Dietary α-Mangostin Provides Protective Effects against Acetaminophen-Induced Hepatotoxicity in Mice via Akt/mTOR-Mediated Inhibition of Autophagy and Apoptosis

Molecular and cellular remodeling of HepG2 cells upon treatment with antitubercular drugs

Drug-induced liver injury (DILI) is an adverse outcome of the currently used tuberculosis treatment regimen, which results in patient noncompliance, poor treatment outcomes, and the emergence of drug-resistant tuberculosis. DILI is primarily caused by the toxicity of the drugs and their metabolites, which affect liver cells, biliary epithelial cells, and liver vasculature. However, the precise mechanism behind the cellular damage attributable to first-line antitubercular drugs (ATDs), as well as the effect of toxicity on the cell survival strategies, is yet to be elucidated. In the current study, HepG2 cells upon treatment with a high concentration of ATDs showed increased perforation within the cell, cuboidal shape, and membrane blebbing as compared with control/untreated cells. It was observed that ATD-induced toxicity in HepG2 cells leads to altered mitochondrial membrane permeability, which was depicted by the decreased fluorescence intensity of the MitoRed tracker dye at higher drug concentrations. In addition, high doses of ATDs caused cell damage through an increase in reactive oxygen species production in HepG2 cells and a simultaneous reduction in glutathione levels. Further, high dose of isoniazid (50-200 mM), pyrazinamide (50-200 mM), and rifampicin (20-100 µM) causes cell apoptosis and affects cell survival during toxic conditions by decreasing the expression of potent autophagy markers Atg5, Atg7, and LC3B. Thus, ATD-mediated toxicity contributes to the reduced ability of hepatocytes to tolerate cellular damage caused by altered mitochondrial membrane permeability, increased apoptosis, and decreased autophagy. These findings further emphasize the need to develop adjuvant therapies that can mitigate ATD-induced toxicity for the effective treatment of tuberculosis.

Chlorogenic acid, rutin, and quercetin from Lysimachia christinae alleviate triptolide-induced multi-organ injury in vivo by modulating immunity and AKT/mTOR signal pathway to inhibit ferroptosis and apoptosis

Drug-induced organ injury is one of the key factors causing organ failure and death in the global public. Triptolide (TP) is the main immunosuppressive component of Tripterygium wilfordii Hook. f. (Leigongteng, LGT) for the first-line management of autoimmune conditions, but it can cause serious multi-organ injury. Lysimachia christinae (Jinqiancao, JQC) is a detoxifying Chinese medicine and could suppress LGT's toxicity. It contains many immune enhancement and organ protection components including chlorogenic acid (CA), rutin (Rut), and quercetin (Que). This study aimed to explore the protection of combined treatments of these organ-protective ingredients of JQC on TP-induced liver, kidney, and heart injury and initially explore the mechanisms. Molecular docking showed that CA, Rut, and Que. bound AKT/mTOR pathway-related molecules intimately and might competitively antagonize TP. Corresponding in vivo results showed that the combination activated TP-inhibited protein of AKT/mTOR pathway, and reversed TP-induced excessive ferroptosis (excessive Fe ²⁺ and lipid peroxidation malondialdehyde accumulation, decreased levels of antioxidant enzymes catalase, glutathione peroxidase, glutathione-s transferase, reduced glutathione, and superoxide dismutase, and down-regulated P62/nuclear factor erythroid-2-related factor 2/heme oxygenase-1 pathway), and apoptosis (activated apoptotic factor Fas and Bax and inhibited Bcl-2) in the organ of mice to varying degrees. In conclusion, the combined treatments of CA, Rut, and Que. from JQC inhibited TP-induced multi-organ injury in vivo, and the mechanism may largely involve immunomodulation and activation of the AKT/mTOR pathway-mediated cell death reduction including ferroptosis and apoptosis inhibition.

Antidotal and protective effects of mangosteen (Garcinia mangostana) against natural and chemical toxicities: A review

Chemical and natural toxic compounds can harm human health through a variety of mechanisms. Nowadays, herbal therapy is widely accepted as a safe method of treating toxicity. Garcinia mangostana (mangosteen) is a tree in the Clusiaceae family, and isoprenylated xanthones, its main constituents, are a class of secondary metabolites having a variety of biological properties, such as anti-inflammatory, anti-oxidant, pro-apoptotic, anti-proliferative, antinociceptive, neuroprotective, hypoglycemic, and anti-obesity. In this review, the protective activities of mangosteen and its major components against natural and chemical toxicities in both in vivo and in vitro experiments were evaluated. The protective effects of mangosteen and its components are mediated primarily through oxidative stress inhibition, a decrease in the number of inflammatory cells such as lymphocytes, neutrophils, and eosinophils, reduction of inflammatory mediators such as tumor necrosis factor-alpha (TNF-α), interleukin-1 (IL-1), interleukin-6 (IL-6), interleukin-8 (IL-8), cyclooxygenase-2 (COX-2), prostaglandin (PG) E2, inducible nitric oxide synthase, and nuclear factor-ĸB (NF-ĸB), modulation of apoptosis and mitogen-activated protein kinase (MAPK) signaling pathways, reducing p65 entrance into the nucleus, α-smooth muscle actin (α-SMA), transforming growth factor β1 (TGFβ1), improving histological conditions, and inhibition in acetylcholinesterase activity.

Natural-Product-Mediated Autophagy in the Treatment of Various Liver Diseases

Autophagy is essential for the maintenance of hepatic homeostasis, and autophagic malfunction has been linked to the pathogenesis of substantial liver diseases. As a popular source of drug discovery, natural products have been used for centuries to effectively prevent the progression of various liver diseases. Emerging evidence has suggested that autophagy regulation is a critical mechanism underlying the therapeutic effects of these natural products. In this review, relevant studies are retrieved from scientific databases published between 2011 and 2022, and a novel scoring system was established to critically evaluate the completeness and scientific significance of the reviewed literature. We observed that numerous natural products were suggested to regulate autophagic flux. Depending on the therapeutic or pathogenic role autophagy plays in different liver diseases, autophagy-regulative natural products exhibit different therapeutic effects. According to our novel scoring system, in a considerable amount of the involved studies, convincing and reasonable evidence to elucidate the regulatory effects and underlying mechanisms of natural-product-mediated autophagy regulation was missing and needed further illustration. We highlight that autophagy-regulative natural products are valuable drug candidates with promising prospects for the treatment of liver diseases and deserve more attention in the future.

The metabolic and molecular mechanisms of α‑mangostin in cardiometabolic disorders (Review)

α-mangostin is a xanthone predominantly encountered in Garcinia mangostana. Extensive research has been carried out concerning the effects of this compound on various diseases, including obesity, cancer and metabolic disorders. The present review suggests that α-mangostin exerts promising anti-obesity, hepatoprotective, antidiabetic, cardioprotective, antioxidant and anti-inflammatory effects on various pathways in cardiometabolic diseases. The anti-obesity effects of α-mangostin include the reduction of body weight and adipose tissue size, the increase in fatty acid oxidation, the activation of hepatic AMP-activated protein kinase and Sirtuin-1, and the reduction of peroxisome proliferator-activated receptor γ expression. Hepatoprotective effects have been revealed, due to reduced fibrosis through transforming growth factor-β 1 pathways, reduced apoptosis and steatosis through reduced sterol regulatory-element binding proteins expression. The antidiabetic effects include decreased fasting blood glucose levels, improved insulin sensitivity and the increased expression of GLUT transporters in various tissues. Cardioprotection is exhibited through the restoration of cardiac functions and structure, improved mitochondrial functions, the promotion of M2 macrophage populations, reduced endothelial and cardiomyocyte apoptosis and fibrosis, and reduced acid sphingomyelinase activity and ceramide depositions. The antioxidant effects of α-mangostin are mainly related to the modulation of antioxidant enzymes, the reduction of oxidative stress markers, the reduction of oxidative damage through a reduction in Sirtuin 3 expression mediated by phosphoinositide 3-kinase/protein kinase B/peroxisome proliferator-activated receptor-γ coactivator-1α signaling pathways, and to the increase in Nuclear factor-erythroid factor 2-related factor 2 and heme oxygenase-1 expression levels. The anti-inflammatory effects of α-mangostin include its modulation of nuclear factor-κB related pathways, the suppression of mitogen-activated protein kinase activation, increased macrophage polarization to M2, reduced inflammasome occurrence, increased Sirtuin 1 and 3 expression, the reduced expression of inducible nitric oxide synthase, the production of nitric oxide and prostaglandin E2, the reduced expression of Toll-like receptors and reduced proinflammatory cytokine levels. These effects demonstrate that α-mangostin may possess the properties required for a suitable candidate compound for the management of cardiometabolic diseases.

Polyvinylpyrrolidone-Modified Taxifolin Liposomes Promote Liver Repair by Modulating Autophagy to Inhibit Activation of the TLR4/NF-κB Signaling Pathway

Taxifolin (TAX) is a hepatoprotective flavanol compound, which is severely limited by poor solubility and low bioavailability. Liposomes (Lips) are used as well-recognized drug carrier systems that improve the water solubility and bioavailability of drugs, but are easily damaged by gastric juice after oral administration, resulting in the release of drugs in the gastric juice. Therefore, it is important to find materials that modify liposomes and avoid the destruction of the liposomal phospholipid bilayer structure by the gastrointestinal environment. Taxifolin liposomes (TAX-Lips) were modified by polyvinylpyrrolidone-k30 (PVP-TAX-Lips) and manufactured using a thin-film hydration technique. Particle size (109.27 ± 0.50 nm), zeta potential (−51.12 ± 3.79 mV), polydispersity coefficient (PDI) (0.189 ± 0.007), and EE (84.7 ± 0.2%) of PVP-TAX-Lips were studied. In addition, the results of in vitro release experiments indicated that the cumulative release rates of TAX-Lips and PVP-TAX-Lips were 89.73 ± 5.18% and 65.66 ± 4.86% in the simulated gastric fluid after 24 h, respectively, while the cumulative release rates were 68.20 ± 4.98% and 55.66 ± 3.92% in the simulated intestinal fluid after 24 h, respectively. Moreover, PVP-TAX-Lips were able to reverse lipopolysaccharide and D-galactosamine (LPS/D-GalN)-induced acute liver injury (ALI) by inducing autophagy to inhibit the expression levels of the TLR4/NF-κB signaling pathway and inflammatory factors, which suggested that PVP-TAX-Lips played an important role in the prevention of ALI and also provided a promising drug delivery system for the application of TAX.

Effect of alpha-mangostin on olanzapine-induced metabolic disorders in rats

Objectives

As olanzapine has side effects such as weight gain and metabolic disorders, and alpha-mangostin has been shown to control metabolic disorders, the effects of alpha-mangostin on metabolic disorders induced by olanzapine were investigated in this study.

Materials and Methods

Obesity was induced in female Wistar rats by daily administration of olanzapine (5 mg/kg/day, IP, 14 days). Rats were divided into 6 groups:1) vehicle (control); 2) olanzapine (5 mg/kg/day); 3,4,5) olanzapine+ alpha-mangostin (10, 20, 40 mg/kg/day, IP); 6) alpha-mangostin (40 mg/kg/day). Weight changes were measured every 3 days and food intake was assessed every day. Systolic blood pressure, plasma levels of blood sugar, triglycerides, total cholesterol, HDL, LDL, leptin, oxidative stress markers (MDA, GSH), AMPK, and P-AMPK protein levels in liver tissue were assessed on the last day of the study.

Results

Administration of olanzapine significantly increased weight gain, food intake, blood pressure, triglycerides, LDL, blood sugar, leptin, and MDA in rat liver tissue and also decreased GSH, AMPK, and P-AMPK in liver tissue compared with the control group. Different doses of alpha-mangostin significantly reduced weight gain, food intake, systolic blood pressure, triglycerides, LDL, blood sugar, leptin, and MDA. Also, they significantly increased GSH, AMPK, and P-AMPK in liver tissue compared with the olanzapine group.

Conclusion

Olanzapine increases leptin levels, food intake, and weight, induces oxidative stress, decreases the levels of AMPK and P-AMPK proteins in liver tissue, and causes metabolic disorders. But, alpha-mangostin reduces the negative effects of olanzapine by activation of AMPK.

Liquiritigenin protects against arsenic trioxide-induced liver injury by inhibiting oxidative stress and enhancing mTOR-mediated autophagy

Liquiritigenin (LQ) has protective effects against various hepatotoxicities. However, its specific role on arsenic trioxide (ATO)-induced hepatotoxicity and the related biomolecular mechanisms remain unclear. The purpose of this study is to explore the protective actions of LQ on ATO-induced hepatotoxicity and its biomolecular mechanisms in mice. LQ was administered orally at 20 and 40 mg/kg per day for seven consecutive days with an intraperitoneal injection of ATO (5 mg/kg). Liver injury was induced by ATO and was alleviated by treatment with LQ as reflected by reduced histopathological damage of liver and decreased serum ALT, AST, and ALP levels. The generation of intracellular ROS induced by ATO was attenuated after LQ treatment. The levels of SOD, CAT, and GSH were elevated with LQ administration while MDA levels decreased. LQ mitigated elevated TNF-α and IL-6 levels as well as the hepatic mitochondrial damage caused by ATO. Moreover, LQ upregulated the expression of LC3-II and enhanced autophagy in the liver of ATO-induced mice. Further studies indicated that LQ significantly suppressed the expression of p-PI3K, p-AKT, and p-mTOR in ATO-induced mice. In conclusion, our findings show that LQ protects against ATO-induced hepatotoxicity due to its antioxidant and anti-inflammatory activities and enhancement of autophagy mediated by the PI3K/AKT/mTOR signaling pathway in mice.

Hepatotoxic effect of tramadol and O-desmethyltramadol in HepG2 cells and potential role of PI3K/AKT/mTOR

1. The aim of this study was to compare the in vitro cytotoxic effect of tramadol and M1 metabolite in HepG2 cell line, the underlying mechanism, and PI3K/AKT/mTOR as potential target.2. Concentrations representing therapeutic level for tramadol (2 µM) and M1 metabolite (0.5 µM) were used. In addition, other increasing concentrations representing higher toxic levels were used (6, 10 µM for tramadol and 1.5, 2.5 µM for M1 metabolites). Cytotoxicity was assessed at 24, 48 and 72 h.3. Both tramadol and M1 metabolites were able to produce cytotoxicity in a dose and time dependent manner. Insignificant difference was detected between cells exposed to tramadol and M1 metabolite at therapeutic concentrations. Tramadol-induced apoptotic and autophagic cell death while M1 metabolite-induced apoptosis only. For PI3K/AKT/mTOR pathway, the therapeutic concentration of tramadol was only able to increase phosphorylation of AKT while higher toxic concentrations were able to increase phosphorylation of whole pathway; Meanwhile, M1 metabolite was able to increase the phosphorylation of the whole pathway significantly in therapeutic and toxic concentrations.4. In conclusion, both tramadol and M1 are equally cytotoxic. Apoptosis and autophagy both mediate hepatic cell death. PI3K/AKT pathway is involved in apoptosis induction while autophagy is regulated through mTOR independent pathway.

Role of gambogenic acid in regulating PI3K/Akt/NF-kβ signaling pathways in rat model of acute hepatotoxicity

The purpose of this study is to investigate the protective effect of gambogenic acid (GA) in acetaminophen (APAP)-induced hepatotoxicity in rat models. GA (10 mg/kg) was administered intraperitoneal (i.p.) to rats for 7 consecutive days followed by APAP (500 mg/kg) single dose (i.p.) on the final day after GA administration. The levels of MDA, GSH, SOD, CAT, GPx, GST, ALP, AST, ALT, proinflammatory cytokines (TNF-α, IL-1β, IL-6), apoptosis markers (caspase-3 and -9, Bax, Bcl-2), 4-hydroxynonenal (4-HNE), and prostaglandin E2 (PGE2) were evaluated. Results exhibited protective effects of GA by inhibiting inflammation, preventing oxidative stress and apoptosis in APAP-induced liver. Histopathological changes caused by APAP were attenuated, protein expressions of phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) were upregulated, and nuclear factor-kappa β (NF-kβ) was downregulated by GA. In summary, GA significantly exerted anti-inflammatory and antiapoptotic effects against APAP-induced hepatotoxicity potentially through regulation of PI3K/Akt and NF-kβ signaling pathways.

A review on α-mangostin as a potential multi-target-directed ligand for Alzheimer's disease

Alzheimer's disease (AD) is an age-related neurodegenerative disease characterized by progressive memory loss, declining language skills and other cognitive disorders. AD has brought great mental and economic burden to patients, families and society. However due to the complexity of AD's pathology, drugs developed for the treatment of AD often fail in clinical or experimental trials. The main problems of current anti-AD drugs are low efficacy due to mono-target method or side effects, especially high hepatotoxicity. To tackle these two main problems, multi-target-directed ligand (MTDL) based on "one molecule, multiple targets" has been studied. MTDLs can regulate multiple biological targets at the same time, so it has shown higher efficacy, better safety. As a natural active small molecule, α-mangostin (α-M) has shown potential multi-factor anti-AD activities in a series of studies, furthermore it also has a certain hepatoprotective effect. The good availability of α-M also provides support for its application in clinical research. In this work, multiple activities of α-M related to AD therapy were reviewed, which included anti-cholinesterase, anti-amyloid-cascade, anti-inflammation, anti-oxidative stress, low toxicity, hepatoprotective effects and drug formulation. It shows that α-M is a promising candidate for the treatment of AD.

Cytotoxic and Antiproliferative Effects of β-Mangostin on Rat C6 Glioma Cells Depend on Oxidative Stress Induction via PI3K/AKT/mTOR Pathway Inhibition

Background

Glioma is the most common malignant tumor of the nervous system, which accounts for more than 45% of central nervous system tumors and seriously threatens our health. Because of high mortality rate, limitations, and many complications of traditional treatment methods, new treatment methods are urgently needed. β-Mangostin is a natural compound derived from the fruit of Garcinia mangostana L. and it has anticancer activity in several types of cancer cells. However, the antitumor effect of β-mangostin in glioma has not been clarified. Hence, this study aimed to investigate its therapeutic effects on gliomas.

Materials and Methods

To study the effect of β-mangostin on glioma cells, cell viability assay, reactive oxygen species production, cell cycle, apoptosis, and mitochondrial membrane potential were evaluated in the C6 cell line in vitro. Immunofluorescence and Western blotting were used to analyze protein expression and phosphorylation to study its mechanism of action. A subcutaneous xenograft model was used to investigate the effect of β-mangostin on tumorigenesis in vivo.

Results

We found that β-mangostin can inhibit glioma cell growth and induce oxidative damage in vitro. In addition, it reduces the phosphorylated form levels of PI3K, AKT and mTOR. Furthermore, the phosphorylated form levels of PI3K, AKT and mTOR were increased after the PI3K inhibitor was added. In vivo experiments showed that β-mangostin can inhibit tumor growth as shown by its reduced size and weight.

Conclusion

This study suggests that β-mangostin can inhibit cell proliferation and induce oxidative damage in cells. It is the first study to demonstrate that β-mangostin induces oxidative damage in glioma cells by inhibiting the PI3K/AKT/mTOR signaling pathway.

α-Mangostin, a Dietary Xanthone, Exerts Protective Effects on Cisplatin-Induced Renal Injury via PI3K/Akt and JNK Signaling Pathways in HEK293 Cells

Previous report has confirmed the beneficial effects of α-mangostin (α-MG), a major and representative xanthone distributed in mangosteen (Garcinia mangostana) on the cisplatin-induced rat model. However, the molecular mechanisms related to its renoprotection have not been elucidated exhaustively. The present study investigated the protective effect of α-MG against cisplatin-induced cytotoxicity in the human embryonic kidney (HEK293) cell model. In this study, α-MG prevented cisplatin-induced cell death, accompanied with the decreased levels of malondialdehyde and increased glutathione content. Particularly, α-MG significantly suppressed the overproduction of reactive oxygen species (ROS), restored the activation of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt), and downregulated the c-JUN N-terminal kinase (JNK) pathways following cisplatin challenge. Subsequently, the cleavage of caspases and poly-ADP-ribose polymerase (PARP) implicating ROS-mediated apoptosis pathways induced by cisplatin was effectively inhibited by α-MG. In conclusion, our findings provided a rationale for the development of α-MG to attenuate cisplatin-induced nephrotoxicity.

Autophagy regulation is an effective strategy to improve the prognosis of chemically induced acute liver injury based on experimental studies

Acute liver injury (ALI) induced by chemicals in current experimental studies is characterized by inflammation, oxidative stress and necrosis, which can greatly influence the long-term outcome and lead to liver failure. In liver cells, different autophagy forms envelop cytoplasm components, including proteins, endoplasmic reticulum (ER), mitochondria and lipids, and they effectively participate in breaking down the cargo enclosed inside lysosomes to replenish cellular energy and contents. In general, autophagy serves as a cell survival mechanism in stressful microenvironments, but it also serves as a destructive mechanism that results in cell death in vitro and in vivo. In experimental animals, multiple chemicals are used to mimic ALI in patients to clarify the potential pathological mechanisms and develop effective strategies in the clinic. In this review, we summarize related publications about autophagy modulation to attenuate chemically induced ALI in vitro and in vivo. We also analysed the underlying mechanisms of autophagy regulators and genetic modifications to clarify how to control autophagy to protect against chemically induced ALI in animal models. We anticipate that selectively controlling the dual effects of hepatic autophagy will help to protect against ALI in various animals, but the detailed mechanisms and effects should be determined further in future studies. In this way, we are more confident that modulating autophagy in liver regeneration can improve the prognosis of ALI.

The PI3K/Akt and NF-κB signaling pathways are involved in the protective effects of Lithocarpus polystachyus (sweet tea) on APAP-induced oxidative stress injury in mice

Acetaminophen (APAP)-induced acute liver injury (ALI) is a health issue that has gradually attracted attention, and is often regarded as a model of drug-induced hepatotoxicity. The leaves of Lithocarpus polystachyus Rehd. (named as “sweet tea”, ST) usually serve as tea drink and folk medicine for healthcare in the southwest part of China. In previous reports, it has been proven to protect various animal models, except for APAP-induced liver injury model. Therefore, this study initially explored the protective effect of ST leaf extract (STL-E) on hepatotoxicity induced by APAP in ICR mice. STL-E of 50 and 100 mg kg⁻¹ were given to each group for 7 days. ALI was intraperitoneally induced by APAP treatment (i.p. 250 mg per kg body weight). Biochemical markers, levels of inflammatory factors, histopathological staining and western blotting were used to analyze the inflammation and apoptosis of liver tissues. Interestingly, the treatment with STL-E significantly attenuated APAP-induced liver injury (p < 0.05). Moreover, STL-E partially mitigated APAP-induced liver injury by effectively activating the PI3K/Akt pathway and inhibiting the NF-κB pathway. In a word, STL-E protected liver against APAP-induced hepatotoxicity by inhibiting the PI3K/Akt-mediated apoptosis signal pathway and inhibiting the NF-κB-mediated signaling pathway.

Acetaminophen (APAP)-induced acute liver injury (ALI) is a health issue that has gradually attracted attention, and is often regarded as a model of drug-induced hepatotoxicity.

CXCL9 regulates acetaminophen-induced liver injury via CXCR3

Drug-induced liver injury has become a serious public health problem. Although the mechanism of acetaminophen (APAP)-induced liver injury has been studied for decades it has not been fully elucidated. In-depth study into the mechanisms underlying APAP-induced liver injury may provide useful information for more effective prevention and treatment. In the present study, the role of C-X-C motif chemokine ligand-9 (CXCL9) in APAP-induced liver injury was investigated thus providing a novel direction for the prevention and treatment of drug hepatitis. A total of 20 fasting male patients ingested APAP tablets at Nanjing First Hospital. In addition, wild type (WT) mice were treated with 250 mg/kg APAP or isodose PBS for 1, 3, 6 and 12 h, respectively. Results from reverse-transcription-quantitative polymerase chain reaction analyses demonstrated that CXCL9 mRNA levels were increased in the blood of patients who took APAP in a fasting state and in the livers of APAP-treated WT mice, compared with their respective controls. Hepatocyte apoptosis in the liver tissue of APAP-treated mice decreased following administration of a CXCL9 neutralizing antibody. Caspase-3, caspase-8 and phosphorylated-AKT (S437) were activated in primary hepatocytes isolated from WT mice following CXCL9 treatment. However, no significant differences in expression of caspase-3, caspase-8 and p-AKT (S437) were detected in hepatocytes isolated from C-X-C motif chemokine receptor 3 (CXCR3)^−/− mice following CXCL9 treatment. After CXCL9 administration, WT mice exhibited higher serum levels of aspartate transaminase and increased caspase-3 and caspase-8 activity in liver tissue compared with controls. The same trends were not observed in CXCR3^−/− mice. In conclusion, CXCL9 regulated APAP-induced liver injury through stimulation of hepatocyte apoptosis via binding to CXCR3. These findings provide a novel prevention and treatment strategy for DILI.

Maltol Improves APAP-Induced Hepatotoxicity by Inhibiting Oxidative Stress and Inflammation Response via NF-κB and PI3K/Akt Signal Pathways

Maltol, a food-flavoring agent and Maillard reaction product formed during the processing of red ginseng (Panax ginseng, C.A. Meyer), has been confirmed to exert a hepatoprotective effect in alcohol-induced oxidative damage in mice. However, its beneficial effects on acetaminophen (APAP)-induced hepatotoxicity and the related molecular mechanisms remain unclear. The purpose of this article was to investigate the protective effect and elucidate the mechanisms of action of maltol on APAP-induced liver injury in vivo. Maltol was administered orally at 50 and 100 mg/kg daily for seven consecutive days, then a single intraperitoneal injection of APAP (250 mg/kg) was performed after the final maltol administration. Liver function, oxidative indices, inflammatory factors—including serum alanine and aspartate aminotransferases (ALT and AST), tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), liver glutathione (GSH), superoxide dismutase (SOD), malondialdehyde (MDA), cytochrome P450 E1 (CYP2E1) and 4-hydroxynonenal (4-HNE) were measured. Results demonstrated that maltol possessed a protective effect on APAP-induced liver injury. Liver histological changes and Hoechst 33258 staining also provided strong evidence for the protective effect of maltol. Furthermore, a maltol supplement mitigated APAP-induced inflammatory responses by increasing phosphorylated nuclear factor-kappa B (NF-κB), inhibitor kappa B kinase α/β (IKKα/β), and NF-kappa-B inhibitor alpha (IκBα) in NF-κB signal pathways. Immunoblotting results showed that maltol pretreatment downregulated the protein expression levels of the B-cell-lymphoma-2 (Bcl-2) family and caspase and altered the phosphorylation of phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) in a dose-dependent manner. In conclusion, our findings clearly demonstrate that maltol exerts a significant liver protection effect, which may partly be ascribed to its anti-inflammatory and anti-apoptotic action via regulation of the PI3K/Akt signaling pathway.

Ginsenoside Rb3 provides protective effects against cisplatin-induced nephrotoxicity via regulation of AMPK-/mTOR-mediated autophagy and inhibition of apoptosis in vitro and in vivo

Objectives

Based on previous reports that ginsenosides have been shown to exert better preventive effects on cisplatin‐induced kidney injury, the present work aims to evaluate the protective effects of ginsenoside Rb3 (G‐Rb3) on cisplatin‐induced renal damage and underlying mechanisms in vivo and in vitro.

Materials and methods

The protective effect of G‐Rb3 on cisplatin‐induced acute renal failure in ICR mouse model and HEK293 cell model was investigated, and the underlying possible mechanisms were also explored. For animal experiment, renal function, kidney histology, inflammation, oxidative stress, relative protein molecules involved in apoptosis and autophagy signalling pathways were assessed. In addition, rapamycin (a specific inhibitor of mTOR), compound C (a specific inhibitor of AMPK) and acetylcysteine (NAC, a specific ROS scavenger) were employed to testify the effects of AMPK/mTOR signal pathway on the protective effects of G‐Rb3 in HEK293 cells.

Results

Pre‐treatment with G‐Rb3 at doses of 10 and 20 mg/kg for ten days significantly reversed the increases in serum creatinine (CRE), blood urea nitrogen (BUN) and malondialdehyde (MDA), and decrease in glutathione (GSH) content and superoxide dismutase (SOD) activity. Histopathological examination further revealed that G‐Rb3 inhibited cisplatin‐induced nephrotoxicity. G‐Rb3 diminished cisplatin‐induced increase in protein expression levels of p62, Atg3, Atg5 and Atg7, and decrease in protein expression level of p‐mTOR and the ratio of LC3‐I/LC3‐II, indicating that G‐Rb3 suppressed cisplatin‐induced activation of autophagy. Inhibition of autophagy induced inactivation of apoptosis, which suggested that autophagy played an adverse effect on cisplatin‐evoked renal damage. Further, we found that G‐Rb3 might potentially modulate the expressions of AMPK‐related signal pathways.

Conclusions

These findings clearly suggested that G‐Rb3‐mediated alleviation of cisplatin‐induced nephrotoxicity was in part due to regulation of AMPK‐/mTOR‐mediated autophagy and inhibition of apoptosis in vitro and in vivo.

Potent effects of dioscin against hepatocellular carcinoma through regulating TP53-induced glycolysis and apoptosis regulator (TIGAR)-mediated apoptosis, autophagy, and DNA damage

BACKGROUND AND PURPOSE

Dioscin shows potent effects against cancers. We aimed to elucidate its pharmacological effects and mechanisms of action on hepatocellular carcinoma (HCC) in vivo and in vitro.

EXPERIMENTAL APPROACH

Effects of dioscin were investigated in SMMC7721 and HepG2 cells, diethylnitrosamine-induced primary liver cancer in rats, and cell xenografts in nude mice. Isobaric tags for relative and absolution quantitation (iTRAQ)-based proteomics was used to find dioscin's targets and investigate its mechanism.

KEY RESULTS

In SMMC7721 and HepG2 cells dioscin markedly inhibited cell proliferation and migration, induced apoptosis, autophagy, and DNA damage. It inhibited DEN-induced primary liver cancer in rats, markedly changed body weights and restored levels of α fetoprotein, alanine transaminase, aspartate transaminase, γ-glutamyltransferase, alkaline phosphatase, and Ki67. It also inhibited growth of xenografts in mice. In SMMC7721 cells, 191 differentially expressed proteins were found after dioscin, based on iTRAQ-based assay. TP53-inducible glycolysis and apoptosis regulator (TIGAR) was identified as being significantly down-regulated by dioscin. Dioscin induced cell apoptosis, autophagy, and DNA damage via increasing expression levels of p53, cleaved PARP, Bax, cleaved caspase-3/9, Beclin-1, and LC3 and suppressing those of Bcl-2, p-Akt, p-mammalian target of rapamycin (mTOR), CDK5, p-ataxia telangiectasia-mutated gene (ATM). The transfection of TIGAR siRNA into SMMC7721 cells and xenografts in nude mice further confirmed that the potent activity of dioscin against HCC is evoked by adjusting TIGAR-mediated inhibition of p53, Akt/mTOR, and CDK5/ATM pathways.

CONCLUSIONS AND IMPLICATIONS

The data suggest that dioscin has potential as a therapeutic, and TIGAR as a drug target for treating HCC.

Recent updates on metabolite composition and medicinal benefits of mangosteen plant

BACKGROUND

Mangosteen (Garcinia mangostana L.) fruit has a unique sweet-sour taste and is rich in beneficial compounds such as xanthones. Mangosteen originally been used in various folk medicines to treat diarrhea, wounds, and fever. More recently, it had been used as a major component in health supplement products for weight loss and for promoting general health. This is perhaps due to its known medicinal benefits, including as anti-oxidant and anti-inflammation. Interestingly, publications related to mangosteen have surged in recent years, suggesting its popularity and usefulness in research laboratories. However, there are still no updated reviews (up to 2018) in this booming research area, particularly on its metabolite composition and medicinal benefits.

METHOD

In this review, we have covered recent articles within the years of 2016 to 2018 which focus on several aspects including the latest findings on the compound composition of mangosteen fruit as well as its medicinal usages.

RESULT

Mangosteen has been vastly used in medicinal areas including in anti-cancer, anti-microbial, and anti-diabetes treatments. Furthermore, we have also described the benefits of mangosteen extract in protecting various human organs such as liver, skin, joint, eye, neuron, bowel, and cardiovascular tissues against disorders and diseases.

CONCLUSION

All in all, this review describes the numerous manipulations of mangosteen extracted compounds in medicinal areas and highlights the current trend of its research. This will be important for future directed research and may allow researchers to tackle the next big challenge in mangosteen study: drug development and human applications.

Fucoidan Alleviates Acetaminophen-Induced Hepatotoxicity via Oxidative Stress Inhibition and Nrf2 Translocation

Acetaminophen (APAP) is a widely used analgesic and antipyretic drug that leads to severe hepatotoxicity at excessive doses. Fucoidan, a sulfated polysaccharide derived from brown seaweeds, possesses a wide range of pharmacological properties. However, the impacts of fucoidan on APAP-induced liver injury have not been sufficiently addressed. In the present study, male Institute of Cancer Research (ICR) mice aged 6 weeks were subjected to a single APAP (500 mg/kg) intraperitoneal injection after 7 days of fucoidan (100 or 200 mg/kg/day) or bicyclol intragastric administration. The mice continued to be administered fucoidan or bicyclol once per day, and were sacrificed at an indicated time. The indexes evaluated included liver pathological changes, levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in the serum, levels of reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH) and catalase (CAT) in the liver, and related proteins levels (CYP2E1, pJNK and Bax). Furthermore, human hepatocyte HL-7702 cell line was used to elucidate the potential molecular mechanism of fucoidan. The mitochondrial membrane potential (MMP) and nuclear factor-erythroid 2-related factor (Nrf2) translocation in HL-7702 cells were determined. The results showed that fucoidan pretreatment reduced the levels of ALT, AST, ROS, and MDA, while it enhanced the levels of GSH, SOD, and CAT activities. Additionally, oxidative stress-induced phosphorylated c-Jun N-terminal protein kinase (JNK) and decreased MMP were attenuated by fucoidan. Although the nuclear Nrf2 was induced after APAP incubation, fucoidan further enhanced Nrf2 in cell nuclei and total expression of Nrf2. These results indicated that fucoidan ameliorated APAP hepatotoxicity, and the mechanism might be related to Nrf2-mediated oxidative stress.