Molecular Mechanisms Of Curcumin Research Articles

A Docking and Network Pharmacology Study on the Molecular Mechanisms of Curcumin in Dental Caries and Streptococcus mutans

A Docking and Network Pharmacology Study on the Molecular Mechanisms of Curcumin in Dental Caries and Streptococcus mutans

Concentration-Dependent Effects of Curcumin on Membrane Permeability and Structure.

Growing evidence suggests that many bioactive molecules can nonspecifically modulate the physicochemical properties of membranes and influence the action of embedded membrane proteins. This study investigates the interactions of curcumin with protein-free model membranes consisting of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and DOPC with cholesterol (4/1 mol ratio). The focus is on the capability of curcumin to modify membrane barrier properties such as water permeability assayed through the droplet interface bilayer (DIB) model membrane. For pure DOPC, our findings show a concentration-dependent biphasic effect: a reduction in water permeability is observed at low concentrations (up to 2 mol %), whereas at high concentrations of curcumin, water permeability increases. In the presence of cholesterol, we observed an overall reduction in water permeability. A combination of complementary experimental methods, including phase transition parameters studied by differential scanning calorimetry (DSC) and structural properties measured by attenuated total reflectance (ATR)-FTIR, provides a deeper understanding of concentration-dependent interactions of curcumin with DOPC bilayers in the absence and presence of cholesterol. Our experimental findings align with a molecular mechanism of curcumin's interaction with model membranes, wherein its effect is contingent on its concentration. At low concentrations, curcumin binds to the lipid-water interface through hydrogen bonding with the phosphate headgroup, thereby obstructing the transport of water molecules. Conversely, at high concentrations, curcumin permeates the acyl chain region, inducing packing disorders and demonstrating evidence of phase separation. Enhanced knowledge of the impact of curcumin on membranes, which, in turn, can affect protein function, is likely to be beneficial for the successful translation of curcumin into effective medicine.

Molecular Mechanisms of Curcumin in the Pathogenesis of Metabolic Dysfunction Associated Steatotic Liver Disease.

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a multifactorial condition characterized by insulin resistance, oxidative stress, chronic low-grade inflammation, and sometimes fibrosis. To date, no effective pharmacological therapy has been approved for the treatment of metabolic-associated steatohepatitis (MASH), the progressive form of MASLD. Recently, numerous in vitro and in vivo studies have described the efficacy of nutraceutical compounds in the diet has been tested. Among them, curcumin is the most widely used polyphenol in the diet showing potent anti-inflammatory and antifibrotic activities. This review aims to summarize the most important basic studies (in vitro and animal models studies), describing the molecular mechanisms by which curcumin acts in the context of MASLD, providing the rationale for its effective translational use in humans.

Deciphering the molecular mechanistic paths describing the chemotherapeutic potential and epigenetic regulation of curcumin in lung cancer: a mini review.

In an uncontrolled inflammatory environment, the complex process of lung carcinogenesis occurs. Lung cancer remains the leading cause of cancer-related mortality worldwide. The average 5-year survival rate is still low despite significant advancements in our knowledge of lung carcinogenesis and the development of innovative therapies in recent decades. Research on adjuvant treatment, lung carcinogenesis pathways, and possible prognostic indicators has to be refocused using an innovative approach. The majority of lung cancers are discovered at an advanced stage when there is little chance of recovery. It has grown in popularity in recent years to supplement already available chemotherapeutic therapies with adjuvant herbal medications, which may lessen toxicity and adverse effects without sacrificing therapeutic efficiency. One such prospective contender is curcumin. In-depth research has been done on curcumin as a multi-target anti-tumor and anti-inflammatory molecule. A pharmacologically active polyphenol produced from turmeric is called curcumin. Over the past few decades, curcumin's therapeutic potential has been thoroughly studied, and data indicate that curcumin may play a part in a variety of biological processes, most notably its potent anticancer activity. Being a pleiotropic chemical, curcumin regulates a variety of molecules that are key players in many cell signaling pathways. It has been shown to stifle transformation, restrain proliferation, and trigger apoptosis. Curcumin can reduce the development of non-small cell LC by downregulating Circular RNA hsa_circ_0007580, which in turn controls the expression of integrin subunit beta 1 by adsorbing miR-384. Nevertheless, despite all these advantages, curcumin's effectiveness is still restricted because of its weak bioavailability, poor absorption within the systemic circulation, and quick removal from the body. In an effort to overcome these constraints, scientists from all around the world are working to develop a synthetic and improved curcuminoid by appropriately altering the parent skeleton structurally. These curcuminoids will simultaneously improve the physicochemical properties and efficacy. This review presents evidence from the most recent clinical trials coupled with the molecular mechanisms of curcumin in LC.

Curcumin inhibits human cancer cell growth and migration through downregulation of SVCT2.

Curcumin is a natural polyphenol that is extracted from the rhizomes of the turmeric plant (Curcuma longa), a member of the ginger family. It has been used for centuries in traditional Indian and Chinese medicine for its medicinal properties, including anti-inflammatory, antioxidant and antitumor effects. SVCT2 (Solute Carrier Family 23 Member 2, also known as SLC23A2) is a protein that plays a role in the transport of Vitamin C (Ascorbic Acid) into cells. SVCT2 plays an important role in tumor progression and metastasis, however, the molecular mechanisms of curcumin on SVCT2 have not been studied to date. Curcumin treatment inhibited proliferation and migration of cancer cells in a dose dependent manner. We found that curcumin reduced the expression of SVCT2 in cancer cells with a wild type p53, but not in those with a mutant type of p53. SVCT2 downregulation also reduced the MMP2 activity. Taken together, our results indicate that curcumin inhibited human cancer cell growth and migration by regulating SVCT2 through a downregulating p53. These findings provide new insights into the molecular mechanisms of curcumin's anticancer effects and potential therapeutic strategies for the treatment of metastatic migration.

Study on the mechanism of curcumin in the treatment of periodontitis through network pharmacology and mole-cular docking.

This study aims to explore the therapeutic targets of curcumin in periodontitis through network pharmacology and molecular docking technology. Targets of curcumin and periodontitis were predicted by different databases, and the protein-protein interaction (PPI) network constructed by String revealed the interaction between curcumin and periodontitis. The key target genes were screened for Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. Molecular docking was performed to analyze the binding potential of curcumin to periodontitis. A total of 672 periodontitis-related disease targets and 107 curcumin-acting targets were obtained from the databases, and 20 key targets were screened. The GO and KEGG analyses of the 20 targets showed that curcumin might play a therapeutic role through the hypoxia-inducible factor (HIF)-1 and parathyroid hormone (PTH) signaling pathways. Molecular docking analysis showed that curcumin had good binding potential with multiple targets. The potential key targets and molecular mechanisms of curcumin in treating periodontitis provide a theoretical basis for new drug development and clinical applications.

Curcumin (CUMINUP60®) mitigates exercise fatigue through regulating PI3K/Akt/AMPK/mTOR pathway in mice

Curcumin is a chemical constituent extracted from Curcuma longa L. Several clinical and preclinical studies have demonstrated that it can mitigate exercise fatigue, but the exact mechanism is still unknown. Therefore, we applied a mouse model of exercise fatigue to investigate the possible molecular mechanisms of curcumin's anti-fatigue effect. Depending on body mass, Kunming mice were randomly divided into control, caffeine (positive drug), and curcumin groups, and were given 28 days intragastric administration. Both the caffeine group and curcumin group showed significant improvement in exercise fatigue compared to the control group, as evidenced by the increase in time to exhaustion, as well as the higher quadriceps coefficient, muscle glycogen (MG) content, and increase in the expression of Akt, AMPK, PI3K, and mTOR proteins. While the curcumin group also significantly improved the exercise fatigue of the mice, demonstrating a lower AMP/ATP ratio and lactic acid (LA) content, and increased glycogen synthase (GS), and myonectin content compared to the caffeine group. Therefore, in the present study, we found that curcumin can exert a similar anti-fatigue effect to caffeine and may act by regulating energy metabolism through modulating the expression of the proteins in the PI3K/Akt/AMPK/mTOR pathway.

Curcumin's mechanism of action against ischemic stroke: A network pharmacology and molecular dynamics study.

Ischemic stroke (IS) is one of the major global causes of death and disability. Because blood clots block the neural arteries provoking ischemia and hypoxia in the brain tissue, IS results in irreversible neurological damage. Available IS treatments are currently limited. Curcumin has gained attention for many beneficial effects after IS, including neuroprotective and anti-inflammatory; however, its precise mechanism of action should be further explored. With network pharmacology, molecular docking, and molecular dynamics (MD), this study aimed to comprehensively and systematically investigate the potential targets and molecular mechanisms of curcumin on IS. We screened 1096 IS-related genes, 234 potential targets of curcumin, and 97 intersection targets. KEGG and GO enrichment analyses were performed on these intersecting targets. The findings showed that the treatment of IS using curcumin is via influencing 177 potential signaling pathways (AGE-RAGE signaling pathway, p53 signaling pathway, necroptosis, etc.) and numerous biological processes (the regulation of neuronal death, inflammatory response, etc.), and the AGE-RAGE signaling pathway had the largest degree of enrichment, indicating that it may be the core pathway. We also constructed a protein-protein interaction network and a component-target-pathway network using network pharmacology. From these, five key targets were screened: NFKB1, TP53, AKT1, STAT3, and TNF. To predict the binding conformation and intermolecular affinities of the key targets and compounds, molecular docking was used, whose results indicated that curcumin exhibited strong binding activity to the key targets. Moreover, 100 ns MD simulations further confirmed the docking findings and showed that the curcumin-protein complex could be in a stable state. In conclusion, curcumin affects multiple targets and pathways to inhibit various important pathogenic mechanisms of IS, including oxidative stress, neuronal death, and inflammatory responses. This study offers fresh perspectives on the transformation of curcumin to clinical settings and the development of IS therapeutic agents.

Cellular and Molecular Mechanisms of Curcumin in Thyroid Gland Disorders.

There is growing literature on the positive therapeutic potentials of curcumin. Curcumin or diferuloylmethane is a polyphenol obtained from the plant Curcuma longa. Curcumin is widely used in Ayurvedic and Chinese medicine for various conditions. The role of curcumin in thyroid gland disorders has been demonstrated by its effects on various biological pathways, including anti-inflammatory, antioxidant, anti-proliferative, apoptosis, angiogenesis, cell cycle and metastasis. In this paper, we have reviewed the recent literature on curcumin applications for thyroid dysfunction, including hyperthyroidism and hypothyroidism, and discussed the molecular mechanisms of these effects. This review aims to summarize the wealth of research related to the therapeutic effect of curcumin on the thyroid gland.

Benefits of Curcumin in the Vasculature: A Therapeutic Candidate for Vascular Remodeling in Arterial Hypertension and Pulmonary Arterial Hypertension?

Growing evidence suggests that hypertension is one of the leading causes of cardiovascular morbidity and mortality since uncontrolled high blood pressure increases the risk of myocardial infarction, aortic dissection, hemorrhagic stroke, and chronic kidney disease. Impaired vascular homeostasis plays a critical role in the development of hypertension-induced vascular remodeling. Abnormal behaviors of vascular cells are not only a pathological hallmark of hypertensive vascular remodeling, but also an important pathological basis for maintaining reduced vascular compliance in hypertension. Targeting vascular remodeling represents a novel therapeutic approach in hypertension and its cardiovascular complications. Phytochemicals are emerging as candidates with therapeutic effects on numerous pathologies, including hypertension. An increasing number of studies have found that curcumin, a polyphenolic compound derived from dietary spice turmeric, holds a broad spectrum of pharmacological actions, such as antiplatelet, anticancer, anti-inflammatory, antioxidant, and antiangiogenic effects. Curcumin has been shown to prevent or treat vascular remodeling in hypertensive rodents by modulating various signaling pathways. In the present review, we attempt to focus on the current findings and molecular mechanisms of curcumin in the treatment of hypertensive vascular remodeling. In particular, adverse and inconsistent effects of curcumin, as well as some favorable pharmacokinetics or pharmacodynamics profiles in arterial hypertension will be discussed. Moreover, the recent progress in the preparation of nano-curcumins and their therapeutic potential in hypertension will be briefly recapped. The future research directions and challenges of curcumin in hypertension-related vascular remodeling are also proposed. It is foreseeable that curcumin is likely to be a therapeutic agent for hypertension and vascular remodeling going forwards.

Curcumin Alleviates Aβ42-Induced Neuronal Metabolic Dysfunction via the Thrb/SIRT3 Axis and Improves Cognition in APPTG Mice.

Curcumin has been reported to have a therapeutic effect on Alzheimer's disease (AD), but the specific mechanism remains to be elucidated. In the present research, we aimed to investigate the effect and molecular mechanism of curcumin on AD. Mouse primary hippocampal neuron cells were treated with various concentrations of beta-amyloid 42 (Aβ42) and the results found that Aβ42 inhibited cell viability in a dose-dependent manner. Compared with 50ng/mL Aβ42, 500ng/mL Aβ42 could further promote cell apoptosis, reduce the ratio of Nicotinamide adenine dinucleotide (NAD(+))/Nicotinamide adenine diphosphate hydride (NADH) and Adenosine 5'-triphosphate (ATP) level, and inhibit Sirtuins 3 (SIRT3) deacetylation activity and protein expression of Thyroid hormone receptor beta (Thrb) and SIRT3. Hence, 500ng/mL Aβ42 was used to establish a cell model of AD. Curcumin significantly reversed the inhibitory effects of Aβ42 on cell viability, SIRT3 deacetylation activity, the ratio of NAD+/NADH, ATP level and the protein expression of Thrb and SIRT3, and the promotive effect on apoptosis. ChIPBase was used to predict the binding region of Thrb and SIRT3. Dual luciferase reporter gene and Chromatin immune precipitation (ChIP) assays were employed to verify the relationship between Thrb and promoter of SIRT3 mRNA. Overexpression of Thrb recovered Aβ42 induced metabolic dysfunction, while Thrb silence aggravated Aβ42 induced metabolic dysfunction. Moreover, Thrb silence or 3-TYP (a selective inhibitor of SIRT3) treatment abolished the amelioration of curcumin on Aβ42 induced metabolic dysfunction. Additionally, curcumin attenuated memory deficits in Amyloid precursor protein transgenic (APPTG) mice. Collectively, curcumin alleviated Aβ42-induced neuronal metabolic dysfunction through increasing Thrb expression and SIRT3 activity and improved cognition in APPTG mice.

Synergistic Effect of Curcuma longa Extract in Combination with Phyllanthus niruri Extract in Regulating Annexin A2, Epidermal Growth Factor Receptor, Matrix Metalloproteinases, and Pyruvate Kinase M1/2 Signaling Pathway on Breast Cancer Stem Cell

AIM: This study aimed to investigate the synergistic effects of the combination between Curcuma longa extract (CL) and Phyllanthus niruri extract (PN) in inhibiting optimally the MDA-MB-231 breast cancer stem cells (BCSCs) growth and metastatic by exploring the target and molecular mechanism using integrative bioinformatics approaches and in vitro. METHODS: CL and PN extracts were prepared by maceration method using ethanol 70%. The antiproliferative effect of CL and PN single and combination treatment was examined by 3-[4,5-dimethyl-2-thiazolyl]-2,5-diphenyl-2H-tetrazolium bromide assay. The bioinformatic approach was performed to identify molecular targets, key proteins, and molecular mechanism of curcumin and phyllanthin as CL and PN secondary metabolite, respectively, targeted at stemness and migration pathway of BCSCs. RESULTS: The in vitro study showed that CL and PN possess cytotoxic activity in time- and dose-dependent manner. The combination of CL and PN has a synergistic effect by modulating the sensitivity of cells. Using a bioinformatics approach, the annexin A2 (ANXA2), epidermal growth factor receptor (EGFR), matrix metalloproteinases (MMPs), and pyruvate kinase M1/2 (PKM) as potential targets of curcumin and phyllanthin correlated with metastatic inhibition of BC. In addition, molecular docking showed that curcumin and phyllanthin performed similar or better interaction to stemness differentiation regulator pathway particularly histone deacetylase 1, EGFR, Heat Shock Protein 90 Alpha Family Class B Member 1, Hypoxia Inducible Factor 1 Subunit Alpha, and MMP9. CONCLUSION: Combination of CL and PN has potential for the treatment of metastatic BCSCs by targeting ANXA2, EGFR, MMPs, and PKM to resolve stemness and inhibit of BCSCs.

Key Developments in the Potential of Curcumin for the Treatment of Peripheral Neuropathies.

Peripheral neuropathies (PN) can be triggered after metabolic diseases, traumatic peripheral nerve injury, genetic mutations, toxic substances, and/or inflammation. PN is a major clinical problem, affecting many patients and with few effective therapeutics. Recently, interest in natural dietary compounds, such as polyphenols, in human health has led to a great deal of research, especially in PN. Curcumin is a polyphenol extracted from the root of Curcuma longa. This molecule has long been used in Asian medicine for its anti-inflammatory, antibacterial, and antioxidant properties. However, like numerous polyphenols, curcumin has a very low bioavailability and a very fast metabolism. This review addresses multiple aspects of curcumin in PN, including bioavailability issues, new formulations, observations in animal behavioral tests, electrophysiological, histological, and molecular aspects, and clinical trials published to date. The, review covers in vitro and in vivo studies, with a special focus on the molecular mechanisms of curcumin (anti-inflammatory, antioxidant, anti-endoplasmic reticulum stress (anti-ER-stress), neuroprotection, and glial protection). This review provides for the first time an overview of curcumin in the treatment of PN. Finally, because PN are associated with numerous pathologies (e.g., cancers, diabetes, addiction, inflammatory disease...), this review is likely to interest a large audience.

Curcumin inhibits migration and invasion of non-small cell lung cancer cells through up-regulation of miR-206 and suppression of PI3K/AKT/mTOR signaling pathway.

Curcumin has been proved to inhibit cell proliferation and induce cell apoptosis in non-small cell lung cancer (NSCLC). However, little is known about antimetastatic effects and molecular mechanisms of curcumin in NSCLC. In this study, we investigated the involvement of miR-206 in curcumin's anti-invasion and anti-migration in NSCLC. Cell proliferation was determined by MTT assay. Cell migration and invasion were analyzed by wound healing assay and transwell assay. MiRNA-206 expression was detected by real-time PCR. Western blot was used to detect the protein expression of PI3K/AKT/mTOR signaling pathway. Curcumin significantly inhibited migration and invasion in A549 cells, accompanied by significantly elevated miR-206 expression. Overexpression of miR-206 could inhibit migration and invasion of A549 cells, but it could also significantly decrease the phosphorylation levels of mTOR and AKT. The inhibition of miR-206 promoted cell migration, invasion and increased the phosphorylation level of mTOR and AKT. Furthermore, miR-206 mimics improved the inhibitory effects of curcumin on cell migration, invasion and the phosphorylation level of mTOR and AKT in A549 cells. On the contrary, MiR-206 inhibitors reversed the inhibitory effects of curcumin on cell migration, invasion and the phosphorylation level of mTOR and AKT. In conclusion, curcumin inhibited cell invasion and migration in NSCLC by elevating the expression of miR-206 which further suppressed the activation of the PI3K/AKT/mTOR pathway.

Molecular Mechanisms of Curcumin in COVID-19 Treatment and Prevention: A Global Health Perspective

Turmeric (Curcuma Longa) has a near 4000-year history of extensive medical use in South Asia. Its main physiologically active phytochemical is curcumin (diferuloylmethane), derived from the rhizome of turmeric. Curcumin is a hydrophobic polyphenol with a diketone moiety connecting two phenoxy rings. It is widely available, and exerts systemic and pleiotropic effects via several key mechanisms. Most famously, it is known to inhibit pro-inflammatory pathways such as PI3k/akt/NF-kB activation. It is also a potent antioxidant and free radical scavenger via a sequential proton loss electron transfer mechanism in ionizing solvents due to its extended conjugating ability across the entire molecule, and its ability to induce NRF-2. It has been implicated in the treatment of diseases ranging from asthma to various cancers, and is also a broad spectrum anti-microbial. COVID-19 is a novel beta-coronavirus that was declared a pandemic by the WHO in March, 2020. It is primarily a respiratory disorder, but it can spread hematogenously and effect many other organs such as the heart, nervous system, and kidneys. There is a significant intersection between the clinical manifestations of COVID-19 and curcumin’s therapeutic effects. In addition, curcumin has been shown to inhibit initial viral infectivity. Thus, there is potential for curcumin to safely both prevent and treat COVID-19 infection across the globe.

Click chemistry-based imaging to study the tissue distribution of the curcumin-protein complex in mice.

Previous studies have shown that curcumin, a bioactive dietary compound with a thiol-reactive α,β-unsaturated carbonyl moiety, can covalently modify protein thiols. However, most of the previous studies were performed in cultured cells or cell-free enzyme systems, and so it remains unknown whether curcumin could covalently modify proteins after oral administration in vivo. Using click chemistry-based fluorescence imaging, here we show that oral administration of dialkyne-curcumin (Di-Cur), a "click" probe mimicking curcumin, results in covalent modifications of cellular proteins in colon and liver tissues, but not in other tissues, in mice. This result suggests that oral administration of curcumin leads to the formation of the curcumin-protein complex in a tissue-specific manner, which could contribute to the biological effects and/or pharmacokinetics of curcumin. Further studies to elucidate the identities of curcumin-binding proteins could greatly help us to better understand the molecular mechanisms of curcumin, and develop novel strategies for disease prevention.

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

Neuroinflammatory disease is a general term used to denote the progressive loss of neuronal function or structure. Many neuroinflammatory diseases, including Alzheimer's, Parkinson's, and multiple sclerosis (MS), occur due to neuroinflammation. Neuroinflammation increases nuclear factor-κB (NF-κB) levels, cyclooxygenase-2 enzymes and inducible nitric oxide synthase, resulting in the release of inflammatory cytokines, such as interleukin-6 (IL-6), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). It could also lead to cellular deterioration and symptoms of neuroinflammatory diseases. Recent studies have suggested that curcumin (the active ingredient in turmeric) could alleviate the process of neuroinflammatory disease. Thus, the present mini-review was conducted to summarize studies regarding cellular and molecular targets of curcumin relevant to neuroinflammatory disorders. A literature search strategy was conducted for all English-language literature. Studies that assessed the various properties of curcuminoids in respect of neuroinflammatory disorders were included in this review. The studies have suggested that curcuminoids have significant anti- neuroinflammatory, antioxidant and neuroprotective properties that could attenuate the development and symptom of neuroinflammatory disorders. Curcumin can alleviate neurodegeneration and neuroinflammation through multiple mechanisms, by reducing inflammatory mediators (such as TNF-α, IL-1β, nitric oxide and NF-κB gene expression), and affect mitochondrial dynamics and even epigenetic changes. It is a promising subject of study in the prevention and management of the neuroinflammatory disease. However, controlled, randomized clinical trials are needed to fully evaluate its clinical potential.

Curcumin in Liver Diseases: A Systematic Review of the Cellular Mechanisms of Oxidative Stress and Clinical Perspective.

Oxidative stress has been considered a key causing factor of liver damage induced by a variety of agents, including alcohol, drugs, viral infections, environmental pollutants and dietary components, which in turn results in progression of liver injury, non-alcoholic steatohepatitis, non-alcoholic liver disease, liver fibrosis and cirrhosis. During the past 30 years and even after the major progress in the liver disease management, millions of people worldwide still suffer from an acute or chronic liver condition. Curcumin is one of the most commonly used indigenous molecules endowed by various shielding functionalities that protects the liver. The aim of the present study is to comprehensively review pharmacological effects and molecular mechanisms, as well as clinical evidence, of curcumin as a lead compound in the prevention and treatment of oxidative associated liver diseases. For this purpose, electronic databases including “Scopus,” “PubMed,” “Science Direct” and “Cochrane library” were extensively searched with the keywords “curcumin or curcuminoids” and “hepatoprotective or hepatotoxicity or liver” along with “oxidative or oxidant.” Results showed that curcumin exerts remarkable protective and therapeutic effects of oxidative associated liver diseases through various cellular and molecular mechanisms. Those mechanisms include suppressing the proinflammatory cytokines, lipid perodixation products, PI3K/Akt and hepatic stellate cells activation, as well as ameliorating cellular responses to oxidative stress such as the expression of Nrf2, SOD, CAT, GSH, GPx and GR. Taking together, curcumin itself acts as a free radical scavenger over the activity of different kinds of ROS via its phenolic, β-diketone and methoxy group. Further clinical studies are still needed in order to recognize the structure-activity relationships and molecular mechanisms of curcumin in oxidative associated liver diseases.

The Effect of Curcumin on P‐glycoprotein Function

Multidrug resistance (MDR) is one of the leading cause of cancer treatment failure. P‐glycoprotein (P‐gp) has been reported as a major mechanism of MDR that increased the efflux of drugs. Three generations of P‐gp inhibitors have been developed, however, systemic toxicities limited the clinical application of these compounds. Therefore, identification of the potent and non‐toxic P‐gp inhibitors from natural products may be an alternative choice. The objective of this study was to investigate the inhibitory effect and molecular mechanism of curcumin on human P‐gp efflux function.HEK293 cell were stably transfected with human P‐gp. The MDR1 shift assay was applied to evaluate whether curcumin is a substrate of P‐gp. The effect of curcumin on P‐gp function was evaluated by rhodamine 123 accumulation assay and calcein AM uptake assay. Rhodamine 123 efflux assay was performed to analyze the inhibitory mechanism.Results from cytotoxicity assay and MDR1 shift assay indicated that curcumin is a safe natural product without cytotoxicity and not a P‐gp substrate. The intracellular fluorescence of rhodamine 123 was higher in curcumin treated P‐gp expressed cells than no‐treatment control, suggesting curcumin may inhibit P‐gp efflux function. Results of calcein‐AM uptake assay and rhodamine 123 efflux assay demonstrated that curcumin significantly inhibited P‐gp efflux function in dose dependent manner. Furthermore, curcumin uncompetitively inhibited rhodamine 123 efflux by P‐gp.This study demonstrated that curcumin, sourced from natural plants, as a potential P‐gp function modulator. Although the exploring of novel inhibitors from natural products is still in the early stages, the promising beginning and detailed mechanism investigation provided by this study will be helpful in the future in vivo studies and clinical use.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Current status and future prospective of Curcumin as a potential therapeutic agent in the treatment of colorectal cancer.

Colorectal cancer (CRC) is the third most common cause of cancer-related deaths worldwide. Hence there is a need to identify new therapeutic agents that improve the current repertoire of chemotherapeutic drugs. The antitumor activity of curcumin has been reported for several tumors, including CRC. A recent phase I trial showed that curcumin is safe and tolerable adjunct to FOLFOX (5-fluorouracil, folinic acid and oxaliplatin) chemotherapy in patient-derived colorectal liver metastases at doses up to 2 g daily. Another trial revealed the effect of combining curcumin with FOLFOX in patients with inoperable colorectal cancer. The aim of current review was to summarize the current knowledge about possible molecular mechanisms of curcumin in CRC with particular emphasis on preclinical and early clinical studies of colorectal cancer.