Saponins (Ginsenosides) from the Leaves of Panax quinquefolius Ameliorated Acetaminophen-Induced Hepatotoxicity in Mice

Riboflavin ameliorates intestinal inflammation via immune modulation and alterations of gut microbiota homeostasis in DSS-colitis C57BL/6 mice

While there have been advancements in understanding the direct and indirect impact of riboflavin (B2) on intestinal inflammation, the precise mechanisms are still unknown. This study focuses on evaluating the effects of riboflavin (B2) supplementation on a colitis mouse model induced with 3% dextran sodium sulphate (DSS). We administered three different doses of oral B2 (VB2L, VB2M, and VB2H) and assessed its impact on various physiological and biochemical parameters associated with colitis. Mice given any of the three doses exhibited relative improvement in the symptoms and intestinal damage. This was evidenced by the inhibition of the pro-inflammatory cytokines TNF-α, IL-1β, and CALP, along with an increase in the anti-inflammatory cytokine IL-10. B2 supplementation also led to a restoration of oxidative homeostasis, as indicated by a decrease in myeloperoxidase (MPO) and malondialdehyde (MDA) levels and an increase in reduced glutathione (GSH) and catalase (CAT) activities. B2 intervention showed positive effects on intestinal barrier function, confirmed by increased expression of tight junction proteins (occludin and ZO-1). B2 was linked to an elevated relative abundance of Actinobacteriota, Desulfobacterota, and Verrucomicrobiota. Notably, Verrucomicrobiota showed a significant increase in the VB2H group, reaching 15.03% relative abundance. Akkermansia exhibited a negative correlation with colitis and might be linked to anti-inflammatory function. Additionally, a remarkable increase in n-butyric acid, i-butyric acid, and i-valeric acid was reported in the VB2H group. The ameliorating role of B2 in gut inflammation can be attributed to immune system modulation as well as alterations in the gut microbiota composition, along with elevated levels of fecal SCFAs.

Protective Mechanisms of Juncus effusus and Carbonized Juncus effusus against D-Galactosamine-Induced Acute Liver Injury in Mice

This study investigated the hepatoprotective effects of Juncus effusus (J. effusus) and Carbonized J. effusus against liver injury caused by D-galactosamine (D-GalN) in mice. J. effusus and Carbonized J. effusus were administered by gavage once daily starting seven days before the D-GalN treatment. The results of the study indicated that J. effusus and Carbonized J. effusus suppressed the D-GalN-induced generation of serum alanine transaminase (ALT), aspartate aminotransferase (AST), hepatic malondialdehyde (MDA) and tumor necrosis factor-alpha (TNF-α) was observed. The values of superoxide dismutase (SOD) exhibited an increase. In addition, J. effusus and Carbonized J. effusus promoted the protein expression of nuclear factor erythroid 2-related factor 2 (Nrf2), NADPH quinone oxidoreductase-1 (NQO-1), heme oxygenase-1 (HO-1) as well as the mRNA expression of Nrf2, HO-1, NQO-1 and Glutamate cysteine ligase catalytic subunit (GCLC). The compressed Carbonized J. effusus demonstrated the optimum impact. These results suggest that J. effusus and Carbonized J. effusus protect against D-GalN-induced acute liver injury through the activation of the Nrf2 pathway.

A systematic review of ginsenoside biosynthesis, spatiotemporal distribution, and response to biotic and abiotic factors in American ginseng

American ginseng (Panax quinquefolius) has gained recognition as a medicinal and functional food homologous product with several pharmaceutical, nutritional, and industrial applications. However, the key regulators involved in ginsenoside biosynthesis, the spatiotemporal distribution characteristics of ginsenosides, and factors influencing ginsenosides are largely unknown, which make it challenging to enhance the quality and chemical extraction processes of the cultivated American ginseng. This review presents an overview of the pharmacological effects, biosynthesis and spatiotemporal distribution of ginsenosides, with emphasis on the impacts of biotic and abiotic factors on ginsenosides in American ginseng. Modern pharmacological studies have demonstrated that American ginseng has neuroprotective, cardioprotective, antitumor, antidiabetic, and anti-obesity effects. Additionally, most genes involved in the upregulation of ginsenoside biosynthesis have been identified, while downstream regulators (OSCs, CYP450, and UGTs) require further investigation. Futhermore, limited knowledge exists regarding the molecular mechanisms of the impact of biotic and abiotic factors on ginsenosides. Notably, the nonmedicinal parts of American ginseng, particularly its flowers, fibrous roots, and leaves, exhibit higher ginsenoside content than its main roots and account for a considerable amount of weight in the whole plant, representing promising resources for ginsenosides. Herein, the prospects of molecular breeding and metabolic engineering based on multi-omics to improve the unstable quality of cultivated American ginseng and the shortage of ginsenosides are proposed. This review highlights the gaps in the current research on American ginseng and proposes solutions to address these limitations, providing a guide for future investigations into American ginseng ginsenosides.

Ginsenoside Rg1 alleviates ANIT-induced cholestatic liver injury by inhibiting hepatic inflammation and oxidative stress via SIRT1 activation

ETHNOPHARMACOLOGICAL RELEVANCE

Ginseng (Panax ginseng C. A. Mey) is a common traditional Chinese medicine used for anti-inflammation, treating colitis, type 2 diabetes, diarrhea, and recovering hepatobiliary function. Ginsenosides, the main active components isolated from ginseng, possess liver and gallbladder diseases therapeutic potential.

AIMS OF THE STUDY

Cholestatic liver injury (CLI) is a liver disease induced by intrahepatic accumulation of toxic bile acids and currently lacks clinically effective drugs. Our previous study found that ginsenosides alleviated CLI by activating sirtuin 1 (SIRT1), but the effective ingredients and the underlying mechanism have not been clarified. This study aimed to identify an effective ingredient with the most significant activation effect on SIRT1 from the five major monomer saponins of ginsenosides: Rb1, Rd, Rg1, 20s-Rg3, and Rc further explore its protective effects on CLI, and elaborate its underlying mechanism.

MATERIALS AND METHODS

Discovery Studio 3.0 was used to conduct molecular docking between monomer saponins and SIRT1, and further detect the influence of monomer saponins on SIRT1 activity in vitro. Finally, it was determined that Rg1 had the most significant stimulative effect on SIRT1, and the hepatoprotective activity of Rg1 in CLI was explored in vivo. Wild-type mice were intragastrically α-naphthylisothiocyanate (ANIT) to establish an experimental model of intrahepatic cholestasis and Rg1 intervention, and then liver injury and cholestasis related indexes were detected. In addition, Liver-specific SIRT1 gene knockout (SIRT1-/-) mice were administered with ANIT and/or Rg1 to further investigate the mechanism of action of Rg1.

RESULTS

The results of molecular docking and in vitro experiments showed that all the five ginsenoside monomers could bind to the active site of SIRT1 and promote SIRT1 activity in HepG2 cells. Among them, Rg1 exhibited the most significant stimulation of SIRT1 activity in cholestasis. Besides, it could ameliorate ANIT-induced inflammation and oxidative stress in HepG2 cells. Therefore, we investigated the hepatoprotective effect and mechanism of Rg1 on CLI. Results showed that Rg1 reversed the ANIT-induced increase in biochemical parameters, improved liver pathological injury, and decreased liver lipid accumulation, reactive oxygen species and pro-inflammatory factor levels. Mechanistically, Rg1 induced SIRT1 expression, followed by promoted the activity of Nrf2 and suppressed the activation of NF-κB. Interestingly, the hepatoprotective effect of Rg1 was blocked in SIRT1-/- mice.

CONCLUSION

Rg1 mitigated ANIT-induced CLI via upregulating SIRT1 expression, and our results suggested that Rg1 is a candidate compound for treating CLI.

Natural Products for Acetaminophen-Induced Acute Liver Injury: A Review

The liver plays a vital role in metabolism, synthesis, and detoxification, but it is susceptible to damage from various factors such as viral infections, drug reactions, excessive alcohol consumption, and autoimmune diseases. This susceptibility is particularly problematic for patients requiring medication, as drug-induced liver injury often leads to underestimation, misdiagnosis, and difficulties in treatment. Acetaminophen (APAP) is a widely used and safe drug in therapeutic doses but can cause liver toxicity when taken in excessive amounts. This study aimed to investigate the hepatotoxicity of APAP and explore potential treatment strategies using a mouse model of APAP-induced liver injury. The study involved the evaluation of various natural products for their therapeutic potential. The findings revealed that natural products demonstrated promising hepatoprotective effects, potentially alleviating liver damage and improving liver function through various mechanisms such as oxidative stress and inflammation, which cause changes in signaling pathways. These results underscore the importance of exploring novel treatment options for drug-induced liver injury, suggesting that further research in this area could lead to the development of effective preventive and therapeutic interventions, ultimately benefiting patients with liver injury caused by medicine.

Protective effect of hot-water and ethanol-aqueous extracts from Anneslea fragrans against acetaminophen-induced acute liver injury in mice

Anneslea fragrans Wall. (AF) is an important medicinal and edible plant in China. The principal objectives of this study are to explore the hepatoprotective effect of ethanol-aqueous (AFE) and hot-water (AFW) extracts in vitro and in vivo. UPLC-ESI-MS/MS analysis showed that AFW and AFE are rich in dihydrochalcones. Both AFW and AFE significantly up-regulated the expressions of SOD, CAT and GSH, reduced the MDA content in acetaminophen (APAP)-induced HepG2 cells, and suppressed the expressions of NO, TNF-α, IL-1β, and IL-6 in LPS-induced RAW246.7 cells. In APAP-induced mice, AFW and AFE administration significantly decreased the plasma levels of AST and ALT, and improved liver tissue damage, the collagen deposition and fibrosis formation. Moreover, AFW and AFE decreased the MDA and ROS accumulations via activating Nrf2 pathway to increase the hepatic GSH contents and activities of SOD, CAT, HO-1, and NQO-1, reduced the levels of NO, TNF-α, IL-1β, and IL-6 by suppressing the JNK/p38/ERK/NF-κB pathways, and alleviated apoptosis via regulating Bcl-2, Bax, caspase-3/9 protein expressions. This study provides a new sight that AFW and AFE may have a potential natural resource for the treatment of liver injury.

The Protective Effect and Mechanism of a Phytochemical Extract from the Wild Vegetable Shutou (Crateva unilocularis Buch.) against Acetaminophen-Induced Liver Injury in Mice

Acetaminophen (APAP) abuse is a common public health problem which can cause severe liver damage. However, strategies for dealing with this situation safely and effectively are very limited. The goal of the current work was to evaluate the protection and potential molecular mechanisms of an ethanol extract from shoots of the wild vegetable shutou (Crateva unilocularis Buch.) (ECS) against APAP-induced liver damage in mice. Mice orally received ECS for seven days (300 or 600 mg/kg b.w. per day) before being intraperitoneally injected with APAP (250 mg/kg). Results exhibited that ECS obviously decreased the content of alkaline phosphatase, alanine aminotransferase, aspartate transaminase, and malondialdehyde (p < 0.05). Catalase and superoxide dismutase were notably restored (p < 0.05), and the content of reduced glutathione was obviously increased (p < 0.05). Moreover, ECS significantly inhibited the secretion of interleukin-1β and tumor necrosis factor-α (p < 0.05). Further analyses of the mechanisms showed that ECS may alleviate oxidative stress in the liver by increasing the expression of the nuclear factor erythroid-2-related factor 2 and NADH quinone oxidoreductase 1 proteins, and may suppress liver inflammation by inhibiting the expression of the phosphorylated-inhibitor kappa B alpha/inhibitor kappa B alpha, phosphorylated-nuclear factor κB/nuclear factor κB, and cyclooxygenase-2 proteins. Meanwhile, ECS inhibited hepatocyte apoptosis by enhancing B-cell lymphoma gene 2 and suppressing Bcl-2-associated X protein. In summary, ECS may be used as a dietary supplement to prevent the liver damage caused by APAP abuse.

Cytotoxic constituents from the leaves and stems of Panax quinquefolius

Four new isolates including one new butanediamide glycoside (1), one new flavonoid glycoside (2) and two new flavonone glycosides (3, 4) were identified from the leaves and stems of Panax quinquefolius, among which 1 possessed the firstly reported N,N'-(5-hydroxy-1,3-phenylene) butanediamide skeleton with an unique 6/9 ranged dual-ring structure. The structures were elucidated by the NMR data, ECD analysis and chemical acid hydrolysis. All the compounds (1-4) were tested for their cytotoxicity against two human cancer cell lines of HepG₂, A549 and HCT116 by the MTT method. Outstandingly, compound 1 exhibited targeted inhibitory proliferation of HCT116 cell with IC₅₀ value of 12.1 μM, whereas compounds 3 and 4 exhibited targeted inhibitory proliferation of HepG₂ cell with IC₅₀ values of 15.3 and 17.3 μM, as well as no obvious cytotoxicity of compounds 1-4 against A549.

8-paradol from ginger exacerbates PINK1/Parkin mediated mitophagy to induce apoptosis in human gastric adenocarcinoma

Gastric cancer (GC) occurs in the gastric mucosa, and its high morbidity and mortality make it an international health crisis. Therefore, novel drugs are needed for its treatment. The use of natural products and their components in cancer treatments has shown promise. Therefore, this study aimed to evaluate the effect of 8-paradol, a phenolic compound isolated from ginger (Zingiber officinale Roscoe), on GC and determine its underlying mechanisms of action. In this study, repeated column chromatography was conducted on ginger EtOH extract to isolate gingerol and its derivatives. The cytotoxicity of the eight ginger compounds underwent a (3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide) tetrazolium reduction (MTT) assay. 8-paradol showed the most potent cytotoxicity effect among the isolated ginger compounds. The underlying mechanism by which 8-paradol regulated specific proteins in AGS cells was evaluated by proteomic analysis. To validate the predicted mechanisms, AGS cells and thymus-deficient nude mice bearing AGS xenografts were used as in vitro and in vivo models of GC, respectively. The results showed that the 8-paradol promoted PINK1/Parkin-associated mitophagy, mediating cell apoptosis. Additionally, the inhibition of mitophagy by chloroquine (CQ) ameliorated 8-paradol-induced mitochondrial dysfunction and apoptosis, supporting a causative role for mitophagy in the 8-paradol-induced anticancer effect. Molecular docking results revealed the molecular interactions between 8-paradol and mitophagy-/ apoptosis-related proteins at the atomic level. Our study provides strong evidence that 8-paradol could act as a novel potential therapeutic agent to suppress the progression of GC by targeting mitophagy pathway.

Breast milk mesenchymal stem cells abate cisplatin-induced cardiotoxicity in adult male albino rats via modulating the AMPK pathway

Myocardial injury influenced by cisplatin (Cis) is a compelling reason to hunt out a treatment modality to overcome such a threat in cisplatin-treated patients. Breast Milk mesenchymal stem cells (Br-MSCs) are a non-invasive, highly reproducible source of stem cells. Herein, we investigate Br-MSCs' role in cardiotoxicity induced by cisplatin. Rats were divided into; control, Cis-treated (received 12 mg/kg single intraperitoneal injection), BrMSCs-treated (received single intraperitoneal injection of 0.5 ml sterilized phosphate-buffered saline containing 2 × 107 cells of Br-MSCs); metformin-treated (received 250 mg/kg/day orally) and BrMSCs + metformin + Cis treated groups. At the experiment end, serum creatine kinase (CK-MB) and cardiac troponin T (cTnT) activates were estimated, cardiac malondialdehyde (MDA), superoxide dismutase (SOD), interleukin-1ß (IL-1ß), tumor necrosis factor-α (TNF-α) levels were measured, cardiac expression of Bax and Bcl-2 and AMP-activated protein kinase (AMPK), as well as heart histopathology, were evaluated. Study results showed that Cis explored acute cardiotoxicity evidenced by deteriorated cardiac indices, induction of oxidative stress, and inflammation with myocardium histological alterations. Treatment with Br-MSCs restored heart function and structure deteriorated by Cis injection. The antioxidant/anti-inflammatory/anti-apoptotic results of Br-MSCs were supported by AMPK activation denoting their protective role against cisplatin-induced cardiac injury. These results were superior when metformin was added to the treatment protocol.

Progress on the efficacy and mechanism of action of panax ginseng monomer saponins treat toxicity

As a traditional Chinese herbal medicine, Panax ginseng C. A. Meyer (PG) has preventive and therapeutic effects on various diseases. Ginsenosides are main active ingredients of PG and have good pharmacological effects. Due to the diversity of chemical structures and physicochemical properties of ginsenosides, Currently, related studies on PG monomer saponins are mainly focused on the cardiovascular system, nervous system, antidiabetic, and antitumor. There are few types of research on the toxin treatment, predominantly exogenous toxicity. PG and its monomer ginsenosides are undoubtedly a practical option for treating exogenous toxicity for drug-induced or metal-induced side effects such as nephrotoxicity, hepatotoxicity, cardiotoxicity, metal toxicity and other exogenous toxicity caused by drugs or metals. The mechanism focuses on antioxidant, anti-inflammatory, and anti-apoptotic, as well as modulation of signaling pathways. It summarized the therapeutic effects of ginseng monomer saponins on exogenous toxicity and demonstrated that ginsenosides could be used as potential drugs to treat exogenous toxicity and reduce drug toxicities.

A review for discovering bioactive minor saponins and biotransformative metabolites in Panax quinquefolius L

Panax quinquefolius L. has attracted extensive attention worldwide because of its prominent pharmacological properties on type 2 diabetes, cancers, central nervous system, and cardiovascular diseases. Ginsenosides are active phytochemicals of P. quinquefolius, which can be classified as propanaxdiol (PPD)-type, propanaxtriol (PPT)-type, oleanane-type, and ocotillol-type oligo-glycosides depending on the skeleton of aglycone. Recently, advanced analytical and isolated methods including ultra-performance liquid chromatography tandem with mass detector, preparative high-performance liquid chromatography, and high speed counter-current chromatography have been used to isolate and identify minor components in P. quinquefolius, which accelerates the clarification of the material basis. However, the poor bioavailability and undetermined bio-metabolism of most saponins have greatly hindered both the development of medicines and the identification of their real active constituents. Thus, it is essential to consider the bio-metabolism of constituents before and after absorption. In this review, we described the structures of minor ginsenosides in P. quinquefolius, including naturally occurring protype compounds and their in vivo metabolites. The preclinical and clinical pharmacological studies of the ginsenosides in the past few years were also summarized. The review will promote the reacquaint of minor saponins on the growing appreciation of their biological role in P. quinquefolius.

Protective Effect of Fresh/Dry Dandelion Extracts on APAP-Overdose-Induced Acute Liver Injury

OBJECITVIE

To compare the liver protective activity of fresh/dried dandelion extracts against acetaminophen (APAP)-induced hepatotoxicity.

METHODS

Totally 90 Kunming mice were randomly divided into 10 groups according to body weight (9 mice for each group). The mice in the normal control and model (vehicle control) groups were administered sodium carboxymethyl cellulose (CMC-Na, 0.5%) only. Administration groups were pretreated with high and low-dose dry dandelion extract (1,000 or 500 g fresh herb dried and then decocted into 120 mL solution, DDE-H and DDE-L); low-, medium- and high-dose dandelion juice (250, 500, 1,000 g/120 mL, DJ-L, DJ-M, and DJ-H); fresh dandelions evaporation juice water (120 mL, DEJW); dry dandelion extract dissolved by pure water (1 kg/120 mL, DDED-PW); dry dandelion extract dissolved by DEJW (120 g/120 mL, DDED-DEJW) by oral gavage for 7 days at the dosage of 0.5 mL solution/10 g body weight; after that, except normal control group, all other groups were intraperitonealy injected with 350 mg/kg APAP to induce liver injury. Twenty hours after APAP administration, serum and liver tissue were collected and serum alanine aminotransferase (AST), aspartate transaminase (ALT), alkaline phosphatase (AKP), malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD) activities were quantified by biochemical kits; tumor necrosis factor (TNF-α), interleukin (IL)-2, and IL-1 β contents in liver tissue were determined by enzyme linked immunosorbent assay kits. Histopathological changes in liver tissues were observed by hematoxylin and eosin staining; TUNEL Assay and Hoechst 33258 staining were applied for cell apoptosis evaluation. The expressions of heme oxygenase-1 (HO-1), nuclear factor erythroid-2-related factor 2 (Nrf-2), caspase-9, B-cell leukemia/lymphoma 2 (Bcl-2), Bax and p-JNK were determined by Western blot analysis.

RESULTS

Pretreatment with fresh dandelion juice (FDJ, including DJ-L, DJ-M, DJ-H, DEJW and DDED-DEJW) significantly decreased the levels of serum ALT, AST, AKP, TNF-α and IL-1β compared with vehicle control group (P<0.05 or P<0.01). Additionally, compared with the vehicle control group, FDJ decreased the levels of hepatic MDA and restored GSH levels and SOD activity in livers (P<0.05 or P<0.01). FDJ inhibited the overexpression of pro-inflammatory factors including cyclooxygenase-2 and inducible nitric oxide synthase in the liver tissues (P<0.05 or P<0.01). Furthermore, Western blot analysis revealed that FDJ pretreatment inhibited activation of apoptotic signaling pathways via decreasing of Bax, and caspase-9 and JNK protein expression, and inhibited activation of JNK pathway (P<0.05 or P<0.01). Liver histopathological observation provided further evidence that FDJ pretreatment significantly inhibited APAP-induced hepatocyte necrosis, inflammatory cell infiltration and congestion.

CONCLUSIONS

FDJ pretreatment protects against APAP-induced hepatic injury by activating the Nrf-2/HO-1 pathway and inhibition of the intrinsic apoptosis pathway, and the effect of fresh dandelion extracts was superior to dried dandelion extracts in APAP hepatotoxicity model mice.

<em>Lactobacillus plantarum</em> Lp2 improved LPS-induced liver injury through the TLR-4/MAPK/NFκB and Nrf2-HO-1/CYP2E1 pathways in mice

Background: Inflammatory liver diseases present a significant public health problem. Probiotics are a kind of living microorganisms, which can improve the balance of host intestinal flora, promote the proliferation of intestinal beneficial bacteria, inhibit the growth of harmful bacteria, improve immunity, reduce blood lipids and so on. Probiotics in fermented foods have attracted considerable attention lately as treatment options for liver injury. Objective: The aim of this study was selected probiotic strain with well probiotic properties from naturally fermented foods and investigated the underlying mechanisms of screened probiotic strain on lipopolysaccharide (LPS)-induced liver injury, which provided the theoretical foundation for the development of probiotics functional food. Design: The probiotic characteristics of Lactobacillus plantarum Lp2 isolated from Chinese traditional fermented food were evaluated. Male KM mice were randomly assigned into three groups: normal chow (Control), LPS and LPS with L. plantarum Lp2. L. plantarum Lp2 were orally administered for 4 weeks before exposure to LPS. The liver injury of LPS-induced mice was observed through the evaluation of biochemical indexes, protein expression level and liver histopathology. Results and discussions: After treatment for 4 weeks, L. plantarum Lp2 administration significantly reduced the LPS-induced liver coefficient and the levels of serum or liver aspartate transaminase (AST), alanine aminotransferase (ALT), tumor necrosis factor α (TNF-α), interleukin-6 (IL-6) and LPS, as well as decreasing the histological alterations and protein compared with the LPS group. Western-blotting results showed that L. plantarum Lp2 activated the signal pathway of TLR4/MAPK/NFκB/NRF2-HO-1/CYP2E1/Caspase-3 and regulated the expression of related proteins. Conclusions: In summary, L. plantarum Lp2 suppressed the LPS-induced activation of inflammatory pathways, oxidative injury and apoptosis has the potential to be used to improve liver injury.

The dual role of immune response in acetaminophen hepatotoxicity: Implication for immune pharmacological targets

Acetaminophen (APAP), one of the most widely used antipyretic and analgesic drugs, principally contributes to drug-induced liver injury when taken at a high dose. APAP-induced liver injury (AILI) results in extensive necrosis of hepatocytes along with the occurrence of multiple intracellular events such as metabolic activation, cell injury, and signaling pathway activation. However, the specific role of the immune response in AILI remains controversial for its complicated regulatory mechanisms. A variety of inflammasomes, immune cells, inflammatory mediators, and signaling transduction pathways are activated in AILI. These immune components play antagonistic roles in aggravating the liver injury or promoting regeneration. Recent experimental studies indicated that natural products showed remarkable therapeutic effects against APAP hepatotoxicity due to their favorable efficacy. Therefore, this study aimed to review the present understanding of the immune response in AILI and attempted to establish ties among a series of inflammatory cascade reactions. Also, the immune molecular mechanisms of natural products in the treatment of AILI were extensively reviewed, thus providing a fundamental basis for exploring the potential pharmacological targets associated with immune interventions.

Total saponins from stems and leaves of Panax quinquefolius L. ameliorate podophyllotoxin-induced myelosuppression and gastrointestinal toxicity

Podophyllotoxin (POD), a natural lignan distributed in podophyllum species, possesses significant antitumor and antiviral activities. But POD often causes serious side effects, such as myelosuppression, gastrointestinal toxicity, neurotoxicity, hepatic and renal dysfunction, and even death, which not only hinder its clinical application but also threaten the patient's health. Therefore, an effective treatment against POD-induced toxicity is important. Our preliminary study found that the total saponins from the stems and leaves of Panax quinquefolius L. (PQS) could significantly reduce the death of mice caused by POD. To reveal how PQS can alleviate POD-induced toxicity, further study was needed. Peripheral blood cell analysis, diarrhea score, and histological examination demonstrated that PQS could relieve myelosuppression and gastrointestinal side effects induced by POD. Then, metabolomics was performed to investigate the possible protective mechanism of PQS on POD-induced myelosuppression and gastrointestinal toxicity. Metabolomics analysis showed that metabolic changes caused by POD could be reversed by PQS to some extent; 23 metabolites altered significantly after POD exposure, and 11 metabolites significantly reversed by PQS pretreatment. Metabolic pathway analysis suggested that PQS might exhibit its protective effects by rebalancing disordered arginine, glutamine, and unsaturated fatty acid metabolism.

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.

Protective effect of Que Zui tea hot-water and aqueous ethanol extract against acetaminophen-induced liver injury in mice via inhibition of oxidative stress, inflammation, and apoptosis

The tender leaves and buds of Vaccinium dunalianum Wight have been traditionally processed as folk tea, known as Que Zui tea (QT), with a wide range of benefits to humans. In this study, Que Zui tea hot-water extract (QTW) and aqueous-ethanol extract (QTE) were tested for their effectiveness to alleviate acetaminophen (APAP)-induced liver damage. QTW and QTE significantly inhibited the alanine aminotransaminase, aspartate aminotransaminase, tumor necrosis factor-α, interleukin-6, and interleukin-1β levels in the serum. Both extracts also ameliorated pathological damage and inhibited oxidative stress in the liver of APAP-induced mice. In addition, QTW and QTE activated the nuclear erythroid related factor 2 signal pathway, and inhibited mitogen-activated protein kinase activation. QTW and QTE also suppressed hepatocyte apoptosis by improvement of Bcl-2/Bax and inhibition of caspase-3 and caspase-9 expression. The results demonstrated that QTW and QTE could effectively protect APAP hepatotoxicity, which might be attributed to their antioxidant, anti-inflammatory and anti-apoptosis activities.

Rutaecarpine Protects against Acetaminophen-Induced Acute Liver Injury in Mice by Activating Antioxidant Enzymes

Rutaecarpine, an indolopyridoquinazolinone alkaloid isolated from the unripe fruit of Evodia rutaecarpa, is used to treat hypertension, postpartum hemorrhage, dysentery, and amenorrhea as a traditional medicine in Asia. We investigated the effect of rutaecarpine on acetaminophen-induced hepatotoxicity in mice. Rutaecarpine was administered orally daily for seven consecutive days, followed by intraperitoneal injection of acetaminophen in mice on day seven to induce hepatotoxicity. Rutaecarpine pretreatment significantly decreased acetaminophen-induced serum alanine aminotransferase (ALT)/aspartate aminotransferase (AST) activities and hepatic malondialdehyde content and prevented acetaminophen-induced hepatic glutathione depletion. Furthermore, CYP2E1 expression was decreased by rutaecarpine pretreatment in a dose-dependent manner. Rutaecarpine pretreatment inhibited acetaminophen-induced expression of inflammatory cytokines by inhibiting NF-κB activation by JNK1/2. Also, rutaecarpine pretreatment promoted Nrf2-mediated activation of the antioxidant enzymes GCLC, HO-1, and NQO1. This indicates that the protective effect of rutaecarpine during acetaminophen-induced acute liver injury is mediated by the activation of antioxidant enzymes. Therefore, rutaecarpine has a protective effect of APAP-induced liver damage.

Oxidative stress-mediated hepatotoxicity in rats induced by ethanol extracts of different parts of Chloranthus serratus

CONTEXT

Chloranthus serratus (Thunb.) Roem. et Schult. (Chloranthaceae) is an herb widely used as a folk medicine treating inflammatory diseases, although it is toxic.

OBJECTIVE

To investigate hepatotoxicity and related mechanisms induced by ethanol extracts of different parts of C. serratus in rats.

MATERIALS AND METHODS

Sprague Dawley rats were divided into control (Con), ethanol extract of roots (ER), stems (ES), and leaves (EL) groups, and acute oral toxicity studies were conducted. The rats received doses of 4.14, 3.20, and 1.16 g/kg/d extracts for 14 days, respectively. Liver index, liver function and oxidative stress biomarkers, liver pathology, ultrastructure, TNF-α, ICAM-1, and Nrf2/HO-1 proteins expression levels were determined.

RESULTS

The LD₅₀ of ER, ES, and EL were higher than 10.35, 8.05, and 2.90 g/kg/p.o., respectively. The liver indexes in the extract groups increased significantly. EL dramatically increased TP, GLB, AST, ALT, ALP, TBA, MDA, ICAM-1, and TNF-α levels (p < 0.01), and induced the most obvious pathological and ultrastructural changes. ES and EL obviously decreased the T-SOD, GSH, CAT, and CHOL levels. Nrf2 and HO-1 proteins expression was reduced significantly in ES (0.77 ± 0.06, 2.33 ± 0.20) and EL (0.23 ± 0.04, 2.14 ± 0.16) groups, and reduced slightly in ER (1.08 ± 0.10; 3.39 ± 0.21) group.

DISCUSSION AND CONCLUSION

ES and EL induce stronger hepatotoxicity than ER through oxidative stress and the Nrf2/HO-1 pathway, and the root is a better medicinal part, which provides a basis for clinical research, safe applications, and reasonable development of C. serratus.

Dandelion polyphenols protect against acetaminophen-induced hepatotoxicity in mice via activation of the Nrf-2/HO-1 pathway and inhibition of the JNK signaling pathway

We investigated the liver protective activity of dandelion polyphenols (DP) against acetaminophen (APAP; Paracetamol)-induced hepatotoxicity. Mice were acclimated for 1 week and randomly divided into the following groups (n = 9 per group): Control, APAP, APAP + DP (100 mg·kg^-1), APAP + DP (200 mg·kg^-1), and APAP + DP (400 mg·kg^-1) groups. Mice were pretreated with DP (100, 200, and 400 mg·kg^-1) by oral gavage for 7 d before being treated with 350 mg·kg^-1 APAP for 24 h to induced hepatotoxicity. Severe liver injury was observed, and hepatotoxicity was analyzed after 24 h by evaluation of biochemical markers, protein expressions levels, and liver histopathology. Pretreatment with DP was able to restore serum liver characteristics (aspartate transaminase, AST; alanine aminotransferase, ALT; alkaline phosphatase, AKP), improve redox imbalance (superoxide dismutase, SOD; glutathione, GSH; malondialdehyde, MDA), and decrease inflammatory factors (tumor necrosis factor-α, TNF-α; interleukin-1β, IL-1β). Pretreatment with DP also significantly inhibited the expression levels of nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Furthermore, DP pretreatment could inhibit the apoptosis of liver cells caused by APAP through up-regulation of Bcl-2 and down-regulation of Bax and caspase-9 protein. DP also down-regulated p-JNK protein expression levels to inhibit APAP-induced mitochondrial oxidative stress and up-regulated the expression of Nrf-2 and its target gene HO-1. The histopathological staining demonstrated that DP pretreatment could inhibit APAP-induced hepatocyte infiltration, congestion, and necrosis. Our results demonstrate that DP pretreatment could protect against APAP-induced hepatic injury by activating the Nrf-2/HO-1 pathway and inhibition of the intrinsic apoptosis pathway.

γ-Oryzanol alleviates acetaminophen-induced liver injury: roles of modulating AMPK/GSK3β/Nrf2 and NF-κB signaling pathways

Acetaminophen (APAP) overdose is a major cause of drug-induced liver injury worldwide. Our current study was performed to assess the potential protective effects of γ-oryzanol (ORY) on APAP-induced liver injury in mice and explore the underlying molecular mechanisms. We unveiled that ORY alleviated the APAP-induced death of HL-7702 hepatocytes in vitro and liver injury in mice. Moreover, ORY promoted the nuclear translocation of Nrf2, increased the expressions of Nrf2-downstream antioxidative enzymes, including HO-1, NQO1, GCLC, and GCLM, and thereby restrained APAP-induced oxidative stress in hepatocytes. Moreover, ORY modulated the AMPK/GSK3β axis that acts upstream of Nrf2 in hepatocytes. Compound C, an inhibitor of AMPK, prevented the ORY-mediated activation of Nrf2 and protection against APAP toxicity in HL-7702 hepatocytes. Additionally, in the liver of mice receiving APAP, ORY suppressed the nuclear translocation of the NF-κB p65 subunit, downregulated the expressions of iNOS and COX-2, and reduced the levels of pro-inflammatory factors including TNF-α, IL-1β, IL-6, and NO. Taken together, our findings revealed that ORY is capable of ameliorating APAP-induced liver injury. The modulation of AMPK/GSK3β/Nrf2 and NF-κB signaling pathways is implicated in the hepatoprotective activity of ORY.

Bacopa Monnieri Protects the Directly Affected Organ as Well as Distant Organs Against I/R Injury by Modulating Anti-Inflammatory and Anti-Nitrosative Pathways in A Rat Model for Infra-Renal Aortic Occlusion

OBJECTIVE

To investigate the protective effect and underlying mechanisms of B. monnieri, a medicinal plant, on kidney and skeletal muscle injury induced by infra-renal abdominal aorta clamping for 2-hours (ischemia) and following removal of the clamp (reperfusion, 2-hours).

METHODS

Rats were divided into four groups (n = 6): (I) animals given only saline (sham-control); (II) animals given B. monnieri extract for 10-days (300 mg/kg/day) (Bacopa-treated sham); (III) animals subjected to ischemia/reperfusion (I/R); (IV) animals given B. monnieri extract and then subjected to I/R. Kidneys and lower extremity muscles were examined for GPx, CAT, iNOS, 3-NT, IL-1β and TNF-α. Apoptosis and injury were evaluated by TUNEL and H&E staining, respectively.

RESULTS

I/R resulted in TUNEL positive cells, periarterial edema and glomerular capillary dilatation, decreased GPx activity, unchanged CAT, iNOS, 3-NT, IL-1β and TNF-α in kidney. B. monnieri minimized renal remote reperfusion injury, and Group IV showed a lower degree of renal histopathology score when compared to the others. B. monnieri mitigated muscle I/R injury, decreased muscle hypertrophy, myofibril abnormalities and apoptosis. Muscle 3-NT and cytokine levels were increased by I/R, and B. monnieri inhibited iNOS and 3-NT both in sham-control and I/R groups. Muscle GPx unaffected by I/R or B. monnieri, but CAT was inhibited only in B. monnieri-treated I/R group. Muscle iNOS, 3-NT, IL-1β, TNF-α levels and CAT activity of B. monnieri-treated I/R rats were lower than those in sham-control or Bacopa-treated sham.

CONCLUSIONS

B. monnieri can protect the directly affected organ as well as distant organs against I/R injury by modulating anti-inflammatory and anti-nitrosative pathways.

Ginsenoside Rb1, A Major Saponin from Panax ginseng, Exerts Protective Effects Against Acetaminophen-Induced Hepatotoxicity in Mice

Acute liver injury (ALI) induced by acetaminophen (APAP) is the main cause of drug-induced liver injury. Previous reports indicated liver failure could be alleviated by saponins (ginsenosides) from Panax ginseng against APAP-induced inflammatory responses in vivo. However, validation towards ginsenoside Rb1 as a major and marker saponin may protect liver from APAP-induced ALI and its mechanisms are poorly elucidated. In this study, the protective effects and the latent mechanisms of Rb1 action against APAP-induced hepatotoxicity were investigated. Rb1 was administered orally with 10mg/kg and 20mg/kg daily for 1 week before a single injection of APAP (250mg/kg, i.p.) 1h after the last treatment of Rb1. Serum alanine/aspartate aminotransferases (ALT/AST), liver glutathione (GSH) depletion, as well as the inflammatory cytokines, such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2), were analyzed to indicate the underlying protective effects of Rb1 against APAP-induced hepatotoxicity with significant inflammatory responses. Histological examination further proved Rb1's protective effects. Importantly, Rb1 mitigated the changes in the phosphorylation of MAPK and PI3K/Akt, as well as its downstream factor NF-κB. In conclusion, experimental data clearly demonstrated that Rb1 exhibited a remarkable liver protective effect against APAP-induced ALI, partly through regulating MAPK and PI3K/Akt signaling pathways-mediated inflammatory responses.

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.

Supplementation of Saponins from Leaves of Panax quinquefolius Mitigates Cisplatin-Evoked Cardiotoxicity via Inhibiting Oxidative Stress-Associated Inflammation and Apoptosis in Mice

Background: Although kidney injury caused by cisplatin has attracted much attention, cisplatin-induced cardiotoxicity is elusive. Our previous studies have confirmed that saponins (ginsenosides) from Panax quinquefolius can effectively reduce acute renal injuries. Our current study aimed to identify the potential effects of saponins from leaves of P. quinquefolius (PQS) on cisplatin-evoked cardiotoxicity. Methods: Mice were intragastrically with PQS at the doses of 125 and 250 mg/kg daily for 15 days. The mice in cisplatin group and PQS + cisplatin groups received four times intraperitoneal injections of cisplatin (3 mg/kg) two days at a time from the 7th day, respectively. All mice were killed at 48 h following final cisplatin injection. Body weights, blood and organic samples were collected immediately. Results: Our results showed that cisplatin-challenged mice experienced a remarkable cardiac damage with obvious histopathological changes and elevation of lactate dehydrogenase (LDH), creatine kinase (CK), creatine kinase isoenzyme MB (CK-MB) and cardiac troponin T (cTnT) concentrations and viabilities in serum. Cisplatin also impaired antioxidative defense system in heart tissues manifested by a remarkable reduction in reduced glutathione (GSH) content and superoxide dismutase (SOD) activity, demonstrating the overproduction of reactive oxygen species (ROS) and oxidative stress. Interestingly, PQS (125 and 250 mg/kg) can attenuate cisplatin-evoked changes in the above-mentioned parameters. Additionally, PQS administration significantly alleviated the oxidation resulted from inflammatory responses and apoptosis in cardiac tissues via inhibition of overexpressions of TNF-α, IL-1β, Bax, and Bad as well as the caspase family members like caspase-3, and 8, respectively. Conclusion: Findings from our present research clearly indicated that PQS exerted significant effects on cisplatin-induced cardiotoxicity in part by inhibition of the NF-κB activity and regulation of PI3K/Akt/apoptosis mediated signaling pathways.

Reversing effects of ginsenosides on LPS-induced hepatic CYP3A11/3A4 dysfunction through the pregnane X receptor

ETHNOPHARMACOLOGICAL RELEVANCE

Ginseng (Panax ginseng C. A. Meyer), a traditional Chinese medicine, is widely used in the adjunctive therapy of the liver diseases.

AIM OF THE STUDY

Ginsenosides are one kind of the main active ingredients in ginseng. Although hepatoprotective mechanisms of ginsenosides, such as anti-oxidation, anti-inflammation and anti-apoptosis, have been well studies, little is known about the effect of ginsenosides on drug metabolism in liver. Since CYP3A11/3A4 is a major enzyme catalyzing the drug metabolism in liver, an investigation of the enzyme's expression during the progression of a liver disease will gain valuable information about the hepatic drug metabolism. The purpose of this study was to determine the effect of ginsenosides on the expression of hepatic CYP3A11/3A4 in the lipopolysaccharides (LPS) injured human HepG2 cells and mice. We hypothesize that ginsenosides are important to stabilize CYP3A11/3A4 expression in an injured liver.

MATERIALS AND METHODS

In this study, LPS was intraperitoneally intermittently injected to induce the liver injury in mice. Ginsenosides were intragastrically administered to mice for 7 days to treat the liver injury. Serum biochemical analysis and histopathological study were taken to evaluate the hepatoprotective effect of ginsenosides. The effect of ginsenosides was also evaluated in human HepG2 cells in the presence and absence of LPS. Real-time PCR and western blotting method were used to detect the mRNA and protein levels of CYP3A11/3A4 in mouse liver tissue and human HepG2 cells. The reporter gene-transfected cells were used to identify upstream targets in HepG2 cells.

RESULTS

LPS injection in mice resulted in the up-regulation of pro-inflammatory cytokines such as IL-1β, IL-6 and TNF-α in liver, up-regulation of hepatic enzymes such as Tbil, ALT, AST and ALP in serum, and down-regulation of CYP3A11/3A4 expression in liver. Ginsenosides treatment reversed the up-regulation of pro-inflammatory cytokines and serum hepatic enzymes elicited by LPS. Pathological results suggest that ginsenosides reduced liver damage. Moreover, ginsenosides reversed the decrease of CYP3A11/3A4 expression in the liver of LPS-injured mouse and in LPS-treated HepG2 cells. To further investigate the regulatory mechanisms, we found that ginsenosides enhanced the rifampicin-induced pregnane X receptor (PXR) transactivation of the CYP3A4 promoter. Treatment of hPXR-over-expressed cells with ginsenosides increased the rifampicin-inducible expression of CYP3A4 in a concentration-dependent manner.

CONCLUSION

Ginsenosides reverse the effects of LPS-induced hepatic CYP3A11/3A4 dysfunction, suggesting that the stabilization of the CYP3A11/3A4 expression in an injured liver appears a novel hepatoprotective mechanism of ginsenosides.

A new ocotillol-type ginsenoside from stems and leaves of Panax quinquefolium L. and its anti-oxidative effect on hydrogen peroxide exposed A549 cells

A new ocotillol-type ginsenoside, namely 12-one-pseudoginsenoside F₁₁ (12-one-PF₁₁), was isolated from stems and leaves of Panax quinquefolium, whose structure was elucidated 6-O-[α-L-rhamnopyranosyl-(1-2)-β-D-glucopyranosyl]-dammar-12-one-20S,24R-epoxy-3β,6α,25-triol. 12-one-PF₁₁ significantly suppressed hydrogen peroxide induced oxidative stress in human lung carcinoma A549 cells. As compared with model group, 12-one-PF₁₁ improved cell viability of A549 cells in a dose-dependent manner, and significantly decreased the generation of malondialdehyde (MDA) and increased production of superoxide dismutase (SOD) and glutathione (GSH) and protein expression levels of nuclear related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) in A549 cells.

Hepatoprotective Effect of Baicalein Against Acetaminophen-Induced Acute Liver Injury in Mice

Baicalein (BAI), one of the main components of Scutellaria baicalensis Georgi, possesses numerous pharmacological properties, including anti-cancer, anti-oxidative, anti-virus and anti-bacterial activities. The purpose of this study was to evaluate the hepatoprotective effect of baicalein against acetaminophen (APAP)-exposed liver injury in mice, and elucidate the underlying hepatoprotective mechanism. Baicalein pretreatment significantly alleviated the elevation of IL-6, IL-1β and TNF-α in serum and hepatic in a dose-dependent manner. It also dose-dependently reduced the hepatic malondialdehyde (MDA) concentration, as well as the depletion of hepatic superoxide dismutase (SOD), hepatic glutathione (GSH) and hepatic catalase (CAT). Moreover, pretreatment with baicalein significantly ameliorated APAP-exposed liver damage and histological hepatocyte changes. Baicalein also relieved APAP-induced autophagy by regulating AKT/mTOR pathway, LC3B and P62 expression. Furthermore, the hepatoprotective effect of baicalein to APAP-induced liver injury involved in Jak2/Stat3 and MAPK signaling pathway. Taken together, our findings suggested that baicalein exhibits the ability to prevent liver from APAP-induced liver injury and provided an underlying molecular basis for potential applications of baicalein to cure liver injuries.

Protective effects of extracts of Schisandra chinensis stems against acetaminophen-induced hepatotoxicity via regulation of MAPK and caspase-3 signaling pathways

The present study was designed to evaluate protective activity of an ethanol extract of the stems of Schisandra chinensis (SCE) and explore its possible molecular mechanisms on acetaminophen (APAP) induced hepatotoxicity in a mouse model. The results of HPLC analysis showed that the main components of SCE included schisandrol A, schisandrol B, deoxyschisandrin, schisandrin B, and schisandrin C and their contents were 5.83, 7.11, 2.13, 4.86, 0.42 mg·g^-1, respectively. SCE extract was given for 7 consecutive days before a single hepatotoxic dose of APAP (250 mg·kg^-1) was injected to mice. Our results showed that SCE pretreatment ameliorated liver dysfunction and oxidative stress, which was evidenced by significant decreases in aspartate transaminase (AST), alanine aminotransferase (ALT), malondialdehyde (MDA) contents and elevations in reduced glutathione (GSH) and superoxide dismutase (SOD) levels. These findings were associated with the result that the SCE pretreatment significantly decreased expression levels of 4-hydroxynonenal (4-HNE) and 3-nitrotyrosine (3-NT). SCE also significantly decreased the expression levels of Bax, mitogen- activated protein kinase (MAPK), and cleaved caspase-3 by APAP exposure. Furthermore, supplementation with SCE suppressed the expression levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), suggesting alleviation of inflammatory response. In summary, these findings from the present study clearly demonstrated that SCE exerted significant alleviation in APAP-induced oxidative stress, inflammation and apoptosis mainly via regulating MAPK and caspase-3 signaling pathways.

Improved protective effects of American ginseng berry against acetaminophen-induced liver toxicity through TNF-α-mediated caspase-3/-8/-9 signaling pathways

BACKGROUND

Similar to the leaves of P. Quinquefolius, American ginseng berry (AGB) is another important part of P. Quinquefolius with alternative therapeutic potential. The liver protection capabilities of the former have been demonstrated previously, however, the later has not yet been evaluated.

PURPOSE

Based on our previous observation, the present work was designed to evaluate the hepatic protective effects for novel mechanisms of AGB in acetaminophen (APAP)-induced liver injury in vivo.

STUDY DESIGN/METHODS

All mice were divided into four groups as follows: normal group, APAP group and APAP + AGB (150 mg/kg and 300 mg/kg) groups. AGB were orally administered for one week before exposure to APAP (250 mg/kg). Severe liver injury was observed and hepatotoxicity was evaluated after 24 h through evaluating the biochemical markers, protein expressions levels and liver histopathology.

RESULTS

Our study results clearly demonstrated that AGB pretreatment ameliorated APAP-induced hepatic injury as evidenced by decreasing plasma alanine aminotransferase (ALT), aspartate transaminase (AST), tumor necrosis factor α (TNF-α) and interleukin-1β (IL-1β) compared to the APAP group. Western blotting analysis showed that pretreatment with AGB decreased the expressions levels of TNF-α and nuclear transcription factor-κB (NF-κB p65) in liver tissues. Meanwhile, the protein expression levels of caspases, cytochrome c, and Bax were elevated by AGB treatment for seven days, while the protein expression level of Bcl-2 was inhibited comparison with that in APAP group. Furthermore, supplement of AGB resulted in increase of superoxide dismutase (SOD) and glutathione (GSH), while decrease of malondialdehyde (MDA) content and the expression levels of 4-hydroxynonenal (4-HNE) and cytochrome P450 E1 (CYP2E1). The results of histopathological staining demonstrated that AGB pretreatment inhibited APAP-induced hepatocyte infiltration, congestion, and necrosis.

CONCLUSION

The present study demonstrated that AGB pretreatment protected liver cells against APAP-induced hepatotoxicity through inhibition of oxidative stress, inflammation responses via TNF-α-mediated caspase-3/-8/-9 signaling pathways.

Isoorientin Ameliorates APAP-Induced Hepatotoxicity via Activation Nrf2 Antioxidative Pathway: The Involvement of AMPK/Akt/GSK3β

Oxidative stress has been highlighted as therapeutic targets for acetaminophen (APAP)-induced hepatotoxicity. Isoorientin (Iso), a well-known flavonoid-like compound, has been shown to have antioxidant potential. However, the effect of Iso on APAP-induced liver injury has not yet been elucidated. The present study investigated the hepatoprotective effect of Iso and its underlying mechanism. C57BL/6J mice were used to evaluate the hepatoprotective effect of Iso in vivo and HepG2 cells were utilized to further decipher the mechanisms of Iso -induced Nrf2 activation. We found that Iso treatment significantly reduced APAP-induced hepatotoxicity by reducing the lethality, histopathological liver changes, and alanine transaminase (ALT) and aspartate aminotransferase (AST) levels in serum. These effects were accompanied by decreased malondialdehyde (MDA) formation and myeloperoxidase level (MPO), and by decreased superoxide dismutase (SOD) and glutathione (GSH) depletion. Moreover, Iso induced Nrf2 activation and translocation as well as upstream AMPK/Akt/GSK3β activation. Furthermore, Iso effectively alleviated mitochondrial dysfunction by reducing c-jun N-terminal kinase phosphorylation and translocation, Bax mitochondrial translocation, and apoptosis-inducing factor and cytochrome c release. Further mechanistic investigations revealed that the activation of Nrf2 by Iso via the AMPK/Akt/GSK3β pathway contributed to the hepatoprotective activity of Iso in vitro. In addition, the Iso-mediated inhibition of APAP-induced the lethality, histopathological changes and mitochondrial dysfunction observed in WT mice was nearly absent in Nrf2^-/- mice. In summary, Iso ameliorated APAP-induced hepatotoxicity by activating Nrf2 via the AMPK/Akt/GSK3β pathway.

Astragaloside IV Attenuates Acetaminophen-Induced Liver Injuries in Mice by Activating the Nrf2 Signaling Pathway

Acetaminophen (APAP) is a well-known antipyretic and analgesic drug. However, the accidental or intentional APAP overdose will induce liver injury and even acute liver failure. Astragaloside IV (AS-IV), a bioactive compound isolated from Astragali Radix, has been reported to have protective effects on the digestive and immune systems because of its anti-oxidant and anti-inflammatory properties. This study aims to observe whether AS-IV pretreatment provides protection against APAP-induced liver failure. The results of serum alanine/aspartate aminotransferases (ALT/AST) analysis, hepatic glutathione (GSH), and malondialdehyde (MDA) amounts, and liver superoxide dismutase (SOD) activity showed that AS-IV protected against APAP-induced hepatotoxicity. Liver histological observation further evidenced this protection provided by AS-IV. AS-IV was found to reverse the APAP-induced increased amounts of pro-inflammatory cytokines, including interleukin 1β (IL-1β), interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α). Western-blot analysis showed that AS-IV increased the transcriptional activation of nuclear factor erythroid 2-related factor 2 (Nrf2), and enhanced the expression of heme oxygenase 1 (HO-1) and reduced nicotinamide adenine dinucleotide phosphate (NAD(P)H): quinone oxidoreductase 1 (NQO1) in the presence of APAP. AS-IV also decreased the expression of kelch-like ECH-associated protein-1 (Keap1). In conclusion, we demonstrated that AS-IV exerted a strong protection against APAP-induced hepatotoxicity by activating Nrf2 antioxidant signaling pathways.

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

Acetaminophen overdose-induced hepatotoxicity is the most common cause of acute liver failure in many countries. Previously, alpha-mangostin (α-MG) has been confirmed to exert protective effects on a variety of liver injuries, but the protective effect on acetaminophen-induced acute liver injury (ALI) remains largely unknown. This work investigated the regulatory effect and underlying cellular mechanisms of α-MG action to attenuate acetaminophen-induced hepatotoxicity in mice. The increased serum aminotransferase levels and glutathione (GSH) content and reduced malondialdehyde (MDA) demonstrated the protective effect of α-MG against acetaminophen-induced hepatotoxicity. In addition, α-MG pretreatment inhibited increases in tumor necrosis factor (TNF-α) and interleukin-1β (IL-1β) caused by exposure of mice to acetaminophen. In liver tissues, α-MG inhibited the protein expression of autophagy-related microtubule-associated protein light chain 3 (LC3) and BCL2/adenovirus E1B protein-interacting protein 3 (BNIP3). Western blotting analysis of liver tissues also proved evidence that α-MG partially inhibited the activation of apoptotic signaling pathways via increasing the expression of Bcl-2 and decreasing Bax and cleaved caspase 3 proteins. In addition, α-MG could in part downregulate the increase in p62 level and upregulate the decrease in p-mTOR, p-AKT and LC3 II /LC3 I ratio in autophagy signaling pathways in the mouse liver. Taken together, our findings proved novel perspectives that detoxification effect of α-MG on acetaminophen-induced ALI might be due to the alterations in Akt/mTOR pathway in the liver.

Mechanisms of acetaminophen-induced liver injury and its implications for therapeutic interventions

Acetaminophen (APAP) overdose is the leading cause of drug-induced acute liver failure in many developed countries. Mitochondrial oxidative stress is considered to be the predominant cellular event in APAP-induced liver injury. Accordingly, N-acetyl cysteine, a known scavenger of reactive oxygen species (ROS), is recommended as an effective clinical antidote against APAP-induced acute liver injury (AILI) when it is given at an early phase; however, the narrow therapeutic window limits its use. Hence, the development of novel therapeutic approaches that can offer broadly protective effects against AILI is clearly needed. To this end, it is necessary to better understand the mechanisms of APAP hepatotoxicity. Up to now, in addition to mitochondrial oxidative stress, many other cellular processes, including phase I/phase II metabolism, endoplasmic reticulum stress, autophagy, sterile inflammation, microcirculatory dysfunction, and liver regeneration, have been identified to be involved in the pathogenesis of AILI, providing new targets for developing more effective therapeutic interventions against APAP-induced liver injury. In this review, we summarize intracellular and extracellular events involved in APAP hepatotoxicity, along with emphatic discussions on the possible therapeutic approaches targeting these different cellular events.

Panax quinquefolius saponin inhibits endoplasmic reticulum stress-mediated apoptosis and neurite injury and improves functional recovery in a rat spinal cord injury model

The treatment goal in spinal cord injury (SCI) is to repair neurites and suppress cell apoptosis. Panax quinquefolius saponin (PQS) is the major active ingredient of American ginseng and has been demonstrated to have anti-inflammatory and anti-apoptotic roles in various diseases. However, the potential effect of PQS on the pathological process of acute SCI remains unknown. This work tested the effects of PQS on acute SCI and clarified its potential mechanisms. PQS treatment ameliorated the damage to spinal tissue and improved the functional recovery after SCI. PQS treatment inhibited endoplasmic reticulum (ER) stress and the associated apoptosis after acute SCI. PQS further abolished the triglyceride (TG)-induced ER stress and associated apoptosis in neuronal cultures. PQS appears to inhibit the ER-stress-induced neurite injury in PC12 cells. Our results suggest that PQS is a novel therapeutic agent for acute central nervous system injury.

Ginsenoside Rk1 ameliorates paracetamol-induced hepatotoxicity in mice through inhibition of inflammation, oxidative stress, nitrative stress and apoptosis

Background

Frequent overdose of paracetamol (APAP) has become the major cause of acute liver injury. The present study was designed to evaluate the potential protective effects of ginsenoside Rk1 on APAP-induced hepatotoxicity and investigate the underlying mechanisms for the first time.

Methods

Mice were treated with Rk1 (10 mg/kg or 20 mg/kg) by oral gavage once per d for 7 d. On the 7th d, all mice treated with 250 mg/kg APAP exhibited severe liver injury after 24 h, and hepatotoxicity was assessed.

Results

Our results showed that pretreatment with Rk1 significantly decreased the levels of serum alanine aminotransferase, aspartate aminotransferase, tumor necrosis factor, and interleukin-1β compared with the APAP group. Meanwhile, hepatic antioxidants, including superoxide dismutase and glutathione, were elevated compared with the APAP group. In contrast, a significant decrease in levels of the lipid peroxidation product malondialdehyde was observed in the ginsenoside Rk1-treated group compared with the APAP group. These effects were associated with a significant increase of cytochrome P450 E1 and 4-hydroxynonenal levels in liver tissues. Moreover, ginsenoside Rk1 supplementation suppressed activation of apoptotic pathways by increasing Bcl-2 and decreasing Bax protein expression levels, which was shown using western blotting analysis. Histopathological observation also revealed that ginsenoside Rk1 pretreatment significantly reversed APAP-induced necrosis and inflammatory infiltration in liver tissues. Biological indicators of nitrative stress, such as 3-nitrotyrosine, were also inhibited after pretreatment with Rk1 compared with the APAP group.

Conclusion

The results clearly suggest that the underlying molecular mechanisms in the hepatoprotection of ginsenoside Rk1 in APAP-induced hepatotoxicity may be due to its antioxidation, antiapoptosis, anti-inflammation, and antinitrative effects.