Oligonol Ameliorates CCl₄-Induced Liver Injury in Rats via the NF-Kappa B and MAPK Signaling Pathways

Dimethyl Bisphenolate Ameliorates Carbon Tetrachloride-Induced Liver Injury by Regulating Oxidative Stress-Related Genes

Liver disease accounts for millions of deaths per year all over the world due to complications from cirrhosis and liver injury. In this study, a novel compound, dimethyl bisphenolate (DMB), was synthesized to investigate its role in ameliorating carbon tetrachloride (CCl4)-induced liver injury through the regulation of oxidative stress-related genes. The structure of DMB was confirmed based on its hydrogen spectrum and mass spectrometry. DMB significantly reduced the high levels of ALT, AST, DBIL, TBIL, ALP, and LDH in a dose-dependent manner in the sera of CCl4-treated rats. The protective effects of DMB on biochemical indicators were similar to those of silymarin. The ROS fluorescence intensity increased in CCl4-treated cells but significantly weakened in DMB-treated cells compared with the controls. DMB significantly increased the content of oxidative stress-related GSH, Nrf2, and GCLC dose-dependently but reduced MDA levels in CCl4-treated cells or the liver tissues of CCl4-treated rats. Moreover, DMB treatment decreased the expression levels of P53 and Bax but increased those of Bcl2. In summary, DMB demonstrated protective effects on CCl4-induced liver injury by regulating oxidative stress-related genes.

Kaempferol Suppresses Carbon Tetrachloride-Induced Liver Damage in Rats via the MAPKs/NF-κB and AMPK/Nrf2 Signaling Pathways

Oxidative stress plays a critical role in the development of liver disease, making antioxidants a promising therapeutic approach for the prevention and management of liver injuries. The aim of this study was to investigate the hepatoprotective effects of kaempferol, an antioxidant flavonoid found in various edible vegetables, and its underlying mechanism in male Sprague-Dawley rats with carbon tetrachloride (CCl₄)-induced acute liver damage. Oral administration of kaempferol at doses of 5 and 10 mg/kg body weight resulted in the amelioration of CCl₄-induced abnormalities in hepatic histology and serum parameters. Additionally, kaempferol decreased the levels of pro-inflammatory mediators, TNF-α and IL-1β, as well as COX-2 and iNOS. Furthermore, kaempferol suppressed nuclear factor-kappa B (NF-κB) p65 activation, as well as the phosphorylation of Akt and mitogen-activated protein kinase members (MAPKs), including extracellular signal-regulated kinase, c-Jun NH₂-terminal kinase, and p38 in CCl₄-intoxicated rats. In addition, kaempferol improved the imbalanced oxidative status, as evidenced by the reduction in reactive oxygen species levels and lipid peroxidation, along with increased glutathione content in the CCl₄-treated rat liver. Administering kaempferol also enhanced the activation of nuclear factor-E2-related factor (Nrf2) and heme oxygenase-1 protein, as well as the phosphorylation of AMP-activated protein kinase (AMPK). Overall, these findings suggest that kaempferol exhibits antioxidative, anti-inflammatory, and hepatoprotective effects through inhibiting the MAPK/NF-κB signaling pathway and activating the AMPK/Nrf2 signaling pathway in CCl₄-intoxicated rats.

Role of Dietary Polyphenols in the Activity and Expression of Nitric Oxide Synthases: A Review

Nitric oxide (NO) plays several key roles in the functionality of an organism, and it is usually released in numerous organs and tissues. There are mainly three isoforms of the enzyme that produce NO starting from the metabolism of arginine, namely endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase (iNOS), and neuronal nitric oxide synthase (nNOS). The expression and activity of these isoforms depends on the activation/deactivation of different signaling pathways at an intracellular level following different physiological and pathological stimuli. Compounds of natural origin such as polyphenols, which are obtainable through diet, have been widely studied in recent years in in vivo and in vitro investigations for their ability to induce or inhibit NO release, depending on the tissue. In this review, we aim to disclose the scientific evidence relating to the activity of the main dietary polyphenols in the modulation of the intracellular pathways involved in the expression and/or functionality of the NOS isoforms.

The Efficacy of Oligonol in Nonalcoholic Fatty Liver Disease: A Randomized Double-Blinded Placebo-Controlled Trial

Introduction: Oligonol, an oligomerized-polyphenol from Litchi chinensis extract, has been shown to alleviate metabolic syndrome. The aim of this study was to evaluate the effects of oligonol in patients with nonalcoholic fatty liver disease (NAFLD). Methods: Adult patients with NAFLD defined by magnetic resonance imaging-derived proton density fat fraction (MRI-PDFF) ≥11% were enrolled and then randomly assigned to receive either oligonol or placebo capsules. Primary endpoint was ≥30% reduction in MRI-PDFF at 24 weeks. Secondary outcomes were reductions in bodyweight, waist circumference, alanine transaminase, fasting blood sugar, and lipid profiles at week 24. Results: Forty patients were enrolled (n = 20/group). Primary endpoint was achieved in 20% in the oligonol group and 15% in the placebo group (p = 0.50). The authors found a reduction in MRI-PDFF between weeks 0 and 24 in the oligonol group; however, the change was not different from the placebo group. Secondary outcomes were similar between two groups. Discussion: Oligonol has not shown a significant therapeutic effect in NAFLD. Future studies with a longer duration of therapy might be needed to achieve the primary endpoint. Clinical Trial Registration Number: Thai Clinical Trial Registry identification number: TCTR20200814001.

Clinical efficacy of oligonol® supplementation on metabolism and muscle health in middle-aged and older adults: A double-blinded randomized controlled trial

BACKGROUND

Oligonol® is a low-molecular-weight polyphenol that has biological effects on metabolism in animals. However, little is known about its roles in muscle function and muscle quality in middle-aged and older adults.

METHODS

120 participants were enrolled for study based on 1:1 randomization. Participants in the intervention group were provided 200 mg oligonol® prepared as capsules, and 200 mg placebo (dextrin) was provided in control group.

RESULTS

Data from 103 participants (52 in the intervention group and 51 in the control group) were available for analysis. The mean age of all participants was 64.0 ± 8.2 years, and two-thirds of the participants were females. Baseline demographic characteristics, functional assessment, laboratory data and muscle parameters were similar between groups. Hip circumference decreased (p = 0.009) during the study period, and the 6-m walking speed increased (p = 0.001) in women in the intervention group. In contrast, 6-m walking speed, 6-min walking distance and handgrip strength were significantly improved in men in the intervention group, but increased total body fat percentage (p = 0.038) and decreased mid-thigh cross-muscle area (CMA) (p = 0.007) were observed in the control group. Compared to the control group, the 12-week interval change in the percentage of mid-thigh CMA was maintained in men in the intervention group but was significantly decreased in the control group (p = 0.03, 95% CI:0.002-0.05).

CONCLUSIONS

Oligonol supplementation (200 mg per day) significantly improved physical performance and muscle mass in men. Further studies are needed to confirm the potential favorable effects of oligonol® supplementation.

New phthalimide analog ameliorates CCl4 induced hepatic injury in mice via reducing ROS formation, inflammation, and apoptosis

The present study aimed, for the first time, to examine the biochemical effects of new phthalimide analog, 2-[2-(2-Bromo-1-ethyl-1H-indol-3-yl) ethyl]-1H-isoindole-1,3(2H)-dione, compared to thalidomide drug against liver injury induced in mice. Carbon tetrachloride was intraperitoneal injected in mice for 6 consecutive weeks at a dose of 0.4 mL/kg twice a week for liver injury induction. Histopathological examination, levels of malondialdehyde, nitric oxide, and antioxidant enzymes were determined. Additionally, the protein levels of vascular endothelial growth factor, proliferating cell nuclear protein, tumor necrosis factor-alfa, nuclear factor kappa B-p65, B-cell lymphoma-2, and cysteine-aspartic acid protease-3 were determined. Results revealed that the treatment with phthalimide analog improved the detected liver damage and presented an obvious antioxidant activity through decreasing malondialdehyde and nitric oxide levels accompanied by increasing the levels of the antioxidant enzymes. Furthermore, the analog exhibited an effective inhibitory activity towards the studied protein expressions in liver tissues. Moreover, the B-cell lymphoma-2 protein level was increased while the cysteine-aspartic acid protease-3 level was suppressed after the treatment with phthalimide analog. Together, these results propose that phthalimide analog can ameliorate carbon tetrachloride-induced liver injury in mice through its potent inhibition mediating effect in oxidative stress, inflammation, and apoptosis mechanisms.

A20 Attenuates Lipopolysaccharide-Induced Inflammation Through MAPK/ERK/JNK Pathway in LX-2 Cells

Background: Hepatic stellate cells (HSCs) are liver-specific pericytes that transform into myofibroblasts, which are involved in pathological vascularization in liver fibrosis. We previously suggested that A20 overexpression suppresses lipopolysaccharide (LPS)-induced inflammation in HSC. We aimed to determine the mechanisms of the anti-inflammatory role of A20 in LX-2 cells. Methods: LX-2 cells were transfected with A20-siRNA or control-siRNA and control adenovirus or A20-carrying adenovirus. Quantitative reverse transcription PCR (RT-qPCR) analysis was employed to quantify mRNA levels of α-SMA, col-I, col-III, IL-6, TGF-β, and PDGF in A20-siRNA LX-2 cells stimulated with LPS. Multiple molecular indices of MAPK/ERK/JNK signal pathway were performed by using Western blotting. Results: Relative to control, the fibrosis-related mRNA levels of α-SMA, col-I, and col-III were increased in A20-siRNA LX-2 cells. Meanwhile, A20-siRNA cells significantly increased IL-6, TGF-β, and PDGF mRNA levels. Relative to controls, stimulating A20 overexpressing LX-2 cells with LPS for 5 and 30 minutes significantly reduced the levels of phosphorylated ERK and JNK, respectively. A20 knockdown in LX-2 cells promotes phosphorylated ERK and JNK levels with LPS for 30 minutes. Conclusions: Our data indicate that A20 could be functional in HSCs through the MAPK/ERK/JNK signaling pathway, highlighting a potential novel therapeutic strategy against liver fibrosis.

Rosmarinic acid attenuates acrylamide induced apoptosis of BRL-3A cells by inhibiting oxidative stress and endoplasmic reticulum stress

Acrylamide (AA) is a common endogenous contaminant in food, with a complex toxicity mechanism. The study on liver damage to experimental animals caused by AA has aroused a great attention. Rosmarinic acid (RosA) as a natural antioxidant shows excellent protective effects against AA-induced hepatotoxicity, but the potential mechanism is still unclear. In the current study, the protective effect of RosA on BRL-3A cell damage induced by AA was explored. RosA increased the activity of SOD and GSH, reduced the content of ROS and MDA, and significantly reduced the oxidative stress (OS) damage of BRL-3A cells induced by AA. RosA pretreatment inhibited the MAPK signaling pathway activated by AA, and down-regulated the phosphorylation of JNK, ERK and p38. RosA pretreatment also reduced the production of calcium ions caused by AA. In addition, the key proteins p-IRE1α, XBP-1s, TRAF2 of the IRE1 pathway, and the expression of endoplasmic reticulum stress (ERS) characteristic proteins GRP78, p-ASK1, Caspase-12 and CHOP were also down-regulated by RosA. NAC blocked the activation of the MAPK signaling pathway and inhibited the ERS pathway. RosA reduced the rate of apoptosis and down-regulated the expression of Bax/Bcl-2 and Caspase-3, thereby inhibiting AA-induced apoptosis. In conclusion, RosA reduced the OS and ERS induced by AA in BRL-3A cells, thereby inhibiting cell apoptosis, and it could be used as a potential protective agent against AA toxicity.

Benomyl induced oxidative stress related DNA damage and apoptosis in H9c2 cardiomyoblast cells

Benomyl, benzimidazole group pesticide, has been prohibited in Europe and USA since 2003 due to its toxic effects and it has been still determined as food and environmental contaminant. In the present study, the toxic effect mechanisms of benomyl were evaluated in rat cardiomyoblast (H9c2) cells. Cytotoxicity was determined by MTT and NRU assay and, oxidative stress potential was evaluated by reactive oxygen species (ROS) production and glutathione levels. DNA damage was assessed by alkaline comet assay. Relative expressions of apoptosis related genes were evaluated; furthermore, NF-κB and JNK protein levels were determined. At 4 μM concentration (at which cell viability was >70%), benomyl increased 2-fold of ROS production level and 2-fold of apoptosis as well as DNA damage. Benomyl down-regulated miR21, TNF-α and Akt1 ≥ 48.75 and ≥ 97.90; respectively. PTEN, JNK and NF-κB expressions were upregulated. The dramatic changes in JNK and NF-κB expression levels were not observed in protein levels. These findings showed the oxidative stress related DNA damage and apoptosis in cardiomyoblast cells exposed to benomyl. However, further mechanistic and in vivo studies are needed to understand the cardiotoxic effects of benomyl and benzimidazol fungucides.

Environmental toxicants, oxidative stress and health adversities: interventions of phytochemicals

OBJECTIVES

Oxidative stress is the most common factor mediating environmental chemical-induced health adversities. Recently, an exponential rise in the use of phytochemicals as an alternative therapeutics against oxidative stress-mediated diseases has been documented. Due to their free radical quenching property, plant-derived natural products have gained substantial attention as a therapeutic agent in environmental toxicology. The present review aimed to describe the therapeutic role of phytochemicals in mitigating environmental toxicant-mediated sub-cellular and organ toxicities via controlling cellular antioxidant response.

METHODS

The present review has covered the recently related studies, mainly focussing on the free radical scavenging role of phytochemicals in environmental toxicology.

KEY FINDINGS

In vitro and in vivo studies have reported that supplementation of antioxidant-rich compounds can ameliorate the toxicant-induced oxidative stress, thereby improving the health conditions. Improving the cellular antioxidant pool has been considered as a mode of action of phytochemicals. However, the other cellular targets of phytochemicals remain uncertain.

CONCLUSIONS

Knowing the therapeutic value of phytochemicals to mitigate the chemical-induced toxicity is an initial stage; mechanistic understanding needs to decipher for development as therapeutics. Moreover, examining the efficacy of phytochemicals against mixer toxicity and identifying the bioactive molecule are major challenges in the field.

Protective Effect of Oligonol on Dimethylnitrosamine-Induced Liver Fibrosis in Rats via the JNK/NF-κB and PI3K/Akt/Nrf2 Signaling Pathways

Oligonol is a low molecular weight polyphenol product derived from lychee fruit by a manufacturing process. We investigated oligonol’s anti-fibrotic effect and the underlying mechanism in dimethylnitrosamine (DMN)-induced chronic liver damage in male Sprague–Dawley rats. Oral administration of oligonol (10 and 20 mg/kg body weight) ameliorated the DMN-induced abnormalities in liver histology and serum parameters in rats. Oligonol prevented the DMN-induced elevations of TNF-α, IL-1β, IL-6, cyclooxygenase-2, and inducible nitric oxide synthase expressions at the mRNA level. NF-κB activation and JNK phosphorylation in DMN-treated rats were ablated by oligonol. Oligonol reduced the enhanced production of hepatic malondialdehyde and reactive oxygen species and recovered protein SH, non-protein SH levels, and catalase activity in the DMN treated liver. Nrf2 translocation into the nucleus was enhanced, and PI3K and phosphorylated Akt levels were increased by administering oligonol. The level of hepatic fibrosis-related factors such as α-smooth muscle actin, transforming growth factor-β1, and type I collagen was reduced in rats treated with oligonol. Histology and immunohistochemistry analysis showed that the accumulation of collagen and activation of hepatic stellate cells (HSCs) in liver tissue were restored by oligonol treatment. Taken together, oligonol showed antioxidative, hepatoprotective, and anti-fibrotic effects via JNK/NF-κB and PI3K/Akt/Nrf2 signaling pathways in DMN-intoxicated rats. These results suggest that antioxidant oligonol is a potentially useful agent for the protection against chronic liver injury.

Pterocarpus mildbraedii (Harms) extract resolves propanil-induced hepatic injury via repression of inflammatory stress responses in Wistar rats

Pterocarpus mildbraedii (PME) is a green leafy vegetable from the Papilionaceae family. This study evaluated the anti-inflammatory activity of PME in Wistar rats exposed to experimental hepatotoxicity using propanil (PRP), a post-emergent herbicide. Animals were grouped as control, PRP, PME, and PME + PRP. After 7 days, the levels of stress-activated protein kinases/c-Jun N-terminal kinase (SAPK/JNK), p38 mitogen-activated protein kinase (p38 MAPK), and signal transducer and activator of transcription (STAT-3) were measured in rat liver. Furthermore, myeloperoxidase (MPO) and nitric oxide (NO) levels, as well as protein expressions of nuclear factor-κB (NF-κB p65), inducible nitric oxide synthase (iNOS), and cyclo-oxygenase-2 (COX-2) were determined. Compared with PRP-treated rats, PME significantly reduced the hepatic MPO and NO levels. PME also diminished NFκB, iNOS, and COX-2 protein expressions in PRP-treated rats. This study showed that Pterocarpus mildbraedii leaves produce active principles with relevant anti-inflammatory potential. PRACTICAL APPLICATIONS: Previous studies have shown that bioactive principles contained in medicinal plants can offer protection against chemically induced inflammation. Pterocarpus mildbraedii leaves, with rich content of polyphenols, flavonoids, and essential fatty acids, could be exploited as a therapeutic agent against pesticide-induced oxidative stress and inflammation. This current study has also shown that the potential of PME as a functional food is boosted by the presence of α-linolenic acid, an omega-3-fatty acid known to possess anti-inflammatory activity. Here, we elucidated the cellular mechanisms of the anti-inflammatory action of PME.

Effect of procyanidins on lipid metabolism and inflammation in rats exposed to alcohol and iron

Background

Lifestyle involving uncontrolled alcohol consumption coupled regularly with red meat and other iron sources has detrimental effects on the liver, which in the long term, results in Alcoholic Liver Disease (ALD). Procyanidin has lately garnered increasing attention and has become the focus of research owing to its antioxidant properties. This study explores the anti-inflammatory effects of procyanidins, in preventing ALD, by analyzing the biological activities of the compound on liver injury caused by excessive alcohol and iron.

Method

Male SPF Wistar rats were placed in 4 groups; the control Group A (basic diet); the model Group B (excess alcohol 8–12 mL/kg/d and iron 1000 mg/kg diet); the low dose procyanidin Group C (model group diet plus 60 mg/kg/d of procyanidin); and the high dose procyanidin Group D (model group diet plus 120 mg/kg/d of procyanidin). Serum biochemical markers for liver damage were measured spectrophotometrically. The NFκB and IκB mRNA expression levels were determined using RT-PCR; the NFκB p65 and IκB protein expression levels were assessed via western blotting, while ELISA was used to detect serum inflammatory factors.

Results

The pathological score of the model Group B, low and high dose procyanidin Groups C and D were 6.58 ± 0.90,4.69 ± 0.70 and 2.00 ± 0.73, respectively (P < 0.05). The results showed that high alcohol and iron contents in the model group led to significant damage of liver structure, increased low-density lipoproteins (LDLs), steatosis, and increased levels of inflammatory cytokines. High amounts of procyanidins led to the preservation of the liver structure, production of high-density lipoproteins, and reduction in serum inflammatory cytokines while also significantly decreasing the expression levels of NFκB p65.

Conclusion

The results prove that procyanidins have hepatoprotective potential and could be effective in reversing histopathology, possibly by alleviating inflammation and improving lipid metabolism.

The Role of Nitric Oxide in Regulating Intestinal Redox Status and Intestinal Epithelial Cell Functionality

Important functions of intestinal epithelial cells (IECs) include enabling nutrient absorption to occur passively and acting as a defense barrier against potential xenobiotic components and pathogens. A compromise to IEC function can result in the translocation of bacteria, toxins, and allergens that lead to the onset of disease. Thus, the maintenance and optimal function of IECs are critically important to ensure health. Endogenous biosynthesis of nitric oxide (NO) regulates IEC functionality both directly, through free radical activity, and indirectly through cell signaling mechanisms that impact tight junction protein expression. In this paper, we review the current knowledge on factors that regulate inducible nitric oxide synthase (iNOS) and the subsequent roles that NO has on maintaining IECs' intestinal epithelial barrier structure, functions, and associated mechanisms of action. We also summarize important findings on the effects of bioactive dietary food components that interact with NO production and affect downstream intestinal epithelium integrity.

Oligonol, a Low Molecular Weight Polyphenol, Enhances Apoptotic Cell Death in Ovarian Cancer Cells via Suppressing NF-κB Activation

BACKGROUND

Oligonol, a low molecular weight polyphenol derived from lychee fruit, not only has anti-inflammatory effects in various disease conditions but also has antitumor-promoting effects. We evaluate the nuclear factor-kappa B (NF-κB)-related anticancer effect of oligonol in ovarian cancer using SKOV-3 cells.

METHODS

Cell viability was examined after oligonol treatment using MTT assay and reactive oxygen species (ROS) production measurement. Subsequently, apoptotic cell death was visualized by the TdT-mediated dUTP nick-end labeling (TUNEL) method. The effect of oligonol on the NF-κB signaling pathway was evaluated using western blot analysis and luciferase activity measurement of p65, an NF-κB subunit.

RESULTS

Cell viability significantly decreased after oligonol treatment of 72 h. Apoptosis-related markers were highly expressed in oligonol-treated cells, and increased apoptosis after oligonol treatment was also confirmed using the TUNEL assay. Western blotting results showed the expression of NF-κB signaling pathway factors, p-ERK, TRAF2, and p-IκBα, increased following treatment with oligonol, whereas p65 and COX-2 expression decreased. Immunofluorescence imaging results showed p65 luciferase activity in the nucleus as well as a shift to cytoplasmic expression.

CONCLUSION

Oligonol treatment significantly enhances apoptotic cell death in SKOV-3 cells, with the suppression of NF-κB activation, which plays an essential role in this anticancer effect.

Hepatoprotective activity of Uncaria tomentosa extract against sub-chronic exposure to fipronil in male rats

The effects of fipronil (FPN) on the liver of rats were studied. Rats (n = 6) were treated with 9.7 mg/kg (1/10 of FPN LD₅₀), and other rats (n = 6) received 120 mg/kg of 10% Uncaria tomentosa extract, while a mixture of 9.7 mg/kg FPN and 120 mg/kg of 10% Uncaria tomentosa extract were administered orally to the rats (n = 6) daily for 6 weeks. Body, hepatic weights, liver enzymes, and lipid profile were determined. Hepatic activities of MDA, TNO, TAC, TNF-α, and IL-6 in liver homogenate were measured. Immunohistochemistry of NF-kB and liver histopathology were performed. Fipronil-treated rats had a significant (P = 0.02) lower weight gain. Moreover, relative liver weight was significantly (P = 0.003) increased in FPN-treated rats. Rats administrated with FPN exhibited a significantly (P = 0.02) higher liver enzymes and promoted levels of MDA, TNO, TNF-α, and IL-6 (P < 0.0001) than that in the other groups. Immunostaining of NF-κB was increased (P < 0.0001) in FPN-treated rats. Interestingly, Uncaria tomentosa alone or with FPN decreased the liver immunostaining of NF-κB. In conclusion, FPN produced liver injury through lipid peroxidation and stimulation of NF-κB. However, Uncaria tomentosa combated the oxidative stress and liver damage induced by FPN via inhibition of NF-κB.

Preventive effect of oligonol on nitric oxide and reactive oxygen species production through regulation of nuclear factor kappa B signaling pathway in RAW 264.7 macrophage cells against sodium nitroprusside

Oligonol attenuated SNP-induced oxidative stress and inflammatory responsesviaregulation of the NF-κB signalling pathway in RAW 264.7 macrophage cells.

Amygdalin attenuates acute liver injury induced by D-galactosamine and lipopolysaccharide by regulating the NLRP3, NF-κB and Nrf2/NQO1 signalling pathways

Acute liver injury (ALI) is a life-threatening syndrome accompanied by overwhelming inflammation. Amygdalin (AGD) has been reported to possess various biological activities, particularly anti-inflammatory activity. The current study was designed to assess the protective effects and underlying mechanisms of AGD against ALI induced by d-galactosamine (GalN) and lipopolysaccharide (LPS) in mice. The results indicated that AGD treatment effectively reduced the lethality, ameliorated the histopathological liver changes, reduced the malondialdehyde (MDA) and myeloperoxidase (MPO) levels, and decreased the alanine transaminase (ALT) and aspartate aminotransferase (AST) levels resulting from LPS/GalN challenge. Moreover, AGD significantly inhibited LPS/GalN-induced inflammatory responses in mice with ALI by reducing not only the secretion of tumour necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 but also the protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Additionally, our results demonstrated that the inhibitory effect of AGD was due to the suppressed activation of nuclear factor-kappa B (NF-κB) and nucleotide-binding domain (NOD-)like receptor protein 3 (NLRP3) inflammasome activity. Furthermore, AGD treatment substantially increased nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear translocation and enhanced NAD (P) H: quinoneoxidoreductase 1 protein expression, which was reversed by a Nrf2 inhibitor, in HepG2 cells. In summary, our investigations suggested that the ability of AGD to ameliorate LPS/GalN-induced ALI may involve the inhibition of the NLRP3 inflammasome and NF-κB signalling pathways and the upregulation of the Nrf2/NQO1 signalling pathway.

Low-Molecular-Weight Oligonol, a Polyphenol Derived from Lychee Fruit, Attenuates Experimental Reflux Esophagitis and HCl/Ethanol-Induced Gastric Ulcer

Oligonol, a polyphenol derived from lychee fruit, is produced by an oligomerization process that converts high-molecular-weight polyphenol polymers into low-molecular-weight oligomers. Evidence suggests that oligonol exerts its beneficial effects based on antioxidant and anti-inflammatory properties. This study was the first to investigate the antioxidative and anti-inflammatory effects of oligonol on gastroesophageal inflammatory models: surgically induced acute reflux esophagitis (RE) and gastric ulcer (GU) induced by HCl/ethanol. In the in vitro study, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazolin-6-sulfonic acid) (ABTS) radical scavenging assays were performed to determine the antioxidant activity of oligonol. The experimental groups were each composed of normal, vehicle, and oligonol groups. RE rats and GU mice were treated orally with oligonol (100 mg/kg bw) or distilled water as a vehicle (n = 8 for each group). Oligonol exhibited potent free radical-scavenging capacities for DPPH and ABTS radicals, activities that were similar to those of ascorbic acid. The in vivo study revealed that oligonol consumption significantly prevented RE and GU formation and decreased the gross mucosal injury from oxidative stress. Oligonol decreased the reactive oxygen species levels and elevated levels of both inflammatory mediators and cytokines (p-IκB, NF-κBp65, COX-2, iNOS, TNF-α, and IL-1β) in the RE and GU models. Oligonol had a protective effect against oxidative stress by regulating antioxidant enzyme (superoxide dismutase, catalase, and GPx-1/2) activities in GU mice. Oligonol has potential as a preventive and therapeutic agent for gastroesophageal inflammatory diseases, including RE and GU.

Madecassoside prevents acute liver failure in LPS/D-GalN-induced mice by inhibiting p38/NF-κB and activating Nrf2/HO-1 signaling

Madecassoside (MA), a triterpenoid saponin isolated from Centella asiatica, exerts various pharmacological activities including antioxidative and anti-inflammatory effects. The aim of this study was to explore the protective effect of MA in the treatment of lipopolysaccharide (LPS) and D-galactosamine (D-GalN)-induced acute liver failure(ALF) in mice. We hypothesized that MA administration may decrease the degree of liver injury caused by LPS/D-GalN. In this study, we investigated this hypothesis by treating a mouse model of LPS/D-GalN-induced liver injury with MA. Our study demonstrated that MA (20 mg/kg and 40 mg/kg) treatment for 10 days attenuated LPS/D-GalN-induced liver injury by protecting liver function, suppressing the production of inflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6, and recovering antioxidant enzyme activity. MA also significantly suppressed LPS-stimulated protein levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 by blocking the phosphorylation of p38 mitogen-activated protein kinase (MAPK) and eukaryotic transcription factor nuclear factor-kappa B (NF-κB). In addition, MA treatment enhanced protein levels of heme oxygenase (HO)-1 and anti-oxidant enzymes (superoxide dismutase, catalase, and glutathione peroxidase) through the upregulation of nuclear factor E2-related factor 2 (Nrf2) in LPS-stimulated liver injury. These results suggest that MA is a promising agent for the treatment of LPS/D-GalN-induced liver injury that could serve as a candidate for the development of a hepatoprotective drug against ALF.

Matrix Remodeling Associated 7 Deficiency Alleviates Carbon Tetrachloride-Induced Acute Liver Injury in Mice

Matrix remodeling associated 7 (MXRA7) was first noted to co-express with a group of matrix remodeling related genes, and its biological functions had remained unclear. In this study, we investigated the presumed function of MXRA7 in a carbon tetrachloride (CCl₄)-induced acute liver injury model in mice. Wild-type, MXRA7^−/− mice, and mice that were pulsed with hydrodynamic injection of vehicle or MXRA7-harboring plasmids were challenged with a single dose of CCl₄ for injury induction. The sera, spleens, and livers were harvested from mice for assay of cytokines/chemokines expression, cellular responses, or histological features. We found that MXRA7 deficiency alleviated, and MXRA7 overexpression aggravated liver damage in CCl₄-challenged mice. FACS analysis showed that MXRA7 deficiency reduced the recruitment of neutrophils through downregulation the expression of CXCL1 and CXCL2 in liver, decreased the number of CD8⁺ T cells in liver and spleen, suppressed the release of IFNγ and TNFα from T cells, and decreased IFNγ in serum and liver. Western blot assay demonstrated that MXRA7 deficiency suppressed the activation of MAPK pathway and AKT/NF-κB pathway, respectively. Lastly, MXRA7 deficiency or overexpression regulated the expression of two matrix remodeling-related genes (fibronectin and TIMP1) in the liver. We concluded that MXRA7 was an active player in CCl₄-induced liver injury, hypothetically by mediating the inflammation or immune compartments and matrix remodeling processes. Further exploration of MXRA7 as a possible new therapeutic target for management of inflammation-mediated liver injury was discussed.

Cav-1 deficiency promotes liver fibrosis in carbon tetrachloride (CCl4)-induced mice by regulation of oxidative stress and inflammation responses

Caveolin-1 (Cav-1), as a membrane protein involved in the formation of caveolae, binds steroid receptors and endothelial nitric oxide synthase, limiting its translocation and activation. In the present study, we investigated the role of Cav-1 in the progression of hepatic fibrosis induced by carbon tetrachloride (CCl₄) in murine animals. Therefore, the wild type (WT) and Cav-1-knockout (Cav-1^-/-) mice were used in our study and subjected to CCl₄. The results indicated that CCl₄ induced the decrease of Cav-1 expression in liver tissue samples. And Cav-1^-/- intensified CCl₄-triggered hepatic injury, evidenced by the stronger hepatic histological alterations, serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels and liver terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive cells. CCl₄ led to oxidative stress, supported by the reduced superoxide dismutase (SOD) activity and glutathione (GSH) levels, as well as enhanced malondialdehyde (MDA) and O₂^- levels in liver samples. And the process was intensified by Cav-1^-/-. Additionally, CCl₄-caused hepatic inflammation was aggregated by Cav-1^-/- via further increasing the secretion of pro-inflammatory cytokines. Moreover, CCl₄-caused fibrosis was strengthened by Cav-1^-/-, which was evidenced by the up-regulation of α-smooth muscle actin (α-SMA), collagen alpha 1 type 1 (Col1A1), lysyl oxidase (Lox) and transforming growth factor-β1 (TGF-β1) in liver tissues. Similar results were observed in TGF-β1-stimulated hepatic stellate cells (HSCs) and LX-2 cells without Cav-1 expressions that in vitro, suppressing Cav-1 further accelerated TGF-β1-induced oxidative stress, inflammation and fibrosis development. In conclusion, our results indicated that Cav-1 played an important role in CCl₄-induced hepatic injury, which may be used as potential therapeutic target for hepatic fibrosis treatment.

Hepatoprotective effect of methyl ferulic acid against carbon tetrachloride-induced acute liver injury in rats

The present study aimed to investigate the hepatoprotective effects of methyl ferulic acid (MFA) against oxidative stress and apoptosis in acute liver injury induced by carbon tetrachloride (CCl₄) in rats, as well as the underlying mechanisms. Sprague Dawley rats were treated with CCl₄ after oral administration of MFA (25, 50, and 100 mg/kg) or dimethyl diphenyl bicarboxylate (200 mg/kg) for 7 days. The hepatoprotective effects of MFA were determined by analyzing serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities as well as changes of oxidant parameters. Histopathological analysis was performed to determine the degree of hepatic injury. The mechanisms were investigated by detecting the levels of NADPH oxidase (NOX) trans-membrane subunit NOX4, its ligand p22^phox, as well as caspase3, cleaved caspase3, B-cell lymphoma (Bcl)-2, Bcl-2-associated X protein (Bax), tumor necrosis factor (TNF)-α, interleukin (IL)-1, reactive oxygen species (ROS), thiobarbituric acid-reactive substances (TBARS), total anti-oxidant capacity (TAC), phosphorylated J-Jun N-terminal kinase (p-JNK) and p-p38 mitogen-activated protein kinase (MAPK) using semi-quantitative polymerase chain reaction, western blot analysis and colorimetric assays. MFA treatment significantly decreased serum enzymatic activities of ALT and AST. MFA markedly increased activities of liver superoxide dismutase, catalase and glutathione peroxidase, and reduced the malondialdehyde concentration. Histopathological examination demonstrated that MFA reduced lipid degeneration, cytoplasmic vacuolization, necrosis and inflammatory cell infiltration in the liversof CCl₄-treated rats. MFA treatment markedly inhibited the expression of inflammatory factors TNF-α and IL-1β. Mechanistic study revealed that MFA decreased the TAC and the levels of ROS and TBARS. Furthermore, MFA treatment led to a reduction of the mRNA and protein expression of NOX4 and p22phox, as well as the protein levels of caspase3, cleaved caspase-3 and Bax, and an upregulation of p-JNK, p-p38 MAPK and Bcl-2 proteins in the liver. The present study demonstrated that MFA has hepatoprotective effects against CCl₄-induced acute liver damage. MFA has anti-oxidant, anti-inflammatory and anti-apoptotic activities and was able to modulate the NOX4/p22^phox/ROS-JNK/p38 MAPK signaling pathway.

Oligonol, a Low-Molecular Weight Polyphenol Derived from Lychee, Alleviates Muscle Loss in Diabetes by Suppressing Atrogin-1 and MuRF1

Stimulation of the ubiquitin-proteasome pathway-especially E3 ubiquitin ligases Atrogin-1 and MuRF1-is associated with muscle loss in diabetes. Elevated lipid metabolites impair myogenesis. Oligonol, a low molecular weight polyphenol derived from lychee, exhibited anti-diabetic and anti-obesity properties, suggesting it could be a proper supplement for attenuating muscle loss. Dietary (10 weeks) oligonol supplementation (20 or 200 mg/kg diet) on the skeletal muscle loss was investigated in diabetic db/db mice. Transcription factors NF-κB and FoxO3a involved in regulation of Atrogin-1 and MuRF1 were also investigated. Attenuation of muscle loss by oligonol (both doses) was associated with down-regulation of Atrogin-1 and MuRF1 gene expression. Oligonol supplementation decreased NF-κB expression in the nuclear fraction compared with db/db mice without oligonol supplement. Upregulation of sirtuin1 (SIRT1) expression prevented FoxO3a nuclear localization in db/db mice supplemented with oligonol. Marked increases in AMPKα activity and Ppara mRNA expression leading to lower lipid accumulation by oligonol provided additional benefits for attenuating muscle loss. Oligonol limited palmitate-induced senescent phenotype and cell cycle arrest and suppressed Atrogin-1 and MuRF1 mRNA expression in palmitate-treated C2C12 muscle cells, thus contributing to improving the impaired myotube formation. In conclusion, oligonol-mediated downregulation of Atrogin-1 and MuRF1 gene expression alleviates muscle loss and improves the impaired myotube formation, indicating that oligonol supplementation may be useful for the attenuation of myotube loss.

Litchi chinensis as a Functional Food and a Source of Antitumor Compounds: An Overview and a Description of Biochemical Pathways

Litchi is a tasty fruit that is commercially grown for food consumption and nutritional benefits in various parts of the world. Due to its biological activities, the fruit is becoming increasingly known and deserves attention not only for its edible part, the pulp, but also for its peel and seed that contain beneficial substances with antioxidant, cancer preventive, antimicrobial, and anti-inflammatory functions. Although literature demonstrates the biological activity of Litchi components in reducing tumor cell viability in in vitro or in vivo models, data about the biochemical mechanisms responsible for these effects are quite fragmentary. This review specifically describes, in a comprehensive analysis, the antitumor properties of the different parts of Litchi and highlights the main biochemical mechanisms involved.

Protective effect of crocin on BPA-induced liver toxicity in rats through inhibition of oxidative stress and downregulation of MAPK and MAPKAP signaling pathway and miRNA-122 expression

Bisphenol A (BPA) is an artificial environmental endocrine disrupting chemical and commonly used as a monomer of polycarbonate plastics and epoxy resins. The aim of the present study is to investigate the hepatoprotective effects of crocin, a constituent of saffron, against BPA-induced liver toxicity. We showed that treatment of male Wistar rats with 0.5 mg/kg BPA for 30 days increased the level of 8-isoprostane, decreased the level of reduced glutathione, elevated serum levels of aspartate aminotransferase, lactate dehydrogenase, triglyceride, and glucose, and induced periportal inflammation. Western blot results revealed that BPA increased the phosphorylation of c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK1/2), and mitogen-activated protein kinase-activated protein kinase (MAPKAPK), but not p38. BPA also reduced the Akt signaling activation and upregulated microRNA (miR-122) expression. Moreover, we showed here that crocin 20 mg/kg administration ameliorated liver damage and improved elevated levels of TG and liver enzymes of BPA-treated rats possibly though antioxidant activity, downregulation of miR-122 transcript level and lowering the phosphorylation of JNK, ERK1/2, and MAPKAPK and subsequently their activities. Overall, the findings suggest that crocin possesses hepatoprotective effects against BPA-induced liver toxicity by enhancing the antioxidative defense system and regulation of important signaling pathway activities and miR-122 expression.

Macrophage Phenotype in Liver Injury and Repair

Macrophages hold a critical position in the pathogenesis of liver injury and repair, in which their infiltrations is regarded as a main feature for both acute and chronic liver diseases. It is noted that, based on the distinct phenotypes and origins, hepatic macrophages are capable of clearing pathogens, promoting/or inhibiting liver inflammation, while regulating liver fibrosis and fibrolysis through interplaying with hepatocytes and hepatic stellate cells (HSC) via releasing different types of pro- or anti-inflammatory cytokines and growth factors. Macrophages are typically categorized into M1 or M2 phenotypes by adapting to local microenvironment during the progression of liver injury. In most occasions, M1 macrophages play a pro-inflammatory role in liver injury, while M2 macrophages exert an anti-inflammatory or pro-fibrotic role during liver repair and fibrosis. In this review, we focused on the up-to-date information about the phenotypic and functional plasticity of the macrophages and discussed the detailed mechanisms through which the phenotypes and functions of macrophages are regulated in different stages of liver injury and repair. Moreover, their roles in determining the fate of liver diseases were also summarized. Finally, the macrophage-targeted therapies against liver diseases were also be evaluated.