5-O-Demethylnobiletin Alleviates CCl4-Induced Acute Liver Injury by Equilibrating ROS-Mediated Apoptosis and Autophagy Induction

The hepatoprotective effect of 4-phenyltetrahydroquinolines on carbon tetrachloride induced hepatotoxicity in rats through autophagy inhibition

BACKGROUND

The liver serves as a metabolic hub within the human body, playing a crucial role in various essential functions, such as detoxification, nutrient metabolism, and hormone regulation. Therefore, protecting the liver against endogenous and exogenous insults has become a primary focus in medical research. Consequently, the potential hepatoprotective properties of multiple 4-phenyltetrahydroquinolines inspired us to thoroughly study the influence of four specially designed and synthesized derivatives on carbon tetrachloride (CCl4)-induced liver injury in rats.

METHODS AND RESULTS

Seventy-seven Wistar albino male rats weighing 140 ± 18 g were divided into eleven groups to investigate both the toxicity profile and the hepatoprotective potential of 4-phenyltetrahydroquinolines. An in-vivo hepatotoxicity model was conducted using CCl4 (1 ml/kg body weight, a 1:1 v/v mixture with corn oil, i.p.) every 72 h for 14 days. The concurrent treatment of rats with our newly synthesized compounds (each at a dose of 25 mg/kg body weight, suspended in 0.5% CMC, p.o.) every 24 h effectively lowered transaminases, preserved liver tissue integrity, and mitigated oxidative stress and inflammation. Moreover, the histopathological examination of liver tissues revealed a significant reduction in liver fibrosis, which was further supported by the immunohistochemical analysis of α-SMA. Additionally, the expression of the apoptotic genes BAX and BCL2 was monitored using real-time PCR, which showed a significant decrease in liver apoptosis. Further investigations unveiled the ability of the compounds to significantly decrease the expression of autophagy-related proteins, Beclin-1 and LC3B, consequently inhibiting autophagy. Finally, our computer-assisted simulation dockingonfirmed the obtained experimental activities.

CONCLUSION

Our findings suggest that derivatives of 4-phenyltetrahydroquinoline demonstrate hepatoprotective properties in CCl4-induced liver damage and fibrosis in rats. The potential mechanism of action may be due to the inhibition of autophagy in liver cells.

Mitochondrial dysfunction: A promising therapeutic target for liver diseases

The liver is an important metabolic and detoxification organ and hence demands a large amount of energy, which is mainly produced by the mitochondria. Liver tissues of patients with alcohol-related or non-alcohol-related liver diseases contain ultrastructural mitochondrial lesions, mitochondrial DNA damage, disturbed mitochondrial dynamics, and compromised ATP production. Overproduction of mitochondrial reactive oxygen species induces oxidative damage to mitochondrial proteins and mitochondrial DNA, decreases mitochondrial membrane potential, triggers hepatocyte inflammation, and promotes programmed cell death, all of which impair liver function. Mitochondrial DNA may be a potential novel non-invasive biomarker of the risk of progression to liver cirrhosis and hepatocellular carcinoma in patients infected with the hepatitis B virus. We herein present a review of the mechanisms of mitochondrial dysfunction in the development of acute liver injury and chronic liver diseases, such as hepatocellular carcinoma, viral hepatitis, drug-induced liver injury, alcoholic liver disease, and non-alcoholic fatty liver disease. This review also discusses mitochondrion-centric therapies for treating liver diseases.

The evidence-based multifaceted roles of hepatic stellate cells in liver diseases: A concise review

Hepatic stellate cells (HSCs) play central roles in liver disease pathogenesis, spanning steatosis to cirrhosis and hepatocellular carcinoma. These cells, located in the liver's sinusoidal space of Disse, transition from a quiescent, vitamin A-rich state to an activated, myofibroblast-like phenotype in response to liver injury. This activation results from a complex interplay of cytokines, growth factors, and oxidative stress, leading to excessive collagen deposition and liver fibrosis, a hallmark of chronic liver diseases. Recently, HSCs have gained recognition for their dynamic, multifaceted roles in liver health and disease. Attention has shifted toward their involvement in various liver conditions, including acute liver injury, alcoholic and non-alcoholic fatty liver disease, and liver regeneration. This review aims to explore diverse functions of HSCs in these acute or chronic liver pathologies, with a focus on their roles beyond fibrogenesis. HSCs exhibit a wide range of actions, including lipid storage, immunomodulation, and interactions with other hepatic and extrahepatic cells, making them pivotal in the hepatic microenvironment. Understanding HSC involvement in the progression of liver diseases can offer novel insights into pathogenic mechanisms and guide targeted therapeutic strategies for various liver conditions.

Comparison of Nutritional Diversity in Five Fresh Legumes Using Flavonoids Metabolomics and Postharvest Botrytis cinerea Defense Analysis of Peas Mediated by Sakuranetin

Legumes possess several bioactive nutrients, including flavonoids, and the study of the flavonoid profile of legumes is of great significance to human health. Using widely targeted metabolomics, we revealed the flavonoid profiles of five popular fresh legumes: cowpea, soybean, pea, fava bean, and kidney bean. A total of 259 flavonoids were identified, and the flavonoid accumulation patterns of the five legumes were remarkably different. In addition to analyzing common and species-specific flavonoids in the five legumes, we also generalized representative flavonoids of various subclasses. We related these to the health-promoting effects of legumes. Furthermore, legumes' total flavonoid content and antioxidant system activity were also detected. Intriguingly, sakuranetin, the sole flavonoid phytoalexin that can be induced by UV radiation, was detected only in the peas by metabolomics. Meanwhile, we found that UV treatment could significantly increase the sakuranetin content and the postharvest Botrytis cinerea resistance of pea pods. This study provides clues for the target diet, industrial development of legumes, and a new idea for the postharvest preservation of peas.

Demethylnobiletin ameliorates cerebral ischemia-reperfusion injury in rats through Nrf2/HO-1 signaling pathway

BACKGROUND

Demethylnobiletin (DN), with a variety of biological activities, is a polymethoxy-flavanone (PMF) found in citrus. In the present study, we explored the biological activities and potential mechanism of DN to improve cerebral ischemia reperfusion injury (CIRI) in rats, and identified DN as a novel neuroprotective agent for patients with ischemic brain injury.

METHODS

Rat CIRI models were established via middle cerebral artery occlusion (MCAO). Primary nerve cells were isolated and cultured in fetal rat cerebral cortex in vitro, and oxygen-glucose deprivation/reperfusion (OGD/R) models of primary nerve cells were induced. After intervention with DN with different concentrations in MCAO rats and OGD/R nerve cells, 2,3,5-triphenyltetrazolium chloride staining was used to quantify cerebral infarction size in CIRI rats. Modified neurological severity score was utilized to assess neurological performance. Histopathologic staining and live/dead cell-viability staining was used to observe apoptosis. Levels of glutathione (GSH), superoxide dismutase (SOD), reactive oxygen species (ROS) and malondialdehyde (MDA) in tissues and cells were detected using commercial kits. DN level in serum and cerebrospinal fluid of MCAO rats were measured by liquid chromatography tandem mass spectrometry. In addition, expression levels of proteins like Kelch like ECH associated protein 1 (Keap1), nuclear factor erythroid 2-related factor 2 (Nfr2) and heme oxygenase 1 (HO-1) in the Nrf2/HO-1 pathway, and apoptosis-related proteins like Cleaved caspase-3, BCL-2-associated X protein (Bax) and B-cell lymphoma-2 (Bcl-2) were determined by Western blot and immunofluorescence.

RESULTS

DN can significantly enhance neurological function recovery by reducing cerebral infarction size and weakening neurocytes apoptosis in MCAO rats. It was further found that DN could improve oxidative stress (OS) injury of nerve cells by bringing down MDA and ROS levels and increasing SOD and GSH levels. Notably, DN exerts its pharmacological influences through entering blood-brain barrier. Mechanically, DN can reduce Keap1 expression while activate Nrf2 and HO-1 expression in neurocytes.

CONCLUSIONS

The protective effect of DN on neurocytes have been demonstrated in both in vitro and in vivo circumstances. It deserves to be developed as a potential neuroprotective agent through regulating the Nrf2/HO-1 signaling pathway to ameliorate neurocytes impairment caused by OS.

Polymethoxyflavone from Citrus depressa as an inhibitor against various variants of SARS-CoV-2 spike protein

ETHNOPHARMACOLOGICAL RELEVANCE

In traditional Taiwanese medicine, Citrus depressa Hayata serves as the raw material of Chen-Pi which has been widely used to treat respiratory ailments. Scientific investigations have validated the attributes of C. depressa, elucidating its valuable properties, including antioxidative, anti-inflammatory, anticancer, neuroprotion, hepatoprotection, and hypolipidemic effects.

AIM OF THE STUDY

This study aims to isolate a universal inhibitor of the SARS-CoV-2 spike protein from C. depressa and confirm the mechanism by which these inhibitors disrupt the binding of the spike protein to hACE2.

MATERIALS AND METHODS

The whole fruit of C. depressa was subjected to ethanol extraction, following by partitioning to obtain water, butanol, and ethyl acetate fractions. To identify the inhibitory components in citrus fruits, we performed both the SPR assay and the SARS-CoV-2 pseudo-virus assays. Subsequently, we employed a bioassay-guided approach to efficiently isolate and characterize the bioactive constituents that hindered the interaction between the SARS-CoV-2 spike protein and hACE2, using a combination of MPLC and Semi-preparative HPLC for compound isolation. ELISA based spike protein binding assay evaluate the inhibitory activities of the extract and potential constituents against multiple spike protein variants. To further shed light on the inhibitory mechanism, candidate inhibitors were validated through the SPR assay and molecular docking.

RESULTS

The crude extract and ethyl acetate layer derived from C. depressa showed significant inhibitory activity on SARS-CoV-2 Omicron BA.4/5, with IC50 of 77.4 μg/mL and 100 μg/mL, respectively. Ten potential compounds from C. depressa have been identified with inhibitory activity against various SARS-CoV-2 spike proteins. 2'-hydroxy-4,4',5',6'-tetramethoxychalcone (Cd3) and 5-hydroxy-3',4',6,7,8-pentamethoxyflavone (Cd8) also showed good inhibitory activity to the spike protein, with KD of 0.79 μM and 37.3 nM, respectively. These findings are in line with prior study, indicating Cd3 and Cd8 can bind to key amino acid residue, disrupting the formation of the spike protein and h-ACE2 complex.

CONCLUSION

This study presents the initial evidence showcasing the inhibitory effect of polymethoxyflavones (PMFs) on the spike protein of SARS-CoV-2. Moreover, the inhibitory activity of C. depressa extracts indicates their potential to prevent infections of different SARS-CoV-2 variants.

Selenizing chitooligosaccharide with site-selective modification to alleviate acute liver injury in vivo

Two selenized chitooligosaccharide (O-Se-COS and N,O-Se-COS) with different sites modification were synthesized to alleviate liver injury in vivo. Comparing to traditional COS, both selenized COS exhibited enhanced reducibility as well as antioxidant capacity in vitro. Furthermore, O-Se-COS demonstrated superior efficacy in reducing intracellular reactive oxygen species (ROS) and mitochondrial damage compared to N,O-Se-COS as its enhanced cellular uptake by the positive/negative charge interactions. Two mechanisms were proposed to explained these results: one is to enhance the enzymatic activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), which effectively scavenge free radicals; the other is to down-regulate intracellular cytochrome P450 (CYP2E1) levels, inhibiting carbon tetrachloride (CCl4)-induced peroxidation damage. In vivo studies further demonstrated the effective alleviation of CCl4-induced liver injury by selenized COS, with therapeutic efficacy observed in the following order: O-Se-COS > N,O-Se-COS > COS. Finally, hemolysis and histological tests confirmed the biosafety of both selenized COS. Taken together, these finding demonstrated that selenium has the potential to improve the biological activity of COS, and precise selenylation was more conducive to achieving the synergistic effect where 1 + 1>2.

CopA3 treatment suppressed multidrug resistivity in HCT-116 cell line by p53-induced degradation of hypoxia-inducible factor 1α

The major reason for multidrug resistance is the failure of chemotherapy in many tumors, including colon cancer. Hypoxia-inducible factor (HIF)-1α is a crucial transcription factor that simulates multiple cellular response to hypoxia. HIF-1α has been known to play a vital role towards tumor resistance; however, its mechanism of action is still not fully elucidated. N this study, we found that HIF-1α remarkably modulated drug resistance-associated proteins upon CopA3 peptide treatment against colon cancer cells. Abnormal rates of tumor growth along with high metastatic potential lacks the susceptibility towards cellular signals is a key characteristic in many tumor types. Moreover, in growing tumors, cells are exposed to insufficient nutrient supply and low oxygen availability. These stress force them to switch into adaptable and aggressive phenotypes. Our study investigated the interaction of HIF-1α and MDR gene association upon CopA3 treatment in the tumor microenvironment. We demonstrate that the multidrug resistance gene is associated with tumor resistance to chemotherapeutics, which upon CopA3 treatment promotes p53 activation and proteasomal degradation of HIF-1α, effecting the angiogenesis response to hypoxia. p53 downregulation augments HIF-1-dependent transcriptional activation of VEGF in response to oxygen deprivation.

Decursinol Angelate Inhibits Glutamate Dehydrogenase 1 Activity and Induces Intrinsic Apoptosis in MDR-CRC Cells

Colorectal cancer (CRC) was the second most commonly diagnosed cancer worldwide and the second most common cause of cancer-related deaths in Europe in 2020. After CRC patients' recovery, in many cases a patient's tumor returns and develops chemoresistance, which has remained a major challenge worldwide. We previously published our novel findings on the role of DA in inhibiting the activity of GDH1 using in silico and enzymatic assays. No studies have been conducted so far to explain the inhibitory role of DA against glutamate dehydrogenase in MDR-CRC cells. We developed a multidrug-resistant colorectal cancer cell line, HCT-116^MDR, after treatment with cisplatin and 5-fluorouracil. We confirmed the MDR phenotype by evaluating the expression of MDR1, ABCB5, extracellular vesicles, polyploidy, DNA damage response markers and GDH1 in comparison with parental HCT-116^WT (HCT-116 wild type). Following confirmation, we determined the IC₅₀ and performed clonogenic assay for the efficacy of decursinol angelate (DA) against HCT-116^MDR (HCT-116 multidrug resistant). Subsequently, we evaluated the novel interactions of DA with GDH1 and the expression of important markers regulating redox homeostasis and cell death. DA treatment markedly downregulated the expression of GDH1 at 50 and 75 μM after 36 h, which directly correlated with reduced expression of the Krebs cycle metabolites α-ketoglutarate and fumarate. We also observed a systematic dose-dependent downregulation of MDR1, ABCB5, TERT, ERCC1 and γH2AX. Similarly, the expression of important antioxidant markers was also downregulated. The markers for intrinsic apoptosis were notably upregulated in a dose-dependent manner. The results were further validated by flow cytometry and TUNEL assay. Additionally, GDH1 knockdown on both HCT-116^WT and HCT-116^MDR corresponded to a decreased expression of γH2AX, catalase, SOD1 and Gpx-1, and an eventual increase in apoptosis markers. In conclusion, inhibition of GDH1 increased ROS production, decreased cell proliferation and increased cell death.

Hepatic ZBTB22-mediated detoxification ameliorates acetaminophen-induced liver injury by inhibiting pregnane X receptor signaling

Overdose acetaminophen (APAP) can cause acute liver injury (ALI), but the underlying mechanism remains undetermined. This study explored the role of hepatic Zinc Finger And BTB Domain Containing 22 (ZBTB22) in defense against APAP-mediated hepatotoxicity. The results showed that hepatic ZBTB22 expression was significantly reduced in patients with ALI and mice. In mouse primary hepatocytes (MPHs), ZBTB22 deletion aggravated APAP overdose-induced ALI, whereas ZBTB22 overexpression attenuated that pathological progression. The results were further verified in ZBTB22 over-express or knockout mice models. In parallel, hepatocyte-specific ZBTB22 knockout also enhanced ALI. Furthermore, ZBTB22 decreased pregnane X receptor (PXR) expression, and the PXR activator pregnane-16α-carbonitrile suppressed the protective effect of ZBTB22 in APAP-induced ZBTB22-overexpressing mice. Collectively, our findings highlight the protective effect of ZBTB22 against APAP-induced ALI and unravel PXR signaling as the potential mechanism. Strategies to increase hepatic ZBTB22 expression represent a promising therapeutic approach for APAP overdose-induced ALI.

Therapeutic propensity of ginsenosides Rg1 and Rg3 in rhabdomyolysis-induced acute kidney injury and renohepatic crosstalk in rats

BACKGROUND

Ginseng is a traditional herbal medicine used for thousands of years in Southeast Asian countries because of its medicinal properties. Ginsenosides Rg1 and Rg3 have demonstrated therapeutic properties against a broad spectrum of diseases.

PURPOSE

Here in this study, we investigated the therapeutic efficacy of Rg1 and Rg3 in alleviating glycerol-induced acute kidney injury, also known as rhabdomyolysis-induced acute kidney injury (RAKI).

METHODS

AKI was induced in male Wistar rats through intramuscular injection of 10 mL/kg glycerol and simultaneous oral treatment of ginsenosides Rg1 and Rg3 for 3 days. We also evaluated the therapeutic potential of Rg1 and Rg3 on human embryonic kidney epithelial (HEK-293). Cell viability and LDH assay were performed on HEK-293 cells to evaluate the toxicity of Rg1 and Rg3. Evaluation of important kidney damage markers such as creatinine and blood urea nitrogen (BUN) was carried out at different time points from the rat serum. Histopathological analysis was performed on kidney tissues. We also performed experiments such as ELISA assay, immunohistochemistry, immunofluorescence staining, COMET assay, western blotting, TUNEL assay, and flow cytometry to obtain results.

RESULTS

Rg1 and Rg3 significantly downregulated the expression of kidney damage markers such as creatinine and BUN in a dose-dependent manner. Histopathological analysis revealed damage across the glomerulus, tubules, and collecting duct rendering the kidney dysfunctional in glycerol treatment groups. However, Rg1 and Rg3 treated groups showed a significant reduction in tubular necrosis at both 10 and 20 mg/kg. There was also a sharp downregulation of oxidative and ER stress markers. Additionally, we observed nuclear translocation of Nrf2 which were more prominent in kidney tissues. Rg1 and Rg3 were also able to mitigate apoptotic cell death in vitro and in vivo evaluated through immunofluorescence staining for p53, TUNEL assay, flow cytometry, and immunoblotting for intrinsic apoptosis markers.

CONCLUSION

In summary, we conclude that Rg1 and Rg3 exhibited natural therapeutic remedy against AKI.

Analysis of Metabolic Differences in the Water Extract of Shenheling Fermented by Lactobacillus fermentum Based on Nontargeted Metabolomics

Objective: To explore the characteristics of metabolites in Shenheling (SHL) fermented by Lactobacillus fermentum. Methods: In this study, ultrahigh-performance liquid chromatography-quadrupole electrostatic field orbit trap mass spectrometry (UHPLC-QE-MS) was used to qualitatively, quantitatively, and differentially analyze the metabolites of SHL before and after fermentation. Results: A total of 102 significant differential metabolites in nine categories were analyzed before and after fermentation. It mainly includes 29 terpenoids, 17 alkaloids, 14 organic acids and derivatives, 10 flavonoids, 9 phenylpropanoids, 6 phenols, 3 aromaticity, and 3 amino acid derivatives. Further screening found that the content of most active substances, such as alkaloids, organic acids, and flavonoids, increased significantly. These metabolites play an important role in improving the taste and efficacy of SHL. After fermentation, the contents of differential metabolites, such as panaquinquecol 2, ginsenoside Rh3, ginsenoside Rg3, dehydronuciferin, nicotinic acid, 5-hydroxytryptophan, azelaic acid, dihydrokaempferol, and chrysin, were increased, which increased the effects of antioxidation, anti-obesity, hypoglycemic, antibacterial, and improved immunity compared with those before fermentation. KEGG pathway analysis identified 10 metabolic pathways. Isoquinoline alkaloid biosynthesis, vitamin B6 metabolism, beta-alanine metabolism, nicotinate, and nicotinamide metabolism, purine metabolism, pantothenate and CoA biosynthesis, glyoxylate and dicarboxylate metabolism, tyrosine metabolism, citrate cycle (TCA cycle), phenylpropanoid biosynthesis, etc. Conclusions: Fermentation significantly changed the metabolites in SHL and played an important role in improving its taste, aroma quality, antioxidant, anti-obesity, and other health care functional components.

Portulaca oleracea alleviates CCl4-induced acute liver injury by regulating hepatic S100A8 and S100A9

Objective

Acute liver injury (ALF) is a potential factor of many serious hepatopathies. Carbon tetrachloride (CCl₄) is a possible environmental toxicant that can induce ALF. Portulaca oleracea (PO) is one of the most popular edible herbs and has several biological activities such as antioxidant, antimicrobial, anti-inflammatory effects. We explored the significance of PO in regulating inflammatory function in animal models and cultured hepatocytes during liver damage caused by CCl₄.

Methods

The effect of PO on ALF was evaluated by CCl₄-induced mice models in vivo. Hepatic levels of transaminase activities and inflammatory factors were examined. The gene and protein expression of S100A8 and S100A9 were measured by RT-PCR and Western blot analysis. Meanwhile, the efficacy of PO was certified by HepG2 cells in vitro. The transaminase activities, inflammatory factors, and the protein expression of S100A8 and S100A9 were also detected.

Results

Animal tests showed that pretreatment with PO reduced the liver pathological tissue damage and the serum levels of ALT, AST, ALT and LDH, as well as reducing the pro-inflammatory cytokines (IL-1β, IL-6, TNF-α) secretion in CCl₄-induced liver injury mice. Simultaneously, HepG2 cells pretreated with PO exhibited a significant decrease in the activities of ALT and AST. Moreover, PO resulted in a significant downregulation of the pro-inflammatory markers S100A8, S100A9 gene and protein expression on CCl₄ induced acute liver injury was demonstrated entirely in vivo and vitro experiments.

Conclusion

PO may down-regulate S100A8 and S100A9 and inhibit pro-inflammatory cytokines' release, indicating a potential clinical effect for controlling the disease.

Vitamin D Receptor Activation Targets ROS-Mediated Crosstalk Between Autophagy and Apoptosis in Hepatocytes in Cholestasic Mice

BACKGROUND & AIMS

Observational epidemiologic studies have associated vitamin D deficiency with cholestasis. We reported previously that activation of the vitamin D/vitamin D receptor (VDR) axis in cholangiocytes mitigates cholestatic liver injury by remodeling the damaged bile duct. However, the function of VDR in hepatocytes during cholestasis remains unclear.

METHODS

Paricalcitol (VDR agonist, 200 ng/kg) was injected intraperitoneally into bile duct-ligated mice every other day for 5 days. Primary hepatocytes and HepG2 hepatoma cells were transfected with Vdr short hairpin RNA, control short hairpin RNA, Vdr plasmid, control vector, Atg5 small interfering RNA (siRNA), and control siRNA. Liver histology, cell proliferation, and autophagy were evaluated.

RESULTS

Treatment with the VDR agonist paricalcitol improved liver injury in bile duct-ligated mice by up-regulating VDR expression in hepatocytes, which in turn reduced hepatocyte apoptosis by inhibiting reactive oxygen species (ROS) generation via suppressing the Ras-related C3 botulinum toxin substrate 1/reduced nicotinamide adenine dinucleotide phosphate oxidase 1 pathway. Mechanistically, upon exposure to an ROS-inducing compound, Vdr siRNA contributed to apoptosis, whereas the Vdr overexpression caused resistance to apoptosis. Interestingly, up-regulated VDR expression also increased the generation of autophagosomes and macroautophagic/autophagic flux, which was the underlying mechanism for reduced apoptosis following VDR activation. Autophagy depletion impaired the positive effects of VDR overexpression, whereas autophagy induction was synergystic with VDR overexpression. Importantly, up-regulation of VDR promoted autophagy activation by suppressing the activation of the extracellular signal-regulated kinase (ERK)/p38 mitogen-activated protein kinase (p38MAPK) pathway. Thus, a p38MAPK inhibitor abrogated the Vdr siRNA-induced decrease in autophagy and the Vdr siRNA-induced increase in apoptosis. In contrast, a Mitogen-activated protein kinase kinase (MEK)/ERK activator prevented the enhancement of autophagy and decreased apoptosis following Vdr overexpression. Moreover, the ROS inhibitor N-acetylcystein (NAC) blocked Vdr siRNA-enhanced activation of the ERK/p38MAPK pathway.

CONCLUSIONS

VDR activation mitigated liver cholestatic injury by reducing autophagy-dependent hepatocyte apoptosis and suppressing the activation of the ROS-dependent ERK/p38MAPK pathway. Thus, VDR activation may be a potential target for the treatment of cholestatic liver disease.

5-Demethylnobiletin mediates cell cycle arrest and apoptosis via the ERK1/2/AKT/STAT3 signaling pathways in glioblastoma cells

5-Demethylnobiletin is the active ingredient in citrus polymethoxyflavones that could inhibit the proliferation of several tumor cells. However, the anti-tumor effect of 5-Demethylnobiletin on glioblastoma and the underlying molecular mechanisms are remains unknown. In our study, 5-Demethylnobiletin markedly inhibited the viability, migration and invasion of glioblastoma U87-MG, A172 and U251 cells. Further research revealed that 5-Demethylnobiletin induces cell cycle arrest at the G0/G1 phase in glioblastoma cells by downregulating Cyclin D1 and CDK6 expression levels. Furthermore, 5-Demethylnobiletin significantly induced glioblastoma cells apoptosis by upregulating the protein levels of Bax and downregulating the protein level of Bcl-2, subsequently increasing the expression of cleaved caspase-3 and cleaved caspase-9. Mechanically, 5-Demethylnobiletin trigged G0/G1 phase arrest and apoptosis by inhibiting the ERK1/2, AKT and STAT3 signaling pathway. Furthermore, 5-Demethylnobiletin inhibition of U87-MG cell growth was reproducible in vivo model. Therefore, 5-Demethylnobiletin is a promising bioactive agent that might be used as glioblastoma treatment drug.

The Chemistry and the Anti-Inflammatory Activity of Polymethoxyflavonoids from Citrus Genus

Polymethoxyflavonoids (PMFs) are a large group of compounds belonging to the more general class of flavonoids that possess a flavan carbon framework decorated with a variable number of methoxy groups. Hydroxylated polymethoxyflavonoids (HPMFs), instead, are characterized by the presence of both hydroxyl and methoxy groups in their structural unities. Some of these compounds are the aglycone part in a glycoside structure in which the glycosidic linkage can involve the -OH at various positions. These compounds are particular to Citrus genus plants, especially in fruits, and they are present mainly in the peel. A considerable number of PMFs and HPMFs have shown promising biological activities and they are considered to be important nutraceuticals, responsible for some of the known beneficial effects on health associated with a regular consumption of Citrus fruits. Among their several actions on human health, it is notable that the relevant contribution in controlling the intracellular redox imbalance is associated with the inflammation processes. In this work, we aim to describe the status concerning the chemical identification and the anti-inflammatory activity of both PMFs and HPMFs. In particular, all of the chemical entities unambiguously identified by isolation and complete NMR analysis, and for which a biochemical evaluation on the pure compound was performed, are included in this paper.

Cyanidin Alleviated CCl4-Induced Acute Liver Injury by Regulating the Nrf2 and NF-κB Signaling Pathways

Acute liver injury has multiple causes and can result in liver failure. In this study, we evaluated the hepatoprotective ability of cyanidin (Cy) and investigated its associated mechanisms. Cy administration significantly and dose-dependently ameliorated acute liver injury induced by carbon tetrachloride (CCl₄). High-dose Cy showed effects comparable to those achieved by the positive control (silymarin). Severe oxidative stress and inflammatory responses in the liver tissue induced by CCl₄ were significantly mitigated by Cy supplementation. The total antioxidant capacity and the activity of superoxide dismutase, catalase, and glutathione peroxidase were increased and the content of malondialdehyde, lipid peroxide, tumor necrosis factor α, interleukin-1β, and interleukin-6 were decreased. Additionally, the Nrf2 and NF-κB signaling pathways, which regulate antioxidative and inflammatory responses, were analyzed using quantitative real-time polymerase chain reaction and western blot assay. Cy treatment not only increased Nrf2 transcription and expression but also decreased NF-κB signaling. Moreover, molecular docking simulation indicated that Cy had high affinity for Keap1 and NF-κB/p65, which may promote nuclear translocation of Nrf2 and inhibit that of NF-κB. In summary, Cy treatment exerted antioxidative and anti-inflammatory effects and ameliorated liver injury by increasing Nrf2 and inhibiting the NF-κB pathway, demonstrating the potential of Cy as a therapeutic agent in liver injury.

LncRNA-Airn alleviates acute liver injury by inhibiting hepatocyte apoptosis via the NF-κB signaling pathway

Acute liver injury is a common and serious syndrome caused by multiple factors and unclear pathogenesis. If the injury persists, liver injury can lead to cirrhosis and liver failure and ultimately results in the development of liver cancer. Emerging evidence has indicated that long noncoding RNAs (lncRNAs) play an important role in the development of liver injury. However, the role of antisense Igf2r RNA (Airn) in acute liver injury and its underlying mechanism remain largely unclear. In this study, we show that Airn is upregulated in liver tissue and primary hepatocytes from an acute liver injury mouse model. Consistently, Airn is also overexpressed in serum samples of patients with acute-on-chronic liver failure and is negatively correlated with the Model for End-Stage Liver Disease (MELD) score. Moreover, gene knockout and rescue assays reveal that Airn alleviates CCl ₄-induced liver injury by inhibiting hepatocyte apoptosis and oxidative stress in vivo. Further investigation reveals that Airn decreases H ₂O ₂-induced hepatocyte apoptosis in vitro. Mechanistically, we reveal that Airn represses CCl ₄- and H ₂O ₂-induced enhancement of phosphorylation of p65 and IκBα, suggesting that Airn inhibits hepatocyte apoptosis by inactivating the NF-κB pathway. In conclusion, our results demonstrate that Airn can alleviate acute liver injury by inhibiting hepatocyte apoptosis via inactivating the NF-κB signaling pathway, and Airn could be a potential biomarker for acute liver injury.

A cationic amino acid polymer nanocarrier synthesized in supercritical CO2 for co-delivery of drug and gene to cervical cancer cells

The present study was undertaken to investigate the ability of a drug curcumin-loaded polymer to inhibit the growth of cervical cancer cells by enhancing the anti-cancer efficiency of curcumin. We synthesized poly(methacryloyl beta-alanine) (PMBA) as a nanocarrier by radical polymerization in supercritical CO₂. The results showed that the curcumin encapsulated and folic acid (FA)-treated PMBA (Poly@Cur-FA) for 24 h activated the reactive oxygen species-mediated programmed cell death machinery in HeLa cells. This remarkable effect of Poly@Cur-FA treatment was visualized using different fluorescent probes, which demonstrated that the Poly@Cur-FA treatment disrupted the cell membrane, as also supported by scanning electron microscopy observations. The effect of Poly@Cur-FA dispersion on the cells was observed under a transmission electron microscope. Further, the HeLa cells were treated with the polymer encapsulated curcumin and Bcl2 siRNA (Pol-Cur-siRNA) for 24 h, which effectively suppressed the Bcl2 and simulated the autophagic pathway. This co-delivery system was designed to inhibit curcumin efflux and can enhance the treatment efficacy by targeting multiple signaling pathways, including cell cycle, apoptotic, and autophagic pathways. Collectively, the Pol-Cur-siRNA system appears to offer an efficient combinational therapeutic strategy that might overcome the problems associated with the chemosensitivity against the standard synthetic anti-cancer drugs. To support the experimental data, an artificial neural network model was developed to foresee the drug and gene release behaviors.

Alanyl-Glutamine Protects against Lipopolysaccharide-Induced Liver Injury in Mice via Alleviating Oxidative Stress, Inhibiting Inflammation, and Regulating Autophagy

Acute liver injury is a worldwide problem with a high rate of morbidity and mortality, and effective pharmacological therapies are still urgently needed. Alanyl-glutamine (Ala-Gln), a dipeptide formed from L-alanine and L-glutamine, is known as a protective compound that is involved in various tissue injuries, but there are limited reports regarding the effects of Ala-Gln in acute liver injury. This present study aimed to investigate the protective effects of Ala-Gln in lipopolysaccharide (LPS)-induced acute liver injury in mice, with a focus on inflammatory responses and oxidative stress. The acute liver injury induced using LPS (50 μg/kg) and D-galactosamine (D-Gal) (400 mg/kg) stimulation in mice was significantly attenuated after Ala-Gln treatment (500 and 1500 mg/kg), as evidenced by reduced plasma alanine transaminase (ALT) (p < 0.01, p < 0.001), aspartate transaminase (AST) (p < 0.05, p < 0.001), and lactate dehydrogenase (LDH) (p < 0.01, p < 0.001) levels, and accompanied by improved histopathological changes. In addition, LPS/D-Gal-induced hepatic apoptosis was also alleviated by Ala-Gln administration, as shown by a greatly decreased ratio of TUNEL-positive hepatocytes, from approximately 10% to 2%, and markedly reduced protein levels of cleaved caspase-3 (p < 0.05, p < 0.001) in liver. Moreover, we found that LPS/D-Gal-triggered oxidative stress was suppressed after Ala-Gln treatment, the effect of which might be dependent on the elevation of SOD and GPX activities, and on GSH levels in liver. Interestingly, we observed that Ala-Gln clearly inhibited LPS/D-Gal exposure-induced macrophage accumulation and the production of proinflammatory factors in the liver. Furthermore, Ala-Gln greatly regulated autophagy in the liver in LPS/D-Gal-treated mice. Using RAW264.7 cells, we confirmed the anti-inflammatory role of Ala-Gln-targeting macrophages.

D-Carvone Attenuates CCl4-Induced Liver Fibrosis in Rats by Inhibiting Oxidative Stress and TGF-ß 1/SMAD3 Signaling Pathway

D-carvone is a natural monoterpene found in abundance in the essential oil of aromatic medicinal plants with a wide range of pharmacological values. However, the impact of D-carvone on liver fibrosis remains unclear. This study aimed to evaluate the anti-fibrotic potential of D-carvone in a rat model of liver fibrosis and to clarify the possible underlying mechanisms. Liver fibrosis was induced in rats by carbon tetrachloride, CCl₄ (2.5 mL/kg, interperitoneally every 72 h for 8 weeks). Oral treatment of rats with D-carvone (50 mg/kg, daily) started on the 3rd week of CCl₄ administration. D-carvone significantly enhanced liver functions (ALT, AST), oxidant/antioxidant status (MDA, SOD, GSH, total antioxidant capacity; TAC), as well as histopathological changes. Moreover, D-carvone effectively attenuated the progression of liver fibrosis, evident by the decreased collagen deposition and fibrosis score by Masson trichrome staining (MT) and α-SMA protein expression. Moreover, D-carvone administration resulted in a significant downregulation of the pro-fibrogenic markers TGF-β1 and SMAD3 and upregulation of MMP9. These findings reveal the anti-fibrotic effect of D-carvone and suggest regulation of the TGF-β1/SMAD3 pathway, together with the antioxidant activity as a mechanistic cassette, underlines this effect. Therefore, D-carvone could be a viable candidate for inhibiting liver fibrosis and other oxidative stress-related hepatic diseases. Clinical studies to support our hypothesis are warranted.

Nonlinear molecular dynamics of quercetin in Gynocardia odorata and Diospyros malabarica fruits: Its mechanistic role in hepatoprotection

Liver performs number of critical physiological functions in human system. Intoxication of liver leads to accumulation of free radicals that eventually cause damage, fibrosis, cirrhosis and cancer. Carbon tetrachloride (CCl₄) belongs to hepatotoxin is converted to a highly reactive free radical by cytochrome P450 enzymes that causes liver damage. Plant extracts derived quercetin has substantial role in hepatoprotection. This study highlights the possible mechanism by which quercetin plays significant role in hepatoprotection. HPLC analysis revealed the abundance of quercetin in the fruit extracts of Gynocardia odorata and Diospyros malabarica, were isolated, purified and subjected to liver function analysis on Wistar rats. Post quercetin treatment improved liver function parameters in the hepatotoxic Wistar rats by augmenting bilirubin content, SGOT and SGPT activity. Gene expression profile of quercetin treated rats revealed down regulation of HGF, TIMP1 and MMP2 expressed during CCl₄ induction. In silico molecular mechanism prediction suggested that quercetin has a high affinity for cell signaling pathway proteins BCL-2, JAK2 and Cytochrome P450 Cyp2E1, which all play a significant role in CCl₄ induced hepatotoxicity. In silico molecular docking and molecular dynamics simulation have shown that quercetin has a plausible affinity for major signaling proteins in liver. MMGBSA studies have revealed high binding of quercetin (ΔG) -41.48±11.02, -43.53±6.55 and -39.89±5.78 kcal/mol, with BCL-2, JAK2 and Cyp2E1, respectively which led to better stability of the quercetin bound protein complexes. Therefore, quercetin can act as potent inhibitor against CCl₄ induced hepatic injury by regulating BCL-2, JAK2 and Cyp2E1.

Orientin Alleviates Liver Inflammation via Downregulation of ZEB-2/PTEN Markers—Hepatic Stellate Cells Approach

Liver inflammation is associated with an increased risk of liver fibrosis that substantially progresses to cirrhosis. Recently, usage of the herbal supplement has been increased because of its emerging role to dominate oxidative stress in hepatic injury. Orientin is one of the bioactive flavonoids that possesses a diversity of curative activities. Therefore, the present study was conducted to evaluate the anti-inflammatory role of orientin (1 mg/kg) in vitro in lipopolysaccharide (LPS)-induced inflammation in hepatic stellate cells (HSCs) and in vivo in carbon tetrachloride (CCl4)-induced liver fibrosis in mice. Moreover, the current study was supported by in silico investigation. Orientin demonstrated protection against LPS-induced HSC inflammation as evidenced by a decrease in iNOS, NO, and TNF-α and inhibition of the fibrotic markers ZEB-2 and PTEN. In addition, orientin afforded protection against CCl4-induced liver fibrosis in mice as shown from decreased AST/ALT ratio, inhibition of the pro-inflammatory mediators TNF-α, IL-6, IL-8, and IFN-γ, reduction of fibrotic markers ZEB-2 and PTEN, and improvement of the histopathological changes. Furthermore, the docking study demonstrated virtual interactions of orientin with ZEB-2 and PTEN. Taken together, the current study suggested that the protective effects of orientin against LPS- and CCl4-induced liver inflammation are via inhibition of fibrotic markers and reduction of pro-inflammatory mediators.

Antioxidant Effects of Irisin in Liver Diseases: Mechanistic Insights

Oxidative stress is a crucial factor in the development of various liver diseases. Irisin, a metabolic hormone discovered in 2012, is mainly produced by proteolytic cleavage of fibronectin type III domain containing 5 (FNDC5) in skeletal muscles. Irisin is induced by physical exercise, and a rapidly growing body of literature suggests that irisin is, at least partially, responsible for the beneficial effects of regular exercise. The major biological function of irisin is believed to be involved in the maintenance of metabolic homeostasis. However, recent studies have suggested the therapeutic potential of irisin against a variety of liver diseases involving its antioxidative function. In this review, we aim to summarize the accumulating evidence demonstrating the antioxidative effects of irisin in liver diseases, with an emphasis on the current understanding of the potential molecular mechanisms.

Protective Effects of Chlorogenic Acid against Carbon Tetrachloride-Induced Hepatotoxicity in Mice

The protective effects of chlorogenic acid (CGA) against liver injury were evaluated by its reduction in carbon tetrachloride (CCl4)-induced hepatic damage in ICR mice. The animals were orally given CGA (60, 100, and 200 mg/kg, respectively) or silymairn (200 mg/kg) daily with 0.3% CCl4 administration (3 mL/kg, dissolved in olive oil) after medicament treatment on the 7th day. Compared with the normal group, CCl4 caused severe impairment in liver according to the evidence of significant reduction in the level of total albumin and expansion (p < 0.05) of the activities in aspartate aminotransferase (AST) and alanine aminotransferase (ALT), cholesterol, triglyceride (TG), and total albumin in serum, decreased the level of glutathione (GSH), and diminished the activities of catalase, superoxide dismutase (SOD), glutathione reductase (GSH-Rd), and glutathione peroxidase (GSH-Px) in liver while increasing the level of hepatic thiobarbituric acid-reactive substances (TBARS). However, oral administration of CGA or silymarin could significantly (p < 0.05) decrease the serum levels of AST, ALT, cholesterol, TG, and total albumin and elevated the serum total albumin and the activities of GSH, catalase, SOD, GSH-Rd, and GSH-Px while leading to decline the TBARS in liver compared with CCl4-intoxicated group. Moreover, histopathology displayed that CGA decreased the formation of lesions in liver resulted from CCl4. The outcomes indicate that CGA shows the efficiency hepatoprotective consequences for CCl4-incited liver injuries in mice by the elevation of the activities of antioxidant enzymes and hindrance of lipid peroxidation.

Preventive Effect of Flavonoid Extract from the Peel of Gonggan (Citrus reticulata Blanco Var. Gonggan) on CCl4-Induced Acute Liver Injury in Mice

Objective

Citrus peel, a waste product of citrus consumption and processing, is rich in flavonoids. This study aimed to study the protective effect of flavonoid extract from the peel of gonggan (Citrus reticulata Blanco var. gonggan) on acute chemical liver injury.

Materials and Methods

We established a chemical liver injury model induced by carbon tetrachloride (CCl₄) in mice. The flavonoid composition in gonggan (Citrus reticulata Blanco var. gonggan) peel was detected by HPLC. The histopathological sections of liver, related biochemical indicators in serum and liver, and related genes were examined to evaluate the protective effect of gonggan peel flavonoid extract (GPFE).

Results

The results showed that GPFE contained narirutin, hesperidin, nobiletin, tangeretin, and 5-demethylnobiletin. After 14 days of intragastric administration of GPFE, the result showed GPFE could reduce the increase in liver index, serum alanine aminotransferase (ALT), and aspartate transaminase (AST) levels caused by CCl₄. At the same time, pathological sections of liver confirmed that GPFE alleviated the damage to liver tissue. Moreover, biochemical indicator results showed that GPFE increased the activities of superoxide dismutase (SOD) and catalase (CAT) in liver tissue and reduced the content of malondialdehyde (MDA). Also, it reduced the levels of inflammation factors: tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), interleukin (IL)-1β, and IL-6. In addition, q-PCR results showed that GPFE upregulated mRNA expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2), copper/zinc superoxide dismutase (SOD1), manganese superoxide dismutase (SOD2), glutathione peroxidase (GSH-Px), γ-glutamylcysteine synthetase (γ-GCS), CAT, and downregulated IL-6 and TNF-α mRNA expression levels. The mechanism of GPFE may be related to the inhibition of oxidative stress and inflammation.

Conclusion

The experiment indicates GPFE has a good protective effect on acute chemical liver injury in mice induced by CCl₄ via antioxidant and anti-inflammatory pathways.

CopA3 peptide induces permanent cell-cycle arrest in colorectal cancer cells

Cell-cycle arrest reflects an accumulation of responses to DNA damage that sequentially affects cell growth and division. Herein, we analyzed the effect of the 9-mer dimer defensin-like peptide, CopA3, against colorectal cancer cell growth and proliferation in a dose-dependent manner upon 96 h of treatment. As observed, CopA3 treatment significantly affected cancer cell growth, reduced colony formation ability, increased the number of SA-β-Gal positive cells, and remarkably reduced Ki67 protein expression. Notably, in HCT-116 cells, CopA3 (5 μM) treatment effectively increased oxidative stress and, as a result, amplified the endogenous ROS, mitochondrial ROS, and NO content in the cells, which further activated the DNA damage response and caused cell-cycle arrest at the G1 phase. The prolonged cell-cycle arrest elevated the release of inflammatory cytokines in the cell supernatant. Nevertheless, mechanistically, NAC treatment effectively reversed the CopA3 effect and significantly reduced the oxidative stress; subsequently rescuing the cells from G1 phase arrest. Overall, CopA3 treatment can inhibit the growth and proliferation of colorectal cancer cells by inducing cell-cycle arrest through the ROS-mediated pathway.

Decursinol Angelate Arrest Melanoma Cell Proliferation by Initiating Cell Death and Tumor Shrinkage via Induction of Apoptosis

Melanoma is known to aggressively metastasize and is one of the prominent causes of skin cancer mortality. This study was designed to assess the molecular mechanism of decursinol angelate (DA) against murine melanoma cell line (B16F10 cells). Treatment of DA resulted in growth inhibition and cell cycle arrest at G0/G1 (p < 0.001) phase, evaluated through immunoblotting. Moreover, autophagy-related proteins such as ATG-5 (p < 0.0001), ATG-7 (p < 0.0001), beclin-1 (p < 0.0001) and transition of LC3-I to LC3-II (p < 0.0001) were markedly decreased, indicating autophagosome inhibition. Additionally, DA treatment triggered apoptotic events which were corroborated by the occurrence of distorted nuclei, elevated reactive oxygen species (ROS) levels and reduction in the mitochondrial membrane potential. Subsequently, there was an increase in the expression of pro-apoptotic protein Bax in a dose-dependent manner, with the corresponding downregulation of Bcl-2 expression and cytochrome C expression following 24 h DA treatment in A375.SM and B16F10 cells. We substantiated our results for apoptotic occurrence through flow cytometry in B16F10 cells. Furthermore, we treated B16F10 cells with N-acetyl-L-cysteine (NAC). NAC treatment upregulated ATG-5 (p < 0.0001), beclin-1 (p < 0.0001) and LC3-I to LC3-II (p < 0.0001) conversion, which was inhibited in the DA treatment group. We also noticed a systematic upregulation of important markers for progression of G1 cell phase such as CDK-2 (p < 0.029), CDK-4 (p < 0.036), cyclin D1 (p < 0.0003) and cyclin E (p < 0.020) upon NAC treatment. In addition, we also observed a significant fold reduction (p < 0.05) in ROS fluorescent intensity and the expression of Bax (p < 0.0001), cytochrome C (p < 0.0001), cleaved caspase-9 (p > 0.010) and cleaved caspase-3 (p < 0.0001). NAC treatment was able to ameliorate DA-induced apoptosis and cell cycle arrest to support our finding. Our in vivo xenograft model also revealed similar findings, such as downregulation of CDK-2 (p < 0.0001) and CDK-4 (p < 0.0142) and upregulation of Bax (p < 0.0001), cytochrome C (p < 0.0001), cleaved caspase 3 (p < 0.0001) and cleaved caspase 9 (p < 0.0001). In summary, our study revealed that DA is an effective treatment against B16F10 melanoma cells and xenograft mice model.