Incomplete Hydrolysis of Curcumin Conjugates by β-Glucuronidase: Detection of Complex Conjugates in Plasma

Curcumin Inhibits the Progression of Non-small Cell Lung Cancer by Regulating DMRT3/SLC7A11 Axis

Non-small cell lung cancer (NSCLC) is a fatal malignancy all over the world. Emerging studies have shown that curcumin might repress NSCLC progression by regulating ferroptosis, but the underlying mechanism remains unclear. 16HBE, LK-2, and H1650 cell viability was detected using Cell Counting Kit-8 assay. LK-2 and H1650 cell proliferation, apoptosis, and angiopoiesis were measured using 5-ethynyl-2'-deoxyuridine, flow cytometry, and tube formation assay. Superoxide dismutase, Malondialdehyde, Glutathione, and lactate dehydrogenase levels in LK-2 and H1650 cells were examined using special assay kits. Fe+ level was assessed using an iron assay kit. Doublesex and Mab-3 related Transcription Factor 3 (DMRT3) and solute carrier family 7 member 11 (SLC7A11) protein levels were detected using western in NSCLC tissues, adjacent matched normal tissues, 16HBE cells, LK-2 cells, H1650 cells, and xenograft tumor tissues. Glutathione peroxidase 4, Acyl-CoA Synthetase Long Chain Family Member 4, and transferrin receptor 1 protein levels in LK-2 and H1650 cells were examined by western blot assay. DMRT3 and SLC7A11 levels were determined using real-time quantitative polymerase chain reaction. After JASPAR prediction, binding between DMRT3 and SLC7A11 promoter was verified using Chromatin immunoprecipitation and dual-luciferase reporter assays in LK-2 and H1650 cells. Role of curcumin on NSCLC tumor growth was assessed using the xenograft tumor model in vivo. Curcumin blocked NSCLC cell proliferation and angiopoiesis, and induced apoptosis and ferroptosis. DMRT3 or SLC7A11 upregulation partly abolished the suppressive role of curcumin on NSCLC development. In mechanism, DMRT3 was a transcription factor of SLC7A11 and increased the transcription of SLC7A11 via binding to its promoter region. Curcumin inhibited NSCLC growth in vivo by modulating DMRT3. Curcumin might constrain NSCLC cell malignant phenotypes partly through the DMRT3/SLC7A11 axis, providing a promising therapeutic strategy for NSCLC.

Therapeutic potential and limitations of curcumin as antimetastatic agent

Treatment of metastatic cancer is one of the biggest challenges in anticancer therapy. Curcumin is interesting nature polyphenolic compound with unique biological and medicinal effects, including repression of metastases. High impact studies imply that curcumin can modulate the immune system, independently target various metastatic signalling pathways, and repress migration and invasiveness of cancer cells. This review discusses the potential of curcumin as an antimetastatic agent and describes potential mechanisms of its antimetastatic activity. In addition, possible strategies (curcumin formulation, optimization of the method of administration and modification of its structure motif) to overcome its limitation such as low solubility and bioactivity are also presented. These strategies are discussed in the context of clinical trials and relevant biological studies.

Hepatoprotective Effect of Kaempferol: A Review of the Dietary Sources, Bioavailability, Mechanisms of Action, and Safety

The liver is the body's most critical organ that performs vital functions. Hepatic disorders can affect the physiological and biochemical functions of the body. Hepatic disorder is a condition that describes the damage to cells, tissues, structures, and functions of the liver, which can cause fibrosis and ultimately result in cirrhosis. These diseases include hepatitis, ALD, NAFLD, liver fibrosis, liver cirrhosis, hepatic failure, and HCC. Hepatic diseases are caused by cell membrane rupture, immune response, altered drug metabolism, accumulation of reactive oxygen species, lipid peroxidation, and cell death. Despite the breakthrough in modern medicine, there is no drug that is effective in stimulating the liver function, offering complete protection, and aiding liver cell regeneration. Furthermore, some drugs can create adverse side effects, and natural medicines are carefully selected as new therapeutic strategies for managing liver disease. Kaempferol is a polyphenol contained in many vegetables, fruits, and herbal remedies. We use it to manage various diseases such as diabetes, cardiovascular disorders, and cancers. Kaempferol is a potent antioxidant and has anti-inflammatory effects, which therefore possesses hepatoprotective properties. The previous research has studied the hepatoprotective effect of kaempferol in various hepatotoxicity protocols, including acetaminophen (APAP)-induced hepatotoxicity, ALD, NAFLD, CCl₄, HCC, and lipopolysaccharide (LPS)-induced acute liver injury. Therefore, this report aims to provide a recent brief overview of the literature concerning the hepatoprotective effect of kaempferol and its possible molecular mechanism of action. It also provides the most recent literature on kaempferol's chemical structure, natural source, bioavailability, and safety.

Comparative Pharmacokinetic of Curcuminoids Formulations with an Omega-3 Fatty Acids Monoglyceride Carrier: A Randomized Cross-Over Triple-Blind Study

There is a growing interest for curcuminoids in the general population and the scientific research community. Curcuminoids, derived from turmeric spice, are lipophiles and therefore have a low solubility in water which hence have a low bioavailability in the human plasma. To circumvent this issue, a natural product developed by Biodroga Nutraceuticals combined curcuminoids with omega-3 fatty acids (OM3) esterified in monoglycerides (MAG). The objective was to perform a 24 h pharmacokinetics in humans receiving a single dose of curcuminoid formulated by three different means, and to compare their plasma curcuminoids concentration. Sixteen males and fifteen females tested three formulations: 400 mg of curcuminoids powder extract, 400 mg of curcuminoids in rice oil and 400 mg of curcuminoids with 1 g MAG-OM3. Blood samples were collected at 0, 1, 2, 3, 4, 5, 6, 8, 10 and 24 h post dose intake. Plasma samples were analyzed by ultra high-performance liquid chromatography with a triple quadrupole mass spectrometer (UPLC-MS/MS). Twenty-four hours after a single dose intake, the total plasma curcuminoids area under the curve (AUC) reached 166.8 ± 17.8 ng/mL*h, 134.0 ± 12.7 ng/mL*h and 163.1 ± 15.3 ng/mL*h when curcuminoids were provided with MAG-OM3, with rice oil or in powder, respectively. The C_max of total curcuminoids reached between 11.9-17.7 ng/mL at around 4 h (T_max). One-hour post-dose, the curcuminoids plasma concentration was 40% higher in participants consuming the MAG-OM3 compared to the other formulations. Thus, in a young population, plasma curcuminoids 24 h pharmacokinetics and its increase shortly after the single dose intake were higher when provided with MAG-OM3 than rice oil.

Polar Phenol Detection in Plasma and Serum: Insights on Sample Pre-Treatment for LC/MS Analysis and Application on the Serum of Corinthian Currant-Fed Rats

Analysis of plasma and serum provides valuable information on the amounts of polar phenols' circulating after ingestion. In the present study, protein precipitation (PPT), liquid-liquid extraction (LLE), solid phase extraction (SPE), enzymatic hydrolysis and their combinations were meticulously evaluated for the extraction of a variety of polar phenolic moieties from plasma and serum. The recovery values of the above methods were compared; satisfactory recoveries (>60%) were attained for most analytes. Polar phenol aglycones undergo degradation with enzymatic hydrolysis; however, their extended phase II metabolism makes enzymatic hydrolysis a mandated process for their analysis in such biofluids. Hence, enzymatic hydrolysis followed by LLE was used for the identification of polar phenols in rats' serum, after the long-term oral consumption of Corinthian Currant. Corinthian Currant is a Greek dried vine product rich in bioactive polar phenolics. Flavonoids and phenolic acids, detected as aglycones, ranged from 0.57 ± 0.08 to 181.66 ± 48.95 and 3.45 ± 1.20 to 897.81 ± 173.96 ng/mL, respectively. The majority of polar phenolics were present as phase II metabolites, representing their fasting state in the blood stream. This is the first study evaluating the presence of polar phenolics in the serum of rats following a long-term diet supplemented with Corinthian Currant as a whole food.

Perspective on Improving the Relevance, Rigor, and Reproducibility of Botanical Clinical Trials: Lessons Learned From Turmeric Trials

Plant-derived compounds, without doubt, can have significant medicinal effects since many notable drugs in use today, such as morphine or taxol, were first isolated from botanical sources. When an isolated and purified phytochemical is developed as a pharmaceutical, the uniformity and appropriate use of the product are well defined. Less clear are the benefits and best use of plant-based dietary supplements or other formulations since these products, unlike traditional drugs, are chemically complex and variable in composition, even if derived from a single plant source. This perspective will summarize key points-including the premise of ethnobotanical and preclinical evidence, pharmacokinetics, metabolism, and safety-inherent and unique to the study of botanical dietary supplements to be considered when planning or evaluating botanical clinical trials. Market forces and regulatory frameworks also affect clinical trial design since in the United States, for example, botanical dietary supplements cannot be marketed for disease treatment and submission of information on safety or efficacy is not required. Specific challenges are thus readily apparent both for consumers comparing available products for purchase, as well as for commercially sponsored vs. independent researchers planning clinical trials to evaluate medicinal effects of botanicals. Turmeric dietary supplements, a top selling botanical in the United States and focus of over 400 clinical trials to date, will be used throughout to illustrate both the promise and pitfalls associated with the clinical evaluation of botanicals.

Triblock Copolymer Nanomicelles Loaded with Curcumin Attenuates Inflammation via Inhibiting the NF-κB Pathway in the Rat Model of Cerebral Ischemia

AIM

Cerebral ischemic injury is one of the debilitating diseases showing that inflammation plays an important role in worsening ischemic damage. Therefore, studying the effects of some potential anti-inflammatory compounds can be very important in the treatment of cerebral ischemic injury.

METHODS

This study investigated anti-inflammatory effects of triblock copolymer nanomicelles loaded with curcumin (abbreviated as NC) in the brain of rats following transient cerebral ischemia/reperfusion (I/R) injury in stroke. After preparation of NC, their protective effects against bilateral common carotid artery occlusion (BCCAO) were explored by different techniques. Concentrations of free curcumin (C) and NC in liver, kidney, brain, and heart organs, as well as in plasma, were measured using a spectrofluorometer. Western blot analysis was then used to measure NF-κB-p65 protein expression levels. Also, ELISA assay was used to examine the level of cytokines IL-1β, IL-6, and TNF-α. Lipid peroxidation levels were assessed using MDA assay and H&E staining was used for histopathological examination of the hippocampus tissue sections.

RESULTS

The results showed a higher level of NC compared to C in plasma and organs including the brain, heart, and kidneys. Significant upregulation of NF-κB, IL-1β, IL-6, and TNF-α expressions compared to control was observed in rats after induction of I/R, which leads to an increase in inflammation. However, NC was able to downregulate significantly the level of these inflammatory cytokines compared to C. Also, the level of lipid peroxidation in pre-treated rats with 80mg/kg NC was significantly reduced.

CONCLUSION

Our findings in the current study demonstrate a therapeutic effect of NC in an animal model of cerebral ischemia/reperfusion (I/R) injury in stroke through the downregulation of NF-κB-p65 protein and inflammatory cytokines.