The beneficial role of curcumin on inflammation, diabetes and neurodegenerative disease: A recent update

Recent advances in encapsulation of curcumin in nanoemulsions: A review of encapsulation technologies, bioaccessibility and applications

Curcumin is widely acknowledged for its beneficial activities. However, its application has remained challenging due to its low aqueous solubility, biochemical/structural degradation and poor bioavailability. For these reasons, many researches are aimed at overcoming these limitations using lipid-based nanosystems to encapsulate curcumin, especially nanoemulsions. This review highlights the theoretical aspects and recent advances of preparation technologies (phase inversion temperature, phase inversion composition, ultrasonication, high pressure homogenization and microfluidization) for encapsulation of curcumin in nanoemulsions. Additionally, the specific factors in designing nanoemulsions systems that affect the chemical stability and in vitro bioaccessibility of the encapsulated curcumin are discussed. Also, the importance of nanoemulsions in improving antioxidant, anti-inflammatory and anticancer activities of curcumin is underlined. Curcumin-loaded nanoemulsions preparation technologies have been proposed to provide efficient, systematic, and practical protocols for improved applications of curcumin. Additionally, key factors that influence curcumin delivery include the nature of emulsifier, the type and the amount of carrier oil and emulsifier-curcumin interactions. The pharmacological activities of curcumin including antioxidant, anti-inflammatory and anticancer activities can be improved by nanoemulsions.

Exercise and Curcumin in Combination Improves Cognitive Function and Attenuates ER Stress in Diabetic Rats

Type 2 diabetes mellitus (T2DM) is a metabolic disease associated with chronic low-grade inflammation that is mainly associated with lifestyles. Exercise and healthy diet are known to be beneficial for adults with T2DM in terms of maintaining blood glucose control and overall health. We investigated whether a combination of exercise and curcumin supplementation ameliorates diabetes-related cognitive distress by regulating inflammatory response and endoplasmic reticulum (ER) stress. This study was performed using male Otsuka Long-Evans Tokushima Fatty (OLETF) rats (a spontaneous diabetes Type 2 model) and Long-Evans Tokushima Otsuka (LETO) rats (LETO controls) by providing them with exercise alone or exercise and curcumin in combination. OLETF rats were fed either a diet of chow (as OLETF controls) or a diet of chow containing curcumin (5 g/kg diet) for five weeks. OLETF rats exercised with curcumin supplementation exhibited weight loss and improved glucose homeostasis and lipid profiles as compared with OLETF controls or exercised OLETF rats. Next, we examined cognitive functions using a Morris water maze test. Exercise plus curcumin improved escape latency and memory retention compared to OLETF controls. Furthermore, OLETF rats exercised and fed curcumin had lower IL6, TNFα, and IL10 levels (indicators of inflammatory response) and lower levels of ER stress markers (BiP and CHOP) in the intestine than OLETF controls. These observations suggest exercise plus curcumin may offer a means of treating diabetes-related cognitive dysfunction.

Identification of carbonylated proteins in a bactericidal process induced by curcumin with blue light irradiation on imipenem-resistant Acinetobacter baumannii

RATIONALE

Antimicrobial photodynamic treatment is potentially an alternative to antibiotics and is also effective against viruses, fungi and some cancers. Our previous studies have shown that blue light combined with curcumin, a chemical from the turmeric plant, exerted effective antimicrobial activity via photodynamic treatment. The study reported in this paper investigates which target proteins are affected after the treatment.

METHODS

We treated imipenem-resistant Acinetobacter baumannii with blue light and curcumin and used protein carbonylation as a marker for oxidative damage. After treatment, the bacterial proteins were extracted and the protein carbonyls marked using dinitrophenylhydrazide. After enzyme digestion, we used liquid chromatography/nano-electrospray ionization (LC/nano-ESI) ion trap mass spectrometry to identify bacterial peptides from a customized database. The functional enrichment analyses of the identified proteins were performed using gene ontology annotation and the STRING protein-protein interaction network.

RESULTS

The application of curcumin with blue light showed good antibacterial activity against imipenem-resistant A. baumannii. Using a shotgun proteomics approach, the carbonylated proteins in A. baumannii caused by the photolytic curcumin were identified. The results showed that the proteins related to membrane structures, translation and response to oxidative stress were preferentially modified.

CONCLUSIONS

The photolytic curcumin treatment could be a potential alternative to antibiotics for bacterial infection. In this study, the shotgun proteomics strategy allows us to explore the possible bactericidal mechanisms under this oxidative stress. The result provides a reference for future studies on the enhancement of the action of photolytic curcumin.

Curcumin and Endometriosis

Endometriosis is one of the main common gynecological disorders, which is characterized by the presence of glands and stroma outside the uterine cavity. Some findings have highlighted the main role of inflammation in endometriosis by acting on proliferation, apoptosis and angiogenesis. Oxidative stress, an imbalance between reactive oxygen species and antioxidants, could have a key role in the initiation and progression of endometriosis by resulting in inflammatory responses in the peritoneal cavity. Nevertheless, the mechanisms underlying this disease are still unclear and therapies are not currently efficient. Curcumin is a major anti-inflammatory agent. Several findings have highlighted the anti-oxidant, anti-inflammatory and anti-angiogenic properties of curcumin. The purpose of this review is to summarize the potential action of curcumin in endometriosis by acting on inflammation, oxidative stress, invasion and adhesion, apoptosis and angiogenesis.

Curcumin, demethoxycurcumin, and bisdemethoxycurcumin induced caspase-dependent and -independent apoptosis via Smad or Akt signaling pathways in HOS cells

Background

Osteosarcoma is the most common primary malignant bone tumor in children and adolescents and has also been associated with a high degree of malignancy and enhanced metastatic capacity. Curcumin (CUR) is well known for its anti-osteosarcoma activity. However, both demethoxycurcumin (DMC), and bisdemethoxycurcumin (BDMC) are natural curcumin analogues/congeners from turmeric whose role in osteosarcoma development remains unknown.

Methods

To evaluate the growth inhibitory effects of CUR, DMC and BDMC on osteosarcoma (HOS and U2OS), breast (MDA-MB-231), and melanoma (A2058) cancer cells, we employed the MTT assay, annexin V-FITC /7-AAD staining, and clonogenic assay.

Results

CUR,DMC, and BDMC all decreased the viability of HOS, U2OS, MDA-MB-231, and A2058 cancer cells. Additionally, CUR,DMC, and BDMC induced the apoptosis of HOS cells through activation of Smad 2/3 or repression of Akt signaling pathway. Furthermore, the combination of CUR,DMC, and BDMC synergistically reduced cell viability, colony formation and increased apoptosis than either two or a single agent in HOS cells.

Conclusions

The combination of these three compounds could be used as a novel target for the treatment of osteosarcoma.

Role of phytochemicals as nutraceuticals for cognitive functions affected in ageing

Cognitive decline can occur with normal ageing and in age-related brain disorders, such as mild cognitive impairment and dementia, including Alzheimer's disease, with limited pharmacological therapies available. Other approaches to reduce cognitive decline are urgently needed, and so, the role of dietary interventions or nutraceuticals has received much attention in this respect. In this review, we examine the evidence for dietary plants and their chemical constituents as nutraceuticals, relevant to both cognitive decline in normal ageing and in dementia. Pharmacological (in vitro and in vivo), clinical and epidemiological evidence is assessed for both frequently consumed plants and their dietary forms, including tea, coffee, cocoa (chocolate), red wine, grapes, citrus and other fruits; in addition to plants used less frequently in certain diets and those that cross the blurred boundaries between foods, nutraceuticals and medicinal plants. For the latter, turmeric, saffron, sage, rosemary and lemon balm are examples of those discussed. LINKED ARTICLES: This article is part of a themed section on The Pharmacology of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.6/issuetoc.

Synergic Effects of Berberine and Curcumin on Improving Cognitive Function in an Alzheimer's Disease Mouse Model

Alzheimer's disease (AD) is one of the most common neurodegenerative diseases, and no effective therapies have been found to prevent or cure AD to date. Berberine and curcumin are extracts from traditional Chinese herbs that have a long history of clinical benefits for AD. Here, using a transgenic AD mouse model, we found that the combined berberine and curcumin treatment had a much better effect on improving the cognitive function of mice than the single-drug treatment, suggesting synergic effects of the combined berberine and curcumin treatment. In addition, we found that the combined berberine and curcumin treatment had significant synergic effects on reducing soluble amyloid-β-peptide_(1-42) production. Furthermore, the combination treatment also had remarkable synergic effects on decreasing inflammatory responses and oxidative stress in both the cortex and hippocampus of AD mice. We also found that the combination treatment performed much better than the single drugs in reducing the APP and BACE1 levels and increasing AMPKα phosphorylation and cell autophagy, which might be the underlying mechanism of the synergic effects. Taken together, the result of this study reveal the synergic effects and potential underlying mechanisms of the combined berberine and curcumin treatment in improving the symptoms of AD in mice. This study sheds light on a new strategy for exploring new phytotherapies for AD and also emphasizes that more research should focus on the synergic effects of herbal drugs in the future.

Curcumin- and Piperine-Loaded Emulsomes as Combinational Treatment Approach Enhance the Anticancer Activity of Curcumin on HCT116 Colorectal Cancer Model

Combination chemotherapy, administrating two chemotherapeutic agents concurrently, comes into prominence, as the heterogeneity or the level of the disease necessitates a collaborative action. Curcumin, isolated from turmeric, and piperine, isolated from black long pepper, are two dietary polyphenols studied for their intrinsic anti-cancer properties against various cancer types including colorectal cancer (CRC). Furthermore, piperine improves the therapeutic effect of curcumin. Addressing this mutual behavior, this study combines curcumin and piperine within emulsome nanoformulations. Curcumin- (CurcuEmulsomes) and piperine-loaded emulsomes (PiperineEmulsomes) have established a uniform, stable, spherical dispersion with average diameters of 184.21 and 248.76 nm, respectively. The solid tripalmitin inner core achieved encapsulation capacities of up to 0.10 mg/ml curcumin and 0.09 mg/ml piperine content. While piperine treatment alone - in its both free and emulsome forms - showed no inhibition in the proliferation of HCT116 cells in vitro, its presence as the second drug agent enhanced curcumin's effect. Combination of 7 μM PiperineEmulsome and 25 μM CurcuEmulsome concentrations was found to be most effective with an inhibition of cell proliferation of about 50% viability. Cell cycle arrest at G2/M phase and induced apoptosis verified the improved anti-cancer characteristics of the therapy. While CurcuEmulsomes achieved a fourfold increase in Caspase 3 level, combination of treatment with PiperineEulsomes achieved a sixfold increase in the level of this apoptotic marker. Combinational treatment of HCT116 cells with CurcuEmulsomes and PiperineEmulsomes improved the anticancer activity of the compounds and highlighted the potential of the approach for further in vivo studies.

Effects of ultraviolet light and curcumin-mediated photodynamic inactivation on microbiological food safety: A study in meat and fruit

BACKGROUND

About one-third of the food produced in the world is lost or wasted every year. Contamination can cause significant food loss throughout the entire supply chain, including harvesting, processing, storage, and transport to consumers. This study evaluated ultraviolet-C (UV-C) light and curcumin-mediated photodynamic inactivation (PDI) for the decontamination of meat and fruit.

METHODS

The cut pieces of food samples contaminated with E. coli or S. aureus were submitted to photonic treatments. For UV-C, samples were irradiated with UV-C lamps (254 nm) for 0, 1, 2, 3, 4, 5 and 10 min. For PDI, samples were incubated using 40 and 80 μM curcumin and irradiated with 450 nm at 5, 10, and 15 J/cm² of light doses. The microbiological analysis was performed by counting the colony-forming unit (CFU).

RESULTS

UV-C irradiation reduced the number of E. coli in beef by (1.0 ± 0.2) log₁₀ CFU/mL after 5 min of exposure. In chicken and pork, the numbers of E. coli were reduced by (1.6 ± 0.7) log₁₀ CFU/mL and (1.6 ± 0.4) log₁₀ CFU/mL after 4 and 10 min of irradiation, respectively. In apple the reductions were (3.2 ± 0.4) and (3.8 ± 0.2) log₁₀ CFU/mL after 5 and 10 min of UV-C irradiation, respectively. PDI (40 μM, 15 J/cm²) reduced the number of S. aureus by (1.5 ± 0.2), (1.4 ± 0.2) and (0.6 ± 0.4) log₁₀ CFU/mL in beef, chicken, and pork meat samples, respectively. In apple the greatest reduction was (2.0 ± 0.4) log₁₀ CFU/mL using 80 μM and 10 J/cm².

CONCLUSION

UV-C irradiation and PDI had an anti-microbial effect in food and our findings indicated that the greatest effect was achieved in apples. Therefore, these techniques may be useful to reduce E. coli and S. aureus contamination levels on the surface of meats and fruits, being promising for applications in the field of microbiological food safety.

Curcumin Attenuates Acrolein-induced COX-2 Expression and Prostaglandin Production in Human Umbilical Vein Endothelial Cells

Objective

Inflammation is crucial to limiting vascular disease. Previously we reported that acrolein, a known toxin in tobacco smoke, might play an important role in the progression of atherosclerosis via an inflammatory response involving cyclooxygenase-2 (COX-2) and prostaglandin production in human umbilical vein endothelial cells (HUVECs). Curcumin has been known to improve vascular function and have anti-inflammatory properties. In this study, we investigated whether curcumin prevents the induction of inflammatory response caused by acrolein.

Methods

Anti-inflammatory effects of curcumin were examined in acrolein-stimulated HUVECs. Induction of proteins, mRNA, prostaglandin and reactive oxygen species (ROS) were measured using immunoblot analysis, real-time reverse-transcription polymerase chain reaction, enzyme-linked immunosorbent assay and flow cytometry, respectively.

Results

Curcumin attenuates inflammatory response via inhibition of COX-2 expression and prostaglandin production in acrolein-induced human endothelial cells. This inhibition by curcumin results in the abolition of phosphorylation of protein kinase C, p38 mitogen-activated protein kinase, and cAMP response element-binding protein. Furthermore, curcumin suppresses the production of ROS and endoplasmic reticulum stress via phosphorylation of eukaryotic initiation factor-2α caused by acrolein.

Conclusion

These results suggest that curcumin might be a useful agent against endothelial dysfunction caused by acrolein-induced inflammatory response.

Impact of a Formulation Containing Unusual Polyunsaturated Fatty Acids, Trace Elements, Polyphenols and Plant Sterols on Insulin Resistance and Associated Disturbances

INTRODUCTION

To evaluate the effect of a lipid-based formulation containing unusual polyunsaturated fatty acids, trace elements, polyphenols and plant sterols on insulin resistance and its associated disturbances among adults at risk of diabetes.

METHODS

This was an 8-week, three-arm, open-label randomized clinical trial. We studied individuals aged ≥ 18 years old with diabetes risk given by a body mass index ≥ 25 kg/m² or a FinnRisc score ≥ 13/20. Participants were randomly assigned to receive: 7 ml sunflower oil (control group), 3.5 ml of the study formulation + 3.5 ml of sunflower oil (low-dose group) or 7 ml of study formulation (high-dose group).

RESULTS

We randomized 25 individuals. After one withdrawal in the high-dose group, the study sample comprised nine patients in the control, nine in the low-dose and six in the high-dose groups. The insulin sensitivity increased significantly and in a dose-dependent fashion, up to 10% in the high-dose group. At week 8 the low-dose group exhibited lower glycemic excursions during the oral glucose tolerance test (OGTT), especially 1 h after the glucose challenge (32 mg/dl or 23% lower vs. control group). The incremental area under the glucose curve in the OGTT was 17.1% lower in the low-dose group vs. the control group. Waist circumference increased in the control group, remained constant in the low-dose group and decreased in the high-dose group. C-reactive protein decreased in both formulation groups, up to 50% in the high-dose group. Participants in the formulation groups exhibited increased secretion of GLP-1 and plasma irisin at week 8 vs. the control group.

CONCLUSION

The formulation induced favorable changes in insulin sensitivity, glucose tolerance, abdominal obesity and inflammation. These effects and their durability will need to be assessed in larger studies.

TRIAL REGISTRATION

NCT03512665.

FUNDING

Team Foods Colombia.

Silica-Lipid Hybrid Microparticles as Efficient Vehicles for Enhanced Stability and Bioaccessibility of Curcumin

Curcumin is an active ingredient with multiple functions, but its application is often restricted due to its poor water solubility, weak stability, and consequently low bioaccessibility. Based on this, the aim of this work is to develop a new vehicle to overcome these restrictions. Here we developed a curcumin-loaded nanoemulsion and then curcumin-loaded silica-lipid hybrid microparticles through emulsification and vacuum drying, respectively. The loading of curcumin in the nanoemulsion and microparticles was (0.30±0.02) and (0.67±0.02) %, respectively. FTIR and XRD analyses of microparticles revealed that curcumin was encapsulated in porous, amorphous silica. In vitro antioxidant activities showed that the encapsulation would not affect the antioxidant activity of curcumin. In vitro simulated digestion indicated that nanoemulsion and microparticles had higher curcumin bioaccessibility than the control group. The storage stability of microparticles remained the same during 6 weeks in the dark at 4, 25 and 40 °C. Moreover, the microparticles had a better chemical stability than nanoemulsion under the light. The cell viability was over 80% when the concentration of nanocarriers was less than 45 μg/mL. Hence, the microparticles could be a promising means to load curcumin and improve its solubility, light stability and bioaccessibility.

Evaluation of curcumin-mediated photodynamic therapy on the reverse of multidrug resistance in tumor cells

Curcumin (CUR) possesses photosensitive anti-tumor activity. However, photoactive CUR mainly targets tumor cells sensitive to chemotherapy, whereas the effect on multi-drug resistant cancer cells has not been fully investigated. The study aimed to investigate the anti-tumor activity of CUR on resistant MCF-7/ADM cells and its underlying mechanism providing insights into CUR-mediated PDT and a reference for reversing multidrug resistance. Cell apoptosis and morphological changes were detected by Annexin V-FITC/PI double staining and immunofluorescence, respectively. The apoptosis mechanism of CUR-mediated PDT was investigated by detecting the levels of reactive oxygen species (ROS), mitochondrial membrane potential, and related proteins. MTT and apoptosis results showed that CUR-mediated PDT significantly enhanced cytotoxicity and induced considerable cell apoptosis. After treatment with CUR-mediated PDT, cells became round in shape and shrunk, F-actin was loosely arranged, and the nucleus decreased in size. In addition, the level of ROS increased over time compared to the control and peaked at 6 h. CUR-mediated PDT induced alterations in the mitochondrial membrane potential, increased the release of mitochondrial cytochrome C (Cyt-c), and downregulated caspase-3/7/9, PARP, and P-gp. In conclusion, CUR-PDT induced apoptosis in resistant MCF-7/ADM cells primarily through endogenous mitochondrial apoptosis pathway. Besides apoptosis activation in resistant cells, the reverse of multidrug resistance was ascribed to the downregulation of P-gp expression to a degree.

The Apoptosis of resistant tumor cells reduced by curcumin-mediated photodynamic therapy.

Combinational treatment of all-trans retinoic acid (ATRA) and bisdemethoxycurcumin (BDMC)-induced apoptosis in liver cancer Hep3B cells

The effects of two-drug combination, all-trans retinoic acid (ATRA) and bisdemethoxycurcumin (BDMC), on apoptosis induction of liver cancer cells were investigated in human liver Hep 3B cells. Two-drug combination caused a more effective decrease in cell viability and in induction of S phase arrest, DNA damage, and cell apoptosis than that of ATRA or BDMC only. Also, the two-drug combination caused more cells to undergo significantly increased ROS productions when compared to that of ATRA or BDMC only. Results of Western blotting demonstrated that two-drug combination increased expressions of Fas, pro-apoptotic proteins, and active form of caspase-3 and -9, but decreased that of anti-apoptotic proteins and XIAP than that of ATRA or BDMC only in Hep 3B cells. In conclusion, ATRA combined with BDMC enhance cell apoptosis and associated protein expression in Hep 3B cells. PRACTICAL APPLICATIONS: Bisdemethoxycurcumin (BDMC) derived from natural plants, turmeric (Curcuma longa), which had been used for Asia food for thousands of years. All-trans retinoid acid (ATRA) is currently used as a primary treatment for patients with acute promyelocytic leukemia. In previous study, ATRA and BDMC were reported to have anti-inflammatory and anticancer effects. Our results showed that treatment of ATRA combined with BDMC showed more effectively apoptosis than that of ATRA or BDMC only in Hep 3B cells. The findings also provided possible pathways concerning the induction of liver cancer cell apoptosis. We conclude that ATRA combined with BDMC may be potent anticancer agents or adjuvants for liver cancer therapy in the future.

The inflammatory effect of epigenetic factors and modifications in type 2 diabetes

Inflammation has a central role in the etiology of type 2 diabetes (T2D) and its complications. Both genetic and epigenetic factors have been implicated in the development of T2D-associated inflammation. Epigenetic mechanisms regulate the function of several components of the immune system. Diabetic conditions trigger aberrant epigenetic alterations that contribute to the progression of insulin resistance and β-cell dysfunction by induction of inflammatory responses. Thus, targeting epigenetic factors and modifications, as one of the underlying causes of inflammation, could lead to the development of novel immune-based strategies for the treatment of T2D. The aim of this review is to provide an overview of the epigenetic mechanisms involved in the propagation and perpetuation of chronic inflammation in T2D. We also discuss the possible anti-inflammatory approaches that target epigenetic factors for the treatment of T2D.

The effect of curcumin on cognition in Alzheimer's disease and healthy aging: A systematic review of pre-clinical and clinical studies

Alzheimer's disease constitutes a growing cause of cognitive impairment in aging population. Given that current treatments do not produce the desired therapeutic effects, the need for finding alternative biological and pharmacological approaches is critical. Accumulating evidence suggests inflammatory and oxidative stress responses as potential causal factors of cognitive impairments in Alzheimer's disease and healthy aging. Curcumin has received increased interest due to its unique molecular structure that targets inflammatory and antioxidant pathways as well as (directly) amyloid aggregation; one of the major hallmarks of Alzheimer's disease. Therefore, this review summarizes preclinical and clinical findings on curcumin as a potential cognitive enhancer in Alzheimer's disease and normal aging. Databases used for literature searches include PubMed, EMBASE and Web of Science; in addition, clinicaltrials.gov was used to search for clinical studies. Overall, animal research has shown very promising results in potentiating cognition, both physiologically and behaviourally. However, human studies are limited and results are less consistent, complicating their interpretation. These inconsistencies may be related to differences in methodology and the included population. Taking into account measurements of important inflammatory and antioxidant biomarkers, optimal dosages of curcumin, food interactions, and duration of treatment would increase our understanding on curcumin's promising effects on cognition. In addition, increasing curcumin's bioavailability could benefit future research.

Effect of curcumin on gene expression and protein level of methionine sulfoxide reductase A (MSRA), SOD, CAT and GPx in Freund's adjuvant inflammation-induced male rats

Objective

Curcumin is the well-known compound which is extracted from turmeric powder, the dried rhizome of the Curcuma longa Linn. This have been used for the treatment of various disorders including inflammation. In this study we have analyzed the effect of curcumin on arthritis induced by adjuvant in rats, considering changes in methionine sulfoxide reductase A (MSRA) expression and antioxidant enzymes levels.

Methods

Five groups of adult male Wistar rats (n=10), were randomly selected as control, placebo, experimental 1, 2 and 3. The induction of arthritis was carried out by injection of 0.1 ml adjuvant in plantar region. The first experimental group received no curcumin treatment, whereas the experimental two and three received curcumin (1 and 2 g/kg daily) respectively, for fourteen days. MSRA gene expression was assessed by real-time PCR and protein levels of MSRA, SOD, CAT and GPx were analyzed via ELISA method.

Results

The results showed no significant weight changes among the groups during the experimental period and the paw swelling caused by adjuvant was recovered within fourteen days of treatment with curcumin. However, the levels of enzymes such as superoxide dismutase, catalase and glutathione peroxidase were increased by a dose dependent manner. These results also illustrated that the gene expression and protein level of MSRA in groups treated with curcumin increased significantly (p≤0.05).

Conclusion

We concluded that the curcumin can be used against inflammation. The increasing level of MSRA can be due to the antioxidant effect of curcumin. The enzymatic level changes (MSRA, SOD, CAT and GPx) may interfere with the aging process and delay it.

Molecular Mechanisms of Curcumin in Neuroinflammatory Disorders: A Mini Review of Current Evidences

OBJECTIVE

Neuroinflammatory disease is a general term used to denote the progressive loss of neuronal function or structure. Many neuroinflammatory diseases, including Alzheimer's, Parkinson's, and multiple sclerosis (MS), occur due to neuroinflammation. Neuroinflammation increases nuclear factor-κB (NF-κB) levels, cyclooxygenase-2 enzymes and inducible nitric oxide synthase, resulting in the release of inflammatory cytokines, such as interleukin-6 (IL-6), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). It could also lead to cellular deterioration and symptoms of neuroinflammatory diseases. Recent studies have suggested that curcumin (the active ingredient in turmeric) could alleviate the process of neuroinflammatory disease. Thus, the present mini-review was conducted to summarize studies regarding cellular and molecular targets of curcumin relevant to neuroinflammatory disorders.

METHODS

A literature search strategy was conducted for all English-language literature. Studies that assessed the various properties of curcuminoids in respect of neuroinflammatory disorders were included in this review.

RESULTS

The studies have suggested that curcuminoids have significant anti- neuroinflammatory, antioxidant and neuroprotective properties that could attenuate the development and symptom of neuroinflammatory disorders. Curcumin can alleviate neurodegeneration and neuroinflammation through multiple mechanisms, by reducing inflammatory mediators (such as TNF-α, IL-1β, nitric oxide and NF-κB gene expression), and affect mitochondrial dynamics and even epigenetic changes.

CONCLUSION

It is a promising subject of study in the prevention and management of the neuroinflammatory disease. However, controlled, randomized clinical trials are needed to fully evaluate its clinical potential.

Curcumin induces secretion of glucagon-like peptide-1 through an oxidation-dependent mechanism

Curcumin shows antiglycemic effects in animals. Curcumin is chemically unstable at physiological pH, and its oxidative degradation products were shown to contribute to its anti-inflammatory effects. Since the degradation products may also contribute to other effects, we analyzed their role in the antiglycemic activity of curcumin. We quantified curcumin-induced release of glucagon-like peptide 1 (GLP-1) from mouse STC-1 cells that represent enteroendocrine L-cells as a major source of this anti-diabetic hormone. Curcumin induced secretion of GLP-1 in a dose-dependent manner. Two chemically stable analogues of curcumin that do not readily undergo degradation, were less active while two unstable analogues were active secretagogues. Chromatographically isolated spiroepoxide, an unstable oxidative metabolite of curcumin with anti-inflammatory activity, also induced secretion of GLP-1. Stable compounds like the final oxidative metabolite bicyclopentadione, and the major plasma metabolite, curcumin-glucuronide, were inactive. GLP-1 secretion induced by curcumin and its oxidative degradation products was associated with activation of PKC, ERK, and CaM kinase II. Since activity largely correlated with instability of curcumin and the analogues, we tested the extent of covalent binding to proteins in STC-1 cells and found it occurred with similar affinity as N-ethylmaleimide, indicating covalent binding occurred with nucleophilic cysteine residues. These results suggest that oxidative metabolites of curcumin are involved in the antiglycemic effects of curcumin. Our findings support the hypothesis that curcumin functions as a pro-drug requiring oxidative activation to reveal its bioactive metabolites that act by binding to target proteins thereby causing a change in function.

Comparison of melatonin and curcumin effect at the light and dark periods on regeneration of sciatic nerve crush injury in rats

Being one of the acute clinical problems, peripheral nerve injury can bring about a number of consequences including severe disability, reduced Quality of life (QOL) and immense costs. Currently, melatonin and curcumin are widely applied because of their immunomodulatory, anti-inflammatory, neuro-protective and antioxidant properties. The present study aims to compare the effects of melatonin and curcumin during light and dark periods on sciatic nerve crush injury repair. Accordingly, rats received IP injections of curcumin (100 mg/kg) and melatonin (10 mg/kg) over two periods of light (9:00 a.m.) and dark (9:00 p.m.) for 4 weeks. In order to evaluate rats, functional (walking track analysis and electrophysiological measurements), histomorphometric and gastrocnemius muscle mass investigations were administered. No statistically significant difference was identified between dark and light curcumin groups while curcumin groups displayed better results than did melatonin groups. In addition, dark melatonin group displayed better results than the light melatonin. On the whole, this study found that melatonin and curcumin can be used to quicken neural recovery and help treat nerve injury. It was also found that better neuroregeneration or nerve regeneration was induced when rats were treated by melatonin during the dark period while effects and injection time did not correlate in curcumin application.

Curcumin: Biological, Pharmaceutical, Nutraceutical, and Analytical Aspects

Turmeric is a curry spice that originated from India, which has attracted great interest in recent decades because it contains bioactive curcuminoids (curcumin, demethoxycurcumin, and bisdemethoxycurcumin). Curcumin (1,7-bis-(4-hydroxy-3-methoxyphenyl)-hepta-1,6-diene-3,5-dione), a lipophilic polyphenol may work as an anticancer, antibiotic, anti-inflammatory, and anti-aging agent as suggested by several in vitro, in vivo studies and clinical trials. However, poor aqueous solubility, bioavailability, and pharmacokinetic profiles limit curcumin’s therapeutic usage. To address these issues, several curcumin formulations have been developed. However, suboptimal sample preparation and analysis methodologies often hamper the accurate evaluation of bioactivities and their clinical efficacy. This review summarizes recent research on biological, pharmaceutical, and analytical aspects of the curcumin. Various formulation techniques and corresponding clinical trials and in vivo outcomes are discussed. A detailed comparison of different sample preparation (ultrasonic, pressurized liquid extraction, microwave, reflux) and analytical (FT-IR, FT-NIR, FT-Raman, UV, NMR, HPTLC, HPLC, and LC-MS/MS) methodologies used for the extraction and quantification of curcuminoids in different matrices, is presented. Application of optimal sample preparation, chromatographic separation, and detection methodologies will significantly improve the assessment of different formulations and biological activities of curcuminoids.

Curcumin: a therapeutic strategy in cancers by inhibiting the canonical WNT/β-catenin pathway

Numerous studies have presented that curcumin could have a positive effect in the prevention of cancer and then in tumor therapy. Several hypotheses have highlighted that curcumin could decreases tumor growth and invasion by acting on both chronic inflammation and oxidative stress. This review focuses on the interest of use curcumin in cancer therapy by acting on the WNT/β-catenin pathway to repress chronic inflammation and oxidative stress. In the cancer process, one of the major signaling pathways involved is the WNT/β-catenin pathway, which appears to be upregulated. Curcumin administration participates to the downregulation of the WNT/β-catenin pathway and thus, through this action, in tumor growth control. Curcumin act as PPARγ agonists. The WNT/β-catenin pathway and PPARγ act in an opposed manner. Chronic inflammation, oxidative stress and circadian clock disruption are common and co-substantial pathological processes accompanying and promoting cancers. Circadian clock disruption related to the upregulation of the WNT/β-catenin pathway is involved in cancers. By stimulating PPARγ expression, curcumin can control circadian clocks through the regulation of many key circadian genes. The administration of curcumin in cancer treatment would thus appear to be an interesting therapeutic strategy, which acts through their role in regulating WNT/β-catenin pathway and PPARγ activity levels.

Anti-inflammatory Action of Curcumin and Its Use in the Treatment of Lifestyle-related Diseases

Chronic inflammation plays a significant role in lifestyle-related diseases, such as cardiovascular diseases and obesity/impaired glucose tolerance. Curcumin is a natural extract that possesses numerous physiological properties, as indicated by its anti-inflammatory action. The mechanisms underlying these effects include the inhibition of nuclear factor-kappaB and Toll-like receptor 4-dependent signalling pathways and the activation of a peroxisome proliferator-activated receptor-gamma pathway. However, the bioavailability of curcumin is very low in humans. To resolve this issue, several drug delivery systems have been developed and a number of clinical trials have reported beneficial effects of curcumin in the management of inflammation-related diseases. It is expected that evidence regarding the clinical application of curcumin in lifestyle-related diseases associated with chronic inflammation will accumulate over time.

Arsenic accumulation in lentil (Lens culinaris) genotypes and risk associated with the consumption of grains

Arsenic (As) is a toxic metalloid. As phyto-toxicity is manifested by its accumulation in different tissue types and subsequent growth inhibition in plants. Despite the vital role of leguminous crops in providing proteins to human diets, a little is known about the As accumulation in lentil. In this study, the rate of As uptake and transport from soil to root, shoot and grain of lentil as well as associated risks with the consumption of As contaminated food were examined. Biomass accumulation of lentil genotypes pardina, red chief and precoz drastically decreased when treated with As at 6 mg kg⁻¹ concentration in comparison to 0 and 3 mg kg⁻¹ As. Quantification of As concentrations following different treatment periods showed that As accumulation in roots and shoots of 0, 3 and 6 mg kg⁻¹ As-treated lentil genotypes was statistically different. Arsenic content in grains of red chief genotype was found significantly lower than pardina and precoz. Moreover, As transport significantly increased in roots and shoots compared to the grains. Due to the high concentrations of As in biomass of lentil genotypes, animal as well as human health risk might be associated with the consumption of the As contaminated legume crops.

Antifungal effect of photodynamic therapy mediated by curcumin on Candida albicans biofilms in vitro

BACKGROUND

Canida albicans can cause opportunistic infections ranging from superficial mucous membrane lesions to life-threatening disease. The aim of this study is to investigate the antifungal effect of photodynamic therapy (PDT) mediated by curcumin (CUR) on C. albicans biofilms in vitro.

METHODS

One standard strain ATCC 90028 and two clinical isolates from HIV (CCA1) and oral lichen planus (CCA2) patients' oral cavities were used in this study. Biofilms were photosensitized with 60 μM CUR and irradiated by light emitting diode (LED) under the wavelength of 455 nm and energy densities of 2.64, 5.28, 7.92, 10.56, 13.2 J/cm². Then the antifungal effects of CUR-PDT were evaluated by XTT reduction assay and confocal light scanning microscopy (CLSM) observations. The effects of CUR-PDT on the expression levels of hypha-specific and biofilm-related genes including EFG1, UME6, HGC1 and ECE1 were assessed by quantitative Real-time PCR (qRT-PCR) method.

RESULTS

The inhibition rates after CUR-PDT in three biofilms(ATCC 90028, CCA1, CCA2)were 90.87%, 66.44% and 86.74% respectively (p < 0.05). Relative gene expression levels of EFG1, UME6, HGC1 and ECE1 were all downregulated after CUR-PDT, with fold-decrease of 6.865, 3.382, 2.167 and 6.887 in ATCC 90028, 2.466, 2.146, 1.627 and 3.102 in CCA1, and 5.406, 2.347, 2.073and 3.711 in CCA2 (p < 0.05).

CONCLUSIONS

Curcumin-mediated PDT could effectively inactivateCandida albicans biofilms in vitro. Expression of genes involved in biofilms formation were downregulated after CUR-PDT.

Effects of curcumin supplementation on markers of inflammation and oxidative stress among healthy overweight and obese girl adolescents: A randomized placebo-controlled clinical trial

INTRODUCTION

It is well known that there is a strong linkage between obesity, systemic low-grade inflammation, and oxidative stress in the pediatric population. Possible strategies that might control obesity and its relevant problems in this crucial group are of utmost importance. Therefore, the aim of this study was to evaluate the effects of curcumin supplements on inflammation, oxidative stress, and chemerin levels in adolescent girls.

METHODS

Totally, 60 overweight and obese adolescent girls were randomly assigned to either placebo or intervention group in a randomized placebo-controlled parallel trial design. Adolescents consumed one 500-mg curcumin or placebo per day along with a slight weight loss diet for 10 weeks. High-sensitive C-reactive protein (hs-CRP), interleukin 6 (IL-6), total antioxidant capacity (TAC), malondialdehyde (MDA), chemerin levels, and anthropometric measurements were assessed at the beginning and end of the trial.

RESULTS

Curcumin supplementation had a significant effect on IL-6 levels and oxidative stress markers including TAC and MDA in crude model. After controlling the effects of confounders, curcumin supplementation had a substantial effect on inflammation (hs-CRP and IL-6) and oxidative stress (TAC) marker of adolescents.

DISCUSSION

Ten weeks of curcumin supplementation had beneficial effects on inflammation and oxidative stress markers among postpubescent overweight and obese girl adolescents.

Curcumin/Liposome Nanotechnology as Delivery Platform for Anti-inflammatory Activities via NFkB/ERK/pERK Pathway in Human Dental Pulp Treated With 2-HydroxyEthyl MethAcrylate (HEMA)

Curcumin, primary component of the spice turmeric extracted from the rhizomes of Curcuma longa, represents the major anti-oxidant and anti-inflammatory substance found in turmeric, acting thought various mechanisms not completely understood. Curcumin modulates cytokines, growth factors, transcription factors, inflammatory molecules and cell signaling pathways. During restorative dentistry practice, free resin monomers of 2-hydroxyethyl methacrylate (HEMA) propagate through dentin micro-channel and pulp into the bloodstream affecting cellular integrity. The study highlights the significance of application of curcumin bioactive component into liposomal formulations (CurLIP) to restore the homeostasis of dental pulp stem cells (hDPSCs) in response to 3 and 5 mmol L^–1 HEMA treatment. Cell proliferation in combination with changes of the morphological features, proinflammatory cytokines secretion as Interleukin (IL) 6, IL8, Monocyte Chemoattractant Protein-1 (MCP1) and Interferon-gamma (IFNγ) were assayed along with the nuclear factor (NF)-kB, an inducible transcription factor involved in the activation of several cell processes associated to extracellular signal-regulated kinases (ERK) and posphorylated (p-) ERK pathway. Our results showed a decreased cell proliferation, morphological changes and upregulation of IL6, IL8, MCP1 and IFNγ in presence of 3 and 5 mmol L^–1 HEMA treatment. CurLIP therapy in hDPSCs provokes an increase in cell proliferation and the block of inflammatory cytokines secretion through the inhibitory regulation of NFkB/ERK and pERK signaling cascade. The natural nanocarrier CurLIP influences numerous biochemical and molecular cascades causing anti-inflammatory properties in response to HEMA treatment in human dental pulp stem cells, representing an innovative endodontic formulation able to improve the quality of dental care with a major human community impact.

Pain reduction and improved vascular health associated with daily consumption of an anti-inflammatory dietary supplement blend

Purpose: The objective for this clinical pilot study was to evaluate changes to chronic pain, vascular health, and inflammatory markers when consuming a dietary supplement blend (DSB, CytoQuel^®), containing curcumin, resveratrol, tocotrienols, N-Acetylcysteine, and epigallocatechin gallate.

Materials and methods: An open-label study design was used where 21 study participants were evaluated at baseline and at 2 and 8 weeks after consuming DSB. Participants were randomized to consume 3 capsules once daily versus 2 capsules twice daily. Pain and activities of daily living questionnaires were used to gather subjective data on pain levels and interference with daily living. Blood pressure was measured in both arms and ankles, and the ankle-brachial index (ABI) calculated. Blood samples were used to evaluate markers associated with inflammation and cardiovascular health.

Results: Highly significant reduction of chronic pain was seen after 8 weeks (p<0.01), both at rest and when physically active. Faster improvement was seen when consuming 3 capsules once daily, compared to 2 capsules twice daily. The pain reduction resulted in improved sleep quality (p<0.1), and improved social functioning (p<0.01), and less need for support from others (p<0.05), Normalization of mildly elevated ABI at study start was seen after 2 weeks. Plasma fibrinogen and von Willebrand Factor and serum matrix metalloproteinase-9 (MMP-9) showed reduction after 2 weeks (not significant), whereas a reduction in serum interleukin-1 receptor antagonist-a (IL-1ra) was statistically significant after 2 weeks (p<0.05). Correlation between pain reduction and changes to MMP-9 after 8 weeks was highly significant (P<0.01), whereas correlation between pain reduction and changes to IL-1ra reached significance at 2 weeks for the group consuming 3 caps once daily (p<0.04).

Conclusion: Consuming DSB helped manage pain, increased comfort during daily activities, and improved vascular function. This was associated with selective effects on specific blood biomarkers associated with inflammation and vascular health.

The effects of curcumin, mangiferin, resveratrol and other natural plant products on aminopeptidase B activity

Aminopeptidase B (Ap-B) is a Zn²⁺-aminopeptidase of the M1 family which is implicated, in conjunction with the nardilysin endoprotease, in the generation of miniglucagon, a peptide involved in the maintenance of glucose homeostasis. Other in vivo physiological roles have been established for this vertebrate enzyme, such as the processing of Arg-extended forms of human insulin and cholecystokinin 9 and the degradation of viral epitopes in the cytoplasm. Among M1 family members, Ap-B is phylogenetically close to leukotriene A₄ hydrolase (LTA₄H), a bi-functional aminopeptidase also able to transform LTA₄ in LTB₄ (a lipid mediator of inflammation). As the activities of LTA₄H are reported to be inhibited by resveratrol, a polyphenolic molecule from red wine, the effect of this molecule was investigated on the Ap-B activity. Several other active phenolic compounds produced in plants were also tested. Among them, curcumin and mangiferin are the most effective inhibitors. Dixon analysis indicates that curcumin is a non-competitive inhibitor with a Ki value of 46 μmol.L^-1. Dixon and Lineweaver-Burk representations with mangiferin show a mixed non-competitive inhibition with Ki' and Ki values of 194 μmol.L^-1 and 105 μmol.L^-1, respectively. At 200 μmol.L^-1, no significant effect was observed with caffeic, chlorogenic, ferulic, salicylic and sinapic acids as well as with resveratrol. Analyses on the 3D-structure of LTA₄H with resveratrol (pdb: 3FTS) and the Ap-B 3D-model allow hypothesis to explain theses results.

Curcumin upregulates the Nrf2 system by repressing inflammatory signaling-mediated Keap1 expression in insulin-resistant conditions

Both oxidative stress and inflammation contribute to the development of insulin resistance (IR). Curcumin (Cur) not only has an anti-inflammatory effect but also has an antioxidative stress effect via the activation of NF-E2-related factor 2 (Nrf2). Since there is close cross-communication between inflammation and oxidative stress, we examined whether Cur could modulate Nrf2 function via its anti-inflammatory ability and investigated its underlying mechanism. In this study, we show that Cur inhibits inflammatory signaling and Kelch-like ECH-associated protein 1 (Keap1) expression, which is accompanied by the activation of the Nrf2 system. We further identified that the proinflammatory cytokine tumor necrosis factor alpha (TNFα) could stimulate Keap1 synthesis and increase Nrf2 polyubiquitination, but these effects could be significantly inhibited by Cur treatment. This study demonstrates that Cur-induced Nrf2 activation occurs through the inhibition of inflammatory signaling-mediated upregulation of Keap1, contributing to its beneficial effects on redox homeostasis and insulin sensitivity.

Full Structural Characterization of Homoleptic Complexes of Diacetylcurcumin with Mg, Zn, Cu, and Mn: Cisplatin-level Cytotoxicity in Vitro with Minimal Acute Toxicity in Vivo

At the present time, scientists place a great deal of effort worldwide trying to improve the therapeutic potential of metal complexes of curcumin and curcuminoids. Herein, the synthesis of four homoleptic metal complexes with diacetylcurcumin (DAC), using a ligand designed to prevent the interaction of phenolic groups, rendering metal complexes through the β-diketone functionality, is reported. Due to their physiological relevance, we used bivalent magnesium, zinc, copper, and manganese for complexation with DAC. The resulting products were characterized by ultraviolet-visible (UV-Vis), fluorescence spectroscopy, infrared spectroscopy (IR), liquid and solid-state nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR), magnetic moment, mass spectrometry (MS), single crystal, and powder X-ray diffraction (SCXRD and PXRD). Crystallization was achieved in dimethylsulfoxide (DMSO) or N,N-dimethylformamide (DMF) as triclinic systems with space group P-1, showing the metal bound to the β-diketone function, while the 1H-NMR confirmed the preference of the enolic form of the ligand. Single crystal data demonstrated a 1:2 metal:ligand ratio. The inhibition of lipid peroxidation was evaluated using the thiobarbituric acid reactive substance assay (TBARS). All four metal complexes (Mg, Zn, Cu, and Mn) exhibited good antioxidant effect (IC50 = 2.03 ± 0.27, 1.58 ± 0.07, 1.58 ± 0.15 and 1.24 ± 0.10 μM respectively) compared with butylated hydroxytoluene (BHT) and α-tocopherol. The cytotoxic activity in human cancer cell lines against colon adenocarcinoma (HCT-15), mammary adenocarcinoma (MCF-7), and lung adenocarcinoma (SKLU-1) was found comparable ((DAC)2Mg), or ca. 2-fold higher ((DAC)2Zn) than cisplatin. The acute toxicity assays indicate class 5 toxicity, according to the Organization for Economic Co-operation and Development (OECD) guidelines at doses of 3 g/kg for all complexes. No mortality or changes in the behavior of animals in any of the treated groups was observed. A therapeutic potential can be envisaged from the relevant cytotoxic activity upon human cancer cell lines in vitro and the undetected in vivo acute toxicity of these compounds.

Demethoxycurcumin: A naturally occurring curcumin analogue for treating non-cancerous diseases

Turmeric extracts contain three primary compounds, which are commonly referred to as curcuminoids. They are curcumin, demethoxycurcumin (DMC), and bisdemethoxycurcumin. While curcumin has been the most extensively studied of the curcuminoids, it suffers from low overall oral bioavailability due to extremely low absorption as a result of low water solubility and instability at acidic pH, as well as rapid metabolism and clearance from the body. However, DMC, which lacks the methoxy group on the benzene ring of the parent structure, has much greater chemical stability at physiological pH and has been recently reported to exhibit antitumor properties. However, the treatment of noncancerous diseases with DMC has not been comprehensively reviewed. Therefore, here we evaluate published scientific literature on the therapeutic properties of DMC. The beneficial pharmacological actions of DMC include anti-inflammatory, neuroprotective, antihypertensive, antimalarial, antimicrobial, antifungal, and vasodilatory properties. In addition, DMC's ability to ameliorate the effects of free radicals and an environment characterized by oxidative stress caused by the accumulation of advanced glycation end-products associated with diabetic nephropathy, as well as DMC's capacity to inhibit the migration and proliferation of vascular smooth muscle cells following balloon angioplasty are also addressed. This review collates the available literature regarding the therapeutic possibilities of DMC in noncancerous conditions.

Effects of Curcumin on Microglial Cells

Microglia are innate immune system cells which reside in the central nervous system (CNS). Resting microglia regulate the homeostasis of the CNS via phagocytic activity to clear pathogens and cell debris. Sometimes, however, to protect neurons and fight invading pathogens, resting microglia transform to an activated-form, producing inflammatory mediators, such as cytokines, chemokines, iNOS/NO and cyclooxygenase-2 (COX-2). Excessive inflammation, however, leads to damaged neurons and neurodegenerative diseases (NDs), such as Parkinson's disease (PD), Alzheimer's disease (AD), Huntington's disease (HD), multiple sclerosis (MS) and amyotrophic lateral sclerosis (ALS). Curcumin is a phytochemical isolated from Curcuma longa. It is widely used in Asia and has many therapeutic properties, including antioxidant, anti-viral, anti-bacterial, anti-mutagenic, anti-amyloidogenic and anti-inflammatory, especially with respect to neuroinflammation and neurological disorders (NDs). Curcumin is a pleiotropic molecule that inhibits microglia transformation, inflammatory mediators and subsequent NDs. In this mini-review, we discuss the effects of curcumin on microglia and explore the underlying mechanisms.

Curcumin and Curcumol Inhibit NF-κB and TGF-β 1/Smads Signaling Pathways in CSE-Treated RAW246.7 Cells

E-Zhu (Curcuma zedoaria) is known as a classical traditional Chinese medicine and widely used in the treatment of cancers, cardiovascular disease, inflammation, and other diseases. Its main components include curcumol and curcumin, which have anti-inflammatory and antifibrosis effects. Here we established an in vitro inflammatory injury model by stimulating RAW246.7 cells with cigarette smoke extract (CSE) and detected the intervention effects of curcumin and curcumol on CSE-treated Raw246.7 macrophage cells to explore whether the two compounds inhibited the expression of inflammatory cytokines by inhibiting the NF-κB signaling pathway. We detected the antifibrosis effects of curcumin and curcumol via TGF-β₁/Smads signaling pathways. The model of macrophage damage group was established by CSE stimulation. Curcumol and curcumin were administered to Raw246.7 macrophage cells. The efficacy of curcumol and curcumin was evaluated by comparing the activation of proinflammatory factors, profibrotic factors, and NF-κB and TGF-β₁/Smads signaling pathway. In addition, CSE-treated group was employed to detect whether the efficacy of curcumol and curcumin was dependent on the NF-κB signaling via the pretreatment with the inhibitor of NF-κB. Our findings demonstrated that curcumol and curcumin could reduce the release of intracellular ROS from macrophages, inhibit the NF-κB signaling pathway, and downregulate the release of proinflammatory factor. Curcumol and curcumin inhibited the TGF-β₁/Smads signaling pathway and downregulated the release of fibrotic factors. Curcumin showed no anti-inflammatory effect in CSE-treated cells after the inhibition of NF-κB. Curcumol and curcumin showed an anti-inflammatory effect by inhibiting the NF-κB signaling pathway.

Ginger and Turmeric Essential Oils for Weed Control and Food Crop Protection

Ginger and turmeric are two food ingredients that are in high demand due to their flavor and positive effects on health. The biological properties of these spices are closely related to the aromatic compounds they contain. The chemical compositions of their essential oils and their in vitro phytotoxic activity against weeds (Portulaca oleracea, Lolium multiflorum, Echinochloa crus-galli, Cortaderia selloana, and Nicotiana glauca) and food crops (tomato, cucumber, and rice) were studied. Forty-one compounds, accounting for a relative peak area of 87.7% and 94.6% of turmeric and ginger essential oils, respectively, were identified by Gas Chromatography–Mass Spectrometry analysis. Ginger essential oil with α-zingiberene (24.9 ± 0.8%), β-sesquiphelladrene (11.7 ± 0.3%), ar-curcumene (10.7 ± 0.2%), and β-bisabolene (10.5 ± 0.3%) as the main compounds significantly inhibited the seed germination of P. oleracea, L. multiflorum, and C. selloana at the highest dose (1 µL/mL) assayed, as well as the hypocotyl and radicle growth of the weeds. Turmeric essential oil with ar-turmerone (38.7 ± 0.8%), β-turmerone (18.6 ± 0.6%), and α-turmerone (14.2 ± 0.9%) as principal components significantly inhibited the seed germination of C. selloana and hypocotyl and radicle growth of weeds (the latter in particular) at the highest dose, whereas it did not affect either the seed germination or seedling growth of the food crops. Turmeric essential oil can be an effective post-emergent bioherbicide against the tested weeds without phytotoxicity to crops.

A New Family of Homoleptic Copper Complexes of Curcuminoids: Synthesis, Characterization and Biological Properties

We report herein the synthesis and crystal structures of five new homoleptic copper complexes of curcuminoids. The scarcity of reports of homoleptic complex structures of curcuminoids is attributed to the lack of crystallinity of such derivatives, and therefore, their characterization by single crystal X-ray diffraction is rare. The ligand design suppressing the phenolic interaction by esterification or etherification has afforded a significant increase in the number of known crystal structures of homoleptic metal complexes of curcuminoids revealing more favorable crystallinity. The crystal structures of the present new copper complexes show four-fold coordination with a square planar geometry. Two polymorphs were found for DiBncOC-Cu when crystallized from DMF. The characterization of these new complexes was carried out using infrared radiation (IR), nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR), and single crystal X-ray diffraction (SCXRD) and the antioxidant and cytotoxic activity of the obtained complexes was evaluated.

Potential therapeutic effect of curcumin, a natural mTOR inhibitor, in tuberous sclerosis complex

BACKGROUND

Curcumin is a polyphenol natural product of the plant Curcuma longa. Recent studies suggest that curcumin inhibit mTOR activity in vitro, which prompts us to investigate curcumin function as a new class of mTOR inhibitor suitable for tuberous sclerosis complex (TSC) treatment.

PURPOSE

We aim to investigate the efficacy of curcumin in the treatment of TSC related manifestations in animal model.

STUDY DESIGN

Solid lipid curcumin particle (SLCP), a novel curcumin formulation, was used to treat TSC related manifestations in Tsc2 knockout mice.

METHODS

The novel object recognition test was used to analyze the recognition memory function. The long-term potentiation was studied using electrophysiological analysis. Western blotting was used to assess the protein expression and activation status.

RESULTS

Recognition memory deficit began as early as 4 weeks of age in both male and female Tsc2^+/- mice. Oral administration with SLCP activates AMPK activity and inhibits mTOR activity in the brain tissue of Tsc2^+/- mice, and can rescue the electrophysiological abnormality and object recognition memory loss in the mice.

CONCLUSIONS

Our results suggest that SLCP could be an effective treatment for TSC patients.

The medicinal uses, toxicities and anti-inflammatory activity of Polyalthia species (Annonaceae)

ETHNOPHARMACOLOGICAL RELEVANCE

Polyalthia is one of the largest and notable genera in Annonaceae family. Polyalthia species have been widely used in folklore medicine for the treatment of rheumatic fever, gastrointestinal ulcer and generalized body pain. Numerous in vitro and in vivo studies on Polyalthia Species have also corroborated the significant anti-inflammatory potential of its extracts and secondary metabolites.

AIM OF THE STUDY

This review is an attempt to assess the anti-inflammatory activity of Polyalthia species by giving critical appraisal and establishing evidences of their traditional uses. Moreover this review will highlight the lead compounds for future drug development that can serve as a potential anti-inflammatory drug with comparative efficacy and minimum side effects.

MATERIALS AND METHODS

An extensive literature review, focusing the anti-inflammatory potential of Polyalthia species was conducted using the following databases:PubMed, ScienceDirect, SpringerLink, Ovid, Scopus and ProQuest, as well as the locally available books, journals and relevant documents. The reference lists of retrieved papers were also searched for additional studies.

RESULTS

The Polyalthia species have shown significant anti-inflammatory activity through various mechanism of action. The most significant anti-inflammatory mechanism includes the inhibition of nuclear factor kappa B (NF-κB), prostaglandins (PGs), pro-inflammatory cytokines, inducible nitric oxide synthase (iNOS) and reactive oxygen species (ROS). The data suggests that hydroxycleroda-3,13-dien-15,16-olide and 16-oxocleroda-3,13-dien-15-oic acid, quercetin, rutin, spinasterol, α-spinasterol, goniothalamin and (-)-5-hydroxygoniothalamin are the most potent anti-inflammatory compounds from Polyalthia species with comparable IC₅₀ with positive controls.

CONCLUSIONS

Numerous pharmacological studies have supported the use of Polyalthia species against pain, rheumatic fever, haemorrhages and inflammation in traditional medicine. Flavonoids, diterpenoids, sterols and styrylpyrones from genus Polyalthia are the most significant class of compounds with potent anti-inflammatory activity. Secondary metabolites from these classes should be brought into further research to fill the gaps of knowledge in pharmacokinetics, pharmacodynamics, bioavailability, and toxicity in order to convert the pre-clinical results into clinical data for further investigation.

Protective Effects of Indian Spice Curcumin Against Amyloid-β in Alzheimer's Disease

The purpose of our article is to assess the current understanding of Indian spice, curcumin, against amyloid-β (Aβ)-induced toxicity in Alzheimer's disease (AD) pathogenesis. Natural products, such as ginger, curcumin, and gingko biloba have been used as diets and dietary supplements to treat human diseases, including cancer, cardiovascular, respiratory, infectious, diabetes, obesity, metabolic syndromes, and neurological disorders. Products derived from plants are known to have protective effects, including anti-inflammatory, antioxidant, anti-arthritis, pro-healing, and boosting memory cognitive functions. In the last decade, several groups have designed and synthesized curcumin and its derivatives and extensively tested using cell and mouse models of AD. Recent research on Aβ and curcumin has revealed that curcumin prevents Aβ aggregation and crosses the blood-brain barrier, reach brain cells, and protect neurons from various toxic insults of aging and Aβ in humans. Recent research has also reported that curcumin ameliorates cognitive decline and improves synaptic functions in mouse models of AD. Further, recent groups have initiated studies on elderly individuals and patients with AD and the outcome of these studies is currently being assessed. This article highlights the beneficial effects of curcumin on AD. This article also critically assesses the current limitations of curcumin's bioavailability and urgent need for new formulations to increase its brain levels to treat patients with AD.