor necrosis factor-α (TNF-α), and inflammatory indicators such as cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in RAW264.7 cells. Daidzin and daidzein partially suppressed MAPK signaling pathways, reducing the phosphorylation of p38 and ERK; whilst phosphorylation of JNK was mildly but not significantly decreased. For the involvement of NF-κB signaling pathways, daidzin only reduced the phosphorylation of p65 whereas daidzein effectively inhibited the phosphorylation of IKKα/β, IκBα and p65. Daidzin and daidzein inhibited p65 nuclear translocation, comparable with dexamethasone (positive control).

Conclusion

This study supports the anti-inflammatory effects of isoflavones daidzin and daidzein, which were at least partially mediated through inactivation of MAPK and/or NF-κB signaling pathways in macrophages.

Curcumin attenuates vascular calcification via the exosomal miR-92b-3p/KLF4 axis

Vascular calcification (VC) is the most widespread pathological change in diseases of the vascular system. However, we do not have a good understanding of the molecular mechanisms and effective therapeutic approaches for VC. Curcumin (CUR) is a natural polyphenolic compound that has hypolipidemic, anti-inflammatory, and antioxidant effects on the cardiovascular system. Exosomes are known to have extensive miRNAs for intercellular regulation. This study investigated whether CUR attenuates VC by affecting the secretion of exosomal miRNAs. Calcification models were established in vivo and in vitro using vitamin D3 and β-glycerophosphate, respectively. Appropriate therapeutic concentrations of CUR were detected on vascular smooth muscle cells (VSMCs) using a cell counting kit 8. Exosomes were extracted by super speed centrifugation from the supernatant of cultured VSMCs and identified by transmission electron microscopy and particle size analysis. Functional and phenotypic experiments were performed in vitro to verify the effects of CUR and exosomes secreted by VSMCs treated with CUR on calcified VSMCs. Compared with the calcified control group, both CUR and exosomes secreted by VSMCs after CUR intervention attenuated calcification in VSMCs. Real-Time quantitative PCR (RT-qPCR) experiments showed that miR-92b-3p, which is important for alleviating VC, was expressed highly in both VSMCs and exosomes after CUR intervention. The mimic miR-92b-3p significantly decreased the expression of transcription factor KLF4 and osteogenic factor RUNX2 in VSMCs, while the inhibitor miR-92b-3p had the opposite effect. Based on bioinformatics databases and dual luciferase experiments, the prospective target of miR-92b-3p was determined to be KLF4. Both mRNA and protein of RUNX2 were decreased and increased in VSMCs by inhibiting and overexpressing of KLF4, respectively. In addition, in the rat calcification models, CUR attenuated vitamin D3-induced VC by increasing miR-92b-3p expression and decreasing KLF4 expression in the aorta. In conclusion, our study suggests that CUR attenuates vascular calcification via the exosomal miR-92b-3p/KLF4 axis.

Skin-targeted delivery of extracellular vesicle-encapsulated curcumin using dissolvable microneedle arrays

Therapeutic benefits of curcumin for inflammatory diseases have been demonstrated. However, curcumin's potential as a clinical therapeutic has been hindered due to its low solubility and stability in vivo. We hypothesized that a hybrid curcumin carrier that incorporates albumin-binding and extracellular vesicle (EV) encapsulation could effectively address the current challenges of curcumin delivery. We further postulated that using dissolvable microneedle arrays (dMNAs) for local delivery of curcumin-albumin-EVs (CA-EVs) could effectively control skin inflammation in vivo. Mild sonication was used to encapsulate curcumin and albumin into EVs, and the resulting CA-EVs were integrated into tip-loaded dMNAs. In vitro and in vivo studies were performed to assess the stability, cellular uptake, and anti-inflammatory bioactivity of dMNA-delivered CA-EVs. Curcumin in CA-EVs exhibited at least five-fold higher stability in vitro than naïve curcumin or curcumin-EVs without albumin. Incorporating CA-EVs into dMNAs did not alter their cellular uptake or anti-inflammatory bioactivity. The dMNA embedded CA-EVs retained their bioactivity when stored at room temperature for at least 12 months. In rat and mice models, dMNA delivered CA-EVs suppressed and significantly reduced lipopolysaccharide and Imiquimod-triggered inflammation. We conclude that dMNA delivery of CA-EVs has the potential to become an effective local-delivery strategy for inflammatory skin diseases. STATEMENT OF SIGNIFICANCE: We introduce and evaluate a skin-targeted delivery system for curcumin that synergistically combines albumin association, extracellular-vesicle encapsulation, and dissolvable microneedle arrays (dMNAs) . In vitro, curcumin-albumin encapsulated extracellular vesicles (CA-EVs) inhibit and reverse the LPS-triggered expression of inflammatory transcription factor NF-κB. The integration of CA-EVs into dMNAs does not affect them physically or functionally. Importantly, dMNAs extend EV storage stability for at least 12 months at room temperature with minimal loss in their bioactivity. We demonstrate that dMNA delivered CA-EVs effectively block and reverse skin inflammation in vivo in mouse and rat models.

Plant-Mediated Green Synthesis of Ag NPs and Their Possible Applications: A Critical Review

The potential applications of Ag NPs are exciting and beneficial in a variety of fields; however, there is less awareness of the new risks posed by inappropriate disposal of Ag NPs. The Ag NPs have medicinal, plasmonic, and catalytic properties. The Ag NPs can be prepared via physical, chemical, or biological routes, and the selection of any specific route depends largely on the end-use. The downside of a physical and chemical approach is that it requires a wide space, high temperature, high temperature for a longer time to preserve the thermal stability of synthesized Ag NPs, and the use of toxic chemicals. Although these methods produce nanoparticles with high purity and well-defined morphology, it is critical to develop cost-effective, energy-efficient, and facile route, such as green synthesis; it suggests the desirable use of renewable resources by avoiding the use of additional solvents and toxic reagents in order to achieve the ultimate goal. However, each method has its pros and cons. The synthesized Ag NPs obtained using the green approach have larger biocompatibility and are less toxic towards the biotic systems. However, identifying the phytoconstituents that are responsible for nanoparticle synthesis is difficult and has been reported as a suitable candidate for biological application. The concentration of the effective bioreducing phytoconstituents plays a crucial role in deciding the morphology of the nanoparticle. Besides these reaction times, temperature, pH, and concentration of silver salt are some of the key factors that determine the morphology. Hence, careful optimization in the methodology is required as different morphologies have different properties and usage. It is due to which the development of methods to prepare nanoparticles effectively using various plant extracts is gaining rapid momentum in recent days. To make sense of what involves in the bioreduction of silver salt and to isolate the secondary metabolites from plants are yet challenging. This review focuses on the contribution of plant-mediated Ag NPs in different applications and their toxicity in the aquatic system.

Curcumin alleviates lipopolysaccharides-induced inflammation and apoptosis in vascular smooth muscle cells via inhibition of the NF-κB and JNK signaling pathways

Curcumin plays an important role in inflammation regulation. This study aimed to investigate the effect of curcumin on vascular smooth muscle cells (VSMCs) inflammation induced by lipopolysaccharide (LPS) and its mechanism. VSMCs were treated with different concentrations of curcumin (0, 50, 100 and 150 μg/mL). MTT assay and flow cytometry were used to analyze the effects of curcumin on LPS-induced VSMCs viability and apoptosis. The expression and release of inflammatory cytokines in VSMCs were detected by real-time quantitative polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA). Moreover, the proteins expressions of NF-κB and JNK signaling pathways were analyzed by western blot. Interestingly, the results showed that curcumin could reduce LPS induced inflammatory injury by increasing VSMC's viability, reducing apoptosis and inhibiting the release of inflammatory cytokines. In addition, curcumin increased the expression of Toll-like receptor 4 (TLR4) in LPS treated VSMCs. Mechanistically, we found that curcumin attenuated LPS-induced cell damage in VSMCs via inhibition of NF-κB and the JNK signal pathway. Curcumin can protect VSMCs from LPS induced inflammatory damage, which may be related to the blocking of NF-κB and the JNK signaling pathway. Herewith, curcumin could be potential therapeutics for the treatment of atherosclerosis.

Curcumin in Metabolic Health and Disease

In recent years, epidemiological studies have suggested that metabolic disorders are nutritionally dependent. A healthy diet that is rich in polyphenols may be beneficial in the treatment of metabolic diseases such as polycystic ovary syndrome, metabolic syndrome, non-alcoholic fatty liver disease, cardiovascular disease, and, in particular, atherosclerosis. Curcumin is a polyphenol found in turmeric and has been reported to have antioxidant, anti-inflammatory, hepatoprotective, anti-atherosclerotic, and antidiabetic properties, among others. This review summarizes the influence of supplementation with curcumin on metabolic parameters in selected metabolic disorders.

Anti-Inflammatory Effects of Curcumin in the Inflammatory Diseases: Status, Limitations and Countermeasures

Curcumin is a natural compound with great potential for disease treatment. A large number of studies have proved that curcumin has a variety of biological activities, among which anti-inflammatory effect is a significant feature of it. Inflammation is a complex and pervasive physiological and pathological process. The physiological and pathological mechanisms of inflammatory bowel disease, psoriasis, atherosclerosis, COVID-19 and other research focus diseases are not clear yet, and they are considered to be related to inflammation. The anti-inflammatory effect of curcumin can effectively improve the symptoms of these diseases and is expected to be a candidate drug for the treatment of related diseases. This paper mainly reviews the anti-inflammatory effect of curcumin, the inflammatory pathological mechanism of related diseases, the regulatory effect of curcumin on these, and the latest research results on the improvement of curcumin pharmacokinetics. It is beneficial to the further study of curcumin and provides new ideas and insights for the development of curcumin anti-inflammatory preparations.

USP18 mitigates lipopolysaccharide-induced oxidative stress and inflammation in human pulmonary microvascular endothelial cells through the TLR4/NF-κB/ROS signaling

As a type I interferon response gene, ubiquitin-specific protease 18 (USP18) has been shown to be widely involved in oxidative stress and immune regulation processes. However, the relationship between USP18 and acute lung injury (ALI) is unclear. This study aimed to analyze the role of USP18 in the pathogenesis of ALI. Lipopolysaccharide (LPS) treatment up-regulated the expression of USP18 mRNA and protein in human pulmonary microvascular endothelial cells (hPMVECs). USP18 overexpression increased the viability of LPS-induced hPMVECs, and reduced LPS-induced cell damage. Additionally, USP overexpression increased the activity of SOD and CAT, and reduced the production of NO and MDA in LPS-induced hPMVECs. Moreover, overexpression of USP18 inhibited the secretion of IL-1β, IL-6, TNF-α, and IL-18 in LPS-induced hPMVECs. USP18 overexpression restrained LPS-induced upregulation of TLR4 and the excessive phosphorylation of p65 and IκBα, as well as the production of reactive oxygen species (ROS). TLR4 agonist MPLA attenuated the inhibitory effect of USP18 overexpression on LPS-induced oxidative stress and inflammation in hPMVECs. In addition, USP18 ameliorated LPS induced ALI in vivo. In conclusion, USP18 may resist LPS-induced oxidative stress and inflammatory response in hPMVECs by inhibiting the TLR4/NF-κB/ROS signaling pathway, which may provide new and complementary strategies for ALI treatment.

Sulfur dioxide-induced exacerbation of airway inflammation via reactive oxygen species production and the toll-like receptor 4/nuclear factor-κB pathway in asthmatic mice

Sulfur dioxide (SO₂) is a common air pollutant that can exacerbate asthmatic airway inflammation. The mechanisms underlying these effects are not yet fully understood. In this study, we investigated the effects of SO₂ exposure (10 mg/m³) on asthmatic airway inflammation in ovalbumin-induced asthmatic mice. Our results showed that SO₂ exposure alone induced slight airway injury, decreased superoxide dismutase activity, and increased nuclear factor-κB (NF-κB) expression in the lungs of mice. Moreover, SO₂ exposure in asthmatic mice induced marked pathological damage, significantly increased the counts of inflammatory cells (e.g., macrophages, lymphocytes, and eosinophils) in bronchoalveolar lavage fluid, and significantly enhanced malondialdehyde and glutathione levels in the lungs. Moreover, the expression of toll-like receptor 4 (TLR4), NF-κB, pro-inflammatory cytokines (e.g., tumor necrosis factor α and interleukin-6), and type II T-helper cell (Th2) cytokines was found to be elevated in the mice exposed to SO₂ and ovalbumin compared to those exposed to ovalbumin alone. These results suggest that SO₂ amplifies Th2-mediated inflammatory responses, which involve reactive oxygen species and TLR4/NF-κB pathway activation; these can further enhance Th2 cytokine expression and eosinophilic inflammation. Thus, our findings provide important evidence to understand a potential mechanism through which SO₂ may exacerbate airway asthmatic inflammation.

Curcumin as a Natural Remedy for Atherosclerosis: A Pharmacological Review

Curcumin, a natural polyphenolic compound present in Curcuma longa L. rhizomes, shows potent antioxidant, anti-inflammatory, anti-cancer, and anti-atherosclerotic properties. Atherosclerosis is a comprehensive term for a series of degenerative and hyperplasic lesions such as thickening or sclerosis in large- and medium-sized arteries, causing decreased vascular-wall elasticity and lumen diameter. Atherosclerotic cerebro-cardiovascular disease has become a major concern for human health in recent years due to its clinical sequalae of strokes and heart attacks. Curcumin concoction treatment modulates several important signaling pathways related to cellular migration, proliferation, cholesterol homeostasis, inflammation, and gene transcription, among other relevant actions. Here, we provide an overview of curcumin in atherosclerosis prevention and disclose the underlying mechanisms of action of its anti-atherosclerotic effects.

Curcumin-laden dual-targeting fucoidan/chitosan nanocarriers for inhibiting brain inflammation via intranasal delivery

Curcumin can reduce the production of brain inflammatory mediators and symptoms of brain diseases. However, a large amount of free curcumin needs to be administered to achieve an effective level in the brain because of its poor water-solubility. Fucoidan and chitosan were reported to respectively target P-selectin and acidic microenvironment expressed by pathologically inflammatory cells/tissues. Herein, the self-assembly of chitosan and fucoidan which could encapsulate curcumin was developed to form the multi-stimuli-responsive nanocarriers, and their pathological pH- and P-selectin-responsive aspects were characterized. Through intranasal delivery to the brain, these curcumin-containing chitosan/fucoidan nanocarriers with dual pH-/P-selectin-targeting properties to the brain lesions improved drug delivery, distribution, and accumulation in the inflammatory brain lesions as evidenced by an augmented inhibitory effect against brain inflammation. This promising multifunctional nanocarrier with a novel drug-delivery route should allow potential clinical biomedical uses by neurosurgeon in the future.

Natural Food Polysaccharides Ameliorate Inflammatory Bowel Disease and Its Mechanisms

Natural polysaccharides and their metabolites’ short chain fatty acids (SCFAs) have attracted much attention. Recently, they have shown great potential in attenuating systemic inflammation activities, especially in inflammatory bowel disease (IBD). IBD is a complex pathological process and is related to epithelial damage and microbiota imbalance in the gut. Recent studies have indicated that natural polysaccharides could improve IBD recovery by different mechanisms. They could not only influence the ratio of intestine microbiota, but also regulate the secretion levels of immunity cytokines through multiple pathways, the latter including modulation of the TLR/MAPK/NF-κB signaling pathways and stimulation of G-protein-coupled receptors. Moreover, they could increase intestinal integrity and modulate oxidative stress. In this review, recent research about how natural polysaccharides impact the pathogenesis of IBD are summarized to prove the association between polysaccharides and disease recovery, which might contribute to the secretion of inflammatory cytokines, improve intestine epithelial damage, reduce oxidative stress, sustain the balanced microenvironment of the intestines, and finally lower the risk of IBD.

In vitro anti-inflammatory and antioxidant activities of ZnFe2 O4 and CrFe2 O4 nanoparticles synthesized using Boswellia carteri resin

The development of plant-based nano-materials is considered an eco-friendly technology because it does not involve hazardous chemicals. In this study, bimetallic ZnFe₂ O₄ and CrFe₂ O₄ nanoparticles were synthesized using an aqueous extract of Boswellia carteri resin. Synthesized ZnFe₂ O₄ and CrFe₂ O₄ nanoparticles were characterized by UV-Vis spectroscopy, FTIR, XRD, and HR-TEM. The anti-inflammatory activity was investigated in LPS-stimulated RAW 264.7 macrophages, whereas antioxidant activity was examined using a Hydrogen Peroxide Scavenging Activity Assay, Nitric Oxide Scavenging Activity Assay, and ABTS Radical Scavenging Assay. ZnFe₂ O₄ and CrFe₂ O₄ nanoparticles demonstrated a moderate scavenger of H₂ O₂ with IC₅₀ values; 87.528 ± 8 μg/ml and 146.4468 ± 12 μg/ml, respectively. While they exhibited a strong scavenger of NO with IC₅₀ values; 4.01 ± 0.7 μg/ml and 4.01 ± 0.7μg/ml, respectively. Interestingly, ZnFe₂ O₄ and CrFe₂ O₄ nanoparticles revealed an excellent anti-inflammatory activity by dose-dependently suppressing mRNA expressions of IL-1b, IL-6, and TNF-α. Also, ZnFe₂ O₄ and CrFe₂ O₄ nanoparticles suppress the protein expression of TNF-α. Together, our results proved that phyto-mediated ZnFe₂ O₄ and CrFe₂ O₄ nanoparticles using Boswellia carteri resin have great potential in biomedical applications such as anti-inflammatory and antioxidant. PRACTICAL APPLICATIONS: Our phyto-synthesized chromium iron oxide bimetallic nanoparticles (NPs) have shown a novel and potent anti-inflammatory activity, with remarkable biosafety toward tested macrophages. Zinc iron oxide bimetallic NPs exhibited anti-inflammatory effect with a lesser extent compared to the former, with moderate cytotoxicity against tested macrophages. Both zinc and chromium iron oxide NPs exhibited an equivalent antioxidant activity. Our resin-capped chromium iron oxide NPs are suggested to be a competing nonsteroidal anti-inflammatory agent; it is further recommended to establish advanced animal studies to confirm their biosafety, stability, and anti-inflammatory activity accompanied with the antioxidant activity.

Curcumin Inhibits Lysophosphatidic Acid Mediated MCP-1 Expression via Blocking ROCK Signalling

Curcumin is a natural compound that has been widely used as a food additive and medicine in Asian countries. Over several decades, diverse biological effects of curcumin have been elucidated, such as anti-inflammatory and anti-oxidative activities. Monocyte chemoattractant protein-1 (MCP-1) is a key inflammatory marker during the development of atherosclerosis, and curcumin blocks MCP-1 expression stimulated by various ligands. Hence, we studied the action of curcumin on lysophosphatidic acid (LPA) mediated MCP-1 expression and explored the specific underlying mechanisms. In human vascular smooth muscle cells, LPA induces Rho-associated protein kinase (ROCK) dependent transforming growth factor receptor (TGFBR1) transactivation, leading to glycosaminoglycan chain elongation. We found that LPA also signals via the TGFBR1 transactivation pathway to regulate MCP-1 expression. Curcumin blocks LPA mediated TGFBR1 transactivation and subsequent MCP-1 expression by blocking the ROCK signalling. In the vasculature, ROCK signalling regulates smooth muscle cell contraction, inflammatory cell recruitment, endothelial dysfunction and vascular remodelling. Therefore, curcumin as a ROCK signalling inhibitor has the potential to prevent atherogenesis via multiple ways.

Potential protective roles of curcumin against cadmium-induced toxicity and oxidative stress

Curcumin, used as a spice and traditional medicine in India, exerts beneficial effects against several diseases, owing to its antioxidant, analgesic, and anti-inflammatory properties. Evidence indicates that curcumin might protect against heavy metal-induced organ toxicity by targeting biological pathways involved in anti-oxidation, anti-inflammation, and anti-tumorigenesis. Curcumin has received considerable attention owing to its therapeutic properties, and the mechanisms underlying some of its actions have been recently investigated. Cadmium (Cd) is a heavy metal found in the environment and used extensively in industries. Chronic Cd exposure induces damage to bones, liver, kidneys, lungs, testes, and the immune and cardiovascular systems. Because of its long half-life, exposure to even low Cd levels might be harmful. Cd-induced toxicity involves the overproduction of reactive oxygen species (ROS), resulting in oxidative stress and damage to essential biomolecules. Dietary antioxidants, such as chelating agents, display the potential to reduce Cd accumulation and metal-induced toxicity. Curcumin scavenges ROS and inhibits oxidative damage, thus resulting in many therapeutic properties. This review aims to address the effectiveness of curcumin against Cd-induced organ toxicity and presents evidence supporting the use of curcumin as a protective antioxidant.

Ameliorative effects of escin on neuropathic pain induced by chronic constriction injury of sciatic nerve

ETHNOPHARMACOLOGY RELEVANCE

Escin is a natural mixture of triterpene saponins extracted from the seeds of Aesculus wilsonii Rehd. And has been reported to possess the therapeutic effects against neuropathic pain (NP). However, the underlying mechanisms remain unclear.

AIM OF THE STUDY

The present study aimed to investigate the therapeutic effects and explore the underlying mechanisms of escin on rats of NP induced by chronic constriction injury (CCI) of sciatic nerve.

MATERIALS AND METHODS

Rats were treated with escin (7, 14, and 28 mg/kg, i. g.) daily from the third day after the surgery (day 0) for consecutive 14 days. Regular behavior and thermal threshold were measured on days 0, 3, 5, 7, 10 and 14. Investigations into mechanisms involved measurement of inflammatory factors and biochemical factors in dorsal root ganglion (DRG). Inflammatory pain responses and nerve injuries were induced by the CCI model. Tonic pain model and acute inflammatory model induced by formalin or carrageenan were established to evaluated the pharmacological effects of escin on acute inflammatory pain. Corresponding behaviors were monitored and relevant gene expression such as c-fos, mu opioid receptor (MOR) and KCNK1 were detected by qRT-PCR. Investigate the neuroprotective effects of escin on PC12 cell injury induced by lipopolysaccharide (LPS). Cell morphology was observed under inverted microscope and neuroprotective effect of escin on cell activity was assessed by MTT assay.

RESULTS

Escin could widen thermal threshold, downregulate the concentration of inflammatory factors like tumor necrosis factor (TNF)-α and interleukin (IL)-1β, suppress the gene expression of toll-like receptor 4 (TLR4), nuclear factor κB (NF-κB), decrease the level of glial fibrillary acidic protein (GFAP) and nerve growth factor (NGF) remarkably. In addition, escin significantly lowered the duration of licking, numbers of flinches and increase in paw edema, showing great therapeutic effects on inflammatory pain responses. Moreover, the activity of injured PC12 cells was significantly improved after escin administrated.

CONCLUSION

Escin exerted the ameliorative effects on NP induced by CCI which may be related to downregulating the release of pro-inflammatory cytokines, suppressing TLR-4/NF-κB signal pathway, thereafter decreasing the level of GFAP and NGF.

The Effect of Antioxidant and Anti-Inflammatory Capacity of Diet on Psoriasis and Psoriatic Arthritis Phenotype: Nutrition as Therapeutic Tool?

Chronic inflammation and increased oxidative stress are contributing factors to many non-communicable diseases. A growing body of evidence indicates that dietary nutrients can activate the immune system and may lead to the overproduction of pro-inflammatory cytokines. Fatty acids as macronutrients are key players for immunomodulation, with n-3 polyunsaturated fatty acids having the most beneficial effect, while polyphenols and carotenoids seem to be the most promising antioxidants. Psoriasis is a chronic, immune-mediated inflammatory disease with multifactorial etiology. Obesity is a major risk factor for psoriasis, which leads to worse clinical outcomes. Weight loss interventions and, generally, dietary regimens such as gluten-free and Mediterranean diet or supplement use may potentially improve psoriasis’ natural course and response to therapy. However, data about more sophisticated nutritional patterns, such as ketogenic, very low-carb or specific macro- and micro-nutrient substitution, are scarce. This review aims to present the effect of strictly structured dietary nutrients, that are known to affect glucose/lipid metabolism and insulin responses, on chronic inflammation and immunity, and to discuss the utility of nutritional regimens as possible therapeutic tools for psoriasis and psoriatic arthritis.

Self-Assembled Herbal Medicine Encapsulated by an Oxidation-Sensitive Supramolecular Hydrogel for Chronic Wound Treatment

Inflammation has been assumed to affect the pathology of wound healing and is associated with many nonhealing chronic wounds. Naturally derived herbal medicines with anti-inflammatory properties are of interest because of their effectiveness and affordability in clinical treatment. Herein, we report a supramolecular hydrogel comprising self-assembled natural herb rhein and an oxidative responsive cross-linked network based on ferrocene and β-cyclodextrin host-guest recognitions. Rhein can directly self-assemble into fibrils, exerting better anti-inflammation efficiency than its free drug form. The adaption of the supramolecular network can greatly improve the stability and retain the structural integrity of encapsulated self-assembled rhein. In addition, host-guest recognition confers dissolution of the hydrogel under oxidative stress, thereby delivering self-assembled rhein to the wound site and exerting better therapeutic efficiency. Evaluations in diabetic mice indicate that the resultant hydrogel promoted chronic wound healing by suppressing excess reactive oxygen species, facilitating the transition of the wound healing process, and restoring the normal wound-repair process. Therefore, the proposed hydrogel has a potential value as an herbal-based dressing for future clinical chronic wound management.

Baicalin inhibits Salmonella typhimurium-induced inflammation and mediates autophagy through TLR4/MAPK/NF-κB signalling pathway

Baicalin has been reported to protect mice against Salmonella typhimurium (S. typhimurium) infection, while its molecular mechanisms are unclear. In this study, multiplicity of infection (MOI) and observation time were measured. Cell viability and LDH levels were examined in RAW264.7 cells and H9 cells. RAW264.7 cells were stimulated with S typhimurium in the presence or absence of Baicalin, and the levels of pro-inflammatory cytokines were detected by enzyme-linked immunosorbent assay (ELISA). The changes in reactive oxygen species (ROS) production were determined by fluorescence microscopy and ELISA. The autophagy and TLR4/MAPK/NF-κB signalling pathway were examined by immunofluorescence microscopy, quantitative reverse transcription-polymerase chain reaction and Western blotting. The results indicated that MOI of 30 and duration of autophagy evident at 5 h were applicable to this study. Baicalin prevented death of macrophages, promoted bactericidal activity, decreased the levels of pro-inflammatory cytokines and ROS and reduced the changes of key biomarkers in autophagy and TLR4/MAPK/NF-κB signalling pathway infected by S typhimurium. TLR4-overexpressed cells, autophagy and TLR4/MAPK/NF-κB signalling pathway were activated by S typhimurium, which was suppressed by Baicalin. Our findings indicated that Baicalin exerts anti-inflammatory and cell-protective effects, and it mediates autophagy by down-regulating the activity of TLR4 infected by S typhimurium.

Rhein Protects Against Neurological Deficits After Traumatic Brain Injury in Mice via Inhibiting Neuronal Pyroptosis

Neurological dysfunction provoked by traumatic brain injury (TBI) makes a huge impact on individual learning ability, memory level, social participation, and quality of life. Pyroptosis, the caspase-1-dependent cell death, which is associated with the release of numerous pro-inflammatory factors, plays a major role in the pathological process after TBI. Inhibition of pyroptosis has been shown to be an attractive strategy for the treatment of various neurological disorders. Here, we found that Rhein, an anthraquinone derived from the medicinal plant rhubarb, attenuated TBI-induced upregulation of pro-inflammatory cytokines, blood lactate dehydrogenase (LDH), and pyroptosis-related proteins, as well as reduced neurological dysfunction in a mouse TBI model. Consistently, Rhein inhibitd equiaxial stretch-induced neuron pyroptosis, LDH release, and upregulation of pro-inflammatory factors in vitro. Thus, our study suggested that Rhein protected against neurological deficits after TBI via inhibiting neuronal pyroptosis.

Renoprotective effects of Tilianin in diabetic rats through modulation of oxidative stress via Nrf2-Keap1 pathway and inflammation via TLR4/MAPK/NF-κB pathways

The present study was undertaken to assess the protective effects of Tilianin (TN) on type-2 diabetes-induced renal dysfunction in experimental rats. Diabetes was induced by injecting Nicotinamide (110 mg/kg) and streptozotocin (55 mg/kg) by i.p. and then the rats were treated with TN (10 and 20 mg/kg) daily by oral gavage for 28 days. TN treatment significantly decreases the BUN, creatinine, 24-hour urinary protein, urea, uric acid, and albumin protein levels. The protein of expression of Nrf2, NQO1, and HO-1 was augmented while the expression of Keap-1 decreased significantly. TN also reduces the oxidative/nitrosative status by lowering MDA content, NO, and MPO levels. TN exerted anti-inflammatory effects by suppressing TLR4/NF-κB/MAPK signaling cascades and inhibiting MyD88, TRAF6, IκBα, p38MAPK, JNK, and ERK2 in the diabetic rats. Histopathological findings supported the biochemical and molecular results. The results showed that TN modulated Nrf2-Keap1 and TLR4/MAPK/NF-κB signaling pathways and provided significant protection against diabetes-induced renal dysfunction.

Chlorogenic Acid Potentiates the Anti-Inflammatory Activity of Curcumin in LPS-Stimulated THP-1 Cells

The anti-inflammatory effects of curcumin are well documented. However, the bioavailability of curcumin is a major barrier to its biological efficacy. Low-dose combination of complimentary bioactives appears to be an attractive strategy for limiting barriers to efficacy of bioactive compounds. In this study, the anti-inflammatory potential of curcumin in combination with chlorogenic acid (CGA), was investigated using human THP-1 macrophages stimulated with lipopolysaccharide (LPS). Curcumin alone suppressed TNF-α production in a dose-dependent manner with a decrease in cell viability at higher doses. Although treatment with CGA alone had no effect on TNF-α production, it however enhanced cell viability and co-administration with curcumin at a 1:1 ratio caused a synergistic reduction in TNF-α production with no impact on cell viability. Furthermore, an qRT-PCR analysis of NF-κB pathway components and inflammatory biomarkers indicated that CGA alone was not effective in reducing the mRNA expression of any of the tested inflammatory marker genes, except TLR-4. However, co-administration of CGA with curcumin, potentiated the anti-inflammatory effects of curcumin. Curcumin and CGA together reduced the mRNA expression of pro-inflammatory cytokines [TNF-α (~88%) and IL-6 (~99%)], and COX-2 (~92%), possibly by suppression of NF-κB (~78%), IκB-β-kinase (~60%) and TLR-4 receptor (~72%) at the mRNA level. Overall, co-administration with CGA improved the inflammation-lowering effects of curcumin in THP-1 cells.

Curcumin Suppresses Aldosterone-Induced CRP Generation in Rat Vascular Smooth Muscle Cells via Interfering with the ROS-ERK1/2 Signaling Pathway

Aldosterone regulates the initiation and development of atherosclerosis which is identified as a chronic inflammatory disease by promoting the generation of C-reactive protein in vascular smooth muscle cells. Curcumin is the most active ingredient of turmeric with anti-inflammation and antioxidation effects. Here, the effect of curcumin on aldosterone-induced C-reactive protein generation in vascular smooth muscle and the molecular mechanisms involved were explored. Primary rat vascular smooth muscle cells and hyperaldosteronism model rats were used in this study. The amount of C-reactive protein, reactive oxygen species, and the signaling pathway-related molecules generated were estimated. We found that curcumin inhibited aldosterone-induced C-reactive protein generation in vascular smooth muscle cells by interfering with the reactive oxygen species-ERK1/2 signal pathway. The results provide new evidence for the potential anti-inflammatory and cardiovascular protective effects of curcumin.

Curcumin analogs as the inhibitors of TLR4 pathway in inflammation and their drug like potentialities: a computer-based study

Toll-like receptor 4 (TLR4) pathway is one of the major pathways that mediate the inflammation in human body. There are different anti-inflammatory drugs available in the market which specifically act on different signaling proteins of TLR4 pathway but they do have few side effects and other limitations for intended use in human body. In this study, Curcumin and its different analogs have been analyzed as the inhibitors of signaling proteins, i.e. Cycloxygenase-2 (COX-2), inhibitor of kappaβ kinase (IKK) and TANK binding kinase-1 (TBK-1) of TLR4 pathway using different computational tools. Initially, three compounds were selected for respective target based on free binding energy among which different compounds were reported to have better binding affinity than commercially available drug (control). Upon continuous computational exploration with induced fit docking (IFD), 6-Gingerol, Yakuchinone A and Yakuchinone B were identified as the best inhibitors of COX-2, IKK, and TBK-1 respectively. Then their drug-like potentialities were analyzed in different experiments where they were also predicted to perform well. Hopefully, this study will uphold the efforts of researchers to identify anti-inflammatory drugs from natural sources.