Protective Effect of Glycyrrhizic Acid on Alcoholic Liver Injury in Rats by Modulating Lipid Metabolism

Hovenia dulcis: a Chinese medicine that plays an essential role in alcohol-associated liver disease

Globally, alcohol-associated liver disease (ALD) has become an increased burden for society. Disulfirams, Benzodiazepines (BZDs), and corticosteroids are commonly used to treat ALD. However, the occurrence of side effects such as hepatotoxicity and dependence, impedes the achievement of desirable and optimal therapeutic efficacy. Therefore, there is an urgent need for more effective and safer treatments. Hovenia dulcis is an herbal medicine promoting alcohol removal clearance, lipid-lowering, anti-inflammatory, and hepatoprotective properties. Hovenia dulcis has a variety of chemical components such as dihydromyricetin, quercetin and beta-sitosterol, which can affect ALD through multiple pathways, including ethanol metabolism, immune response, hepatic fibrosis, oxidative stress, autophagy, lipid metabolism, and intestinal barrier, suggesting its promising role in the treatment of ALD. Thus, this work aims to comprehensively review the chemical composition of Hovenia dulcis and the molecular mechanisms involved in the process of ALD treatment.

Tiaogan Jiejiu Tongluo Formula attenuated alcohol-induced chronic liver injury by regulating lipid metabolism in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Tiaogan Jiejiu Tongluo Formula (TJTF), a traditional Chinese medicine formula, is modified from the well-known ancient prescription Danzhi-Xiaoyao Powder (DXP). Owing to its ability to regulate liver, strengthen spleen, detoxicating, and dredge collaterals in Chinese medicine, TJTF is usually used to treat anxiety, hypertension, alcoholic fatty liver disease in clinical application. However, the protective effect and potential molecular mechanism of TJTF on alcoholic liver injury has not fully been clarified.

AIM OF THE STUDY

To explore the effect of TJTF on chronic alcoholic liver injury and figure out whether its effects were due to the regulation of lipid metabolism.

MATERIAL AND METHODS

75 male SD rats were divided into the following five groups, control group, EtOH group, TJTF high dose group, TJTF low dose group and silybin group. Then a chronic alcoholic liver injury model was established by increasing concentration of 56% ethanol in rats. The rats in each TJTF group were given the corresponding dose of TJTF, the rats in the silybin group were given silybin, the rats in the control group and the EtOH group were given distilled water by gavage, once a day for 8 consecutive weeks. The components of TJTF were analyzed by UPLC-Q-TOF-MS. Hematoxylin and Eosin (H&E) was used to assess the severity of liver injury. in the pathological examination. Periodic acid-Schiff (PAS) and oil red O staining were used to evaluate the degree of the liver glycogen accumulation and lipid deposition, respectively. The serum ALT, AST, T-CHO, TG, LDL-C, ADH, HDL-C, and ALDH levels as well as liver tissue GSH, MDA, and SOD levels were analyzed in rats. Immunohistochemistry and western blotting were used to detect lipid metabolism-related proteins expressed in rat liver.

RESULTS

TJTF significantly alleviated the chronic liver injury caused by alcohol in rats, and enhanced liver function. TJTF significantly decreased AST, ALT, ADH levels and increased ALDH level of serum, and increased GSH, SOD levels and decreased MDA level of liver tissue. In addition, TJTF significantly decreased the serum T-CHO, TG and LDL-C levels and increased HDL-C level in chronic alcoholic liver injury rats by regulating the expression of lipid metabolism associated proteins including p-LKB1, p-AMPKα, p-ACC, FAS, HMGCR, SREBP-1c, PPARα and CPT-1A. The results of western blot and immunohistochemical staining confirmed that TJTF can inhibit lipid production and promote fatty acid oxidation in the liver tissue of chronic alcoholic liver injury rats by activating the LKB1-AMPKα axis and then downregulating the protein expressions of p-ACC, FAS, HMGCR and SREBP-1c, as well as promoting the protein expressions of PPARα and CPT-1A. Meanwhile, TJTF also increased the glycogen content of liver and alleviated the liver damage.

CONCLUSION

According to current research, TJTF is effective in treating chronic liver damage induced by alcohol in rats. Additionally, TJTF exhibits the protective benefits by modulating LKB1-AMPKα signal axis, which in turn inhibits the synthesis of lipids and promotes the oxidation of fatty acids.

Impact of Phytochemicals on PPAR Receptors: Implications for Disease Treatments

Peroxisome proliferator-activated receptors (PPARs) are members of the ligand-dependent nuclear receptor family. PPARs have attracted wide attention as pharmacologic mediators to manage multiple diseases and their underlying signaling targets. They mediate a broad range of specific biological activities and multiple organ toxicity, including cellular differentiation, metabolic syndrome, cancer, atherosclerosis, neurodegeneration, cardiovascular diseases, and inflammation related to their up/downstream signaling pathways. Consequently, several types of selective PPAR ligands, such as fibrates and thiazolidinediones (TZDs), have been approved as their pharmacological agonists. Despite these advances, the use of PPAR agonists is known to cause adverse effects in various systems. Conversely, some naturally occurring PPAR agonists, including polyunsaturated fatty acids and natural endogenous PPAR agonists curcumin and resveratrol, have been introduced as safe agonists as a result of their clinical evidence or preclinical experiments. This review focuses on research on plant-derived active ingredients (natural phytochemicals) as potential safe and promising PPAR agonists. Moreover, it provides a comprehensive review and critique of the role of phytochemicals in PPARs-related diseases and provides an understanding of phytochemical-mediated PPAR-dependent and -independent cascades. The findings of this research will help to define the functions of phytochemicals as potent PPAR pharmacological agonists in underlying disease mechanisms and their related complications.

Rapid identification of chemical components in Zhizi Baipi decoction by ultra performance liquid chromatography quadrupole time-of-flight mass spectrometry coupled with a novel informatics UNIFI platform

Zhizi Baipi Decoction is a classic traditional Chinese medicine formula for the treatment of jaundice and various liver diseases. The chemical components of Zhizi baipi decoction were not clear resulting from the paucity of relevant studies, which hindered the elucidation of the pharmacological mechanism, the comprehensive development and utilization of Zhizi baipi decoction in clinical. In this study, ultra performance liquid chromatography-quadrupole-time of flight mass spectrometry combined with UNIFI natural product information analysis platform was used to rapidly analyze and identify the chemical components in Zhizi baipi decoction. A total of 122 chemical components, including 53 flavonoids, 16 alkaloids, 25 terpenoids, 5 phenylpropanoids, 14 organic acids, and 7 others, were identified from Zhizi baipi decoction. These compounds may be the active components of Zhizi baipi decoction. The method established in this study can systematically, rapidly, and accurately resolve the chemical components in Zhizi baipi decoction, which lays the foundation for further establishment of the pharmacodynamic substance basis and quality control of Zhizi baipi decoction. This article is protected by copyright. All rights reserved.

Rhoifolin Alleviates Alcoholic Liver Disease In Vivo and In Vitro via Inhibition of the TLR4/NF-κB Signaling Pathway

Background: Alcoholic liver disease (ALD) is a common chronic liver disorder worldwide, which is detrimental to human health. A preliminary study showed that the total flavonoids within Citrus grandis “Tomentosa” exerted a remarkable effect on the treatment of experimental ALD. However, the active substances of Citrus grandis “Tomentosa” were not elucidated. Rhoifolin (ROF) is a flavonoid component present in high levels. Therefore, this research aimed to evaluate the hepatoprotective effects of ROF and its possible mechanisms.

Methods: Molecular docking was performed to analyze the binding energy of ROF to the main target proteins related to ALD. Subsequently, mice were fed ethanol (ETH) for 49 days to establish the chronic alcoholic liver injury models. The liver pathological injury, serum aminotransferase levels, and oxidative stress levels in the liver tissue were measured. Human normal hepatocytes (LO2 cells) were incubated with ETH to construct the alcoholic liver cell model. The inflammatory markers and apoptosis factors were evaluated using real-time PCR and flow cytometry. Finally, the effects of ROF on the CYP2E1 and NF-κB signaling pathways were tested in vitro and in vivo.

Results: Molecular docking results demonstrated that ROF was able to successfully dock with the target proteins associated with ALD. In animal studies, ROF attenuated ETH-induced liver damage in mice by decreasing the serum concentrations of AST and ALT, reducing the expression of inflammatory cytokines, and maintaining antioxidant balance in the liver tissue. The in vitro experiments demonstrated that ROF suppressed ETH-induced apoptosis in LO2 cells by promoting Bcl-2 mRNA and inhibiting Bax mRNA and caspase 3 protein expression. ROF decreased the level of LDH, ALT, AST, ROS, and MDA in the supernatant; induced the activity of GSH and SOD; and inhibited TNF-α, IL-6, and IL-1β expression levels. Mechanistically, ROF could significantly downregulate the expression levels of CYP2E1, TLR4, and NF-κB phosphorylation.

Conclusion: This study indicates that ROF is the active component within the total flavonoids, which may alleviate ETH-induced liver injury by inhibiting NF-κB phosphorylation. Therefore, ROF may serve as a promising compound for treating ALD.

The genus Glycyrrhiza (Fabaceae family) and its active constituents as protective agents against natural or chemical toxicities

Licorice is the dried roots and rhizomes of various species of the genus Glycyrrhiza (Fabaceae) that have been used in folk medicine from ancient times. Many important research projects have established several beneficial effects for this medicinal herb, including antiinflammatory, antimicrobial, antiviral, antiprotozoal, antioxidant, antihyperglycemic, antihyperlipidemic, hepatoprotective, and neuroprotective. Licorice contains important bioactive components, such as glycyrrhizin (glycyrrhizic, glycyrrhizinic acid), liquiritigenin, liquiritin, and glycyrrhetinic acid. The protective effects of licorice and its main chemical components against toxins and toxicants in several organs including the brain, heart, liver, kidney, and lung have been shown. In this comprehensive review article, the protective effects of these constituents against natural, industrial, environmental, and chemical toxicities with attention on the cellular and molecular mechanism are introduced. Also, it has been revealed that this plant and its main compounds can inhibit the toxicity of different toxins by the antioxidant, antiinflammatory, and anti-apoptotic properties as well as the modulation of Inhibitor of kappaB kinase (IKK), Extracellular signal-regulated protein kinase1/2 (ERK1/2), p38, inducible nitric oxide synthase, and nuclear factor-κB (NF-κB) signaling pathways. More high-quality investigations in both experimental and clinical studies need to firmly establish the efficacy of licorice and its main constituents against toxic agents.

Identification of anti-inflammatory compounds from Zhongjing formulae by knowledge mining and high-content screening in a zebrafish model of inflammatory bowel diseases

BACKGROUND

Inflammatory bowel diseases (IBD) are chronic relapsing intestinal inflammations with increasing global incidence, and new drug development remains in urgent demand for IBD management. To identify effective traditional Chinese medicine (TCM) formulae and compounds in IBD treatment, we innovatively combined the techniques of knowledge mining, high-content screening and high-resolution mass spectrometry, to conduct a systematic screening in Zhongjing formulae, which is a large collection of TCM prescriptions with most abundant clinical evidences.

METHODS

Using Word2vec-based text learning, the correlations between 248 Zhongjing formulae and IBD typical symptoms were analyzed. Next, from the top three formulae with predicted relationship with IBD, TCM fractions were prepared and screened on a transgenic zebrafish IBD model for their therapeutic effects. Subsequently, the chemical compositions of the fraction hits were analyzed by mass spectrometry, and the major compounds were further studied for their anti-IBD effects and potential mechanisms.

RESULTS

Through knowledge mining, Peach Blossom Decoction, Pulsatilla Decoction, and Gegen Qinlian Decoction were predicted to be the three Zhongjing formulae mostly related to symptoms typical of IBD. Seventy-four fractions were prepared from the three formulae and screened in TNBS-induced zebrafish IBD model by high-content analysis, with the inhibition on the intestinal neutrophil accumulation and ROS level quantified as the screening criteria. Six herbal fractions showed significant effects on both pathological processes, which were subsequently analyzed by mass spectrometry to determine their chemical composition. Based on the major compounds identified by mass spectrometry, a second-round screen was conducted and six compounds (palmatine, daidzin, oroxyloside, chlorogenic acid, baicalin, aesculin) showed strong inhibitory effects on the intestinal inflammation phenotypes. The expression of multiple inflammatory factors, including il1β, clcx8a, mmp and tnfα, were increased in TNBS-treated fish, which were variously inhibited by the compounds, with aesculin showing the most potent effects. Moreover, aesculin and daidzin also upregulated e-cadherin's expression.

CONCLUSION

Taken together, we demonstrated the regulatory effects of several TCM formulae and their active compounds in the treatment of IBD, through a highly efficient research strategy, which can be applied in the discovery of effective TCM formulae and components in other diseases.

Research progress on the protective effects of licorice-derived 18β-glycyrrhetinic acid against liver injury

The first description of the medical use of licorice appeared in "Shennong Bencao Jing", one of the well-known Chinese herbal medicine classic books dated back to 220-280 AD. As one of the most commonly prescribed Chinese herbal medicine, licorice is known as "Guo Lao", meaning "a national treasure" in China. Modern pharmacological investigations have confirmed that licorice possesses a number of biological activities, such as antioxidation, anti-inflammatory, antiviral, immune regulation, and liver protection. 18β-glycyrrhetinic acid is one of the most extensively studied active integrants of licorice. Here, we provide an overview of the protective effects of 18β-glycyrrhetinic acid against various acute and chronic liver diseases observed in experimental models, and summarize its pharmacological effects and potential toxic/side effects at higher doses. We also make additional comments on the important areas that may warrant further research to support appropriate clinical applications of 18β-glycyrrhetinic acid and avoid potential risks.

Glycyrrhizin improves bone metabolism in ovariectomized mice via inactivating NF-κB signaling

OBJECTIVES

Postmenopausal osteoporosis (PMO) is a prevalent metabolic bone disease with high morbidity and serious complications. Here, we studied the effect of glycyrrhizin on bone metabolism using the ovariectomized (OVX) mouse model.

METHODS

Osteoclast-related gene expression and osteoclastic function were evaluated in RAW264.7 cells and bone marrow-derived monocytes (BMMs) by real-time polymerase chain reaction and bone resorption assay. For animal studies, female C57BL/6J mice were randomly divided into sham operated, OVX and OVX with glycyrrhizin groups. Bone mass and trabecular microarchitecture were analyzed by micro-computed tomography, dual X-ray absorptiometry, and histomorphometric analysis. Receptor activator of nuclear factor-κB (NF-κB) ligand-induced osteoclastogenesis and the NF-κB signaling pathway were studied by tartrate-resistant acid phosphatase staining and western blotting, respectively.

RESULTS

Glycyrrhizin inhibits RANKL-induced expression of Nfatc-1, c-Fos, Trap, Ds-stamp, and Ctsk in RAW264.7 cells. Also, fewer bone resorption pits form when BMMs are incubated in the presence of glycyrrhizin. Glycyrrhizin ameliorates bone loss and improves trabecular bone parameters in OVX mice. BMMs isolated from OVX mice show higher ability of RANKL-induced osteoclastogenesis, which is tremendously reversed by glycyrrhizin. There is significantly higher phosphorylation of IκB-α at Ser32 and NF-κB p65 at Ser536, as well as increased protein levels of c-FOS and NFATc-1 in BMMs of OVX mice, which are all greatly suppressed by glycyrrhizin.

CONCLUSIONS

Our findings imply that glycyrrhizin is a potential efficient adjuvant therapeutic for PMO.

Glycyrrhizic acid protects juvenile epileptic rats against hippocampal damage through activation of Sirtuin3

Glycyrrhizic acid (GA) and Sirtuin3 (Sirt3) were both found to be involved in epilepsy (EP), but their interaction was rarely studied. Herein, we aim to investigate the underlying mechanism of GA with the interaction of Sirt3 in juvenile EP rats. The EP model in juvenile rats was established by lithium chloride-pilocarpine and treated with different concentrations of GA, GA + DMSO or GA + 3-TYP [a selective inhibitor of Sirtuin3 (Sirt3)]. The expression of Sirt3, mitochondrial autophagy-related genes (C-III core 1, COX IV, LC3-I, LC3-II), apoptosis-related genes (Bcl-2, Bax, Caspase-3), glutathione (GSH), superoxide dismutase (SOD), malondialchehyche (MDA) and reactive oxygen species (ROS) as well as mitochondrial membrane potential were subsequently detected. The juvenile EP rats treated with GA showed increased level of C-III core 1 and COX IV, increased LC3-I/LC3-II, GSH and SOD, decreased MDA, increased expression of Sirt3, and Bcl-2, and decreased expression of Bax and Caspase-3. However, inhibition of Sirt3 caused reverse results. Collectively, GA could alleviate hippocampal pathological damage, promote mitochondrial autophagy and reduce oxidative stress in juvenile EP rats through activation of Sirt3. Understanding of these mechanisms may allow devising of novel therapeutics for pediatric EP.

Natural limonoids protect mice from alcohol-induced liver injury

Background Alcoholic liver disease (ALD) is regarded as a global health problem with limited therapeutic options. Previous studies highlighted some anticancer, antiviral, and hepatoprotective activities of limonoids, but the effects of these compounds on ALD remain unknown. The present study aimed to evaluate the effect of some natural limonoids on ethanol-induced liver injury. Methods Thirty-five albino mice (Mus musculus) were administered with 40% ethanol in the presence or absence of the different limonoids [including three havanensin-type limonoids, TS1, TS3, Rubescin D isolated from an African medicinal plant, Trichilia rubescens Oliv. (Meliaceae), and one limonin], or silymarin at 50 mg/kg for 3 days. Thereafter, the effect of the most active compound was evaluated in a chronic model of ALD. For this purpose, 24 mice with each group consisting of six mice were administered orally with 40% ethanol and limonoid at different doses (50, 75, and 100 mg/kg) for 28 days. Finally, biochemical parameters such as alanine aminotransferase (ALT), superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), triglyceride (TG), and tumor necrosis factor α (TNF-α) levels were quantified in liver homogenates. Results All tested limonoids significantly (p < 0.01) reduced ALT levels relative to the negative control in the acute model. However, in comparison to other limonoids, limonin at 50 and 75 mg/kg significantly reduced TG, MDA, and TNF-α levels (1.8-fold); alleviated leukocyte infiltration in liver tissue; significantly increased the activity of SOD; and decreased those of CAT better than silymarin used as a positive control at 50 mg/kg. Conclusions These data suggest that limonin possesses protective effects on long-term alcohol poisoning partially due to antioxidant and anti-inflammatory mechanisms.

Glycyrrhizic-Acid-Based Carbon Dots with High Antiviral Activity by Multisite Inhibition Mechanisms

With the gradual usage of carbon dots (CDs) in the area of antiviral research, attempts have been stepped up to develop new antiviral CDs with high biocompatibility and antiviral effects. In this study, a kind of highly biocompatible CDs (Gly-CDs) is synthesized from active ingredient (glycyrrhizic acid) of Chinese herbal medicine by a hydrothermal method. Using the porcine reproductive and respiratory syndrome virus (PRRSV) as a model, it is found that the Gly-CDs inhibit PRRSV proliferation by up to 5 orders of viral titers. Detailed investigations reveal that Gly-CDs can inhibit PRRSV invasion and replication, stimulate antiviral innate immune responses, and inhibit the accumulation of intracellular reactive oxygen species (ROS) caused by PRRSV infection. Proteomics analysis demonstrates that Gly-CDs can stimulate cells to regulate the expression of some host restriction factors, including DDX53 and NOS3, which are directly related to PRRSV proliferation. Moreover, it is found that Gly-CDs also remarkably suppress the propagation of other viruses, such as pseudorabies virus (PRV) and porcine epidemic diarrhea virus (PEDV), suggesting the broad antiviral activity of Gly-CDs. The integrated results demonstrate that Gly-CDs possess extraordinary antiviral activity with multisite inhibition mechanisms, providing a promising candidate for alternative therapy for PRRSV infection.

Microparticle-enhanced Chaetomium globosum DX-THS3 β-d-glucuronidase production by controlled fungal morphology in submerged fermentation

Glycyrrhetinic acid monoglucuronide (GAMG) is a novel and low-calorie sweetener that is widely applied in the food industry. This study aimed to enhance the production of fungal β-d-glucuronidase (GUS) via a novel fermentation technique by evaluating the effects of the various microparticles on Chaetomium globosum DX-THS3 GUS production. Results showed that the silica microparticle greatly affected the morphology of DX-THS3 strain relative to the other microparticles. Microbial structure imaging results showed that the smallest average diameter of fungal pellets was achieved (0.7 ± 0.1 mm) by adding 10 g/L (600 mesh) of silica. The diameter of the control was 3.0 ± 0.5 mm in shake flask fermentation. The GUS activity and biomass of DX-THS3 reached 680 U/mL and 4.2 g/L, respectively, with the use of 10 g/L of silica microparticles, whereas those of the control were 210 U/mL and 2.8 g/L via shake flask fermentation. The findings in this study may provide a potential strategy for designing the morphology of filamentous fungi using microparticles in the industrial production of GAMG.

Formulation of injectable glycyrrhizic acid-hydroxycamptothecin micelles as new generation of DNA topoisomerase I inhibitor for enhanced antitumor activity

To develop a new drug delivery system is one of the useful approaches to break through the limitation of hydroxycamptothecin (HCPT), a typical DNA topoisomerase I (Topo I) inhibitor in clinical appliance. Injectable glycyrrhizic acid-hydroxycamptothecin (GL-HCPT) micelles that were able to dramatically improve the solubility and stability of HCPT were prepared through self-assembly process and evaluated both in vitro and in vivo. With a mean particle size (PS) of 105.7 ± 9.7 nm and a drug loading (DL) of 9.0 ± 1.5%, GL-HCPT micelles were rapidly internalized by HepG2 cells after 1 h, significantly increasing the intracellular accumulation of HCPT. Compared with the current used HCPT injection and HCPT/GL physical mixture, GL-HCPT micelles showed enhanced antitumor activity against liver cancer cells (HepG2 and Huh7) as well as a superior suppression on the tumor growth of HepG2 tumor bearing mice. Interestingly, GL-HCPT micelles gathered in liver and simultaneously reduced the drug accumulation in normal tissues, thereby exhibiting minimal cytotoxicity to human normal liver cells (LO2). Therefore, we offered a convenient and cost-effective strategy to construct an intravenous drug delivery system (GL-HCPT micelles) as new generation of DNA Topo I inhibitor for enhanced cancer chemotherapy.

Natural products in licorice for the therapy of liver diseases: Progress and future opportunities

Liver diseases related complications represent a significant source of morbidity and mortality worldwide, creating a substantial economic burden. Oxidative stress, excessive inflammation, and dysregulated energy metabolism significantly contributed to liver diseases. Therefore, discovery of novel therapeutic drugs for the treatment of liver diseases are urgently required. Licorice is one of the most commonly used herbal drugs in Traditional Chinese Medicine for the treatment of liver diseases and drug-induced liver injury (DILI). Various bioactive components have been isolated and identified from the licorice, including glycyrrhizin, glycyrrhetinic acid, liquiritigenin, Isoliquiritigenin, licochalcone A, and glycycoumarin. Emerging evidence suggested that these natural products relieved liver diseases and prevented DILI through multi-targeting therapeutic mechanisms, including anti-steatosis, anti-oxidative stress, anti-inflammation, immunoregulation, anti-fibrosis, anti-cancer, and drug-drug interactions. In the current review, we summarized the recent progress in the research of hepatoprotective and toxic effects of different licorice-derived bioactive ingredients and also highlighted the potency of these compounds as promising therapeutic options for the treatment of liver diseases and DILI. We also outlined the networks of underlying molecular signaling pathways. Further pharmacology and toxicology research will contribute to the development of natural products in licorice and their derivatives as medicines with alluring prospect in the clinical application.

Dihydromyricetin alleviates acetaminophen-induced liver injury via the regulation of transformation, lipid homeostasis, cell death and regeneration

AIMS

We previously reported that Hovenia dulcis Thunb. extract, a traditional Chinese medicine rich in dihydromyricetin (DHM), exhibited a significant hepatoprotective effect against acetaminophen (APAP)-induced liver injury. However, whether DHM plays a protective role in APAP hepatotoxicity and what mechanisms are involved remain unclear. In this study, we evaluated the hepatoprotective effects of DHM against APAP-induced liver injury.

MAIN METHODS

Male C57BL/6 mice were used for the experiment. LC-MS, q-PCR, immunochemistry and western blot analysis were employed to mechanism analysis.

KEY FINDINGS

DHM exhibited a protective effect against APAP-induced liver injury. Further mechanistic investigations revealed that the protective effect of DHM against APAP hepatotoxicity had multi-target and multi-pathway characteristics involving APAP metabolism, lipid regulation, and hepatocyte death and regeneration. DHM pretreatment resulted in cytochrome P450 2E1 inhibition and UDP-glucuronosyltransferase 1A1 activation, affecting APAP biotransformation. Moreover, DHM pretreatment significantly ameliorated lipid dysregulation via peroxisome proliferator-activated receptor and sterol regulatory element-binding protein-1c (SREBP-1c) signalling pathways. Furthermore, DHM regulated the expression of cell death- and liver regeneration-associated proteins.

SIGNIFICANCE

These results suggested that DHM alleviated APAP-induced liver injury in mice by inhibiting hepatocyte death, promoting p53-related regeneration, and regulating lipid homeostatic imbalance and APAP transformation. Based on these findings, DHM provides a potential and novel approach for preventing and treating APAP-induced liver damage, and SREBP-1c signalling might be a new therapeutic target for APAP hepatotoxicity.

Retraction: Zhao et al. Protective Effect of Glycyrrhizic Acid on Alcoholic Liver Injury in Rats by Modulating Lipid Metabolism. Molecules 2018, 23(7), 1623

As the authors of the title paper [...]

Glycyrrhizin protects against sodium iodate-induced RPE and retinal injury though activation of AKT and Nrf2/HO-1 pathway

Glycyrrhizin is a bioactive triterpenoid saponin extracted from a traditional Chinese medicinal herb, glycyrrhiza, and has been reported to protect the organs such as liver and heart from injuries. However, there is no report about the effects of glycyrrhizin on atrophic age‐related macular degeneration (AMD). This study investigated the effects of glycyrrhizin on retinal pigment epithelium (RPE) in vitro and retina of mice in vivo treated with sodium iodate (SI). Glycyrrhizin significantly inhibited SI‐induced reactive oxygen species (ROS), and decreased apoptosis of RPE in vitro. The underlying mechanisms included increased phosphorylation of Akt, and increased expression of nuclear factor erythroid 2‐related factor2 (Nrf‐2) and HO‐1, thereby protecting RPE from SI‐induced ROS and apoptosis. Furthermore, glycyrrhizin significantly decreased the apoptosis of retinal cells in vivo, resulting in the inhibition of thinning of retina, decreasing the number of drusen and improving the function of retina. These findings suggested that glycyrrhizin may be a potential candidate for the treatment of atrophic AMD in clinical practice.