Bringing Curcumin to the Clinic in Cancer Prevention: a Review of Strategies to Enhance Bioavailability and Efficacy

Stable Dietary Ora-Curcumin Formulation Protects from Experimental Colitis and Colorectal Cancer

Inflammatory bowel disease (IBD) is a chronic gut disorder that also elevates the risk of colorectal cancer (CRC). The global incidence and severity of IBD are rising, yet existing therapies often lead to severe side effects. Curcumin offers potent anti-inflammatory and chemotherapeutic properties. However, its clinical translation is hindered by rapid metabolism, as well as poor water solubility and stability, which limits its bioavailability. To address these challenges, we developed OC-S, a water-soluble and colon-targeted curcumin formulation that protects against colitis in mice. The current study advances OC-S as a dietary supplement by establishing its stability and compatibility with various commercial dietary products. Further, OC-S exhibited specific binding to inflamed colon tissue, potentially aiding in targeted drug retention at the inflammation site in colitis with diarrhea symptoms. We further investigated its efficacy in vivo and in vitro using a murine model of colitis and tumoroids from APCmin mice. OC-S significantly reduced colitis severity and pro-inflammatory cytokine expression compared with curcumin, even at very low doses (5 mg/kg/day). It also demonstrated higher anti-proliferative activity in CRC cells and colon cancer tumoroids vs. curcumin. Overall, this study demonstrated that OC-S effectively targets and retains water-soluble curcumin at the inflamed colon sites, while showing promise in addressing both colitis and colorectal cancer, which potentially paves the way for OC-S to advance into clinical development as a dietary product for both IBD and CRC.

The mechanisms of natural products for eye disorders by targeting mitochondrial dysfunction

The human eye is susceptible to various disorders that affect its structure or function, including glaucoma, age-related macular degeneration (AMD) and diabetic retinopathy (DR). Mitochondrial dysfunction has been identified as a critical factor in the pathogenesis and progression of eye disorders, making it a potential therapeutic target in the clinic. Natural products have been used in traditional medicine for centuries and continue to play a significant role in modern drug development and clinical therapeutics. Recently, there has been a surge in research exploring the efficacy of natural products in treating eye disorders and their underlying physiological mechanisms. This review aims to discuss the involvement of mitochondrial dysfunction in eye disorders and summarize the recent advances in the application of natural products targeting mitochondria. In addition, we describe the future perspective and challenges in the development of mitochondria-targeting natural products.

Green Cancer Prevention and Beyond

The concept of green chemoprevention was introduced in 2012 by Drs. Jed Fahey and Thomas Kensler as whole-plant foods and/or extract-based interventions demonstrating cancer prevention activity. Refining concepts and research demonstrating proof-of-principle approaches are highlighted within this review. Early approaches included extensively investigated whole foods, including broccoli sprouts and black raspberries showing dose-responsive effects across a range of activities in both animals and humans with minimal or no apparent toxicity. A recent randomized crossover trial evaluating the detoxification of tobacco carcinogens by a broccoli seed and sprout extract in the high-risk cohort of current smokers highlights the use of a dietary supplement as a potential next-generation green chemoprevention or green cancer prevention approach. Challenges are addressed, including the selection of dose, duration and mode of delivery, choice of control group, and standardization of the plant food or extract. Identification and characterization of molecular targets and careful selection of high-risk cohorts for study are additional important considerations when designing studies. Goals for precision green cancer prevention include acquiring robust evidence from carefully controlled human studies linking plant foods, extracts, and compounds to modulation of targets for cancer risk reduction in individual cancer types.

Curcumin-loaded nanocomplexes alleviate the progression of fluke-related cholangiocarcinoma in hamsters

Background

Curcumin-loaded nanocomplexes (CNCs) previously demonstrated lower toxicity and extended release better than is the case for free curcumin. Here, we evaluated the efficacy of CNCs against opisthorchiasis-associated cholangiocarcinoma (CCA) in hamsters.

Method

Dose optimization (dose and frequency) was performed over a 1-month period using hamsters, a model that is widely used for study of opisthorchiasis-associated cholangiocarcinoma. In the main experimental study, CCA was induced by a combination of fluke, Opisthorchis viverrini (OV), infection and N-nitrosodimethylamine (NDMA) treatment. Either blank (empty) nanocomplexes (BNCs) or different concentrations of CNCs (equivalent to 10 and 20 mg cur/kg bw) were given to hamsters thrice a week for 5 months. The histopathological changes, biochemical parameters, and the expression of inflammatory/oncogenic transcription factors were investigated. In addition, the role of CNCs in attenuating CCA genesis, as seen in an animal model, was also confirmed in vitro using CCA cell lines.

Results

The optimization study revealed that treatment with CNCs at a dose equivalent to 10 mg cur/kg bw, thrice a week for 1 month, led to a greater reduction of inflammation and liver injury induced in hamsters by OV + NDMA than did treatments at other dose rates. Oral administration with CNCs (10 mg cur/kg bw), thrice a week for 5 months, significantly increased survival rate, reduced CCA incidence, extent of tumor development, cholangitis, bile duct injury and cholangiofibroma. In addition, this treatment decreased serum ALP and ALT activities and suppressed expression of NF-κB, FOXM1, HMGB1, PCNA and formation of 8-nitroguanine. Treatment of CCA cell lines with CNCs also reduced cell proliferation and colony formation, similar to those treated with NF-κB and/or FOXM1 inhibitors.

Conclusion

CNCs (10 mg cur/kg bw) attenuate the progression of fluke-related CCA in hamsters partly via a NF-κB and FOXM1-mediated pathway.

Curcumin and analogues against head and neck cancer: From drug delivery to molecular mechanisms

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) is one of the most life-threatening diseases which also causes economic burden worldwide. To overcome the limitations of traditional therapies, investigation into alternative adjuvant treatments is crucial.

PURPOSE

Curcumin, a turmeric-derived compound, demonstrates significant therapeutic potential in diverse diseases, including cancer. Furthermore, research focuses on curcumin analogues and novel drug delivery systems, offering approaches for improved efficacy. This review aims to provide a comprehensive overview of curcumin's current findings, emphasizing its mechanisms of anti-HNSCC effects and potential for clinical application.

METHOD

An electronic search of Web of Science, MEDLINE, and Embase was conducted to identify literature about the application of curcumin or analogues in HNSCC. Titles and abstracts were screened to identify potentially eligible studies. Full-text articles will be obtained and independently evaluated by two authors to make the decision of inclusion in the review.

RESULTS

Curcumin's clinical application is hindered by poor bioavailability, prompting the exploration of methods to enhance it, such as curcumin analogues and novel drug delivery systems. Curcumin could exhibit anti-cancer effects by targeting cancer cells and modulating the tumor microenvironment in HNSCC. Mechanisms of action include cell cycle arrest, apoptosis promotion, reactive oxygen species induction, endoplasmic reticulum stress, inhibition of epithelial-mesenchymal transition, attenuation of extracellular matrix degradation, and modulation of tumor metabolism in HNSCC cells. Curcumin also targets various components of the tumor microenvironment, including cancer-associated fibroblasts, innate and adaptive immunity, and lymphovascular niches. Furthermore, curcumin enhances the anti-cancer effects of other drugs as adjunctive therapy. Two clinical trials report its potential clinical applications in treating HNSCC.

CONCLUSION

Curcumin has demonstrated therapeutic potential in HNSCC through in vitro and in vivo studies. Its effectiveness is attributed to its ability to modulate cancer cells and interact with the intricate tumor microenvironment. The development of curcumin analogues and novel drug delivery systems has shown promise in improving its bioavailability, thereby expanding its clinical applications. Further research and exploration in this area hold great potential for harnessing the full therapeutic benefits of curcumin in HNSCC treatment.

Gut Microbiota and Aging: Traditional Chinese Medicine and Modern Medicine

The changing composition of gut microbiota, much like aging, accompanies people throughout their lives, and the inextricable relationship between both has recently attracted extensive attention as well. Modern medical research has revealed that a series of changes in gut microbiota are involved in the aging process of organisms, which may be because gut microbiota modulates aging-related changes related to innate immunity and cognitive function. At present, there is no definite and effective method to delay aging. However, Nobel laureate Tu Youyou's research on artemisinin has inspired researchers to study the importance of Traditional Chinese Medicine (TCM). TCM, as an ancient alternative medicine, has unique advantages in preventive health care and in treating diseases as it already has formed an independent understanding of the aging system. TCM practitioners believe that the mechanism of aging is mainly deficiency, and pathological states such as blood stasis, qi stagnation and phlegm coagulation can exacerbate the process of aging, which involves a series of organs, including the brain, kidney, heart, liver and spleen. Our current understanding of aging has led us to realise that TCM can indeed make some beneficial changes, such as the improvement of cognitive impairment. However, due to the multi-component and multi-target nature of TCM, the exploration of its mechanism of action has become extremely complex. While analysing the relationship between gut microbiota and aging, this review explores the similarities and differences in treatment methods and mechanisms between TCM and Modern Medicine, in order to explore a new approach that combines TCM and Modern Medicine to regulate gut microbiota, improve immunity and delay aging.

Cannabinoid compounds in combination with curcumin and piperine display an anti-tumorigenic effect against colon cancer cells

Currently, use of cannabinoids is limited to improve adverse effects of chemotherapy and their palliative administration during treatment is curiously concomitant with improved prognosis and regressed progression in patients with different tumor types. Although, non-psychoactive cannabidiol (CBD) and cannabigerol (CBG) display antineoplastic effects by repressing tumor growth and angiogenesis both in cell line and animal models, their use as chemotherapeutic agents is awaiting further investigation. Both clinical and epidemiological evidence supported by experimental findings suggest that micronutrients such as curcumin and piperine may present a safer strategy in preventing tumorigenesis and its recurrence. Recent studies demonstrated that piperine potentiates curcumin's inhibitory effect on tumor progression via enhancing its delivery and therapeutic activity. In this study, we investigated a plausible therapeutic synergism of a triple combination of CBD/CBG, curcumin, and piperine in the colon adenocarcinoma using HCT116 and HT29 cell lines. Potential synergistic effects of various combinations including these compounds were tested by measuring cancer cell proliferation and apoptosis. Our findings revealed that different genetic backgrounds of HCT116 and HT29 cell lines resulted in divergent responses to the combination treatments. Triple treatment showed synergism in terms of exhibiting anti-tumorigenic effects by activating the Hippo YAP signaling pathway in the HCT116 cell line.

The multifaceted roles of natural products in mitochondrial dysfunction

Mitochondria are the primary source of energy production in cells, supporting the metabolic demand of tissue. The dysfunctional mitochondria are implicated in various diseases ranging from neurodegeneration to cancer. Therefore, regulating dysfunctional mitochondria offers a new therapeutic opportunity for diseases with mitochondrial dysfunction. Natural products are pleiotropic and readily obtainable sources of therapeutic agents, which have broad prospects in new drug discovery. Recently, many mitochondria-targeting natural products have been extensively studied and have shown promising pharmacological activity in regulating mitochondrial dysfunction. Hence, we summarize recent advances in natural products in targeting mitochondria and regulating mitochondrial dysfunction in this review. We discuss natural products in terms of their mechanisms on mitochondrial dysfunction, including modulating mitochondrial quality control system and regulating mitochondrial functions. In addition, we describe the future perspective and challenges in the development of mitochondria-targeting natural products, emphasizing the potential value of natural products in mitochondrial dysfunction.

Microwave-Induced CuO Nanorods: A Comparative Approach between Curcumin, Quercetin, and Rutin to Study Their Antioxidant, Antimicrobial, and Anticancer Effects against Normal Skin Cells and Human Breast Cancer Cell Lines MCF-7 and T-47D

Herein, we explore the biological properties of curcumin, quercetin, and rutin by loading them onto porous CuO nanorods (NRs). The CuO NRs were synthesized using the microwave irradiation method through a chemical reaction between CuSO₄·5H₂O and NaOH in the presence of the anionic stabilizer sodium dodecyl sulfate. The shape and surface morphology of CuO NRs were examined with two microscopic techniques: high-resolution transmission electron microscopy (HR-TEM) and field emission scanning electron microscopy (FESEM). Their average diameter was measured by TEM to be 15 ± 2 nm. The porosity and interfacial area of the fabricated material were determined by Brunauer-Emmett-Teller analysis. After successful synthesis, CuO NRs were loaded with polyphenolic curcumin, quercetin, and rutin, with the loading efficiency of 57.8, 62.2, and 81.2%, respectively, which was confirmed by UV-visible and infra-red spectroscopy and finally with a thermal gravimetric technique. Their radical scavenging activity was measured with the 2,2-diphenyl-1-picrylhydrazyl radical and compared with the control (ascorbic acid). Further, good bactericidal effects were observed against both Gram-positive bacterial strains, including Staphylococcus aureus and Bacillus subtilis, and Gram-negative bacterial strains, including Salmonella typhi, Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae. Excellent anticancer activity was observed against normal skin cells and breast cancer cells T-47D and MCF-7.

Nanogels as Potential Delivery Vehicles in Improving the Therapeutic Efficacy of Phytopharmaceuticals

Nanogel is a promising drug delivery approach to improve the pharmacokinetics and pharmacodynamic prospect of phytopharmaceuticals. In the present review, phytopharmaceuticals with astonishing therapeutic utilities are being explored. However, their in vivo delivery is challenging, owing to poor biopharmaceutical attributes that impact their drug release profile, skin penetration, and the reach of optimal therapeutic concentrations to the target site. Nanogel and its advanced version in the form of nanoemulgel (oil-in-water nanoemulsion integrated gel matrix) offer better therapeutic prospects than other conventional counterparts for improving the biopharmaceutical attributes and thus therapeutic efficacy of phytopharmaceuticals. Nanoemulgel-loaded phytopharmaceuticals could substantially improve permeation behavior across skin barriers, subsequently enhancing the delivery and therapeutic effectiveness of the bioactive compound. Furthermore, the thixotropic characteristics of polymeric hydrogel utilized in the fabrication of nanogel/nanoemulgel-based drug delivery systems have also imparted improvements in the biopharmaceutical attributes of loaded phytopharmaceuticals. This formulation approach is about to be rife in the coming decades. Thus, the current review throws light on the recent studies demonstrating the role of nanogels in enhancing the delivery of bioactive compounds for treating various disease conditions and the challenges faced in their clinical translation.

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

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

An In Vitro and In Silico Study of Antioxidant Properties of Curcuminoid N-alkylpyridinium Salts: Initial Assessment of Their Antitumoral Properties

In this work, we report the synthesis of curcuminoids with ionic liquid characteristics, obtained by incorporating alkyl-substituted pyridinium moiety rather than one phenyl group through a two-step process. The antioxidant capacity of the obtained compounds was evaluated in vitro by 1,1-diphenyl-picrylhydrazyl (DPPH) free radical scavenging and ferric reducing antioxidant power (FRAP) assays, showing that some derivatives are more potent than curcumin. Pyridine curcuminoids (group 4) and curcuminoid N-alkylpyridinium salts with two methoxyl groups in the phenyl ring (group 7), presented the best antioxidant capacity. The experimental results were rationalized by density functional theory (DFT) calculations of the bond dissociation enthalpy (BDE) for O–H in each compound. The computational calculations allowed for insight into the structural–antioxidant properties relationship in these series of compounds. BDEs, obtained in the gas phase and water, showed a notable impact of water solvation on the stabilization of some radicals. The lower values of BDEs in the water solution correspond to the structurally related compounds curcuminoid-pyridine 4c and curcuminoid pyridinium salt 7a, which is consistent with the experimental results. Additionally, an assessment of cell viability and cell migration assays was performed for human colon cancer (HT29), human breast cancer (MCF7) cells, in addition to NIH3T3 murine fibroblast, as a model of non-cancer cell type. These compounds mainly cause inhibition of the cell migration observed in MCF7 cancer cells without affecting the non-tumoral NIH3T3 cell line: Neither in viability nor in migration.

Nano-strategies as Oral Drug Delivery Platforms for Treatment of Cancer: Challenges and Future Perspectives

Oral drug administration is the oldest and widely used method for drug administration. The objectives behind developing an oral drug delivery for the treatment of cancer are to achieve low cost treatment by utilizing novel techniques to target cancer through gut-associated lymphoid tissue (GALT) and to enhance patient comfort and compliance through a hospital-free treatment leading to "Chemotherapy at Home." Unfortunately, due to the physiological environment of the GIT and physicochemical properties of drug candidate, the efficacy of oral drug delivery methods is limited in the treatment of cancer. Due to their low hydrophilicity, high P-gp efflux and restricted intestinal permeability most of the anti-cancer drugs fail to achieve oral bioavailability. The review focuses on the efforts, challenges, opportunities and studies conducted by scientists worldwide on the oral administration of anticancer medications via nanocarriers such as liposomes, SLNs and dendrimers, because of their potential to overcome the epithelial barrier associated with GALT, as well as the applications of different polymers in targeting the cancer. The oral delivery can set newer horizons in cancer therapy to make it more patient friendly.

Curcumin encapsulation in functional PLGA nanoparticles: A promising strategy for cancer therapies

Nanoparticles have emerged as promising drug delivery systems for the treatment of several diseases. Novel cancer therapies have exploited these particles as alternative adjuvant therapies to overcome the traditional limitations of radio and chemotherapy. Curcumin is a natural bioactive compound found in turmeric, that has been reported to show anticancer activity against several types of tumors. Despite some biological limitations regarding its absorption in the human body, curcumin encapsulation in poly(lactic-co-glycolic acid) (PLGA), a non-toxic, biodegradable and biocompatible polymer, represents an effective strategy to deliver a drug to a tumor site. Furthermore, PLGA nanoparticles can be engineered with targeting moieties to reach specific cancer cells, thus enhancing the antitumor effects of curcumin. We herein aim to bring an up-to-date summary of the recently developed strategies for curcumin delivery to different types of cancer cells through encapsulation in PLGA nanoparticles, correlating their effects with those of curcumin on the biological capabilities acquired by cancer cells (cancer hallmarks). We discuss the targeting strategies proposed for advanced curcumin delivery and the respective improvements achieved for each cancer cell analyzed, in addition to exploring the encapsulation techniques employed. The conjugation of correct encapsulation techniques with tumor-oriented targeting design can result in curcumin-loaded PLGA nanoparticles that can successfully integrate the elaborate network of development of alternative cancer treatments along with traditional ones. Finally, the current challenges and future demands to launch these nanoparticles in oncology are comprehensively examined.

PLGA-Based Curcumin Delivery System: An Interesting Therapeutic Approach in the Treatment of Alzheimer's Disease

Progressive degeneration and dysfunction of the nervous system because of oxidative stress, aggregations of misfolded proteins, and neuroinflammation are the key pathological features of neurodegenerative diseases. Alzheimer's disease is a chronic neurodegenerative disorder driven by uncontrolled extracellular deposition of β-amyloid (Aβ) in the amyloid plaques and intracellular accumulation of hyperphosphorylated tau protein. Curcumin is a hydrophobic polyphenol with noticeable neuroprotective and anti-inflammatory effects that can cross the blood-brain barrier. Therefore, it is widely studied for the alleviation of inflammatory and neurological disorders. However, the clinical application of curcumin is limited due to its low aqueous solubility and bioavailability. Recently, nano-based curcumin delivery systems are developed to overcome these limitations effectively. This review article discusses the effects and potential mechanisms of curcumin-loaded PLGA nanoparticles in Alzheimer's disease.

Antioxidant activity of Curcumin

In the past few years, multiple drugs have been produced from traditional raw materials and recent pandemic disease COVID-19 once again research on this matter is being conducted to determine potential therapeutic purposes of different Ayurvedic Indian medicines and herbs. One such medicinal herb is Curcuma longa. Curcumin is strong antioxidant, anti-inflammatory, antispasmodic, antiangiogenic, anti-carcinogenic, as shown by multiple in vitro and in vivo studies. The action of the growth factor receptors is inhibited by curcumin. The anti-inflammatory effect of curcumin is obtained on the cytokines, proteolytic enzymes, eicosanoids, and lipid mediators. The superoxide radicals, nitric oxide and hydrogen peroxide, are sifted by curcumin, while lipid peroxidation is inhibited. Such properties of the compound thus form the foundation for its various therapeutic and pharmacological effects could also hold antiviral properties including COVID-19. The aim of this research is to summarize the updated pharmacological activities of curcumin.

Poloxamer188-based nanoparticles improve the anti-oxidation and anti-degradation of curcumin

Curcumin (CUR) is a food additive approved by World Health Organization. But the shortcomings, such as poor water solubility, easy oxidation and degradation, limit its application. In this study, the CUR-loaded poloxamer₁₈₈-based nanoparticles (CUR/PTT NPs) were fabricated to improve the stability and water solubility of CUR. Studies found the spherical CUR/PTT NPs had an average size of 98.71 ± 0.64 nm. Stability experiments displayed CUR/PTT NPs were extremely stable in different conditions. XRD analysis indicated the changes of crystal structures of CUR might be the main cause of the improved water solubility. Reducing power and anti-degradation tests suggested CUR/PTT NPs could improve the anti-oxidation and anti-degradation of CUR. Additionally, the results of body weight gains, hematological examination, organ coefficients, hematoxylin and eosin staining demonstrated CUR/PTT NPs bearing the excellent in vivo bio-security. Therefore, this study may provide a new idea for the combination of food industry and nanoparticles.

Increasing Post-Digestive Solubility of Curcumin Is the Most Successful Strategy to Improve its Oral Bioavailability: A Randomized Cross-Over Trial in Healthy Adults and In Vitro Bioaccessibility Experiments

SCOPE

Different mechanistic approaches to improve the low oral bioavailability of curcumin have been developed, but not yet directly compared in humans.

METHODS AND RESULTS

In a randomized, double-blind, cross-over trial with 12 healthy adults, the 24 h pharmacokinetics of a single dose of 207 mg curcumin is compared from the following formulations: native, liposomes, with turmeric oils, with adjuvants (including piperine), submicron-particles, phytosomes, γ-cyclodextrin complexes, and micelles. No free, but only conjugated curcumin is detected in all subjects. Compared to native curcumin, a significant increase in the area under the plasma concentration-time curve is observed for micellar curcumin (57-fold) and the curcumin-γ-cyclodextrin complex (30-fold) only. In vitro digestive stability, solubility, and micellization efficiency of micellar curcumin (100%, 80%, and 55%) and curcumin-γ-cyclodextrin complex (73%, 33%, and 23%) are higher compared to all other formulations (<72%, <8%, and <4%). The transport efficiencies through Caco-2 cell monolayers of curcumin from the digested mixed-micellar fractions did not differ significantly.

CONCLUSION

The improved oral bioavailability of micellar curcumin, and to a lesser extent of γ-cyclodextrin curcumin complexes, appears to be facilitated by increased post-digestive stability and solubility, whereas strategies targeting post-absorptive processes, including inhibition of biotransformation, appear ineffective.

Polyphenols as adjunctive treatments in psychiatric and neurodegenerative disorders: Efficacy, mechanisms of action, and factors influencing inter-individual response

The pathophysiology of psychiatric and neurodegenerative disorders is complex and multifactorial. Polyphenols possess a range of potentially beneficial mechanisms of action that relate to the implicated pathways in psychiatric and neurodegenerative disorders. The aim of this review is to highlight the emerging clinical trial and preclinical efficacy data regarding the role of polyphenols in mental and brain health, elucidate novel mechanisms of action including the gut microbiome and gene expression, and discuss the factors that may be responsible for the mixed clinical results; namely, the role of interindividual differences in treatment response and the potentially pro-oxidant effects of some polyphenols. Further clarification as part of larger, well conducted randomized controlled trials that incorporate precision medicine methods are required to inform clinical efficacy and optimal dosing regimens.

Curcumin-loaded nanocomplexes: Acute and chronic toxicity studies in mice and hamsters

We recently developed a modified solid dispersion of curcumin-loaded nanocomplexes (CNCs) in gums which promoted the prolonged and sustained release of curcumin. However, its safety assessment has not yet been investigated. Here, acute and chronic toxicities of CNCs were assayed using mice and hamsters. CNCs were orally administered to the animals. Doses of CNCs used for acute toxicity testing were 0.1, 1.1, 11.0 g/kg body weight for mice and 0.2, 2.1 and 21.4 g/kg body weight for hamsters. Doses of CNCs for chronic toxicity testing were 0.09, 0.27, 0.8 g/kg body weight/day for mice and 0.18, 0.54 and 1.61 g/kg body weight/day for hamsters. This regimen was followed daily for 6 months. Low and medium doses of CNCs did not induce any side effects in acute and chronic toxicity tests in either animal species. However, in acute toxicity testing, the organ-weight to body-weight ratio of spleen was significantly increased in mice treated with 11 g/kg body weight along with elevated levels of some biochemical parameters. There was a significant increase in organ-weight to body-weight ratios of stomach, liver and heart in hamsters treated with 21.4 g/kg body weight, but no elevated levels of biochemical parameters. Oral LD50 of CNCs in mice and hamsters were 8.9 and 16.8 g/kg body weight (equivalent to 2.5 and 4.7 g curcumin/kg body weight), respectively. Daily CNCs high-dose treatment for 6 months significantly increased organ-weight to body-weight ratios of stomach and intestine in mice and of lung and heart in hamsters. Elevated levels of glucose, total protein, ALT, AST and globulin in mice, and increased levels of AST, but decrease in cholesterol, in hamsters were concurrently observed with inflammation in liver and lung. These abnormalities were resolved within 28 days after cessation of treatment. The no-observed-adverse-effect level of CNCs was determined at 0.27 and 0.54 g/kg body weight/day in mice and hamsters. In conclusion, toxicity of high-dose CNCs treatment was graded as very low, possibly due to the components of the nanocomplex.

A Novel Folic Acid Receptor-Targeted Drug Delivery System Based on Curcumin-Loaded β-Cyclodextrin Nanoparticles for Cancer Treatment

Purpose

A novel folate receptor-targeted β-cyclodextrin (β-CD) drug delivery vehicle was constructed to improve the bioavailability, biosafety, and drug loading capacity of curcumin. Controlled release and targeted delivery was achieved by modifying the nanoparticles with folic acid (FA).

Methods

Folate-conjugated β-CD-polycaprolactone block copolymers were synthesized and characterized. Curcumin-loaded nanoparticles (FA-Cur-NPs) were structured by self-assembly. The physicochemical properties, stability, release behavior and tumor-targeting ability of the fabricated nanoparticles were studied.

Results

The average particle size and drug loading of FA-Cur-NPs was 151.8 nm and 20.27%, respectively. Moreover, the FA-Cur-NPs exhibited good stability in vitro for 72 h. The drug release profiles showed that curcumin from FA-Cur-NPs was released significantly faster in a pH 6.4 phosphate buffered solution (PBS) than in pH 7.4, indicating that curcumin can be enriched around the tumor site compared with normal cells. Additionally, the internalization of FA-Cur-NPs was aided by FA receptor-mediated endocytosis, and its cytotoxicity was proportional to the cellular uptake efficiency. Furthermore, in vivo studies confirmed that FA-Cur-NPs exhibited marked accumulation in the tumor site and excellent antitumor activity.

Conclusion

These findings suggest that FA-Cur-NPs are a promising approach for improving cancer therapy through active targeting and controllable release.

Design, green synthesis, antioxidant activity screening, and evaluation of protective effect on cerebral ischemia reperfusion injury of novel monoenone monocarbonyl curcumin analogs

Antioxidants with high efficacy and low toxicity have the potential to treat cerebral ischemia reperfusion injury (CIRI). Dienone monocarbonyl curcumin analogs (DMCA) capable of overcoming the instability and pharmacokinetic defects of curcumin possess notable antioxidant activity but are found to be significantly toxic. In this study, a novel skeleton of the monoenone monocarbonyl curcumin analogue sAc possessing reduced toxicity and improved stability was designed on the basis of the DMCA skeleton. Moreover, 32 sAc analogs were obtained by applying a green, simple, and economical synthetic method. Multiple sAc analogs with an antioxidant protective effect in PC12 cells were screened using an H₂O₂-induced oxidative stress damage model, and quantitative evaluation of structure-activity relationship (QSAR) model with regression coefficient of R² = 0.918921 was built through random forest algorithm (RF). Among these compounds, the optimally active compound sAc15 elicited a potent protective effect on cell growth of PC12 cells by effectively eliminating ROS generation in response to oxidative stress injury by activating the Nrf2/HO-1 antioxidant signaling pathway. In addition, sAc15 exhibited good protection against CIRI in the mice middle cerebral artery occlusion (MCAO) model. In this paper, we provide a novel class of antioxidants and a potential compound for stroke treatment.

New Insights into Oral Cancer-Risk Factors and Prevention: A Review of Literature

The oral cancer constitutes 48% of head and neck cancer cases. Ninety percent of oral cancer cases are histologically diagnosed as oral squamous cell carcinomas (OSCCs). Despite new management strategies, the 5-year survival rate of oral cancer is still below 50% in most countries. Head and neck cancers are heterogeneous tumors, and this characteristic of them provides a challenge to treatment plan. Due to the poor outcomes in oral cancer, prevention is a necessity. In this review, a relevant English Literature search in PubMed, ScienceDirect, and Google Scholar from 2000 to mid-2018 was performed. All published articles related to oral cancer and its prevention were included. The risk factors of oral cancer and strategies of oral cancer prevention will be discussed.

Fabrication of curcumin-zein-ethyl cellulose composite nanoparticles using antisolvent co-precipitation method

The stable colloidal nano-dispersion of curcumin (CU) loaded zein-ethyl cellulose (ZN-EC) as three hydrophobic agent in water was prepared using two step antisolvent co-precipitation method. The EC coated NPs were prepared by adding EC in ethyl acetate to the ZN-CU NPs at a concentration ratio of 1: 3.5 w/v. The prepared colloidal suspension of ZN-EC showed high physical stability during storage time. The particle diameters and zeta potential values of ZN-CU and ZN-CU-EC colloidal suspensions were 140 ± 12 nm, 38 ± 2 mV and 179 ± 12 nm, 12 ± 2 mV, respectively. Based on Scanning electron microscopy (SEM) images, participation of EC on the surface of ZN-CU particles could reduce the sticky appearance of particles. Encapsulation efficiency of CU in NPs did not improve after precipitation of EC, but the stability of NPs against pH changes, increased and release rate of CU from NPs at different pH values (3-8) were significantly reduced in comparison of ZN-CU NPs. The EC coated NPs showed the excessive protection for CU antioxidant activity during storage. In conclusion, the prepared NPs, with high physical stability, have good potential for encapsulation and delivery of CU to colon region.

Enhancing the performance of PEG-b-PCL-based nanocarriers for curcumin through its conjugation with lipophilic biomolecules

Curcumin is a natural substance extracted from Curcuma longa Linn with beneficial pharmaceutical properties such as anticancer activity against several cellular lines. However, it presents poor bioavailability due to its low solubility in aqueous media and chemical instability. In this research, curcumin was encapsulated in polymer micelles obtained by the self-assembly of a biodegradable poly (ethylene glycol)-block-poly(ɛ-caprolactone) copolymer conjugated with cholesterol or oleic acid. A hydroxyl-terminated poly (ethylene glycol)-block-poly(ɛ-caprolactone) was reacted with cholesteryl chloroformate or oleyl chloride to obtain conjugated copolymers. The resulting polymeric materials were characterised through proton nuclear magnetic resonance, gel permeation chromatography and differential scanning calorimetry, and their critical aggregation concentration was measured through fluorescence spectroscopy. Poly (ethylene glycol)-block-poly(ɛ-caprolactone) conjugated with cholesterol and oleic acid posed an improved capacity of encapsulating curcumin, resulting in the loading capacities of 8.8% and 15.2%, respectively. Cell viability studies confirmed that curcumin loaded in polymer micelles maintained its anticancer activity against MCF-7 human breast cancer cells but presented low cytotoxicity against mouse fibroblasts. Hence, these formulations have good potential for applications in drug delivery systems for breast cancer treatment.

Effects of Photosensitization of Curcumin in Human Glioblastoma Multiforme Cells

BACKGROUND/AIM

There is no satisfactory treatment of glioblastoma multiforme, a highly invasive brain tumor. The aim of this study was to analyze the cytotoxic effects of curcumin (CUR) alone and as a photosensitizer on glioblastoma cells.

MATERIALS AND METHODS

The SNB-19 cells where incubated for 2 and 24 h with 5-200 mM of CUR. The cells were radiated with blue light (6 J/cm²) and compared to non-irradiated ones. The effects of treatment were assessed by measuring mitochondrial activity with the MTT method and apoptosis progression by flow cytometry. To investigate CUR uptake, fluorescence imaging of cells was performed.

RESULTS

Photosensitization of CUR decreased the EC₅₀ 6.3 times when the incubation time was 2 h and over 90% of cells underwent apoptosis. The study of the uptake of CUR showed that during the 2 h, CUR was placed in the entire cytoplasm, and over time, its amount decreased and localized in the subcellular compartments.

CONCLUSION

CUR is a promising medicament that can be used as a photosensitizer in photodynamic therapy for glioma treatment.

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

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

Epigenetic Gene Regulation by Dietary Compounds in Cancer Prevention

Traditionally, cancer has been viewed as a set of diseases that are driven by the accumulation of genetic mutations, but we now understand that disruptions in epigenetic regulatory mechanisms are prevalent in cancer as well. Unlike genetic mutations, however, epigenetic alterations are reversible, making them desirable therapeutic targets. The potential for diet, and bioactive dietary components, to target epigenetic pathways in cancer is now widely appreciated, but our understanding of how to utilize these compounds for effective chemopreventive strategies in humans is in its infancy. This review provides a brief overview of epigenetic regulation and the clinical applications of epigenetics in cancer. It then describes the capacity for dietary components to contribute to epigenetic regulation, with a focus on the efficacy of dietary epigenetic regulators as secondary cancer prevention strategies in humans. Lastly, it discusses the necessary precautions and challenges that will need to be overcome before the chemopreventive power of dietary-based intervention strategies can be fully harnessed.

Dietary Curcumin: Correlation between Bioavailability and Health Potential

The yellow pigment curcumin, extracted from turmeric, is a renowned polyphenol with a broad spectrum of health properties such as antioxidant, anti-inflammatory, anti-cancer, antidiabetic, hepatoprotective, anti-allergic, anti-dermatophyte, and neuroprotective. However, these properties are followed by a poor pharmacokinetic profile which compromises its therapeutic potential. The association of low absorption by the small intestine and the extensive reductive and conjugative metabolism in the liver dramatically weakens the oral bioavailability. Several strategies such as inhibition of curcumin metabolism with adjuvants as well as novel solid and liquid oral delivery systems have been tried to counteract curcumin poor absorption and rapid elimination from the body. Some of these drug deliveries can successfully enhance the solubility, extending the residence in plasma, improving the pharmacokinetic profile and the cellular uptake.

Chemopreventive Effect of Phytosomal Curcumin on Hepatitis B Virus-Related Hepatocellular Carcinoma in A Transgenic Mouse Model

Chronic hepatitis B virus (HBV) infection is a major risk factor for the development of hepatocellular carcinoma (HCC), a leading cause of cancer mortality worldwide. Hepatitis B X protein (HBx) and pre-S2 mutant have been proposed as the two most important HBV oncoproteins that play key roles in HCC pathogenesis. Curcumin is a botanical constituent displaying potent anti-inflammatory and anti-cancer properties without toxic side effects. Phytosomal formulation of curcumin has been shown to exhibit enhanced bioavailability, improved pharmacokinetics, and excellent efficacy against many human diseases. However, effectiveness of phytosomal curcumin for HCC treatment remains to be clarified. In this study, we evaluated chemopreventive effect of phytosomal curcumin on HBV-related HCC by using a transgenic mouse model specifically expressing both HBx and pre-S2 mutant in liver. Compared with unformulated curcumin, phytosomal curcumin exhibited significantly greater effects on suppression of HCC formation, improvement of liver histopathology, decrease of lipid accumulation and leukocyte infiltration, and reduction of total tumor volume in transgenic mice. Moreover, phytosomal curcumin exerted considerably stronger effects on activation of anti-inflammatory PPARγ as well as inhibition of pro-inflammatory NF-κB than unformulated curcumin. Furthermore, phytosomal curcumin showed a comparable effect on suppression of oncogenic mTOR activation to unformulated curcumin. Our data demonstrated that phytosomal curcumin has promise for HCC chemoprevention in patients with chronic HBV infection.

Simultaneous determination of curcumin, tetrahydrocurcumin, quercetin, and paeoniflorin by UHPLC-MS/MS in rat plasma and its application to a pharmacokinetic study

Curcumin (CUR) is a bioactive compound present in many composite prescriptions of traditional Chinese medicine together with quercetin (QR) and paeoniflorin (PF). Little is known about the influence of QR and PF on the absorption and metabolism of CUR when the three compounds are orally co-administered. In this study, a rapid, sensitive, and reliable ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated for the simultaneous determination of CUR, tetrahydrocurcumin (THC), QR, and PF in rat plasma by using tinidazole as the internal standard (IS). A liquid-liquid extraction method with ethyl acetate was used to pre-treat the plasma samples. Chromatographic separation was conducted on a C18 column with isocratic elution using acetonitrile and 0.1% formic acid water solution (80:20, v/v) as the mobile phase at the flow rate of 0.3 mL/min. A TSQ Quantum Access Max API mass spectrometer equipped with electrospray ionisation (ESI) source in selection reaction monitoring (SRM) mode was employed to determine transitions of m/z 369.0 → 176.9, 373.1 → 137.0, 303.0 → 228.9, 478.9 → 120.9, 248.1 → 121.0 for CUR, THC, QR, PF, and IS, respectively. The selectivity, precision, accuracy, extraction recovery, matrix effect, and stability of the method were validated. This developed and validated method was successfully applied in the pharmacokinetic study of CUR, THC, QR, and PF in rats. The effects of QR and PF on the pharmacokinetics of CUR and its metabolite, THC, were evaluated in the plasma of Sprague-Dawley rats that were orally co-administered CUR, QR, and PF. The results showed that the combined use of QR, PF, and CUR has a possible influence on the metabolism and excretion of CUR. Our work provides a fundamental method for the rapid simultaneous determination of CUR, THC, QR, and PF in rat plasma. Furthermore, this study will provide a basic method for the analysis of pharmacokinetic interaction of CUR, QR, and PF and offer a scientific basis for a possible combination therapy with the three compounds.

Diacetylcurcumin: a new photosensitizer for antimicrobial photodynamic therapy in Streptococcus mutans biofilms

This study evaluated the effect of antimicrobial photodynamic therapy (aPDT) on S. mutans using diacetylcurcumin (DAC) and verified DAC toxicity. In vitro, S. mutans biofilms were exposed to curcumin (CUR) and DAC and were light-irradiated. Biofilms were collected, plated and incubated for colony counts. DAC and CUR toxicity assays were conducted with Human Gingival Fibroblast cells (HGF). In vivo, G. mellonella larvae were injected with S. mutans and treated with DAC, CUR and aPDT. The hemolymph was plated and incubated for colony counts. Significant reductions were observed when DAC and CUR alone were used and when aPDT was applied. HGF assays demonstrated no differences in cell viability for most groups. DAC and CUR reduced the S. mutans load in G. mellonella larvae both alone and with aPDT. Systematic toxicity assays on G. mellonella demonstrated no effect of DAC and CUR or aPDT on the survival curve.

Bioactivity of dietary polyphenols: The role of metabolites

A polyphenol-rich diet protects against chronic pathologies by modulating numerous physiological processes, such as cellular redox potential, enzymatic activity, cell proliferation and signaling transduction pathways. However, polyphenols have a low oral bioavailability mainly due to an extensive biotransformation mediated by phase I and phase II reactions in enterocytes and liver but also by gut microbiota. Despite low oral bioavailability, most polyphenols proved significant biological effects which brought into attention the low bioavailability/high bioactivity paradox. In recent years, polyphenol metabolites have attracted great interest as many of them showed similar or higher intrinsic biological effects in comparison to the parent compounds. There is a huge body of literature reporting on the biological functions of polyphenol metabolites generated by phase I and phase II metabolic reactions and gut microbiota-mediated biotransformation. In this respect, the review highlights the pharmacokinetic fate of the major dietary polyphenols (resveratrol, curcumin, quercetin, rutin, genistein, daidzein, ellagitannins, proanthocyanidins) in order to further address the efficacy of biometabolites as compared to parent molecules. The present work strongly supports the contribution of metabolites to the health benefits of polyphenols, thus offering a better perspective in understanding the role played by dietary polyphenols in human health.

Beneficial effect of additional treatment with widely available anticancer agents in advanced small lung cell carcinoma: A case report

Small-cell lung carcinoma is a type of lung cancer characterized by very poor prognosis, as the majority of the patients have already developed metastases at initial diagnosis. Small-cell lung cancer accounts for ~15% of all lung cancer cases. The present study reports the case of a female patient with advanced-stage small-cell lung cancer. The patient received the standard treatments (6 cycles of platinum and etoposide chemotherapy followed by Gamma Knife treatment of suspicious mediastinal lymphnodes); in addition, naturally derived agents (curcumin, parthenolide, betuline, sulforaphane, withanolides, lactoferrin, pomegranate fruit extract, flaxseed and dioscorea) were alternately administered at increased doses, while previously prescribed medications for other comorbidities (metformin and atorvastatin) were continued. Complete regression of the tumour was observed, and the patient remains in full remission and cancer-free for >7 years. Moreover, no treatment-related side effects and no drug interactions were observed.

Chondroprotective effect of curcumin and lecithin complex in human chondrocytes stimulated by IL-1β via an anti-inflammatory mechanism

A complex of curcumin and lecithin developed to improve the solubility of curcumin, enhanced its chondroprotective effect via an anti-inflammatory mechanism. In macrophage, proinflammatory cytokines, such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, prostaglandin E2 (PGE2), and nitric oxide (NO) were quantified. In addition, the activity of nuclear factor (NF)-κB was examined. With chondrocytes, inflammatory mediators were assessed by measuring the secretion levels of IL-6, IL-8, and PGE2, also the mRNA expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). Metalloproteinases (MMPs), tissue inhibitor of metalloprotease (TIMP)-1, type II collagen (COL2), proteoglycan (PG), and hyaluronic acid (HA) were measured with respect to the articulation surface. The complex promoted the anti-inflammatory effect by the inhibition of inflammatory mediators. In addition, mRNA expression levels ameliorated. Furthermore, it was effective in decreasing extracellular secretion of polypeptides, also corresponding intracellular MMPs and TIMP-1. In conclusion, the complex may be developed as a functional supplement to maintain articulation health.

Femtosecond laser pulse assisted photoporation for drug delivery in Chronic myelogenous leukemia cells

Chronic myelogenous leukemia (CML) is a myeloproliferative disorder occurs in the pluripotent hematopoietic stem cell. Currently, first-generation tyrosine kinase inhibitor (TKI) imatinib is the mainstay for the treatment of CML. Second generation TKI's like ponatinib, dasatinib, nilotinib, and bafetinib were treated against resistant CML. However, several CML patients develop resistance towards all existing inhibitors. Curcumin (Curcuma longa) a plant-derived natural compound is an effective bioactive component against various cancers including CML. Many studies have shown that curcumin induces time- and dose-dependent apoptosis in CML cells by regulating various downstream molecular regulators. Despite curcumin's selective cytotoxicity towards cancer cells, it has very poor bioavailability both in in-vitro and in-vivo conditions. In this present study, we have used femtosecond laser (fs-laser) pulses to ablate the cell membrane and standardized the conditions required for creating a cell membrane pores with less lethality. Following fs-laser pulse irradiation, K562 cells were incubated along with curcumin 30 μM for 0 h, 6 h,12 h and 24 h. Interestingly irradiated cells have shown higher sensitivity towards curcumin than non-irradiated cells. Immunoblotting studies showed higher induction levels of cleaved caspase 3 and 9 in irradiated population than non-irradiated. In summary, the results prove that irradiation by fs-laser pulses enhanced the bioavailability of curcumin and shows caspase-mediated cell death in irradiated CML cells than other populations.

Turmeric extract, with absorbable curcumin, has potent anti-metastatic effect in vitro and in vivo

BACKGROUND

Curcumin, a well-studied component in turmeric, exhibits potent antitumor effects in colorectal cancer. Previous studies showed that turmerones raised the accumulation of curcumin inside colonic cells, and curcumin present in turmeric ethanolic extract had enhanced anti-tumor activities in mice. Metastasis accounts for more than 90% colorectal cancer deaths. However, the anti-metastatic effect of turmeric extract on colorectal cancer is still unknown.

METHODS

In the present study, colony formation, scratch, transwell and Western blot were used to assess colony formation, motility, migration and underlying mechanisms in vitro, respectively. Anti-tumor and anti-metastatic effects in vivo were investigated using an orthotopic xenograft model.

RESULTS

Turmeric extract exhibited cytotoxic effect, inhibited colony formation, decreased cell motility, migration and epithelial-mesenchymal transitions through regulating multiple pathways including cofilin, FAK/p-Src, AKT, Erk and STAT3 signaling pathways in murine colorectal cancer cells. Furthermore, turmeric extract at 200 mg/kg could decrease colon tumor burden and inhibit liver and lung metastasis in vivo. Treatment of turmeric extract enhanced immunity through T cell stimulation, changed tumor microenvironment, exerted anti-metastatic effects which were shown for the first time in pre-clinical colorectal cancer models. The decrease of immunity after FOLFOX treatment was also firstly demonstrated in mouse model.

CONCLUSIONS

Turmeric extract was demonstrated for the first time for its anti-tumor and anti-metastatic effects in both colorectal cancer cells and orthotopic mouse model through regulation of multiple targets. These findings strongly suggested the promising use of turmeric extract as chemopreventive or chemotherapeutic agent for colorectal cancer patients with metastasis.

New bow-tie cationic carbosilane dendritic system with a curcumin core as an anti-breast cancer agent

A water soluble “bow-tie” cationic carbosilane dendrimer with curcumin in the core displays antioxidant and antitumoral activities against breast cancer cells.

The anti-inflammatory activity of curcumin is mediated by its oxidative metabolites

The spice turmeric, with its active polyphenol curcumin, has been used as anti-inflammatory remedy in traditional Asian medicine for centuries. Many cellular targets of curcumin have been identified, but how such a wide range of targets can be affected by a single compound is unclear. Here, we identified curcumin as a pro-drug that requires oxidative activation into reactive metabolites to exert anti-inflammatory activities. Synthetic curcumin analogs that undergo oxidative transformation potently inhibited the pro-inflammatory transcription factor nuclear factor κB (NF-κB), whereas stable, non-oxidizable analogs were less active, with a correlation coefficient (R²) of IC₅₀versus log of autoxidation rate of 0.75. Inhibition of glutathione biosynthesis, which protects cells from reactive metabolites, increased the potency of curcumin and decreased the amount of curcumin-glutathione adducts in cells. Oxidative metabolites of curcumin adducted to and inhibited the inhibitor of NF-κB kinase subunit β (IKKβ), an activating kinase upstream of NF-κB. An unstable, alkynyl-tagged curcumin analog yielded abundant adducts with cellular protein that were decreased by pretreatment with curcumin or an unstable analog but not by a stable analog. Bioactivation of curcumin occurred readily in vitro, which may explain the wide range of cellular targets, but if bioactivation is insufficient in vivo, it may also help explain the inconclusive results in human studies with curcumin so far. We conclude that the paradigm of metabolic bioactivation uncovered here should be considered for the evaluation and design of clinical trials of curcumin and other polyphenols of medicinal interest.

A Comparative Pharmacokinetic Assessment of a Novel Highly Bioavailable Curcumin Formulation with 95% Curcumin: A Randomized, Double-Blind, Crossover Study

OBJECTIVE

Curcumin exhibits many beneficial health-promoting characteristics. However, its poor oral absorption precludes its general use. This study assessed the bioavailability of a novel curcumin formulation compared to 95% curcumin and published results for various other curcumin formulations.

METHODS

A randomized, crossover, double-blind, comparator-controlled pharmacokinetic study was performed in 12 healthy adult subjects to determine the appearance of free curcumin and its metabolites curcumin sulfate and curcumin glucuronide in plasma after a single dose of a novel proprietary curcumin liquid droplet micromicellar formulation (CLDM) and unformulated 95% curcumin powder in capsule form. An equivalent 400-mg dose of each product was administered. The 95% curcumin contained 323 mg curcumin, and the CLDM contained 64.6 mg curcumin. Blood samples were drawn and plasma was analyzed for curcumin and its 2 conjugates without enzymatic hydrolysis by liquid chromatography-tandem mass spectroscopy.

RESULTS

Plasma levels of curcumin sulfate and curcumin glucuronide after 1.5 hours from CLDM were approximately 20 and 300 ng/mL, respectively, whereas the levels for 95% curcumin were near baseline. Free curcumin reached a maximum level of 2 ng/mL for CLDM and 0.3 ng/mL for 95% curcumin at 1.5 hours. For the CLDM, a small secondary free curcumin peak occurred at 12 hours and a tertiary 1.5-ng/mL peak occurred at 24 hours. The total curcumin absorbed as represented by the area under the curve (AUC)/mg administered curcumin for CLDM was 522 times greater than for the 95% curcumin.

CONCLUSIONS

The novel CLDM formulation facilitates absorption and produces exceedingly high plasma levels of both conjugated and total curcumin compared to 95% curcumin. A comparison of the C_max/mg curcumin and AUC/mg of administered curcumin for CLDM with data from pharmacokinetic studies of various enhanced absorption formulations indicate that the greatest absorption and bioavailability are produced with the novel CLDM formulation.