Neuronal modulation of hepatic lipid accumulation induced by bingelike drinking

Excessive alcohol consumption, including binge drinking, is a common cause of fatty liver disease. Binge drinking rapidly induces hepatic steatosis, an early step in the pathogenesis of chronic liver injury. Despite its prevalence, the process by which excessive alcohol consumption promotes hepatic lipid accumulation remains unclear. Alcohol exerts potent effects on the brain, including hypothalamic neurons crucial for metabolic regulation. However, whether or not the brain plays a role in alcohol-induced hepatic steatosis is unknown. In the brain, alcohol increases extracellular levels of adenosine, a potent neuromodulator, and previous work implicates adenosine signaling as being important for the development of alcoholic fatty liver disease. Acute alcohol exposure also increases both the activity of agouti-related protein (AgRP)-expressing neurons and AgRP immunoreactivity. Here, we show that adenosine receptor A2B signaling in the brain modulates the extent of alcohol-induced fatty liver in mice and that both the AgRP neuropeptide and the sympathetic nervous system are indispensable for hepatic steatosis induced by bingelike alcohol consumption. Together, these results indicate that the brain plays an integral role in alcohol-induced hepatic lipid accumulation and that central adenosine signaling, hypothalamic AgRP, and the sympathetic nervous system are crucial mediators of this process.

Resveratrol Treatment Enhances the Cellular Response to Leptin by Increasing OBRb Content in Palmitate-Induced Steatotic HepG2 Cells

The interaction of leptin with its hepatic longest receptor (OBRb) promotes the phosphorylation of signal transducer and activator of transcription-3 (STAT3), protecting the liver from lipid accumulation. However, leptin signalling is disrupted in hepatic steatosis, causing leptin resistance. One promising strategy to combat this problem is the use of bioactive compounds such as polyphenols. Since resveratrol (RSV) is a modulator of lipid homeostasis in the liver, we investigated whether treatment with different doses of RSV restores appropriate leptin action and fat accumulation in palmitate-induced steatotic human hepatoma (HepG2) cells. Both RSV metabolism and the expression of molecules implicated in leptin signalling were analysed. RSV at a 10 μM concentration was entirely metabolized to resveratrol-3-sulfate after 24 and counteracted leptin resistance by increasing the protein levels of OBRb. In addition, RSV downregulated the expression of lipogenic genes including fatty acid synthase (Fas) and stearoyl-CoA desaturase-1 (Scd1) without any significant change in Sirtuin-1 (SIRT1) enzymatic activity. These results demonstrate that RSV restored leptin sensitivity in a cellular model of hepatic steatosis in a SIRT1-independent manner.

Impact of a (poly)phenol-rich extract from the brown algae Ascophyllum nodosum on DNA damage and antioxidant activity in an overweight or obese population: a randomized controlled trial

Background

Epidemiologic evidence suggests that a diet rich in (poly)phenols has beneficial effects on many chronic diseases. Brown seaweed is a rich source of (poly)phenols.

Objective

The aim of this study was to investigate the bioavailability and effect of a brown seaweed (Ascophyllum nodosum) (poly)phenol extract on DNA damage, oxidative stress, and inflammation in vivo.

Design

A randomized, double-blind, placebo-controlled crossover trial was conducted in 80 participants aged 30-65 y with a body mass index (in kg/m2) ≥25. The participants consumed either a 400-mg capsule containing 100 mg seaweed (poly)phenol and 300 mg maltodextrin or a 400-mg maltodextrin placebo control capsule daily for an 8-wk period. Bioactivity was assessed with a panel of blood-based markers including lymphocyte DNA damage, plasma oxidant capacity, C-reactive protein (CRP), and inflammatory cytokines. To explore the bioavailability of seaweed phenolics, an untargeted metabolomics analysis of urine and plasma samples after seaweed consumption was determined by ultra-high-performance liquid chromatography-high-resolution mass spectrometry.

Results

Consumption of the seaweed (poly)phenols resulted in a modest decrease in DNA damage but only in a subset of the total population who were obese. There were no significant changes in CRP, antioxidant status, or inflammatory cytokines. We identified phlorotannin metabolites that are considered potential biomarkers of seaweed consumption including pyrogallol/phloroglucinol-sulfate, hydroxytrifurahol A-glucuronide, dioxinodehydroeckol-glucuronide, diphlorethol sulfates, C-O-C dimer of phloroglucinol sulfate, and C-O-C dimer of phloroglucinol.

Conclusions

To the best of our knowledge, this work represents the first comprehensive study investigating the bioactivity and bioavailability of seaweed (poly)phenolics in human participants. We identified several potential biomarkers of seaweed consumption. Intriguingly, the modest improvements in DNA damage were observed only in the obese subset of the total population. The subgroup analysis should be considered exploratory because it was not preplanned; therefore, it was not powered adequately. Elucidation of the biology underpinning this observation will require participant stratification according to weight in future studies. This trial was registered at clinicaltrials.gov as NCT02295878.

Seasonal consumption of polyphenol-rich fruits affects the hypothalamic leptin signaling system in a photoperiod-dependent mode

Leptin has a central role in the maintenance of energy homeostasis, and its sensitivity is influenced by both the photoperiod and dietary polyphenols. The aim of this study was to investigate the effect of seasonal consumption of polyphenol-rich fruits on the hypothalamic leptin signaling system in non-obese and obese animals placed under different photoperiods. Non-obese and diet-induced obese male Fischer 344 rats were placed under either a short-day (SD) or long-day (LD) photoperiod and were supplemented with either 100 mg/kg of lyophilized red grapes or cherries. In non-obese animals, both fruits reduced energy balance independent of the photoperiod to which they were placed. However, the hypothalamic gene expression of Pomc was significantly up-regulated only in the SD photoperiod. In contrast, in obese animals only cherry significantly decreased the energy balance, although both fruits were able to counteract the diet-induced increase in hypothalamic AgRP mRNA levels when consumed during the SD photoperiod. In conclusion, the consumption of rich-polyphenol fruits may increase leptin sensitivity through the modulation of the hypothalamic leptin signal pathway mainly when consumed in the SD photoperiod. Therefore, fruit seasonality should be considered, as it can influence energy homeostasis and obesity.

Tracking (Poly)phenol components from raspberries in ileal fluid

The (poly)phenols in ileal fluid after ingestion of raspberries were analyzed by targeted and nontargeted LC-MS(n) approaches. Targeted approaches identified major anthocyanin and ellagitannin components at varying recoveries and with considerable interindividual variation. Nontargeted LC-MS(n) analysis using an orbitrap mass spectrometer gave exact mass MS data which were sifted using a software program to select peaks that changed significantly after supplementation. This method confirmed the recovery of the targeted components but also identified novel raspberry-specific metabolites. Some components (including ellagitannin and previously unidentified proanthocyanidin derivatives) may have arisen from raspberry seeds that survived intact in ileal samples. Other components include potential breakdown products of anthocyanins, unidentified components, and phenolic metabolites formed either in the gut epithelia or after absorption into the circulatory system and efflux back into the gut lumen. The possible physiological roles of the ileal metabolites in the large bowel are discussed.

Supported discharge shortens hospital stay in patients hospitalized because of an exacerbation of COPD

This prospective, controlled, but not formally randomized study investigates the feasibility and efficiency of an alternative to standard hospitalization for patients with exacerbated chronic obstructive pulmonary disease (COPD), based upon supported discharge with nurse supervision at home. Over a 12-month period, emergency physicians, not directly involved in the study, admitted 205 patients with exacerbated COPD to the authors' respiratory unit. Patients were included in the supported discharge group (n=105) if they voluntarily chose to participate in the programme and lived in the city of Palma de Mallorca (where adequate home support could be provided). Patients not fulfilling these criteria (mainly residents outside the city) served as controls (n=100). Inpatient treatment was standardized in all patients and included oxygen therapy, bronchodilators, antibiotics and steroids. Both groups were comparable in terms of age (mean +/- SD: 70 +/- 10 versus 65 +/- 11 yr for supported discharge and control group, respectively), severity of airflow obstruction (forced expiratory volume in one second 45 +/- 18% reference versus 46 +/- 19% ref.), comorbidity and socioeconomic status. Length of hospital stay (LOS) in the supported discharge group was shorter (5.9 +/- 2.8 versus 8.0 +/- 5.1 days, p < 0.001). After discharge, a respiratory nurse visited supported discharge patients at home during 7.3 +/- 3.8 days. Only one patient (1%) required hospital readmission during this period of time. The reduced LOS resulted in a lower utilization of hospital beds at any given point in time throughout the study period. Within the framework and potential limitations of this study, the results indicate that the supported discharge programme in Spain: 1) allows a significant reduction in the length of hospital stay of patients hospitalized because of an exacerbation of chronic obstructive pulmonary disease; 2) does not result in an inappropriately increased rate of hospital readmissions; and 3) reduces the utilization of hospital resources.