Hepatic metabolic effects of Curcuma longa extract supplement in high-fructose and saturated fat fed rats

High-resolution magic angle spinning NMR for intact biological specimen analysis: Initial discovery, recent developments, and future directions

High-resolution magic angle spinning (HRMAS) NMR, an approach for intact biological material analysis discovered more than 25 years ago, has been advanced by many technical developments and applied to many biomedical uses. This article provides a history of its discovery, first by explaining the key scientific advances that paved the way for HRMAS NMR's invention, and then by turning to recent developments that have profited from applying and advancing the technique during the last 5 years. Developments aimed at directly impacting healthcare include HRMAS NMR metabolomics applications within studies of human disease states such as cancers, brain diseases, metabolic diseases, transplantation medicine, and adiposity. Here, the discussion describes recent HRMAS NMR metabolomics studies of breast cancer and prostate cancer, as well as of matching tissues with biofluids, multimodality studies, and mechanistic investigations, all conducted to better understand disease metabolic characteristics for diagnosis, opportune windows for treatment, and prognostication. In addition, HRMAS NMR metabolomics studies of plants, foods, and cell structures, along with longitudinal cell studies, are reviewed and discussed. Finally, inspired by the technique's history of discoveries and recent successes, future biomedical arenas that stand to benefit from HRMAS NMR-initiated scientific investigations are presented.

The effects of curcumin supplementation on metabolic biomarkers and body mass index in patients with nonalcoholic fatty liver disease, a systematic review and meta-analysis of randomized controlled trials

Background and Aims:

Curcumin is one of the most commonly used indigenous molecules endowed with various shielding functionalities that protect the liver. In the present research, we aimed to investigate the effects of curcumin on metabolic factors and body mass index (BMI) in patients with non-alcoholic fatty liver disease (NAFLD), using a meta-analysis of randomized, controlled trials.

Methods::

Online databases PubMed, Embase, Web of Science, and Science Direct were searched until April 2021 to identify eligible articles. Fourteen trials were included. Results: The results showed that curcumin consumption could significantly reduce AST (-0.35, (-0.57 to -0.14)), total cholesterol (-0.81, (-1.34 to -0.27)), TG (-0.49, (-0.71 to -0.27)), and FBS (-0.28, (-0.46 to -0.09)) in patients with NAFLD. However, the improvements in ALT (-0.29, (-0.58 to 0.00)), LDL (-0.48, (-0.97 to 0.01)), HDL (0.03, (-0.38 to 0.44)), and BMI (-0.13, (-0.29 to 0.02)) were not statistically significant. Furthermore, the findings revealed that the optimal dose and duration of curcumin consumption for patients with NAFLD is <500 mg/d for less than 10 weeks.

Conclusions:

The present study suggests that consuming curcumin can improve liver enzymes, lipid profile, FBS, and BMI in patients with NAFLD. Moreover, curcumin supplementation may provide beneficial effects on metabolic biomarkers and body weight if used at the appropriate dose and duration. Further RCTs are required to confirm our findings.

Rodent models and metabolomics in non-alcoholic fatty liver disease: What can we learn?

Non-alcoholic fatty liver disease (NAFLD) prevalence has increased drastically in recent decades, affecting up to 25% of the world’s population. NAFLD is a spectrum of different diseases that starts with asymptomatic steatosis and continues with development of an inflammatory response called steatohepatitis, which can progress to fibrosis. Several molecular and metabolic changes are required for the hepatocyte to finally vary its function; hence a “multiple hit” hypothesis seems a more accurate proposal. Previous studies and current knowledge suggest that in most cases, NAFLD initiates and progresses through most of nine hallmarks of the disease, although the triggers and mechanisms for these can vary widely. The use of animal models remains crucial for understanding the disease and for developing tools based on biological knowledge. Among certain requirements to be met, a good model must imitate certain aspects of the human NAFLD disorder, be reliable and reproducible, have low mortality, and be compatible with a simple and feasible method. Metabolism studies in these models provides a direct reflection of the workings of the cell and may be a useful approach to better understand the initiation and progression of the disease. Metabolomics seems a valid tool for studying metabolic pathways and crosstalk between organs affected in animal models of NAFLD and for the discovery and validation of relevant biomarkers with biological understanding. In this review, we provide a brief introduction to NAFLD hallmarks, the five groups of animal models available for studying NAFLD and the potential role of metabolomics in the study of experimental NAFLD.

Blueberry Counteracts Prediabetes in a Hypercaloric Diet-Induced Rat Model and Rescues Hepatic Mitochondrial Bioenergetics

The paramount importance of a healthy diet in the prevention of type 2 diabetes is now well recognized. Blueberries (BBs) have been described as attractive functional fruits for this purpose. This study aimed to elucidate the cellular and molecular mechanisms pertaining to the protective impact of blueberry juice (BJ) on prediabetes. Using a hypercaloric diet-induced prediabetic rat model, we evaluated the effects of BJ on glucose, insulin, and lipid profiles; gut microbiota composition; intestinal barrier integrity; and metabolic endotoxemia, as well as on hepatic metabolic surrogates, including several related to mitochondria bioenergetics. BJ supplementation for 14 weeks counteracted diet-evoked metabolic deregulation, improving glucose tolerance, insulin sensitivity, and hypertriglyceridemia, along with systemic and hepatic antioxidant properties, without a significant impact on the gut microbiota composition and related mechanisms. In addition, BJ treatment effectively alleviated hepatic steatosis and mitochondrial dysfunction observed in the prediabetic animals, as suggested by the amelioration of bioenergetics parameters and key targets of inflammation, insulin signaling, ketogenesis, and fatty acids oxidation. In conclusion, the beneficial metabolic impact of BJ in prediabetes may be mainly explained by the rescue of hepatic mitochondrial bioenergetics. These findings pave the way to support the use of BJ in prediabetes to prevent diabetes and its complications.

Evaluation of the Rotating-Frame Relaxation (T1ρ) Filter and Its Application in Metabolomics as an Alternative to the Transverse Relaxation (T2) Filter

Nuclear magnetic resonance (NMR)-based metabolomic studies commonly involve the use of T2 filter pulse sequences to eliminate or attenuate the broad signals from large molecules and improve spectral resolution. In this paper, we demonstrate that the T1ρ filter-based pulse sequence represents an interesting alternative because it allows the stability and the reproducibility needed for statistical analysis. The integrity of the samples and the stability of the instruments were assessed for different filter durations and amplitudes. We showed that the T1ρ filter pulse sequence did not induce sample overheating for a filter duration of up to 500 ms. The reproducibility was evaluated and compared with the T2 filter in serum and liver samples. The implementation is relatively simple and provides the same statistical and analytical results as those obtained with the standard filters. Regarding tissues analysis, because the duration of the filter is the same as that of the spin-lock, the synchronization of the echo delays with the magic angle spinning (MAS) rate is no longer necessary as for T2 filter-based sequences. The results presented in this article aim at establishing a new protocol to improve metabolomic studies and pave the way for future developments on T1ρ alternative filters, in liquid and HR-MAS NMR experiments.

Preclinical Evidence of Curcuma longa and Its Noncurcuminoid Constituents against Hepatobiliary Diseases: A Review

Hepatobiliary disease currently serves as an important public health issue due to the fact that it is one of the major causes of death among economically active individuals and can easily progress to chronic diseases. Despite the development of vaccines and numerous drugs, a definite treatment remains lacking owing to different stages of the disease itself, its intricate pathogenesis, an effect uncertainty for long-term use, resistance, and side effects. Curcuma longa (C. longa), which belongs to the family Zingiberaceae and the genus Curcuma, has long been used not only as spice for curry or dye but also as a constituent of herbal formula for the treatment of different diseases due to its bioactive activities. Recently, many studies on the experimental results of C. longa have been published relative to hepatobiliary diseases such as fatty liver, hepatitis, cirrhosis, and tumors. Therefore, in this review, we aimed to summarize the pharmacological effects and underlying molecular mechanisms of C. longa and its four compounds, β-elemene, germacrone, ar-turmerone, and bisacurone, against hepatobiliary diseases. C. longa exhibited antioxidant, hepatoprotective, antisteatotic, anti-inflammatory, antifibrotic, antitumor, and cholagogic effects by regulating apoptosis, CYP2E1, Nrf, lipid metabolism-related factors, TGF-β, NF-κB, CYP7A1, and so on. In particular, β-elemene could be an attractive compound owing to its remarkable hepatoprotective, anti-inflammatory, antifibrotic, and antitumor activities. Altogether, the present review provides a preclinical basis for the efficacy of C. longa as an effective therapeutic agent for the prevention and treatment of hepatobiliary diseases, despite the need for further studies to establish the extraction conditions and separation of active constituents with high bioavailability, and warrants further evaluation in clinical trials.

Untargeted UPLC-MS metabolomics reveals multiple changes of urine composition in healthy adult volunteers after consumption of curcuma longa L. extract

Curcuma longa L. is used as food supplement to prevent diseases, although limited studies have been performed on healthy subjects up to now. In the present work, an untargeted UPLC-MS metabolomics approach was applied to study the changes of 24-hours urinary composition on healthy volunteers due to a 28-days daily consumption of a dried C. longa extract containing a standardized amount of curcuminoids. Changes in the excretion of different metabolites were observed after supplementation. Curcumin and two metabolic derivatives (hexahydrocurcumin and dihydrocurcumin) were detected in urine, indicating the absorption of the main curcuminoid from the extract and its further metabolism by liver and gut microbiota. For the first time ar-turmerone, the main apolar constituent of curcuma, was detected in urine in intact form, and its presence was confirmed by a targeted GC-MS analysis. The increase of tetranor-PGJM and tetranor-PGDM, two prostaglandin-D2 metabolites, was observed, being related to the anti-inflammatory effect exerted by curcuma. The variation of the amounts of HPAG, PAG, proline-betaine and hydroxyphenyllactic acid indicate that the supplementation induced changes to the activity of gut microbiota. Finally, the reduced excretion of niacin metabolites (nicotinuric acid, trigonelline and 2PY) and medium- and short-chain acylcarnitines suggests that curcuma could induce the mitochondrial β-oxidation of fatty acids for energy production in healthy subjects. Overall, the results indicate that a prolonged daily consumption of a dried curcuma extract exerts multiple effects on healthy subjects, furthermore they show the opportunity offered by untargeted metabolomics for the study of the bioactivity of natural extracts in healthy human volunteers.

Influence of enhanced bioavailable curcumin on obesity-associated cardiovascular disease risk factors and arterial function: A double-blinded, randomized, controlled trial

OBJECTIVES

This study aimed to determine whether an enhanced bioavailable curcumin formulation, CurQfen®, would improve circulating cardiovascular disease-related blood biomarkers and arterial function in young (age 18-35 y), obese (body mass index ≥ 30.0 kg/m²) men.

METHODS

This double-blinded, placebo-controlled trial evaluated 22 men. The participants were matched based on body mass index and randomized to the intervention (curcumin formulated with fenugreek soluble fiber, for enhanced absorption) or control (fenugreek soluble fiber) group for 12 wk at 500mg/d without dietary modification or exercise. Blood samples and endothelial function measures were acquired at 0 and 12 wk, and blood samples were analyzed for cardiovascular disease-related blood biomarkers. Furthermore, central (aortic) blood pressure and augmentation index were monitored at 0, 4, 8, and 12 wk.

RESULTS

After 12 wk of intervention, homocysteine levels were lower (curcumin before: 12.22 ± 2.29 µg/mL, after: 8.62 ± 1.02 µg/mL versus placebo before: 9.45 ± 0.84 µg/mL, after: 11.84 ± 1.63 µg/mL; P = 0.04) and high-density lipoprotein levels were higher (curcumin before: 40.77 ± 5.37 mg/dL, after: 54.56 ± 11.72 mg/dL versus placebo before: 61.20 ± 5.76 mg/dL, after: 48.82 ± 5.49 mg/dL; P = 0.04) in the curcumin group relative to the placebo group. However, there was no significant difference in changes between the circulating concentrations of glucose, insulin, leptin, adiponectin, or oxidative stress biomarkers in the curcumin group compared with the placebo group (P > 0.05). No changes were found with endothelial function, augmentation index, or central blood pressure in the curcumin group compared with the placebo group (P > 0.05).

CONCLUSIONS

Our data provide evidence for an enhanced bioavailable curcumin to improve homocysteine and high-density lipoprotein concentrations, which may promote favorable cardiovascular health in young, obese men. Improvements in endothelial function or blood pressure were not observed with curcumin supplementation, thus further investigation is warranted.

Tissue metabolomics study to reveal the toxicity of a traditional Tibetan medicine 'Renqing Changjue' in rats

Renqing Changjue (RQCJ), a precious Traditional Tibetan Medicine (TTM), has been widely used in the management of diseases of the digestive system, toxinosis and pyreticosis. However, in the formula, a significant level of heavy metals, which are potential toxic elements, are present. Therefore, it is important to assess the toxicity of RQCJ dynamically and holistically. In the present study, a ¹H NMR metabolomics approach and inductively coupled plasma mass spectrometry (ICP-MS) were implemented to analyze the samples of liver, kidney and spleen from rats treated with RQCJ. The results revealed that 9 metabolites in the liver, 13 metabolites in the kidney and 16 metabolites in the spleen were significantly altered, which suggest that disturbances in TCA cycle, amino acid metabolism, energy metabolism and oxidative stress are produced by successive administration of RQCJ over 15 days. Complemented by histopathology and biochemical assay, the trends of the metabolite levels indicate that RQCJ caused tissue injury to a certain extent, which was evidenced by the high levels of As and Hg in the tissue. The toxic effects of RQCJ were alleviated in liver and kidney during the recovery period, and RQCJ may cause long-term damage in spleen. These findings provide a significant experimental proof on the estimated safety and valuable information about the metabolism of RQCJ, which will be valuable in determining the health risks of the drug.

Modulation of hepatic inflammation and energy-sensing pathways in the rat liver by high-fructose diet and chronic stress

PURPOSE

High-fructose consumption and chronic stress are both associated with metabolic inflammation and insulin resistance. Recently, disturbed activity of energy sensor AMP-activated protein kinase (AMPK) was recognized as mediator between nutrient-induced stress and inflammation. Thus, we analyzed the effects of high-fructose diet, alone or in combination with chronic stress, on glucose homeostasis, inflammation and expression of energy sensing proteins in the rat liver.

METHODS

In male Wistar rats exposed to 9-week 20% fructose diet and/or 4-week chronic unpredictable stress we measured plasma and hepatic corticosterone level, indicators of glucose homeostasis and lipid metabolism, hepatic inflammation (pro- and anti-inflammatory cytokine levels, Toll-like receptor 4, NLRP3, activation of NFκB, JNK and ERK pathways) and levels of energy-sensing proteins AMPK, SIRT1 and peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α).

RESULTS

High-fructose diet led to glucose intolerance, activation of NFκB and JNK pathways and increased intrahepatic IL-1β, TNFα and inhibitory phosphorylation of insulin receptor substrate 1 on Ser³⁰⁷. It also decreased phospho-AMPK/AMPK ratio and increased SIRT1 expression. Stress alone increased plasma and hepatic corticosterone but did not influence glucose tolerance, nor hepatic inflammatory or energy-sensing proteins. After the combined treatment, hepatic corticosterone was increased, glucose tolerance remained preserved, while hepatic inflammation was partially prevented despite decreased AMPK activity.

CONCLUSION

High-fructose diet resulted in glucose intolerance, hepatic inflammation, decreased AMPK activity and reduced insulin sensitivity. Chronic stress alone did not exert such effects, but when applied together with high-fructose diet it could partially prevent fructose-induced inflammation, presumably due to increased hepatic glucocorticoids.