Nano Encapsulated Curcumin: And Its Potential for Biomedical Applications

Curcumin, a yellow-colored polyphenol extracted from the rhizome of turmeric root, is commonly used as a spice and nutritional supplement. It exhibits many pharmacological activities such as anti-inflammatory, anti-bacterial, anti-cancer, anti-Alzheimer, and anti-fungal. However, the therapeutic application of curcumin is limited by its extremely low solubility in aqueous buffer, instability in body fluids, and rapid metabolism. Nano delivery system has shown excellent potential to improve the solubility, biocompatibility and therapeutic effect of curcumin. In this review, we focus on the recent development of nano encapsulated curcumin and its potential for biomedical applications.

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

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

Lajis N, Abas F, Othman I, Naidu R. Mechanism of Anti-Cancer Activity of Curcumin on Androgen-Dependent and Androgen-Independent Prostate Cancer

Prostate cancer (PCa) is a heterogeneous disease and ranked as the second leading cause of cancer-related deaths in males worldwide. The global burden of PCa keeps rising regardless of the emerging cutting-edge technologies for treatment and drug designation. There are a number of treatment options which are effectively treating localised and androgen-dependent PCa (ADPC) through hormonal and surgery treatments. However, over time, these cancerous cells progress to androgen-independent PCa (AIPC) which continuously grow despite hormone depletion. At this particular stage, androgen depletion therapy (ADT) is no longer effective as these cancerous cells are rendered hormone-insensitive and capable of growing in the absence of androgen. AIPC is a lethal type of disease which leads to poor prognosis and is a major contributor to PCa death rates. A natural product-derived compound, curcumin has been identified as a pleiotropic compound which capable of influencing and modulating a diverse range of molecular targets and signalling pathways in order to exhibit its medicinal properties. Due to such multi-targeted behaviour, its benefits are paramount in combating a wide range of diseases including inflammation and cancer disease. Curcumin exhibits anti-cancer properties by suppressing cancer cells growth and survival, inflammation, invasion, cell proliferation as well as possesses the ability to induce apoptosis in malignant cells. In this review, we investigate the mechanism of curcumin by modulating multiple signalling pathways such as androgen receptor (AR) signalling, activating protein-1 (AP-1), phosphatidylinositol 3-kinases/the serine/threonine kinase (PI3K/Akt/mTOR), wingless (Wnt)/ß-catenin signalling, and molecular targets including nuclear factor kappa-B (NF-κB), B-cell lymphoma 2 (Bcl-2) and cyclin D1 which are implicated in the development and progression of both types of PCa, ADPC and AIPC. In addition, the role of microRNAs and clinical trials on the anti-cancer effects of curcumin in PCa patients were also reviewed.

Therapeutic Potential of Curcumin in the Treatment of Glioblastoma Multiforme

Glioblastoma multiforme (GBM) is the most common primary malignant brain tumor. Despite standard multimodality treatment, the highly aggressive nature of GBM makes it one of the deadliest human malignancies. The anti-cancer effects of dietary phytochemicals like curcumin provide new insights to cancer treatment. Evaluation of curcumin's efficacy against different malignancies including glioblastoma has been a motivational research topic and widely studied during the recent decade. In this review, we discuss the recent observations on the potential therapeutic effects of curcumin against glioblastoma. Curcumin can target multiple signaling pathways involved in developing aggressive and drug-resistant features of glioblastoma, including pathways associated with glioma stem cell activity. Notably, combination therapy with curcumin and chemotherapeutics like temozolomide, the GBM standard therapy, as well as radiotherapy has shown synergistic response, highlighting curcumin's chemo- and radio-sensitizing effect. There are also multiple reports for curcumin nanoformulations and targeted forms showing enhanced therapeutic efficacy and passage through blood-brain barrier, as compared with natural curcumin. Furthermore, in vivo studies have revealed significant anti-tumor effects, decreased tumor size and increased survival with no notable evidence of systemic toxicity in treated animals. Finally, a pharmacokinetic study in patients with GBM has shown a detectable intratumoral concentration, thereby suggesting a potential for curcumin to exert its therapeutic effects in the brain. Despite all the evidence in support of curcumin's potential therapeutic efficacy in GBM, clinical reports are still scarce. More studies are needed to determine the effects of combination therapies with curcumin and importantly to investigate the potential for alleviating chemotherapy- and radiotherapy-induced adverse effects.

Curcumin ameliorates health-related quality of life in patients with liver cirrhosis: A randomized, double-blind placebo-controlled trial

OBJECTIVES

Current study aimed to find the effects of curcumin on quality of life (QoL) in liver cirrhotic patients.

DESIGN

In this randomized double-masked placebo-controlled trial, 70 cases with liver cirrhosis aged 20-70 years were randomly divided into two groups to receive 1000 mg/day curcumin (n = 35) or placebo (n = 35) for 12 weeks. The health-related QoL (HRQoL) was assessed by CLDQ, LDSI 2.0, and SF-36.

RESULTS

Fifty-eight patients (28 in curcumin and 30 in placebo groups) finished the research. Compared with baseline, overall scores as well as most of CLDQ domains (e.g. Fatigue, Emotional Function, Worry, Abdominal Symptoms, and Systemic Symptoms) and the Physical and Mental health (Total) scores and most of SF-36 domains (e.g. Physical Functioning, Bodily Pain, Vitality, Social Functioning, and Mental Health) increased considerably (P < 0.05) after curcumin administration. Furthermore, curcumin reduced most of LDSI 2.0 domains (e.g. Itch, Joint pain, Pain in the right upper abdomen, Sleeping during the day, Decreased appetite, Depression, Fear of complication, Jaundice, Hindrance in Financial Affairs, Change in use of time, Decreased sexual interest, and Decreased sexual activity) significantly (P < 0.05). Significant differences were noticed between two groups in CLDQ domains and overall scores, LDSI 2.0 domains and overall scores, SF-36 Physical and Mental health (total) scores and all its domains scores (P < 0.05), adjusting for baseline values and disease duration.

CONCLUSIONS

Curcumin improved QoL in liver cirrhotic patients according to CLDQ, LDSI 2.0, and SF-36 domains. Additional studies are warranted to consider curcumin as a safe, accessible, and low-cost complementary therapeutic option in cirrhosis.

Molecular mechanisms linking environmental toxicants to cancer development: Significance for protective interventions with polyphenols

Human exposure to environmental toxicants with diverse mechanisms of action is a growing concern. In addition to well-recognized carcinogens, various chemicals in environmental and occupational settings have been suggested to impact health, increasing susceptibility to cancer by inducing genetic and epigenetic changes. Accordingly, in this review, we have discussed recent insights into the pathological mechanisms of these chemicals, namely their effects on cell redox and calcium homeostasis, mitochondria and inflammatory signaling, with a focus on the possible implications for multi-stage carcinogenesis and its reversal by polyphenols. Plant-derived polyphenols, such as epigallocatechin-gallate, resveratrol, curcumin and anthocyanins reduce the incidence of cancer and can be useful nutraceuticals for alleviating the detrimental outcomes of harmful pollutants. However, development of therapies based on polyphenol administration requires further studies to validate the biological efficacy, identifying effective doses, mode of action and new delivery forms. Innovative microphysiological testing models are presented and specific proposals for future trials are given. Merging the current knowledge of multifactorial actions of specific polyphenols and chief environmental toxicants, this work aims to potentiate the delivery of phytochemical-based protective treatments to individuals at high-risk due to environmental exposure.

Accelerated Muscle Recovery After In Vivo Curcumin Supplementation

The currently available treatment options for muscle injuries are suboptimal and often delay muscle recovery. In this study, the effects of curcumin on inflammation and skeletal muscle regeneration after contusion-induced injury in mice were investigated. The mice were randomly assigned to 4 groups, namely normal control (NC), with induced injury (mass-drop injury, MDI) and without treatment (MDI [M]), with induced injury and diclofenac (DCF) treatment (MDI + DCF [M + D]), and with induced injury and curcumin treatment (MDI + curcumin [M + C]). Contusion-induced injury was inflicted on the left gastrocnemius muscle, and DCF or curcumin was orally administered after injury once per day for 7 days. The M group exhibited significantly higher lipid peroxidation, myeloperoxidase (MPO), and desmin than the NC group. The M + D and M + C groups have lower lipid peroxidation and neutrophils (decrease in MPO protein) and higher muscle satellite cell regeneration (increase in desmin protein) than the M group. Additionally, for the contusion-induced muscle injury, curcumin could affect the specific proteins of inflammation, neutrophils, and differentiation of satellite cells, including Ikk-α/ß, MPO, and myogenin. In conclusion, curcumin potentially accelerates muscle recovery; therefore, it may be a potential candidate for further research as an effective treatment to enhance muscle repair.

Natural Products and Their Therapeutic Effect on Autism Spectrum Disorder

Autism is a complex neurodevelopmental disorder that is evident in early childhood and can persist throughout the entire life. The disease is basically characterized by hurdles in social interaction where the individuals demonstrate repetitive and stereotyped interests or patterns of behavior. A wide number of neuroanatomical studies with autistic patients revealed alterations in brain development which lead to diverse cellular and anatomical processes including atypical neurogenesis, neuronal migration, maturation, differentiation, and degeneration. Special education programs, speech and language therapy, have been employed for the amelioration of behavioral deficits in autism. Although commonly prescribed antidepressants, antipsychotics, anticonvulsants, and stimulants have revealed satisfactory responses in autistic individuals, adverse side effects and increased risk of several other complications including obesity, dyslipidemia, diabetes mellitus, thyroid disorders, etc. have compelled the researchers to turn their attention toward herbal remedies. Alternative approaches with natural compounds are on continuous clinical trial to confirm their efficacy and to understand their potential in autism treatment. This chapter aims to cover the major plant-based natural products which hold promising outcomes in the field of reliable therapeutic interventions for autism.

The effect of curcumin supplementation on circulating adiponectin: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

Our objective was to perform a systematic review and meta-analysis on randomized controlled trials (RCTs) assessing the effect of curcumin on serum adiponectin concentration.

METHODS

We searched PubMed/Medline, Scopus, ISI Web of Science, Cochrane Library, and Google scholar databases up to April 2019. RCTs conducted among human adults studied the effects of curcumin on serum adiponectin concentrations as an outcome variable was included. The weighted mean differences (WMD) and standard deviations (SD) of change in serum adiponectin levels were calculated. The random effects model was used for deriving a summary of mean estimates with their corresponding SDs.

RESULTS

Out of 313 records, 6 trials that enrolled 652 subjects were included. The pooled results showed that curcumin supplementation significantly increased adiponectin concentrations in comparison with placebo (WMD: 0.82 Hedges' g; 95% confidence interval (CI): 0.33 to 1.30, P˂0.001). Greater effects on adiponectin were observed in trials lasting ≤10 weeks (WMD: 1.05 Hedges' g; 95% CI: 0.64 to 1.45, P˂0.001).

CONCLUSION

Curcumin significantly improves adiponectin concentrations. However, due to some limitations in this study, further studies are needed to reach a definitive conclusion about the effect of curcumin on the levels of adiponectin.

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.

Strategy for improved therapeutic efficiency of curcumin in the treatment of gastric cancer

Gastric cancer is a common oncological disease. Although enormous efforts have been expended, possible therapeutic modalities are still limited. For this reason, new therapeutic approaches and agents are highly requested and intensively developed. One strategy is the application of natural agents, such as curcumin, with proven anticancer effects and low toxicity for patients. Therefore, this review discusses the potential application of curcumin in the therapy of gastric cancer and its potential incorporation in therapeutic regimens. Because one of the largest impediments for widespread curcumin application is its limited bioavailability (caused mainly by its very low water solubility), studied strategies (drug delivery systems and curcumin derivatization) aimed to solve this obstacle are discussed in more detail.

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.

Status of inflammation in relation to health related quality of life in hepatocellular carcinoma patients

PURPOSE

Both Inflammation and health-related quality of life (HRQoL) are independent prognosticators in HCC patients. We hypothesized that inflammation can cause impairment in HRQoL and investigated the correlation between inflammatory status and HRQoL in HCC patients.

METHODS

Clinical, laboratory and HRQoL (using EORTC QLQ-C30, QLQ-HCC18, C30 and HCC18 index-scores) data were prospectively collected from HCC patients at diagnosis. Correlation analyses were performed between HRQoL and inflammation-based markers including C-reactive protein (CRP), CRP/albumin ratio (CRP/alb), Glasgow Prognostic Score (GPS), Inflammation-Based Index (IBI) and Prognostic Index (PI).

RESULTS

Among 445 HCC patients, higher inflammatory states were significantly correlated with worse HRQoL. For CRP and CRP/alb ratio, the HRQoL factors with higher correlations included C30 and HCC18 index-scores, certain QLQ-C30 domains and items ('physical functioning', 'role functioning', 'fatigue', 'pain', 'appetite loss') and QLQ-HCC18 items ('fatigue', 'body image', 'nutrition' and 'abdominal swelling'), where the Pearson's correlation coefficients were up to 0.416. Multivariate analyses indicated that worse HRQoL factors were significantly correlated with worse scores in GPS, IBI and PI.

CONCLUSION

In HCC patients, inflammatory status correlates with HRQoL at presentation. In particular, relatively stronger correlations with CRP-based markers have been observed in HRQoL scales that assess constitutional symptoms (QLQ-C30 'physical functioning', 'role functioning', 'fatigue', 'appetite loss' and QLQ-HCC18 'fatigue' and 'nutrition') and tumor burden (QLQ-C30 'pain' and QLQ-HCC18 'abdominal swelling' and 'body image'). Future studies are warranted to evaluate whether intervention that reduces inflammation could improve HRQoL in HCC patients.

Exosomes as Drug Carriers for Cancer Therapy

Exosomes, biological extracellular vesicles, have recently begun to find use in targeted drug delivery in solid tumor research. Ranging from 30-120 nm in size, exosomes are secreted from cells and isolated from bodily fluids. Exosomes provide a unique material platform due to their characteristics, including physical properties such as stability, biocompatibility, permeability, low toxicity, and low immunogenicity-all critical to the success of any nanoparticle drug delivery system. In addition to traditional chemotherapeutics, natural products and RNA have been encapsulated for the treatment of breast, pancreatic, lung, prostate cancers, and glioblastoma. This review discusses current research on exosomes for drug delivery to solid tumors.

Advances in phytochemical delivery systems for improved anticancer activity

Natural compounds have significant anticancer pharmacological activities, but often suffer from low bioavailability and selectivity that limit therapeutic use. The present work critically analyzes the latest advances on drug delivery systems designed to enhance pharmacokinetics, targeting, cellular uptake and efficacy of anticancer phytoconstituents. Various phytochemicals, including flavonoids, resveratrol, celastrol, curcumin, berberine and camptothecins, carried by liposomes, nanoparticles, nanoemulsions and films showed promising results. Strategies to avoid drug metabolism, overcome physiological barriers and achieve higher concentration at cancer sites through skin, buccal, nasal, vaginal, pulmonary and colon targeted delivery are presented. Current limitations, challenges and future research directions are also discussed.

Correlations of health-related quality of life with serum inflammatory indicators IL-8 and mIBI in patients with hepatocellular carcinoma

PURPOSE

Health-related quality of life (HRQoL) is a significant prognostic factor for overall survival in hepatocellular carcinoma (HCC) patients, and this is independent of stage and liver function. Inflammation plays a significant role in HCC development and progression. It was hypothesized that the inflammatory status of HCC patients may affect their HRQoL. The relationship between HRQoL and inflammatory status was explored using indicators IL-8 level and modified inflammation-based index (mIBI, based on IL-8, C-reactive protein, and albumin).

METHODS

From 2007-2011, HCC patients were enrolled prospectively. Baseline HRQoL assessment utilized the European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30 and QLQ-HCC18; clinical and laboratory data were collected at diagnosis. Two summary indices, C30 and HCC18 index-scores, were calculated. Correlation analyses were performed between HRQoL and inflammatory markers.

RESULTS

In the 445 patients studied, significant correlations were found between IL-8 levels and EORTC QLQ-C30, QLQ-HCC18, C30, and HCC18 index-scores. The strongest correlated factors were those reflective of constitutional symptoms, namely QLQ-C30 "appetite loss" (with Pearson's correlation coefficient, r=0.322, P<0.0001); QLQ-C30 "fatigue" (r=0.311, P<0.0001); QLQ-C30 "role functioning" (r=-0.305, P<0.0001); QLQ-HCC18 "nutrition" (r=0.317, P<0.0001); and QLQ-HCC18 "fatigue" (r=0.306, P<0.0001). In addition, moderate but significant correlations were also observed with HCC18 index score (r=0.321, P<0.0001), and C30 index score (r=0.306, P<0.0001). HRQoL factors were also significantly correlated with mIBI.

CONCLUSION

Baseline HRQoL using the conventional assessments of EORTC QLQ-C30 and QLQ-HCC18, as well as C30 and HCC18 index-scores, significantly correlated with inflammatory indicators (IL-8 level and mIBI) in HCC patients. Among the strongest correlations were those between IL-8 level and the two index-scores, as well as HRQoL aspects that represent constitutional symptoms. When paralleled with molecular findings, traditional HRQoL assessment in HCC has gained a new level of understanding: pattern recognition within an HRQoL instrument could potentially identify patients with more severe inflammatory state.

The Antitumor Effect of Curcumin in Urothelial Cancer Cells Is Enhanced by Light Exposure In Vitro

The natural compound curcumin exerts antitumor properties in vitro, but its clinical application is limited due to low bioavailability. Light exposure in skin and skin cancer cells has been shown to improve curcumin bioavailability; thus, the object of this investigation was to determine whether light exposure might also enhance curcumin efficacy in bladder cancer cell lines. RT112, UMUC3, and TCCSUP cells were preincubated with low curcumin concentrations (0.1-0.4 μg/ml) and then exposed to 1.65 J/cm² visible light for 5 min. Cell growth, cell proliferation, apoptosis, cell cycle progression, and cell cycle regulating proteins along with acetylation of histone H3 and H4 were investigated. Though curcumin alone did not alter cell proliferation or apoptosis, tumor cell growth and proliferation were strongly blocked when curcumin was combined with visible light. Curcumin-light caused the bladder cancer cells to become arrested in different cell phases: G0/G1 for RT112, G2/M for TCCSUP, and G2/M- and S-phase for UMUC3. Proteins of the Cdk-cyclin axis were diminished in RT112 after application of 0.1 and 0.4 μg/ml curcumin. Cell cycling proteins were upregulated in TCCSUP and UMUC3 in the presence of 0.1 μg/ml curcumin-light but were partially downregulated with 0.4 μg/ml curcumin. 0.4 μg/ml (but not 0.1 μg/ml) curcumin-light also evoked late apoptosis in TCCSUP and UMUC3 cells. H3 and H4 acetylation was found in UMUC3 cells treated with 0.4 μg/ml curcumin alone or with 0.1 μg/ml curcumin-light, pointing to an epigenetic mechanism. Light exposure enhanced the antitumor potential of curcumin on bladder cancer cells but by different molecular action modes in the different cell lines. Further studies are necessary to evaluate whether intravesical curcumin application, combined with visible light, might become an innovative tool in combating bladder cancer.

A Review of Curcumin and Its Derivatives as Anticancer Agents

Cancer is the second leading cause of death in the world and one of the major public health problems. Despite the great advances in cancer therapy, the incidence and mortality rates of cancer remain high. Therefore, the quest for more efficient and less toxic cancer treatment strategies is still at the forefront of current research. Curcumin, the active ingredient of the Curcuma longa plant, has received great attention over the past two decades as an antioxidant, anti-inflammatory, and anticancer agent. In this review, a summary of the medicinal chemistry and pharmacology of curcumin and its derivatives in regard to anticancer activity, their main mechanisms of action, and cellular targets has been provided based on the literature data from the experimental and clinical evaluation of curcumin in cancer cell lines, animal models, and human subjects. In addition, the recent advances in the drug delivery systems for curcumin delivery to cancer cells have been highlighted.

The immunomodulatory potential of natural compounds in tumor-bearing mice and humans

Cancer is considered a fetal disease caused by uncontrolled proliferation and progression of abnormal cells. The most efficient cancer therapies suppress tumor growth, prevent progression and metastasis, and are minimally toxic to normal cells. Natural compounds have shown a variety of chemo-protective effects alone or in combination with standard cancer therapies. Along with better understanding of the dynamic interactions between our immune system and cancer development, nutritional immunology-the use of natural compounds as immunomodulators in cancer patients-has begun to emerge. Cancer cells evolve strategies that target many aspects of the immune system to escape or even edit immune surveillance. Therefore, the immunesuppressive tumor microenvironment is a major obstacle in the development of cancer therapies. Because interaction between the tumor microenvironment and the immune system is a complex topic, this review focuses mainly on human clinical trials and animal studies, and it highlights specific immune cells and their cytokines that have been modulated by natural compounds, including carotenoids, curcumin, resveratrol, EGCG, and β-glucans. These natural compounds have shown promising immune-modulating effects, such as inhibiting myeloid-derived suppressor cells and enhancing natural killer and cytolytic T cells, in tumor-bearing animal models, but their efficacy in cancer patients remains to be determined.

Cellular and molecular mechanisms of curcumin in prevention and treatment of disease

Curcumin is a naturally occurring polyphenolic compound present in rhizome of Curcuma longa belonging to the family zingiberaceae. Growing experimental evidence revealed that curcumin exhibit multitarget biological implications signifying its crucial role in health and disease. The current review highlights the recent progress and mechanisms underlying the wide range of pharmacological effects of curcumin against numerous diseases like neuronal, cardiovascular, metabolic, kidney, endocrine, skin, respiratory, infectious, gastrointestinal diseases and cancer. The ability of curcumin to modulate the functions of multiple signal transductions are linked with attenuation of acute and chronic diseases. Numerous preclinical and clinical studies have revealed that curcumin modulates several molecules in cell signal transduction pathway including PI3K, Akt, mTOR, ERK5, AP-1, TGF-β, Wnt, β-catenin, Shh, PAK1, Rac1, STAT3, PPARγ, EBPα, NLRP3 inflammasome, p38MAPK, Nrf2, Notch-1, AMPK, TLR-4 and MyD-88. Curcumin has a potential to prevent and/or manage various diseases due to its anti-inflammatory, anti-oxidant and anti-apoptotic properties with an excellent safety profile. In contrast, the anti-cancer effects of curcumin are reflected due to induction of growth arrest and apoptosis in various premalignant and malignant cells. This review also carefully emphasized the pharmacokinetics of curcumin and its interaction with other drugs. Clinical studies have shown that curcumin is safe at the doses of 12 g/day but exhibits poor systemic bioavailability. The use of adjuvant like piperine, liposomal curcumin, curcumin nanoparticles and curcumin phospholipid complex has shown enhanced bioavailability and therapeutic potential. Further studies are warranted to prove the potential of curcumin against various ailments.

A Phase 2 Study to Assess the Immunomodulatory Capacity of a Lecithin-based Delivery System of Curcumin in Endometrial Cancer

Curcumin is a botanical with anti-tumor and immunomodulatory properties. We hypothesized that curcumin supplementation might influence inflammatory biomarker levels in endometrial carcinoma (EC). In this open-label, non-randomized phase 2 study (NCT02017353), seven EC patients consumed 2 g/day Curcumin Phytosome (CP) orally for 2 weeks. Blood was taken at baseline, days 1, 7, 14, and 21. The following analytes were measured: curcuminoids and metabolites, 56 inflammatory biomarkers, COX-2, frequencies of myeloid-derived suppressor cells, dendritic cells and NK cells, expression of MHC molecules on leukocytes and monocytes and activation/memory status of T cells. Patients completed quality of life (QoL) questionnaires at baseline and end of treatment. Curcumin metabolites were detectable in plasma upon CP intake. CP downregulated MHC expression levels on leukocytes (P = 0.0313), the frequency of monocytes (P = 0.0114) and ICOS expression by CD8⁺ T cells (P = 0.0002). However, CP upregulated CD69 levels on CD16⁻ NK cells (P = 0.0313). No differences were observed regarding inflammatory biomarkers, frequencies of other immune cell types, T cell activation and COX-2 expression. A non-significant trend to improved QoL was observed. Overall, CP-induced immunomodulatory effects in EC were modest without significant QoL changes. Given the small population and the observed variability in inter-patient biomarker levels, more research is necessary to explore whether benefits of CP can be obtained in EC by different supplementation regimens.

Clinical Trial Registration:www.ClinicalTrials.gov, identifier NCT02017353; www.clinicaltrialsregister.eu, identifier 2013-001737-40.

Integrative Treatment for Colorectal Cancer: A Comprehensive Approach

A comprehensive approach to integrative treatment of colorectal cancer (CRC) patients involves three spheres of intervention: lifestyle, biology, and conventional treatment. Individualization of treatment is emphasized. The lifestyle sphere includes nutritional therapies, biobehavioral strategies with circadian interventions, and physical care modalities. The biology sphere comprises six host factors in the patient's internal biochemical environment or "terrain": inflammation, glycemia, oxidative stress, immune dysregulation, coagulopathy, and stress chemistries. Laboratory testing of these factors guides integrative lifestyle and supplement recommendations. The conventional treatment sphere includes individualized lifestyle recommendations, and supplements or drugs used to enhance tolerability or effectiveness of conventional treatments. Innovative strategies are implemented, including chronomodulated chemotherapy, chemosensitivity testing, and using results of molecular genomic testing to guide nutritional infusions and supplement recommendations. In the lifestyle sphere, substantial evidence from cohort studies supports recommendations for a diet that emphasizes plant and fish proteins, healthful fats in amounts that are tailored to the clinical circumstance of the patient, and carbohydrates based on unrefined whole grains, vegetables and whole fruits. High glycemic diets and refined carbohydrates, especially sugar-sweetened beverages, should be avoided. Biobehavioral strategies include practice of the relaxation response and related approaches. In addition, specific strategies to promote robust circadian organization (CO) are used to combat quality of life concerns and worsened survival that accompany disrupted CO. Physical activity, including aerobic activity and muscle strengthening, is recommended at all disease stages. In the biology sphere, supplements and lifestyle recommendations for inflammation and glycemia are discussed. In the conventional treatment sphere, supplements and innovative and complementary therapies that may remedy treatment toxicities are reviewed. Approaching CRC treatment with a comprehensive, individualized intervention enables safe and beneficial outcomes in this patient population, which can vary widely in individual biology, treatment toxicities, and disease complications. Further research in integrative therapies for CRC patients is needed.

Effects of curcumin on hypoxia-inducible factor as a new therapeutic target

Hypoxia-inducible factor-1 (HIF-1) is a transcription factor that consists of two subunits, the HIF-1α and HIF-1β (ARNT). Under hypoxic conditions, HIF-1 is an adaptive system that regulates the transcription of multiple genes associated with growth, angiogenesis, proliferation, glucose transport, metabolism, pH regulation and cell death. However, aberrant HIF-1 activation contributes to the pathophysiology of several human diseases such as cancer, ischemic cardiovascular disorders, and pulmonary and kidney diseases. A growing body of evidence indicates that curcumin, a natural bioactive compound of turmeric root, significantly targets both HIF-1 subunits, but is more potent against HIF-1α. In this review, we have summarized the knowledge about the pharmacological effects of curcumin on HIF-1 and the related molecular mechanisms that may be effective candidates for the development of multi-targeted therapy for several human diseases.

Effect of fisetin supplementation on inflammatory factors and matrix metalloproteinase enzymes in colorectal cancer patients

A growing body of evidence indicates that inflammation is associated with tumorigenesis, metastasis and chemotherapeutic resistance in patients with colorectal cancer (CRC). Natural flavonoids are promising agents for inflammation-related tumor progression in patients with CRC. This study aimed to assess the efficacy of flavonoid fisetin supplementation on the inflammatory status and matrix metalloproteinase (MMP) levels in these patients. In this double-blind, randomized placebo-controlled clinical trial, 37 CRC patients undergoing chemotherapy were assigned to receive either 100 mg fisetin (n = 18) or placebo (n = 19) for seven consecutive weeks. The supplementation began one week before chemotherapy and continued until the end of the second chemotherapy cycle. Levels of interleukin (IL)-8, IL-10, high-sensitivity C-reactive protein (hs-CRP), MMP-7, and MMP-9 were measured in plasma using ELISA, before and after the intervention. The trial was registered at http://www.irct.ir (code: IRCT2015110511288N9). The participants were 55.59 ± 15.46 years old with 62.16% being male. After the intervention, the plasma levels of IL-8 and hs-CRP reduced significantly in the fisetin group (p < 0.04 and p < 0.01, respectively). Additionally, fisetin supplementation suppressed the values of MMP-7 levels (p < 0.02). However, significant changes were observed only in IL-8 concentrations in the fisetin group when compared with the placebo group (p < 0.03). The changes in the levels of other metabolic factors were not statistically significant. According to the results, fisetin could improve the inflammatory status in CRC patients, suggesting it as a novel complementary antitumor agent for these patients and warranting further studies.

Curcumin: A naturally occurring autophagy modulator

Autophagy is a self-degradative process that plays a pivotal role in several medical conditions associated with infection, cancer, neurodegeneration, aging, and metabolic disorders. Its interplay with cancer development and treatment resistance is complicated and paramount for drug design since an autophagic response can lead to tumor suppression by enhancing cellular integrity and tumorigenesis by improving tumor cell survival. In addition, autophagy denotes the cellular ability of adapting to stress though it may end up in apoptosis activation when cells are exposed to a very powerful stress. Induction of autophagy is a therapeutic option in cancer and many anticancer drugs have been developed to this aim. Curcumin as a hydrophobic polyphenol compound extracted from the known spice turmeric has different pharmacological effects in both in vitro and in vivo models. Many reports exist reporting that curcumin is capable of triggering autophagy in several cancer cells. In this review, we will focus on how curcumin can target autophagy in different cellular settings that may extend our understanding of new pharmacological agents to overcome relevant diseases.

Heat shock protein 27 influences the anti-cancer effect of curcumin in colon cancer cells through ROS production and autophagy activation

The problem of therapeutic resistance and chemotherapeutic efficacy is tricky and critical in the management of colorectal cancer (CRC). Curcumin is a promising anti-cancer agent. Heat shock protein 27 (HSP27) is correlated with CRC progression and is said to affect CRC response to different therapies. However, the role of HSP27 on the therapeutic efficacy of curcumin remains unknown. HSP27 was silenced using small hairpin RNA (shRNA) technique. The cytotoxic and apoptotic effects of curcumin were assessed by sulforhodamine B (SRB) colorimetric assay, flow cytometric cell cycle analysis, and annexin V/propidium iodide (PI) double-labeling assays. Total reactive oxygen species (ROS)/superoxide and autophagy detection were performed, and the levels of apoptosis-related proteins were examined by Western blotting. It was found that the silencing of HSP27 (HSP27-KD) resulted in increased treatment resistance to curcumin in CRC cells. In addition, cell cycle analysis showed that the curcumin treatment caused cell cycle arrest at the G2/M phase in the control group, and apoptosis was reduced in the HSP27-KD group. Curcumin treatment also resulted in a decrease in anti-apoptotic proteins, p-Akt, Akt, Bcl-2 and p-Bad, and increase in pro-apoptotic proteins Bad and c-PARP levels in the control cells but not in the HSP27-KD cells. This was also followed by low reactive oxygen/nitrogen species (ROS/RNS), superoxide and autophagy induction levels in the HSP27-KD cells as compared to the control cells. Therefore, as silencing of HSP27 increases curcumin resistance by reducing apoptosis and reactive oxidative stress production, HSP27 is a potential selective target for curcumin treatment in CRC.

The regulation and importance of monocyte chemoattractant protein-1

PURPOSE OF REVIEW

Monocyte chemoattractant protein (MCP)-1, a chemokine regulating monocyte chemotaxis and T-lymphocyte differentiation by binding to the CC chemokine receptor 2 (CCR2), plays a crucial role in the pathogenesis of inflammatory diseases, atherosclerosis and cancer. This review summarizes the current knowledge on the regulation and importance of the MCP-1/CCR2 axis, focusing on the therapeutic potential of its inhibition.

RECENT FINDINGS

Differential modulation of MCP-1 and CCR2 lead to downstream activation pathways, pathogenetic to differing disease conditions characterized by dysregulated monocyte/macrophage tissue recruitment. Pharmacological targeting of the MCP-1/CCR2 axis has led to selective MCP-1/CCR2 antagonists that have now entered phase I/II clinical trials for the treatment of inflammatory diseases, atherosclerosis and cancer. The pleiotropic nonselective MCP-1/CCR2 inhibition by current pharmacological agents is thought to contribute to their anti-inflammatory and antiatherosclerotic effects that is also seen for nutraceutical compounds such as curcumin.

SUMMARY

MCP-1 has a critical role in regulating chemotaxis both in health and disease, with increasing interest in its pharmacological inhibition. However, the therapeutic efficacy and safety of targeting the MCP-1/CCR2 axis is still in evolution.

The Effects of Curcumin on Serum Heat Shock Protein 27 Antibody Titers in Patients with Metabolic Syndrome

Metabolic syndrome (MetS) is associated with an increased risk of cardiovascular disease and diabetes mellitus. Inflammation and oxidant stress are features of MetS that can enhance the expression and release of heat shock proteins (Hsps), including the small heat shock protein, Hsp 27, and that may subsequently lead to the production of Hsp27 antibodies (anti-Hsp 27). Curcumin is an anti-inflammatory and antioxidant phytochemical that may ameliorate these features of MetS. We investigated the effects of unformulated curcumin and phospholipidated curcumin on antibody titers to heat shock protein 27 (anti-Hsp 27) in patients with MetS. A randomized double-blind, placebo-controlled clinical trial design was used in 120 patients with MetS (diagnosed according to the International Diabetes Federation [IDF] criteria). Participants were randomly allocated to 3 groups, with 40 individuals per group, that received either 1 g/d curcumin, phospholipidated curcumin, or a placebo for 6 weeks. The changes in serum concentrations of anti-Hsp 27 did not differ significantly between study groups (p = .283). There was no significant difference between baseline and end-of-trial concentrations of anti-Hsp 27 in groups supplemented with curcumin (p = .177), phospholipidated curcumin (p = .798), or placebo (p = .663). Curcumin supplementation (1 g/d) has no significant effects on anti-Hsp 27 titers in patients with MetS.

Correction to: In Vitro-In Vivo Dose Response of Ursolic Acid, Sulforaphane, PEITC, and Curcumin in Cancer Prevention

The citation of the author name "Ah-Ng Tony Kong" in PubMed is not the author's preference. Instead of "Kong AT", the author prefers "Kong AN".

Natural Bioactive Food Components for Improving Enteral Tube Feeding Tolerance in Adult Patient Populations

Tube feeding (TF) is the most common form of nutrition support. In recent years, TF administration has increased among patient populations within and outside hospital settings, in part due to greater insurance coverage, reduced use of parenteral nutrition, and improved formularies suitable for sole source nutrition. With increasing life expectancy and improved access to TFs, the number of adults dependent on enteral nutrition is expected to grow. However, enteral TF intolerance (ETFI) is the most common complication of TFs, typically presenting with at least 1 adverse gastrointestinal event, including nausea, diarrhea, and constipation. ETFI often leads to reductions in TF volume with associated energy and protein deficits. Potentially ensuing malnutrition is a major public health concern due its effects on increased risk of morbidity and mortality, infections, prolonged hospital length of stay, and higher healthcare costs. As such, there is a need for intervention strategies to prevent and reduce ETFI. Incorporating whole foods with bioactive properties is a promising strategy. Emerging research has elucidated bioactive properties of whole foods with specific benefits for the prevention and management of adverse gastrointestinal events commonly associated with TFs. However, lack of evidence-based recommendations and technological challenges have limited the use of such foods in commercial TF formulas. This review addresses research gaps by discussing 5 whole foods (rhubarb, banana, curcumin, peppermint oil, and ginger) with bioactive attributes identified through literature searches and clinical experience as having substantial scientific rationale to consider their application for ETFI in adult populations.

In Vitro-In Vivo Dose Response of Ursolic Acid, Sulforaphane, PEITC, and Curcumin in Cancer Prevention

According to the National Center of Health Statistics, cancer was the culprit of nearly 600,000 deaths in 2016 in the USA. It is by far one of the most heterogeneous diseases to treat. Treatment for metastasized cancers remains a challenge despite modern diagnostics and treatment regimens. For this reason, alternative approaches are needed. Chemoprevention using dietary phytochemicals such as triterpenoids, isothiocyanates, and curcumin in the prevention of initiation and/or progression of cancer poses a promising alternative strategy. However, significant challenges exist in the extrapolation of in vitro cell culture data to in vivo efficacy in animal models and to humans. In this review, the dose at which these phytochemicals elicit a response in vitro and in vivo of a multitude of cellular signaling pathways will be reviewed highlighting Nrf2-mediated antioxidative stress, anti-inflammation, epigenetics, cytoprotection, differentiation, and growth inhibition. The in vitro-in vivo dose response of phytochemicals can vary due, in part, to the cell line/animal model used, the assay system of the biomarker used for the readout, chemical structure of the functional analog of the phytochemical, and the source of compounds used for the treatment study. While the dose response varies across different experimental designs, the chemopreventive efficacy appears to remain and demonstrate the therapeutic potential of triterpenoids, isothiocyanates, and curcumin in cancer prevention and in health in general.

Protective effects of curcumin against doxorubicin-induced toxicity and resistance: A review

Doxorubicin (DOX)-induced toxicity and resistance are major obstacles in chemotherapeutic approaches. Despite effective in the treatment of numerous malignancies, some clinicians have voiced concern that DOX has the potential to cause debilitating consequences in organ tissues, especially the heart. The mechanisms of toxicity and resistance are respectively related to induction of reactive oxygen species (ROS) and up-regulation of ATP-binding cassette (ABC) transporter. Curcumin (CUR) with several biological and pharmacological properties is expected to restore DOX-mediated impairments to tissues. This review is intended to address the current knowledge on DOX adverse effects and CUR protective actions in the heart, kidneys, liver, brain, and reproductive organs. Coadministration of CUR and DOX is capable of ameliorating DOX toxicity pertained to antioxidant, apoptosis, autophagy, and mitochondrial permeability.

Protective effects of curcumin against aflatoxicosis: A comprehensive review

Aflatoxicosis is a deleterious medical condition that results from aflatoxins (AFs) or ochratoxins (OTs). Contamination with these toxins exerts detrimental effects on the liver, kidneys, reproductive organs, and also on immunological and cardiovascular systems. Aflatoxicosis is closely associated with overproduction of reactive oxygen species (ROS) as key contributors to oxidative and nitrosative stress responses, and subsequent damages to lipids, proteins, RNA, and DNA. The main target organ for AF toxicity is the liver, where DNA adducts, degranulation of endoplasmic reticulum, increased hepatic lipid peroxide, GSH depletion, mitochondrial dysfunction, and reduction of enzymatic and non-enzymatic antioxidants are manifestations of aflatoxicosis. Curcuma longa L. (turmeric) is a medicinal plant widely utilized all over the world for culinary and phytomedical purposes. Considering the antioxidant characteristic of curcumin, the main active component of turmeric, this review is intended to critically summarize the available evidence supporting possible effectiveness of curcumin against aflatoxicosis. Curcumin can serve as a promising candidate for attenuation of the adverse consequences of aflatoxicosis, acting mainly through intrinsic antioxidant effects aroused from its structure, modulation of the immune system as reflected by interleukin-1β and transforming growth factor-β, and interfering with AF's biotransformation by cytochrome P450 isoenzymes CYP1A, CYP3A, CYP2A, CYP2B, and CYP2C.

Cadmium-induced toxicity is rescued by curcumin: A review

Cadmium (Cd) is one of the most common environmental and occupational heavy metals with extended distribution. Exposure to Cd may be associated with several deleterious consequences on the liver, bones, kidneys, lungs, testes, brain, immunological, and cardiovascular systems. Overproduction of reactive oxygen species (ROS) as the main mechanism behind its toxicity causes oxidative stress and subsequent damages to lipids, proteins, and DNA. Therefore, antioxidants along with chelating agents have shown promising outcomes against Cd-induced toxicity. Curcumin with various beneficial effects and medical efficacy has been evaluated for its inhibitory activities against biological impairments caused by Cd. Thus, this article is intended to address the effectiveness of curcumin against toxicity following Cd entry. Curcumin can afford to attenuate lipid peroxidation, glutathione depletion, alterations in antioxidant enzyme, and so forth through scavenging and chelating activities or Nrf2/Keap1/ARE pathway induction. © 2017 BioFactors, 43(5):645-661, 2017.

Effects of Curcumin on Tobacco Smoke-induced Hepatic MAPK Pathway Activation and Epithelial-Mesenchymal Transition In Vivo

Tobacco smoke is a major risk factor for hepatic cancer. Epithelial-mesenchymal transition (EMT) induced by tobacco smoke is crucially involved in the initiation and development of cancer. Mitogen-activated protein kinase (MAPK) pathways play important roles in tobacco smoke-associated carcinogenesis including EMT process. The chemopreventive effect of curcumin supplementation against cancers has been reported. In this study, we investigated the effects of tobacco smoke on MAPK pathway activation and EMT alterations, and then the preventive effect of curcumin was examined in the liver of BALB/c mice. Our results indicated that exposure of mice to tobacco smoke for 12 weeks led to activation of ERK1/2, JNK, p38 and ERK5 pathways as well as activator protein-1 (AP-1) proteins in liver tissue. Exposure of mice to tobacco smoke reduced the hepatic mRNA and protein expression of the epithelial markers, while the hepatic mRNA and protein levels of the mesenchymal markers were increased. Treatment of curcumin effectively attenuated tobacco smoke-induced activation of ERK1/2 and JNK MAPK pathways, AP-1 proteins and EMT alterations in the mice liver. Our data suggested the protective effect of curcumin in tobacco smoke-triggered MAPK pathway activation and EMT in the liver of BALB/c mice, thus providing new insights into the chemoprevention of tobacco smoke-associated hepatic cancer. Copyright © 2017 John Wiley & Sons, Ltd.

Curcumin mediates anticancer effects by modulating multiple cell signaling pathways

Curcumin, a component of a spice native to India, was first isolated in 1815 by Vogel and Pelletier from the rhizomes of Curcuma longa (turmeric) and, subsequently, the chemical structure of curcumin as diferuloylmethane was reported by Milobedzka et al. [(1910) 43., 2163-2170]. Since then, this polyphenol has been shown to exhibit antioxidant, anti-inflammatory, anticancer, antiviral, antibacterial, and antifungal activities. The current review primarily focuses on the anticancer potential of curcumin through the modulation of multiple cell signaling pathways. Curcumin modulates diverse transcription factors, inflammatory cytokines, enzymes, kinases, growth factors, receptors, and various other proteins with an affinity ranging from the pM to the mM range. Furthermore, curcumin effectively regulates tumor cell growth via modulation of numerous cell signaling pathways and potentiates the effect of chemotherapeutic agents and radiation against cancer. Curcumin can interact with most of the targets that are modulated by FDA-approved drugs for cancer therapy. The focus of this review is to discuss the molecular basis for the anticancer activities of curcumin based on preclinical and clinical findings.