Zanthoxylum bungeanum amides ameliorates nonalcoholic fatty liver via regulating gut microbiota and activating AMPK/Nrf2 signaling

ETHNOPHARMACOLOGICAL RELEVANCE

Zanthoxylum bungeanum Maxim. (Rutaceae) is a known herbal medicine with various bioactivities, including anti-obesity, lipid-lowering, learning & memory improving and anti-diabetes, and amides in Z. bungeanum (AZB) are considered as the major active agents for its bioactivities.

AIM OF THE STUDY

This research was carried out to uncover the anti-NAFL effect of AZB and its corresponding molecular mechanisms.

METHODS

The central composite design-response surface methodology (CCD-RSM) was utilized to optimize the AZB extraction process, and the anti-NAFL effect of AZB was investigated on high fat diet (HFD) fed mice (HFD mice). The levels of ROS in liver tissues were determined using laser confocal microscopy with DCFH-DA probe staining, and anti-enzymes (such as HO-1, SOD, CAT & GSH-PX) and MDA in liver tissues were measured using commercial detecting kits. GC-MS was used to determine the short-chain fatty acids (SCFAs) contents in feces and blood of mice. 16S high-throughput sequencing, western blotting (WB) assay and immunofluorescence (IF) were used to explore the intestinal flora changes in mice and the potential mechanisms of AZB for treatment of NAFL.

RESULTS

Our results showed AZB reduced body weight, alleviated liver pathological changes, reduced fat accumulation, and improved oxidative stress in HFD mice. In addition, we also found AZB improved OGTT and ITT, reduced TG, TC, LDL-C, whereas increased HDL-C in HFD mice. AZB increased total number of the species and interspecies kinship of gut microbiota and reduced the richness and diversity of gut microbiota in HFD mice. Moreover, AZB decreased the ratio of Firmicutes/Bacteroidota, whereas increased the abundance of Allobaculum, Bacteroides and Dubosiella in feces of HFD-fed mice. Furthermore, AZB increased the production of SCFAs, and up-regulated the phosphorylation of AMPK and increased the nuclear transcription of Nrf2 in liver of HFD mice.

CONCLUSION

Collectively, our results suggested AZB can improve NAFL, which could reduce body weight, reverse liver lesions and fat accumulation, improve oxidative stress in liver tissues of HFD mice. Furthermore, the mechanisms are related to increase of the abundance of high-producing bacteria for SCFAs (e.g. Allobaculum, Bacteroides and Dubosiella) to activate AMPK/Nrf2 signaling.

Transient elastography and controlled attenuation parameter to evaluate hepatic steatosis and liver stiffness in postpartum patients

INTRODUCTION

Nonalcoholic fatty liver disease (NAFLD) affects 30% of adults in the United States. Transient elastography (TE) (Fibroscan, Echosens, Paris, France) with controlled attenuation parameter (CAP) is a noninvasive way to evaluate liver steatosis and liver stiffness. The primary objective of this study was to assess prevalence of elevated liver stiffness and steatosis immediately postpartum. Furthermore, we sought to evaluate whether there were differences in rates of metabolic disorders of pregnancy (gestational diabetes mellitus (GDM), gestational hypertension, and preeclampsia) and pre-pregnancy conditions (type 2 diabetes mellitus (DM), chronic hypertension, and obesity) in those with elevated postpartum liver steatosis/liver stiffness.

METHODS

IRB approved prospective cross-sectional study in which TE and liver function tests were performed 1-2 days postpartum. CAP ≥300 dB/m was classified as significant steatosis. Increased liver stiffness was defined as ≥7 kPa. Prevalence was determined by proportion of individuals undergoing TE/CAP who met criteria. Chi-square analysis was used to compare differences between groups.

RESULTS

Eighty-nine patients were included: 20 (22%) had GDM, 13 (15%) had gestational hypertension, and 15 (17%) had preeclampsia. Women with kPa ≥7 were more likely to have ALT ≥25, type 2 diabetes, and preeclampsia (p < .05). Pre-gravid BMI, BMI at delivery, and GDM were not associated with increased kPa. Pregravid BMI ≥25 and chronic hypertension were associated with CAP ≥ 300 dB/m (p < .05). GDM, preeclampsia, and gestational hypertension were not associated with CAP ≥300 dB/m.

CONCLUSIONS

Patients with preeclampsia, type 2 diabetes, and elevated ALT were more likely to have elevated postpartum liver stiffness. Pregravid BMI ≥25 and ≥30 were associated with increased liver steatosis, although did not impact liver stiffness. GDM was not associated with increased liver stiffness or steatosis. Consideration should be made for screening pregnant patients with preeclampsia, type 2 DM and overweight or obese BMI for liver disease in the postpartum period with potential for lifestyle intervention.

Ultrasonic Sound Speed Estimation for Liver Fat Quantification: A Review by the AIUM-RSNA QIBA Pulse-Echo Quantitative Ultrasound Initiative

Non-alcoholic fatty liver disease (NAFLD) is a significant cause of diffuse liver disease, morbidity and mortality worldwide. Early and accurate diagnosis of NALFD is critical to identify patients at risk of disease progression. Liver biopsy is the current gold standard for diagnosis and prognosis. However, a non-invasive diagnostic tool is desired because of the high cost and risk of complications of tissue sampling. Medical ultrasound is a safe, inexpensive and widely available imaging tool for diagnosing NAFLD. Emerging sonographic tools to quantitatively estimate hepatic fat fraction, such as tissue sound speed estimation, are likely to improve diagnostic accuracy, precision and reproducibility compared with existing qualitative and semi-quantitative techniques. Various pulse-echo ultrasound speed of sound estimation methodologies have been investigated, and some have been recently commercialized. We review state-of-the-art in vivo speed of sound estimation techniques, including their advantages, limitations, technical sources of variability, biological confounders and existing commercial implementations. We report the expected range of hepatic speed of sound as a function of liver steatosis and fibrosis that may be encountered in clinical practice. Ongoing efforts seek to quantify sound speed measurement accuracy and precision to inform threshold development around meaningful differences in fat fraction and between sequential measurements.

Ionizing radiation promotes, whereas calorie restriction suppresses, NASH and hepatocellular carcinoma in mice

The pathological conditions of nonalcoholic fatty liver disease and nonalcoholic steatohepatitis (NASH) are the major risk factors for hepatocellular carcinoma (HCC). Exposure to DNA-damaging agents such as ionizing radiation is another risk factor for HCC; calorie restriction (CR), however, effectively delays the onset of radiation-induced HCC. We investigated whether NASH is relevant to radiation-induced HCC and the cancer-preventing effect of CR. Eight-day-old male B6C3F1 mice were irradiated with 3.8 Gy of X-rays and then fed a standard diet or 30% CR diet from 49 days of age until necropsy, which was performed from 56 to 600 days with ~100-day intervals to assess both pathological changes and gene expression levels. We found that early-life exposure to radiation accelerated lipid accumulation and NASH-like histopathological changes in the liver, accompanied by accelerated development of HCC. CR ameliorated the changes in lipid metabolism in the liver and reversed the NASH-like pathology, which effectively delayed HCC development. Gene-expression profiling revealed the radiation-related activation and CR-related suppression of the peroxisome proliferator-activated receptor gamma/Cd36 pathway of transmembrane fatty-acid translocation before development of the NASH-like state. Thus, early-life exposure to radiation affects lipid metabolism and induces a steatoinflammatory microenvironment that favors HCC development. Therefore, targeting this pathway by CR (or measures that mimic CR) may be a promising strategy for preventing HCC caused by either radiation or other DNA-damaging agents.

Ghrelin protects against ischemia/reperfusion-induced hepatic injury via inhibiting Caspase-11-mediated noncanonical pyroptosis

BACKGROUND

Ischemia/reperfusion (I/R) injury is a complication of liver transplantation. I/R-induced inflammatory cell death, namely, pyroptosis, that is triggered by overactive inflammasomes results in the production of proinflammatory cytokines. Hepatic I/R injury correlates with the activation of the Caspase-11-mediated pyroptosis pathway. We investigated whether ghrelin, which is a pleiotropic gut hormone, may have anti-hepatic I/R injury effects, but the mechanism by which Ghrelin ameliorates hepatic I/R -induced injury remains a mystery.

METHODS

Hepatic I/R injury was induced in a mouse model by clamping the left and right lobes of the liver for 90 min followed by reperfusion for 6 h, 12 h, or 24 h. As treatment, a saline with or without ghrelin was infused via the tail vain. Hepatocytes were isolated using a two-step collagenase liver perfusion method.

RESULTS

In our study, treatment with ghrelin protected against hepatic I/R injury as shown by decreased alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) levels (p < 0.001) and reduced the histological injury in liver tissues compared with untreated controls. The LDH level of primary hepatocytes was increased by hypoxia/reoxygenation (H/R), and it was then restored to normal levels by ghrelin-treatment (p < 0.05). Western blotting analysis showed that ghrelin significantly inhibited the expression of pyroptosis-related proteins, including Caspase-11, GSDMD-N, NLRP3 and HMGB1, both in vivo and in vitro (all p < 0.05) compared with the untreated controls. Immunofluorescence showed that the expression of Gasdamin D (GSDMD) in hepatocytes was increased after I/R or H/R, whereas GSDMD expression was reduced by ghrelin treatment (p < 0.05).

CONCLUSIONS

Our findings suggest that ghrelin ameliorated I/R-induced hepatic injury by inhibiting Caspase-11-mediated pyroptosis. Ghrelin may be a potential therapeutic option to prevent hepatic I/R injury after liver transplantation.

Antifibrotic therapy in nonalcoholic steatohepatitis: time for a human-centric approach

Nonalcoholic steatohepatitis (NASH) might soon become the leading cause of end-stage liver disease and indication for liver transplantation worldwide. Fibrosis severity is the only histological predictor of liver-related morbidity and mortality in NASH identified to date. Moreover, fibrosis regression is associated with improved clinical outcomes. However, despite numerous clinical trials of plausible drug candidates, an approved antifibrotic therapy remains elusive. Increased understanding of NASH susceptibility and pathogenesis, emerging human multiomics profiling, integration of electronic health record data and modern pharmacology techniques hold enormous promise in delivering a paradigm shift in antifibrotic drug development in NASH. There is a strong rationale for drug combinations to boost efficacy, and precision medicine strategies targeting key genetic modifiers of NASH are emerging. In this Perspective, we discuss why antifibrotic effects observed in NASH pharmacotherapy trials have been underwhelming and outline potential approaches to improve the likelihood of future clinical success.

Liver biopsy-based validation, confirmation and comparison of the diagnostic performance of established and novel non-invasive steatotic liver disease indexes: Results from a large multi-center study

BACKGROUND

Non-invasive tools (NIT) for metabolic-dysfunction associated liver disease (MASLD) screening or diagnosis need to be thoroughly validated using liver biopsies.

PURPOSE

To externally validate NITs designed to differentiate the presence or absence of liver steatosis as well as more advanced disease stages, to confirm fully validated indexes (n = 7 NITs), to fully validate partially validated indexes (n = 5 NITs), and to validate for the first time one new index (n = 1 NIT).

METHODS

This is a multi-center study from two Gastroenterology-Hepatology Departments (Greece and Australia) and one Bariatric-Metabolic Surgery Department (Italy). Overall, n = 455 serum samples of patients with biopsy-proven MASLD (n = 374, including 237 patients with metabolic-dysfunction associated steatohepatitis (MASH)) and Controls (n = 81) were recruited. A complete validation analysis was performed to differentiate the presence of MASLD vs. Controls, MASH vs. metabolic-dysfunction associated steatotic liver (MASL), histological features of MASH, and fibrosis stages.

RESULTS

The index of NASH (ION) demonstrated the highest differentiation ability for the presence of MASLD vs. Controls, with the area under the curve (AUC) being 0.894. For specific histological characterization of MASH, no NIT demonstrated adequate performance, while in the case of specific features of MASH, such as hepatocellular ballooning and lobular inflammation, ION demonstrated the best performance with AUC being close to or above 0.850. For fibrosis (F) classification, the highest AUC was reached by the aspartate aminotransferase to platelet ratio index (APRI) being ~0.850 yet only with the potential to differentiate the severe fibrosis stages (F3, F4) vs. mild or moderate fibrosis (F0-2) with an AUC > 0.900 in patients without T2DM. When we excluded patients with morbid obesity, the differentiation ability of APRI was improved, reaching AUC = 0.802 for differentiating the presence of fibrosis F2-4 vs. F0-1. The recommended by current guidelines index FIB-4 seemed to differentiate adequately between severe (i.e., F3-4) and mild or moderate fibrosis (F0-2) with an AUC = 0.820, yet this was not the case when FIB-4 was used to classify patients with fibrosis F2-4 vs. F0-1. Trying to improve the predictive value of all NITs, using Youden's methodology, to optimize the suggested cut-off points did not materially improve the results.

CONCLUSIONS

The validation of currently available NITs using biopsy-proven samples provides new evidence for their ability to differentiate between specific disease stages, histological features, and, most importantly, fibrosis grading. The overall performance of the examined NITs needs to be further improved for applications in the clinic.

Vibration Controlled Transient Elastography in Screening for Silent Liver Diseases

OBJECTIVES

The objective of this study was to screen for significant hepatic fibrosis or steatosis in asymptomatic, apparently healthy subjects by using Vibration-controlled transient elastography and controlled attenuation parameter (CAP).

METHODS

Prospectively, 433 asymptomatic apparently healthy adults were included. Fibroscan/CAP examination was performed for all of them. Subjects with liver stiffness measurement > 6 kPa or CAP >248 dB/m were further evaluated to assess underlying chronic liver disease.

RESULTS

According to fibroscan/CAP examination, subjects were classified into four subgroups: normal (119) with CAP score of 215.85 ± 24.81 dB/m and fibrosis score of 4.47 ± 0.81 kPa, subjects with steatosis only 133 with CAP score of 309.41 ± 42.6 dB/m and fibrosis score of 4.74 ± 0.82 kPa, subjects with both steatosis and fibrosis 95 with CAP score of 318.20 ± 39.89 dB/m and fibrosis score of 7.92 ± 2.58 kPaand subjects with fibrosis only 86 with CAP score of 213.48 ± 22.62 dB/m and fibrosis score of 6.96 ± 1.11 kPa. S0 was present in 205 (47.3%), S1 in 48 (10.2%), S2 in 16 (3.7%) and S3 in 168 (38.8%) of studied subjects, whereas F0-1 was present in 371 (85.7%), F2 in 44 (10.16%), F3 in 16 (3.7%) subjects and F4 in only one (0.23%) subject. Subjects with both steatosis and fibrosis showed significantly higher transaminases, triglycerides and total cholesterol levels than other subgroups.

CONCLUSIONS

Most asymptomatic, apparently healthy subjects (72%) have significant steatosis and fibrosis. Liver stiffness measurement and CAP might represent promising first-line noninvasive procedures to screen for silent liver diseases in the general population.

Four indices on Gd-EOB-DTPA-enhanced MRI can estimate liver functional reserve compared to ICG-R15: A systematic review and meta-analysis

AIMS

To evaluate the value of four indices of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced (Gd-EOB-DTPA) magnetic resonance as a potential imaging marker of liver functional reserve.

METHODS

PubMed/Medline, Embase, Cochrane Library, and Web of Science were searched for studies concerning the relationship between Gd-EOB-DTPA-enhanced MRI and liver functional reserve estimated by ICG-R15, Pooled correlation coefficient (r) and 95% confidence intervals (CIs) were calculated, Meanwhile, Sensitivity and subgroup analyses were performed along with Egger's test for the estimation of publication bias and potential heterogeneity.

RESULTS

14 publications with 1285 patients were included. The pooled r between relative liver enhancement (RLE), reduction rate of T1 relaxation time of the liver (rrT1), liver-to-spleen ratio (LSR), liver-to-muscle ratio (LMR), and ICG-R15 were -0.49 (95% CI, -0.56 to -0.41, p < 0.05), -0.47 (95% CI, -0.57 to -0.36, p < 0.05), -0.45 (95% CI, -0.55 to -0.34, p < 0.05), -0.50 (95% CI, -0.61 to -0.38, p < 0.05). moderate heterogeneity was observed between studies on rrT1, LSR, LMR, and ICG-R15 (p ≤ 0.05), but no significant heterogeneity was observed between RLE and ICG-R15. Further analysis shows that there was a notable heterogeneity between subgroup analysis of LSR and ICG-R15 stratified by years of publication, as well as rrT1 and LMR stratified by total patients and study design, the distribution funnel plots and the results of Egger's test showed no evidence of publication bias.

CONCLUSIONS

RLE, LSR, LMR, and rrT1 all correlated significantly with ICG-R15-estimated hepatic functional reserve. The four indices represent a promising imaging biomarker in the prediction of liver functional reserve.

The Early-Enhancing Hepatic Vein: Differentiating Focal Nodular Hyperplasia and Hepatic Adenoma With Pathologic Validation in MRI

BACKGROUND

Focal nodular hyperplasia (FNH) and hepatic adenoma (HA) are two common benign liver lesions with different management options. In particular, resection is considered for large HA lesions to avoid possible bleeding complications or rarely malignant degeneration.

PURPOSE

To determine whether early enhancement of a draining hepatic vein (EDHV) and absence of perilesional enhancement (PLE) on arterial phase MR images are useful for distinguishing FNH from HA.

STUDY TYPE

Retrospective.

POPULATION

A total of 34 patients: 16 with FNH and 18 with HA lesions.

FIELD STRENGTH/SEQUENCE

A1.5 T, axial T1 fat-suppressed arterial postcontrast.

ASSESMENT

Four abdominal radiologists blinded to pathologic diagnosis assessed for the presence or absence of EDHV in association with the lesion, definitively characterized by pathology. This was considered present if contrast could be identified in a hepatic vein contiguous with the lesion in question. Secondarily, PLE was evaluated.

STATISTICAL TESTS

Fleiss's multirater kappa statistic, Chi-squared statistic, Phi-coefficient. Significance level P < 0.05.

RESULTS

Considering all observations obtained from the four readers, an EDHV was identified with FNH 48.5% of the time. EDHV was seen with HA in 8.8% of cases. PLE was seen with significantly greater frequency in HA. The presence of an EDHV was associated with the absence of PLE.

DATA CONCLUSION

In a lesion that may be either an FNH or HA, confident identification on arterial phase images of an EDHV should lead the reader to favor FNH, while the presence PLE should dissuade the reader from FNH.

EVIDENCE LEVEL

4.

TECHNICAL EFFICACY

Stage 2.

Exploring the therapeutic potential of a nano micelle containing a carbon monoxide-releasing molecule for metabolic-associated fatty liver disease by modulating hypoxia-inducible factor-1α

Metabolic-associated fatty liver disease (MAFLD) encompasses a spectrum of chronic liver diseases, including steatohepatitis, cirrhosis, and liver cancer. Despite the increasing prevalence and severity of MAFLD, no approved pharmacological interventions are currently available. Hypoxia-inducible factor-1α (HIF-1α) has emerged as a crucial early mediator in the pathogenesis of MAFLD. Previously, we demonstrated the potent anti-inflammatory properties of the nano-designed carbon monoxide (CO) donor, styrene maleic acid copolymer (SMA) encapsulating CO-releasing molecule (SMA/CORM2), which effectively suppressed HIF-1α in various inflammatory disorders. Here, we investigated the therapeutic potential of SMA/CORM2 in a mouse model of MAFLD induced by a high-fat methionine- and choline-deficient (HF-MCD) diet. Following 4 weeks of HF-MCD diet consumption, we observed pronounced hepatic lipid accumulation accompanied by disrupted lipid metabolism, polarization of macrophages towards the pro-inflammatory M1 phenotype, activation of the NLRP3 inflammasome, and upregulation of the TGF-β fibrosis signaling pathway. Notably, the early and upstream event driving these pathological changes was the upregulation of HIF-1α. Treatment with SMA/CORM2 (10 mg/kg, three times per week) led to a significant increase in CO levels in both the circulation and liver, resulting in remarkable suppression of HIF-1α expression even before the onset of apparent pathological changes induced by the HF-MCD diet. Consequently, SMA/CORM2 administration exerted a significantly protective and therapeutic effect on MAFLD. In vitro studies using hepatocytes treated with high concentrations of fatty acids further supported these findings, as knockdown of HIF-1α using short hairpin RNA (shRNA) elicited similar effects to SMA/CORM2 treatment. Collectively, our results highlight the therapeutic potential of SMA/CORM2 in the management of MAFLD through suppression of HIF-1α. We anticipate that SMA/CORM2, with its ability to modulate HIF-1α expression, may hold promise for future applications in the treatment of MAFLD. STATEMENT OF SIGNIFICANCE: Carbon monoxide (CO) is a crucial gaseous signaling molecule that plays a vital role in maintaining homeostasis and is a potential target for treating many inflammatory diseases. Developing drug delivery systems that can deliver CO stably and target specific tissues is of great interest. Our team previously developed a nano micellar CO donor, SMA/CORM2, which exhibits superior bioavailability to native CORM2 and shows therapeutic potential in many inflammatory disease models. In this study, we showed that SMA/CORM2, through controlled CO release, significantly ameliorated steatohepatitis and liver fibrosis induced by an HF-MCD diet by suppressing an HIF-1α mediated inflammatory cascade. These findings provide new insight into the anti-inflammatory function of CO and a promising approach for controlling metabolic-associated fatty liver disease.