Potential therapeutic effects of curcumin, the anti-inflammatory agent, against neurodegenerative, cardiovascular, pulmonary, metabolic, autoimmune and neoplastic diseases. Int J Biochem Cell Biol. 2009;41:40-59. [PMID: 18662800 DOI: 10.1016/j.biocel.2008.06.010]

Design and self-assembly of a leucine-enkephalin analogue in different nanostructures: application of nanovesicles

An opioid (leucine-enkephalin) conformational analogue forms diverse nanostructures such as vesicles, tubes, and organogels through self-assembly. The nanovesicles encapsulate the natural hydrophobic drug curcumin and allow the controlled release through cation-generated porogens in membrane mimetic solvent.

Curcumin loaded NLC induces histone hypoacetylation in the CNS after intraperitoneal administration in mice

The natural p300-specific histone acetyltransferase (HAT) inhibitor, curcumin (CUR), has been widely investigated for its potential therapeutic effect as an anticancer and anti-inflammatory agent. Notwithstanding this interesting pharmacological profile, CUR shows some drawbacks, such as poor absorption and a very fast metabolism and elimination, that limit its clinical use. Aim of the present study was to formulate CUR loaded nanostructured lipid carriers (NLC-CUR) in order to improve the bioavailability and stability of this compound after systemic administration with increased effects in the central nervous system (CNS). NLC-CUR were prepared and characterized on their physicochemical properties by PCS and DSC analyses. Thus, NLC-CUR were systemically injected and the effects in the CNS were compared with a CUR control formulation containing 0.05% DMSO (DMSO-CUR). Our results demonstrate that CUR is able to decrease histone acetylation in the CNS when included in NLCs. Western blot analysis shows that intraperitoneal injection of NLC-CUR (100mg/kg) in mice induces a marked hypoacetylation of histone 4 (H4) at lysine 12 (K12) in the spinal cord compared with control group. Notably, DMSO-CUR (100mg/kg) did not change the H4K12 acetylation level in the CNS. Our study suggests a novel approach to ameliorate the pharmacokinetics of CUR that allows a better permeation in the CNS.

Recent progress of research on medicinal mushrooms, foods, and other herbal products used in traditional Chinese medicine

This article will review selected herbal products used in traditional Chinese medicine, including medicinal mushrooms ( bā xī mó gū; Agaricus blazei, yún zhī; Coriolus versicolor, líng zhī; Ganoderma lucidum, xiāng xùn; shiitake, Lentinus edodes, niú zhāng zhī; Taiwanofungus camphoratus), Cordyceps ( dōng chóng xià cǎo), pomegranate ( shí liú; Granati Fructus), green tea ( lǜ chá; Theae Folium Non Fermentatum), garlic ( dà suàn; Allii Sativi Bulbus), turmeric ( jiāng huáng; Curcumae Longae Rhizoma), and Artemisiae Annuae Herba ( qīng hāo; sweet wormwood). Many of the discussed herbal products have gained popularity in their uses as dietary supplements for health benefits. The review will focus on the active constituents of the herbs and their bioactivities, with emphasis on the most recent progress in research for the period of 2003 to 2011.

BDMC33, A curcumin derivative suppresses inflammatory responses in macrophage-like cellular system: role of inhibition in NF-κB and MAPK signaling pathways

Our preliminary screening has shown that curcumin derivative BDMC33 [2,6-bis(2,5-dimethoxybenzylidene)cyclohexanone] exerted promising nitric oxide inhibitory activity in activated macrophages. However, the molecular basis and mechanism for its pharmacological action is yet to be elucidated. The aim of this study was to investigate the anti-inflammatory properties of BDMC33 and elucidate its underlying mechanism action in macrophage cells. Our current study demonstrated that BDMC33 inhibits the secretion of major pro-inflammatory mediators in stimulated macrophages, and includes NO, TNF-α and IL-1β through interference in both nuclear factor kappaB (NF-κB) and mitogen activator protein kinase (MAPK) signaling cascade in IFN-γ/LPS-stimulated macrophages. Moreover, BDMC33 also interrupted LPS signaling through inhibiting the surface expression of CD-14 accessory molecules. In addition, the inhibitory action of BDMC33 not only restricted the macrophages cell (RAW264.7), but also inhibited the secretion of NO and TNF-α in IFN-γ/LPS-challenged microglial cells (BV-2). The experimental data suggests the inflammatory action of BDMC33 on activated macrophage-like cellular systems, which could be used as a future therapeutic agent in the management of chronic inflammatory diseases.

Recovery from spinal cord injury using naturally occurring antiinflammatory compound curcumin: laboratory investigation

OBJECT

Spinal cord injury (SCI) is a debilitating disease. Primary SCI results from direct injury to the spinal cord, whereas secondary injury is a side effect from subsequent edema and ischemia followed by activation of proinflammatory cytokines. These cytokines activate the prosurvival molecule nuclear factor-κB and generate obstacles in spinal cord reinnervation due to gliosis. Curcumin longa is an active compound found in turmeric, which acts as an antiinflammatory agent primarily by inhibiting nuclear factor-κB. Here, the authors study the effect of curcumin on SCI recovery.

METHODS

Fourteen female Sprague-Dawley rats underwent T9-10 laminectomy and spinal cord contusion using a weight-drop apparatus. Within 30 minutes after contusion and weekly thereafter, curcumin (60 mg/kg/ml body weight in dimethyl sulfoxide) or dimethyl sulfoxide (1 ml/kg body weight) was administered via percutaneous epidural injection at the injury site. Spinal cord injury recovery was assessed weekly by scoring hindlimb motor function. Animals were killed 6 weeks postcontusion for histopathological analysis of spinal cords and soleus muscle weight evaluation.

RESULTS

Curcumin-treated rats had improved motor function compared with controls starting from Week 1. Body weight gain significantly improved, correlating with improved Basso-Beattie-Bresnahan scores. Soleus muscle weight was greater in curcumin-treated rats than controls. Histopathological analysis validated these results with increased neural element mass with less gliosis at the contusion site in curcumin-treated rats than controls.

CONCLUSIONS

Epidural administration of curcumin resulted in improved recovery from SCI. This occurred with no adverse effects noted in experimental animals. Therefore, curcumin treatment may translate into a novel therapy for humans with SCI.

Polyphenols and human health: a prospectus

The lay press often heralds polyphenols as panacea for all sorts of diseases. The rationale is that their antioxidant activity would prevent free radical damage to macromolecules. However, basic and clinical science is showing that the reality is much more complex than this and that several issues, notably content in foodstuff, bioavailability, or in vivo antioxidant activity are yet to be resolved. We summarize the recent findings concerning the effects of polyphenols on human health, analyze the current limitations at pitfalls, and propose future directions for research.

Reversion of multidrug resistance by co-encapsulation of doxorubicin and curcumin in chitosan/poly(butyl cyanoacrylate) nanoparticles

Co-encapsulated doxorubicin (DOX) and curcumin (CUR) in poly(butyl cyanoacrylate) nanoparticles (PBCA-NPs) were prepared with emulsion polymerization and interfacial polymerization. The mean particle size and mean zeta potential of CUR-DOX-PBCA-NPs were 133 ± 5.34 nm in diameter and +32.23 ± 4.56 mV, respectively. The entrapment efficiencies of doxorubicin and curcumin were 49.98 ± 3.32% and 94.52 ± 3.14%, respectively. Anticancer activities and reversal efficacy of the formulations and various combination approaches were assessed using 3-[4,5-dimethylthiazol-2-yl] 2,5-diphenyltetrazolium bromide assay and western blotting. The results showed that the dual-agent loaded PBCA-NPs system had the similar cytotoxicity to co-administration of two single-agent loaded PBCA-NPs (DOX-PBCA-NPs+CUR-PBCA-NPs), which was slightly higher than that of the free drug combination (DOX+CUR) and one free drug/another agent loaded PBCA-NPs combination (DOX+CUR-PBCA-NPs or CUR+DOX-PBCA-NPs). The simultaneous administration of doxorubicin and curcumin achieved the highest reversal efficacy and down-regulation of P-glycoprotein in MCF-7/ADR cell lines, an MCF-7 breast carcer cell line resistant to adriamycin. Multidrug resistance can be enhanced by combination delivery of encapsulated cytotoxic drugs and reversal agents.

Barrier protective activities of curcumin and its derivative

AIM AND OBJECTIVE

Curcumin, a poly-phenolic compound, possesses diverse pharmacologic activities. However, the barrier protective functions of curcumin or its derivative have not yet been studied. The objective of this study was to investigate the barrier protective activities of curcumin and its derivative (bisdemethoxycurcumin, BDMC) on lipopolysaccharide (LPS) barrier disruption in human umbilical vein endothelial cells (HUVECs) were investigated.

METHODS

The barrier protective effects of curcumin and BDMC such as permeability, expression of cell adhesion molecules, monocytes adhesion and migration toward HUVECs were tested.

RESULTS

Curcumin and BDMC inhibited LPS-induced barrier permeability, monocyte adhesion and migration; inhibitory effects were significantly correlated with inhibitory functions of curcumin and BDMC on LPS-induced cell adhesion molecules (vascular cell adhesion molecules, intracellular cell adhesion molecule, E-selectin). Furthermore, LPS-induced nuclear factor-κB (NF-κB) activation and tumor necrosis factor-α (TNF-α) release from HUVECs were inhibited by curcumin and BDMC. Surprisingly, the barrier protective activities of BDMC were better than those of curcumin, indicating that the methoxy group in curcumin negatively regulated barrier protection function of curcumin.

CONCLUSION

Given these results, curcumin or its derivative, BDMC, showed barrier protective activities and they could be a therapeutic candidates for various systemic inflammatory diseases.

Controlled systemic delivery by polymeric implants enhances tissue and plasma curcumin levels compared with oral administration

Curcumin possesses potent anti-inflammatory and anti-proliferative activities but with poor biopharmaceutical attributes. To overcome these limitations, curcumin implants were developed and tissue (plasma, brain and liver) curcumin concentrations were measured in female ACI rats for 3 months. Biological efficacy of tissue levels achieved was analyzed by modulation of hepatic cytochromes. Curcumin implants exhibited diffusion-mediated biphasic release pattern with ∼2-fold higher in vivo release as compared to in vitro. Plasma curcumin concentration from implants was ∼3.3 ng/ml on day 1, which dropped to ∼0.2 ng/ml after 3 months, whereas only 0.2-0.3 ng/ml concentration was observed from 4-12 days with diet and was undetected subsequently. Almost 10-fold higher curcumin levels were observed in brain on day 1 from implants compared with diet (30.1 ± 7.3 vs 2.7 ± 0.8 ng/g) and were still significant even after 90 days (7.7 ± 3.8 vs 2.2 ± 0.8 ng/g). Although curcumin levels were similar in liver from both the routes (∼25-30 ng/g from day 1-4 and ∼10-15 ng/g at 90 days), implants were more efficacious in altering hepatic CYP1A1 levels and CYP3A4 activity at ∼28-fold lower doses at 90 days. Curcumin implants provided much higher plasma and tissue concentrations and are a viable alternative for delivery of curcumin to various organs like brain.

Inhibition of the NF-κB signaling pathway by the curcumin analog, 3,5-Bis(2-pyridinylmethylidene)-4-piperidone (EF31): anti-inflammatory and anti-cancer properties

Nuclear factor kappa B (NF-κB) is a key signaling molecule in the elaboration of the inflammatory response. Data indicate that curcumin, a natural ingredient of the curry spice turmeric, acts as a NF-κB inhibitor and exhibits both anti-inflammatory and anti-cancer properties. Curcumin analogs with enhanced activity on NF-κB and other inflammatory signaling pathways have been developed including the synthetic monoketone compound 3,5-Bis(2-fluorobenzylidene)-4-piperidone (EF24). 3,5-Bis(2-pyridinylmethylidene)-4-piperidone (EF31) is a structurally-related curcumin analog whose potency for NF-κB inhibition has yet to be determined. To examine the activity of EF31 compared to EF24 and curcumin, mouse RAW264.7 macrophages were treated with EF31, EF24, curcumin (1-100 μM) or vehicle (DMSO 1%) for 1h. NF-κB pathway activity was assessed following treatment with lipopolysaccharide (LPS) (1 μg/mL). EF31 (IC(50)~5 μM) exhibited significantly more potent inhibition of LPS-induced NF-κB DNA binding compared to both EF24 (IC(50)~35 μM) and curcumin (IC(50) >50 μM). In addition, EF31 exhibited greater inhibition of NF-κB nuclear translocation as well as the induction of downstream inflammatory mediators including pro-inflammatory cytokine mRNA and protein (tumor necrosis factor-α, interleukin-1β, and interleukin-6). Regarding the mechanism of these effects on NF-κB, EF31 (IC(50)~1.92 μM) exhibited significantly greater inhibition of IκB kinase β compared to EF24 (IC(50)~131 μM). Finally, EF31 demonstrated potent toxicity in NF-κB-dependent cancer cell lines while having minimal and reversible toxicity in RAW264.7 macrophages. These data indicate that EF31 is a more potent inhibitor of NF-κB activity than either EF24 or curcumin while exhibiting both anti-inflammatory and anticancer activities. Thus, EF31 represents a promising curcumin analog for further therapeutic development.

Preventive effects of curcumin on the development of azoxymethane-induced colonic preneoplastic lesions in male C57BL/KsJ-db/db obese mice

Obesity-related metabolic abnormalities include a state of chronic inflammation and adipocytokine imbalance, which increase the risk of colon cancer. Curcumin, a component of turmeric, exerts both cancer preventive and antiinflammatory properties. Curcumin is also expected to have the ability to reverse obesity-related metabolic derangements. The present study examined the effects of curcumin on the development of azoxymethane (AOM)-induced colonic premalignant lesions in C57BL/KsJ-db/db (db/db) obese mice. Feeding with a diet containing 0.2% and 2.0% curcumin caused a significant reduction in the total number of colonic premalignant lesions compared with basal diet-fed mice. The expression levels of tumor necrosis factor-α, interleukin-6, and cyclooxygenase-2 (COX-2) mRNAs on the colonic mucosa of AOM-treated mice were significantly decreased by curcumin administration. Dietary feeding with curcumin markedly activated AMP-activated kinase, decreased the expression of COX-2 protein, and inhibited nuclear factor-κB activity on the colonic mucosa of AOM-treated mice. Curcumin also increased the serum levels of adiponectin while conversely decreasing the serum levels of leptin and the weights of fat. In conclusion, curcumin inhibits the development of colonic premalignant lesions in an obesity-related colorectal carcinogenesis model, at least in part, by attenuating chronic inflammation and improving adipocytokine imbalance. Curcumin may be useful in the chemoprevention of colorectal carcinogenesis in obese individuals.

Effect of citrus polyphenol- and curcumin-supplemented diet on inflammatory state in obese cats

Among obesity-associated disorders, low-grade inflammation has been described. The putative therapeutic properties of citrus and curcumin polyphenols could be associated with their anti-inflammatory properties. Two diets supplemented either with hesperidin (0.05 %) and naringin (0.1 %) from citrus extract or with highly bioavailable curcumin from Curcuma longa extract (0.09 %) were fed to eight obese cats for two 8-week periods (cross-over study design) while maintaining animals in an obese state. Plasma acute-phase protein (APP; α1-acid glycoprotein (AGP), serum amyloid A and haptoglobin) levels were assessed before and at the end of each test period. TNF-α, IL-1β, IL-2, IL-4, IL-5, IL-10, IL-12, IL-18, transforming growth factor-β, interferon (IFN)-γ mRNA levels were determined in peripheral blood mononuclear cells (PBMC) by real-time PCR. Compared with pre-study values, supplementation with citrus polyphenols resulted in lower plasma AGP and haptoglobin concentrations, while that with curcumin resulted in lower plasma AGP concentration. There were no differences between the supplementations. TNF-α, IL-1β, IL-4, IL-5, IL-10, IL-12, IL-18, transforming growth factor-β, mRNA levels remained unaffected by either dietary supplementation. In contrast, IFN-γ and IL-2 mRNA levels were lower at the end of the citrus and the curcumin supplementation, respectively. There were no differences between the supplementations. The present study results show a slight effect of citrus and curcumin supplementation on inflammatory markers expressed by PBMC, and a decreased concentration of APP, which are mainly expressed by the liver. This would confirm that hesperidin and naringin or highly bioavailable curcumin extract have beneficial effects, targeted in the liver and could improve the obesity-related inflammatory state.

Curcumin attenuates Concanavalin A-induced liver injury in mice by inhibition of Toll-like receptor (TLR) 2, TLR4 and TLR9 expression

Curcumin has antiviral, antioxidant, and anti-inflammatory properties. However, the hepatoprotective effects and molecular mechanisms of curcumin on acute liver injury have not been carefully examined. The aims of this study were to examine the anti-inflammatory effect of curcumin on Concanavalin A (Con A) induced hepatitis, and to elucidate its underlying molecular mechanisms in mice. Mice received curcumin (200 mg/kg body weight) by gavage before Con A intravenous administration. We found that curcumin pretreatment was able to significantly reduce the elevated plasma aminotransferase levels and liver necrosis in Con A-induced hepatitis. Also, curcumin pretreatment reduced intrahepatic expression of genes encoding pro-inflammatory molecules such as tumor necrosis factor α (TNF-α) and interferon γ (IFN-γ) as compared with the vehicle controls, but augmented anti-inflammatory cytokine interleukin 10 (IL-10) by enzyme linked immunosorbent assay (ELISA). Furthermore, the expression levels of Toll-like receptor (TLR) 2, TLR4 and TLR9 mRNA or protein in liver tissues were significantly lowered by curcumin treatment. Curcumin pretreatment did not affect hepatic Kupffer cell numbers after Con A injection. These results suggest that curcumin pretreatment protects against T cell-mediated hepatitis in mice. The beneficial effect of curcumin may be partly mediated by inhibiting the expression levels of TLR2, TLR4 and TLR9 in the liver.

The effect of curcumin in the ectonucleotidases and acetylcholinesterase activities in synaptosomes from the cerebral cortex of cigarette smoke-exposed rats

With the evidence that curcumin may be a potent neuroprotective agent and that cigarette smoke is associated with a decline in the cognitive performance as our bases, we investigated the activities of Ecto-Nucleoside Triphosphate Diphosphohydrolase (NTPDase), 5'-nucleotidase and acetylcholinesterase (AChE) in cerebral cortex synaptosomes from cigarette smoke-exposed rats treated with curcumin (Cur). The experimental procedures entailed two sets of experiments. In the first set, the groups were vehicle, Cur 12·5, 25 and 50 mg·kg(-1) ; those in the second set were vehicle, smoke, smoke and Cur 12·5, 25 and 50 mg·kg(-1) . Curcumin prevented the increased NTPDase, 5'-nucleotidase and AChE activities caused by smoke exposure. We suggest that treatment with Cur was protective because the decrease of ATP and acetylcholine (ACh) concentrations is responsible for cognitive impairment, and both ATP and ACh have key roles in neurotransmission.

Multitargeting by curcumin as revealed by molecular interaction studies

Curcumin (diferuloylmethane), the active ingredient in turmeric (Curcuma longa), is a highly pleiotropic molecule with anti-inflammatory, anti-oxidant, chemopreventive, chemosensitization, and radiosensitization activities. The pleiotropic activities attributed to curcumin come from its complex molecular structure and chemistry, as well as its ability to influence multiple signaling molecules. Curcumin has been shown to bind by multiple forces directly to numerous signaling molecules, such as inflammatory molecules, cell survival proteins, protein kinases, protein reductases, histone acetyltransferase, histone deacetylase, glyoxalase I, xanthine oxidase, proteasome, HIV1 integrase, HIV1 protease, sarco (endo) plasmic reticulum Ca(2+) ATPase, DNA methyltransferases 1, FtsZ protofilaments, carrier proteins, and metal ions. Curcumin can also bind directly to DNA and RNA. Owing to its β-diketone moiety, curcumin undergoes keto-enol tautomerism that has been reported as a favorable state for direct binding. The functional groups on curcumin found suitable for interaction with other macromolecules include the α, β-unsaturated β-diketone moiety, carbonyl and enolic groups of the β-diketone moiety, methoxy and phenolic hydroxyl groups, and the phenyl rings. Various biophysical tools have been used to monitor direct interaction of curcumin with other proteins, including absorption, fluorescence, Fourier transform infrared (FTIR) and circular dichroism (CD) spectroscopy, surface plasmon resonance, competitive ligand binding, Forster type fluorescence resonance energy transfer (FRET), radiolabeling, site-directed mutagenesis, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), immunoprecipitation, phage display biopanning, electron microscopy, 1-anilino-8-naphthalene-sulfonate (ANS) displacement, and co-localization. Molecular docking, the most commonly employed computational tool for calculating binding affinities and predicting binding sites, has also been used to further characterize curcumin's binding sites. Furthermore, the ability of curcumin to bind directly to carrier proteins improves its solubility and bioavailability. In this review, we focus on how curcumin directly targets signaling molecules, as well as the different forces that bind the curcumin-protein complex and how this interaction affects the biological properties of proteins. We will also discuss various analogues of curcumin designed to bind selective targets with increased affinity.

Curcumin sensitizes chemotherapeutic drugs via modulation of PKC, telomerase, NF-κB and HDAC in breast cancer

Background: Several tumor markers are overexpressed in breast cancer. Chemotherapy in breast cancer fails due to resistance to chemotherapeutic drugs. A phytochemical such as curcumin can be used in a therapeutic modality as it elicits anti-tumor effects. Methods: Action of curcumin on the expression of several tumor markers, such as protein kinase C, telomerase, NF-κB and histone deacetylase in MCF-7 (ER positive), MDA-MB-231 (ER negative), MCF-12F (control) and also in mice mammary tumors were investigated. Results: Curcumin downregulated the expression of tumor markers both in vitro and in vivo and sensitized tumor cells to the chemotherapeutic drugs cyclophosphamide and paclitaxel. Discussion: Curcumin may be of considerable value in synergistic therapy of cancer such that the drug dose level could be minimized reducing the associated toxicity.

Redox balance in the pathogenesis of nonalcoholic fatty liver disease: mechanisms and therapeutic opportunities

Nonalcoholic fatty liver disease (NAFLD) is currently the most common liver disease in the world. It encompasses a histological spectrum, ranging from simple, nonprogressive steatosis to nonalcoholic steatohepatitis (NASH), which may progress to cirrhosis and hepatocellular carcinoma. While liver-related complications are confined to NASH, emerging evidence suggests both simple steatosis and NASH predispose to type 2 diabetes and cardiovascular disease. The pathogenesis of NAFLD is currently unknown, but accumulating data suggest that oxidative stress and altered redox balance play a crucial role in the pathogenesis of steatosis, steatohepatitis, and fibrosis. We will examine intracellular mechanisms, including mitochondrial dysfunction and impaired oxidative free fatty acid metabolism, leading to reactive oxygen species generation; additionally, the potential pathogenetic role of extracellular sources of reactive oxygen species in NAFLD, including increased myeloperoxidase activity and oxidized low density lipoprotein accumulation, will be reviewed. We will discuss how these mechanisms converge to determine the whole pathophysiological spectrum of NAFLD, including hepatocyte triglyceride accumulation, hepatocyte apoptosis, hepatic inflammation, hepatic stellate cell activation, and fibrogenesis. Finally, available animal and human data on treatment opportunities with older and newer antioxidant will be presented.

Curcumin inhibits neuronal and vascular degeneration in retina after ischemia and reperfusion injury

BACKGROUND

Neuron loss, glial activation and vascular degeneration are common sequelae of ischemia-reperfusion (I/R) injury in ocular diseases. The present study was conducted to explore the ability of curcumin to inhibit retinal I/R injury, and to investigate underlying mechanisms of the drug effects.

METHODOLOGY/PRINCIPAL FINDINGS

Different dosages of curcumin were administered. I/R injury was induced by elevating the intraocular pressure for 60 min followed by reperfusion. Cell bodies, brn3a stained cells and TUNEL positive apoptotic cells in the ganglion cell layer (GCL) were quantitated, and the number of degenerate capillaries was assessed. The activation of glial cells was measured by the expression level of GFAP. Signaling pathways including IKK-IκBα, JAK-STAT1/3, ERK/MAPK and the expression levels of β-tubulin III and MCP-1 were measured by western blot analysis. Pre-treatment using 0.01%-0.25% curcumin in diets significantly inhibited I/R-induced cell loss in GCL. 0.05% curcumin pre-treatment inhibited I/R-induced degeneration of retinal capillaries, TUNEL-positive apoptotic cell death in the GCL, brn3a stained cell loss, the I/R-induced up-regulation of MCP-1, IKKα, p-IκBα and p-STAT3 (Tyr), and down-regulation of β-tubulin III. This dose showed no effect on injury-induced GFAP overexpression. Moreover, 0.05% curcumin administered 2 days after the injury also showed a vaso-protective effect.

CONCLUSIONS/SIGNIFICANCE

Curcumin protects retinal neurons and microvessels against I/R injury. The beneficial effects of curcumin on neurovascular degeneration may occur through its inhibitory effects on injury-induced activation of NF-κB and STAT3, and on over-expression of MCP-1. Curcumin may therefore serve as a promising candidate for retinal ischemic diseases.

The molecular basis of nutritional intervention in multiple sclerosis: a narrative review

It is commonly accepted that nutrition is one of the possible environmental factors involved in the pathogenesis of multiple sclerosis (MS), but its role as complementary MS treatment is unclear and largely disregarded. At present, MS therapy is not associated to a particular diet, probably due to lack of information on the effects of nutrition on the disease. To overcome the distrust of the usefulness of dietary control in MS and to encourage nutritional interventions in the course of the disease, it is necessary to assess the nature and the role of bioactive dietary molecules and their targets, and establish how a dietary control can influence cell metabolism and improve the wellness of MS patients. The aim of this review is to provide a rationale for a nutritional intervention in MS by evaluating at the molecular level the effects of dietary molecules on the inflammatory and autoimmune processes involved in the disease. Present data reveal that healthy dietary molecules have a pleiotropic role and are able to change cell metabolism from anabolism to catabolism and down-regulate inflammation by interacting with enzymes, nuclear receptors and transcriptional factors. The control of gut dysbiosis and the combination of hypo-caloric, low-fat diets with specific vitamins, oligoelements and dietary integrators, including fish oil and polyphenols, may slow-down the progression of the disease and ameliorate the wellness of MS patients.

Effect of different curcuminoid supplement dosages on total in vivo antioxidant capacity and cholesterol levels of healthy human subjects

The impact of consuming curcuminoids containing curcumin at 500 mg/day and 6 g/day for 7 days on plasma antioxidant capacity and serum cholesterol level were determined by using vitamin E 200 IU/day consumption as a comparison. Group A and group B subjects consumed 500 mg and 6 g curcumin, respectively, but group C subjects consumed vitamin E 200 IU. By using the oxygen radical absorbance capacity (ORAC) assay, it was found that plasma antioxidant capacity of group A rose from a baseline of 13% to 24% on day 1 and day 7, as against a 19-20% increase for group B. Serum cholesterol and triglyceride levels were significantly decreased after curcumin treatment at 500 mg/day. By consuming vitamin E, both ORAC values and plasma α-tocopherol concentrations were significantly increased, but only very slight responses on serum cholesterol or triglyceride levels were observed. It is therefore suggested that curcumin supplement would not be appropriate for healthy people except for reducing serum cholesterol or triglyceride levels. The dosage of a daily curcumin supplement at 500 mg is more effective than 6 g, although vitamin E is also considered to be an effective antioxidant supplement.

Effect of Curcumin Against Proteus mirabilis During Crystallization of Struvite from Artificial Urine

We investigated the activity of curcumin against Proteus mirabilis and the struvite crystallization in relation to urinary stones formation. In order to evaluate an activity of curcumin we performed an in vitro experiment of struvite growth from artificial urine. The crystallization process was induced by Proteus mirabilis to mimic the real urinary tract infection, which usually leads to urinary stone formation. The results demonstrate that curcumin exhibits the effect against Proteus mirabilis inhibiting the activity of urease-an enzyme produced by these microorganisms. Addition of curcumin increases the induction time and decreases the efficiency of growth of struvite compared with the absence of curcumin. Interestingly, the addition of curcumin does not affect the crystal morphology and habit. In conclusion, curcumin has demonstrated its significant potential to be further investigated for its use in the case of struvite crystallization induced for the growth by Proteus mirabilis in relation to urinary stone formation.

Curcumin attenuates allergic airway inflammation and hyper-responsiveness in mice through NF-κB inhibition

ETHNOPHARMACOLOGICAL RELEVANCE

Curcumin, a polyphenol compound from Curcuma longa L. has been used for centuries as an anti-inflammatory remedy including asthma. Curcumin has been reported to exert an anti-inflammatory effect, in part, through inhibition of the NF-κB pathway.

AIM OF THE STUDY

The purposes of this study were to determine whether curcumin inhibits NF-κB-dependent transcription in vitro, and test whether treatment with curcumin reduces allergen-induced airway inflammation and hyper-responsiveness in a mouse model of asthma through inhibition of NF-κB pathway.

MATERIALS AND METHODS

The effect of curcumin on NF-κB transcriptional activity was investigated using a cell-based luciferase reporter assay in A549 cells and by measuring inhibitory κBα (IκBα), p65, and p50 levels after exposure of Raw264.7 cells to lipopolysaccharide (LPS). BALB/c mice were sensitized to ovalbumin (OVA) by intraperitoneal injection, and challenged with repeated exposure to aerosolized OVA. The effects of daily administered curcumin (200mg/kg body weight, i.p.) on airway hyper-responsiveness (AHR), inflammatory cell number, and IgE levels in bronchoalveolar lavage (BAL) fluid were analyzed. NF-κB activation in lung tissue was also assessed by Western blot analyses.

RESULTS

Curcumin inhibited NF-κB-dependent transcription in reporter assays in A549 cells with an IC(50) of 21.50±1.25μM. Curcumin stabilized IκBα and inhibited nuclear translocation of p65 and p50 in LPS-activated Raw264.7 cells, and curcumin-treated mice showed reduced nuclear translocation of p65 in lung tissue. Treatment with curcumin significantly attenuated AHR and reduced the numbers of total leukocytes and eosinophils in BAL fluid. Infiltration of inflammatory cells and mucus occlusions in lung tissue were significantly ameliorated by treatment with curcumin, which also markedly decreased the level of IgE in BAL fluid.

CONCLUSION

Curcumin attenuates the development of allergic airway inflammation and hyper-responsiveness, possibly through inhibition of NF-κB activation in the asthmatic lung tissue. Our results indicate that curcumin may attenuate development of asthma by inhibition of NF-κB activation.

The neuroprotective effect of curcumin and Nigella sativa oil against oxidative stress in the pilocarpine model of epilepsy: a comparison with valproate

Oxidative stress has been implicated to play a role in epileptogenesis and pilocarpine-induced seizures. The present study aims to evaluate the antioxidant effects of curcumin, Nigella sativa oil (NSO) and valproate on the levels of malondialdehyde, nitric oxide, reduced glutathione and the activities of catalase, Na⁺, K⁺-ATPase and acetylcholinesterase in the hippocampus of pilocarpine-treated rats. The animal model of epilepsy was induced by pilocarpine and left for 22 days to establish the chronic phase of epilepsy. These animals were then treated with curcumin, NSO or valproate for 21 days. The data revealed evidence of oxidative stress in the hippocampus of pilocarpinized rats as indicated by the increased nitric oxide levels and the decreased glutathione levels and catalase activity. Moreover, a decrease in Na⁺, K⁺-ATPase activity and an increase in acetylcholinesterase activity occurred in the hippocampus after pilocarpine. Treatment with curcumin, NSO or valproate ameliorated most of the changes induced by pilocarpine and restored Na⁺, K⁺-ATPase activity in the hippocampus to control levels. This study reflects the promising anticonvulsant and potent antioxidant effects of curcumin and NSO in reducing oxidative stress, excitability and the induction of seizures in epileptic animals and improving some of the adverse effects of antiepileptic drugs.

Non-antibacterial tetracyclines modulate mediators of periodontitis and atherosclerotic cardiovascular disease: a mechanistic link between local and systemic inflammation

Periodontitis, one of the most common chronic inflammatory diseases afflicting man, is increasingly being recognized as a risk factor for atherosclerotic cardiovascular disease (ASCVD). Non-antimicrobial tetracyclines are known to have inhibitory effects on inflammatory mediators and effector molecules, including cytokines and matrix metalloproteinases (MMPs), associated with both diseases. In this paper, we discuss the evidence that doxycycline and related non-antibiotic chemically modified tetracyclines (e.g., CMT-3) can effectively reduce cytokine (TNF-α, IL-6, and MCP-1) production by human mononuclear inflammatory cells when stimulated either by endotoxin (LPS) or by a complex of C-reactive protein/oxidized LDL cholesterol relevant to the pathogenesis of periodontal disease and ASCVD, respectively. This inhibition by tetracycline compounds appears to be mediated at least in part by a suppression of the phosphorylation/activation of the NFκB cell signaling pathway. We are currently conducting clinical trials on patients who exhibit both diseases, and our preliminary data suggest that virtually all acute coronary syndrome (ACS) patients exhibit moderate-to-severe periodontitis, a higher incidence of this oral inflammatory disease than that seen in the population at large. In other studies, a non-antimicrobial formulation of doxycycline (SDD) has been found to dramatically reduce hsCRP, IL-6 and MMP-9 levels in plasma of ACS patients, and SDD has also been found to significantly increase serum levels of both cardio-protective HDL cholesterol and its core molecule apolipoprotein A-I in ASCVD-vulnerable patients with periodontitis. Our current research suggests that one mechanism involved may be the ability of SDD to inhibit MMP-mediated HDL loss by protecting apolipoprotein A-I from proteinase attack. These pleiotropic mechanisms of non-antimicrobial tetracyclines provide significant therapeutic potential to treat chronic inflammatory diseases including both periodontitis and ASCVD.

Established and novel NF-κB inhibitors lead to downregulation of TLR3 and the proliferation and cytokine secretion in HNSCC

The transcriptional activation of NF-κB signalling has been identified as a major pathway involved in inflammation and tumor aggressiveness in a number of human cancers. Here we identify the impact of miscellaneous known and so far unknown NF-κB inhibitors originating from different drug classes on the function and proliferation of HNSCC. In detail: HNSCC cell lines were exposed to Acetylsalicylic Acid (ASA), Celecoxib, Dexamethasone, Curcumin and EPs 7630. Our major interest was to detect upstream alterations in cell signalling after applying NF-κB inhibiting substances. The inhibition of NF-κB signalling leads to an upstream regulation of Toll-like-receptor 3 (TLR3), a predominant receptor driving cell expansion. We find a marked downregulation of TLR3 and IKK complex, documenting upstream responses to NF-κB inhibition by every agent tested. In a second step we further analyse proliferation, cytokine production and alterations in the expression of downstream proteins such as cyclin D1 and c-Myc. Our data demonstrate decreased proliferation in response to incubation with aforementioned agents. Modulation of TLR3 and NF-κB expression is accompanied by altered profiles of IL-6 and IL-8 which are relevant cytokines in HNSCC progression. Proto-oncogenes cyclin D1 and c-myc are downregulated by all substances. Apart from the interplay of cytokines and TLR3, we substantiated EPs 7630 as a new and natural NF-κB inhibitor.

Epigenetics: deciphering its role in diabetes and its chronic complications

1. Increasing evidence suggests that epigenetic factors might regulate the complex interplay between genes and the environment, and affect human diseases, such as diabetes and its complications. 2. Clinical trials have underscored the long lasting beneficial effects of strict glycaemic control for reducing the progression of diabetic complications. They have also shown that diabetic complications, such as diabetic nephropathy, a chronic kidney disorder, can continue even after blood glucose normalization, suggesting a metabolic memory of the prior glycaemic state. 3. Dysregulation of epigenetic post-transcriptional modifications of histones in chromatin, including histone lysine methylation, has been implicated in aberrant gene regulation associated with the pathology of diabetes and its complications. Genome-wide studies have shown cell-type specific changes in histone methylation patterns under diabetic conditions. In addition, studies in vascular cells have shown long lasting changes in epigenetic modifications at key inflammatory gene promoters after prior exposure to diabetic conditions, suggesting a possible mechanism for metabolic memory. 4. Recent studies have shown roles for histone methylation, DNA methylation, as well as microRNA in diabetic nephropathy. Whether these epigenetic factors play a role in metabolic memory of diabetic kidney disease is less well understood. 5. The incidence of diabetes is growing rapidly, as also the cost of treating the resulting complications. A better understanding of metabolic memory and the potential involvement of epigenetic mechanisms in this phenomenon could enable the development of new therapeutic targets for the treatment and/or prevention of sustained diabetic complications.

Rescue of photoreceptor degeneration by curcumin in transgenic rats with P23H rhodopsin mutation

The P23H mutation in the rhodopsin gene causes rhodopsin misfolding, altered trafficking and formation of insoluble aggregates leading to photoreceptor degeneration and autosomal dominant retinitis pigmentosa (RP). There are no effective therapies to treat this condition. Compounds that enhance dissociation of protein aggregates may be of value in developing new treatments for such diseases. Anti-protein aggregating activity of curcumin has been reported earlier. In this study we present that treatment of COS-7 cells expressing mutant rhodopsin with curcumin results in dissociation of mutant protein aggregates and decreases endoplasmic reticulum stress. Furthermore we demonstrate that administration of curcumin to P23H-rhodopsin transgenic rats improves retinal morphology, physiology, gene expression and localization of rhodopsin. Our findings indicate that supplementation of curcumin improves retinal structure and function in P23H-rhodopsin transgenic rats. This data also suggest that curcumin may serve as a potential therapeutic agent in treating RP due to the P23H rhodopsin mutation and perhaps other degenerative diseases caused by protein trafficking defects.

Curcumin protects mice against concanavalin A-induced hepatitis by inhibiting intrahepatic intercellular adhesion molecule-1 (ICAM-1) and CXCL10 expression

The effect of curcumin on liver injury caused by Concanavalin A (Con A) has not been carefully examined. This study was designed to evaluate the protective effect of curcumin on Con A-induced hepatitis in mice. Liver injured mice received curcumin by gavage at a dose of 200 mg/kg body weight before Con A intravenous administration. Curcumin was effective in reducing the elevated plasma levels of aminotransferases and the incidence of liver necrosis compared with Con A-injected control group. Enzyme-linked immunosorbent assay (ELISA) showed that curcumin suppressed proinflammatory cytokines such as tumor necrosis factor (TNF)-α, interferon (IFN)-γ, and interleukin (IL)-4 production in Con A-injected mice. The reduced severity of hepatitis in curcumin pretreated mice correlated with decrease in numbers of liver CD4(+) T cells but not CD8(+) T cells by immunohistochemical analysis. Furthermore, the expression levels of intercellular adhesion molecule-1 (ICAM-1) and the interferon-inducible chemokine CXCL10 in hepatic tissue were significantly decreased by curcumin pretreatment. In conclusion, curcumin pretreatment protects against T cell-mediated hepatitis in mice.

Prameha in Ayurveda: correlation with obesity, metabolic syndrome, and diabetes mellitus. Part 2--management of Prameha

BACKGROUND

Obesity, metabolic syndrome, and diabetes mellitus are increasing to epidemic proportions globally. Prameha is a syndrome described in the ancient Ayurvedic texts that includes clinical conditions involved in obesity, prediabetes, diabetes mellitus, and metabolic syndrome.

MATERIALS AND METHODS

Various dietary, lifestyle, and psychologic factors are involved in the etiology of Prameha, particularly in relation to disturbances in fat and carbohydrate metabolism.

RESULTS

The Ayurvedic management of Prameha emphasizes dietary and lifestyle recommendations and herbal preparations, in accordance with the psychophysiologic constitution of the patient. Ayurveda also addresses the management of psychologic factors that contribute to the development of Prameha. Ayurvedic treatment known as Apatarpana (balanced diet with restricted calories) and Santarpana (highly nutritious, high-calorie diet intended to increase weight) are recommended for patients with type 2 and type 1 diabetes, respectively. Various Ayurvedic herbs and herbomineral formulations are utilized, based on the stage and type of disease as well as the psychophysiologic constitution of the patient. A large body of research has been conducted on these Ayurvedic herbs.

CONCLUSIONS

Integrating the theory and modalities of Ayurveda in the management of these disorders may prove to be beneficial.

Aromatic-turmerone inhibits α-MSH and IBMX-induced melanogenesis by inactivating CREB and MITF signaling pathways

This study investigated the anti-melanogenic effect of aromatic (ar)-turmerone on alpha-melanocyte stimulating hormone (α-MSH) and 3-isobuty-1-methxlzanthine (IBMX)-induced tyrosinase (Tyr), tyrosinase-related protein 1 (TRP-1), and tyrosinase-related protein 2 (TRP-2) expression in B16F10 melanoma cells. We demonstrated that ar-turmerone inhibits α-MSH and IBMX-induced melanin synthesis and tyrosinase activity. Data also showed that ar-turmerone inhibits the expression of tyrosinase, TRP-1, and TRP-2 in α-MSH- and IBMX-stimulated B16F10 cells. In addition, ar-turmerone exhibits stronger anti-melanogenic effects than curcumin. Furthermore, ar-turmerone strongly inhibited α-MSH- and IBMX-induced microphthalmia-associated transcription factor by suppressing the activity of cyclic adenosine monophosphate (cAMP)-responsive element binding protein in α-MSH-stimulated B16F10 cells. Our data revealed that ar-turmerone is a novel, effective, anti-melanogenic agent that functions by downregulating tyrosinase, Trp-1, and Trp-2 gene expression. Therefore, ar-turmerone may be a useful therapeutic agent for treating hyperpigmentation disorders, such as freckles and melasma, and as a beneficial additive in whitening cosmetics.

The targets of curcumin

Curcumin (diferuloylmethane), an orange-yellow component of turmeric or curry powder, is a polyphenol natural product isolated from the rhizome of the plant Curcuma longa. For centuries, curcumin has been used in some medicinal preparation or used as a food-coloring agent. In recent years, extensive in vitro and in vivo studies suggested curcumin has anticancer, antiviral, antiarthritic, anti-amyloid, antioxidant, and anti-inflammatory properties. The underlying mechanisms of these effects are diverse and appear to involve the regulation of various molecular targets, including transcription factors (such as nuclear factor-kB), growth factors (such as vascular endothelial cell growth factor), inflammatory cytokines (such as tumor necrosis factor, interleukin 1 and interleukin 6), protein kinases (such as mammalian target of rapamycin, mitogen-activated protein kinases, and Akt) and other enzymes (such as cyclooxygenase 2 and 5 lipoxygenase). Thus, due to its efficacy and regulation of multiple targets, as well as its safety for human use, curcumin has received considerable interest as a potential therapeutic agent for the prevention and/or treatment of various malignant diseases, arthritis, allergies, Alzheimer's disease, and other inflammatory illnesses. This review summarizes various in vitro and in vivo pharmacological aspects of curcumin as well as the underlying action mechanisms. The recently identified molecular targets and signaling pathways modulated by curcumin are also discussed here.

Curcumin inhibits melanogenesis in human melanocytes

Plant derived compounds, as potentially safe and effective skin lightening agents (SLAs), have attracted great attention from many researchers. Curcumin is a plant-derived polyphenol, which has been reported to suppress melanogenesis in B16 melanoma cells. However, little is known about whether curcumin affects melanogenesis in cultured human melanocytes. In addition, the molecular mechanism for the antimelanogenic effects of curcumin remains largely unknown. The present study assessed the effects of curcumin on melanin synthesis, cellular tyrosinase activity, the expression of melanogenesis-related proteins (microphthalmia-associated transcription factor (MITF), tyrosinase, tyrosinase-related protein 1 and 2 (TRP-1, TRP-2)), and activation of melanogenesis-regulating signals including phosphatidylinositol 3-kinase (PI3K)/Akt/ glycogen synthase kinase 3 (GSK 3β), extracellular signal-regulated kinase (ERK) and p38 MAPK in human melanocytes. The results showed that the melanin content and tyrosinase activity, as well as the expression of melanogenesis-related proteins in human melanocytes, were significantly inhibited by curcumin in a dose dependent manner. In addition, PI3K/Akt/ GSK 3β, ERK and p38 MAPK were activated by curcumin, while inhibitors of these signals attenuated the inhibitory effects of curcumin on melanogenesis. These results suggest that curcumin inhibits melanogenesis in human melanocytes through activation of Akt/GSK 3β, ERK or p38 MAPK signaling pathways.

Anethole exerts antimetatstaic activity via inhibition of matrix metalloproteinase 2/9 and AKT/mitogen-activated kinase/nuclear factor kappa B signaling pathways

Anethole is known to possess anti-inflammatory and anti-tumor activities and to be a main constituent of fennel, anise, and camphor. In the present study, we evaluated anti-metastatic and apoptotic effects of anethole on highly-metastatic HT-1080 human fibrosarcoma tumor cells. Despite weak cytotoxicity against HT-1080 cells, anethole inhibited the adhesion to Matrigel and invasion of HT-1080 cells in a dose-dependent manner. Anethole was also able to down-regulate the expression of matrix metalloproteinase (MMP)-2 and -9 and up-regulate the gene expression of tissue inhibitor of metalloproteinase (TIMP)-1. The similar inhibitory effect of anethole on MMP-2 and -9 activities was confirmed by zymography assay. Furthermore, anethole significantly decreased mRNA expression of urokinase plasminogen activator (uPA), but not uPA receptor (uPAR). In addition, anethole suppressed the phosphorylation of AKT, extracellular signal-regulated kinase (ERK), p38 and nuclear transcription factor kappa B (NF-κB) in HT-1080 cells. Taken together, our findings indicate that anethole is a potent anti-metastatic drug that functions through inhibiting MMP-2/9 and AKT/mitogen-activated protein kinase (MAPK)/NF-κB signal transducers.

Advanced drug delivery systems of curcumin for cancer chemoprevention

Since ancient times, chemopreventive agents have been used to treat/prevent several diseases including cancer. They are found to elicit a spectrum of potent responses including anti-inflammatory, antioxidant, antiproliferative, anticarcinogenic, and antiangiogenic activity in various cell cultures and some animal studies. Research over the past 4 decades has shown that chemopreventives affect a number of proteins involved in various molecular pathways that regulate inflammatory and carcinogenic responses in a cell. Various enzymes, transcription factors, receptors, and adhesion proteins are also affected by chemopreventives. Although, these natural compounds have shown significant efficacy in cell culture studies, they elicited limited efficacy in various clinical studies. Their introduction into the clinical setting is hindered largely by their poor solubility, rapid metabolism, or a combination of both, ultimately resulting in poor bioavailability upon oral administration. Therefore, to circumvent these limitations and to ease their transition to clinics, alternate strategies should be explored. Drug delivery systems such as nanoparticles, liposomes, microemulsions, and polymeric implantable devices are emerging as one of the viable alternatives that have been shown to deliver therapeutic concentrations of various potent chemopreventives such as curcumin, ellagic acid, green tea polyphenols, and resveratrol into the systemic circulation. In this review article, we have attempted to provide a comprehensive outlook for these delivery approaches, using curcumin as a model agent, and discussed future strategies to enable the introduction of these highly potent chemopreventives into a physician's armamentarium.