Cyanidin 3-O-β-Glucoside Ameliorates Ethanol-Induced Acute Liver Injury by Attenuating Oxidative Stress and Apoptosis: The Role of SIRT1/FOXO1 Signaling

Cyanidin-3-O-glucoside alleviates ethanol-induced liver injury by promoting mitophagy in a Gao-binge mouse model of alcohol-associated liver disease

BACKGROUND

Alcohol-associated liver disease (ALD) is a leading cause of liver disease-related deaths worldwide. Unfortunately, approved medications for the treatment of this condition are quite limited. One promising candidate is the anthocyanin, Cyanidin-3-O-glucoside (C3G), which has been reported to protect mice against hepatic lipid accumulation, as well as fibrosis in different animal models. However, the specific effects and mechanisms of C3G on ALD remain to be investigated.

EXPERIMENTAL APPROACH

In this report, a Gao-binge mouse model of ALD was used to investigate the effects of C3G on ethanol-induced liver injury. The mechanisms of these C3G effects were assessed using AML12 hepatocytes.

RESULTS

C3G administration ameliorated ethanol-induced liver injury by suppressing hepatic oxidative stress, as well as through reducing hepatic lipid accumulation and inflammation. Mechanistically, C3G activated the AMPK pathway and enhanced mitophagy to eliminate damaged mitochondria, thus reducing mitochondria-derived reactive oxidative species in ethanol-challenged hepatocytes.

CONCLUSIONS

The results of this study indicate that mitophagy plays a potentially important role underlying the hepatoprotective action of C3G, as demonstrated in a Gao-binge mouse model of ALD. Accordingly, C3G may serve as a promising, new therapeutic drug candidate for use in ALD.

Zhizhu Decoction Alleviates Intestinal Barrier Damage via Regulating SIRT1/FoxO1 Signaling Pathway in Slow Transit Constipation Model Mice

OBJECTIVE

To explore the possible effects and mechanism of Zhizhu Decoction (ZZD) on the pathophysiology of slow transit constipation (STC).

METHODS

A total of 54 C57BL/6 mice was randomly divided into the following 6 groups by a random number table, including control, STC model (model), positive control, and low-, medium- and high-doses ZZD treatment groups (5, 10, 20 g/kg, namely L, M-, and H-ZZD, respectively), 9 mice in each group. Following 2-week treatment, intestinal transport rate (ITR) and fecal water content were determined, and blood and colon tissue samples were collected. Hematoxylin-eosin and periodic acid-Schiff staining were performed to evaluate the morphology of colon tissues and calculate the number of goblet cells. To determine intestinal permeability, serum levels of lipopolysaccharide (LPS), low-density lipoprotein (LDL) and mannose were measured using enzyme-linked immunosorbent assay (ELISA). Western blot analysis was carried out to detect the expression levels of intestinal tight junction proteins zona-occludens-1 (ZO-1), claudin-1, occludin and recombinant mucin 2 (MUC2). The mRNA expression levels of inflammatory cytokines including tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-4, IL-10 and IL-22 were determined using reverse transcription-quantitative reverse transcription reaction. Colon indexes of oxidative stress were measured by ELISA, and protein expression levels of colon silent information regulator 1/forkhead box O transcription factor 1 (SIRT1/FoxO1) antioxidant signaling pathway were detected by Western blot.

RESULTS

Compared with the model group, ITR and fecal moisture were significantly enhanced in STC mice in the M-ZZD and H-ZZD groups (P<0.01). Additionally, ZZD treatment notably increased the thickness of mucosal and muscular tissue, elevated the number of goblet cells in the colon of STC mice, reduced the secretion levels of LPS, LDL and mannose, and upregulated ZO-1, claudin-1, occludin and MUC2 expressions in the colon in a dose-dependent manner, compared with the model group (P<0.05 or P<0.01). In addition, ZZD significantly attenuated intestinal inflammation and oxidative stress and activated the SIRT1/FoxO1 signaling pathway (P<0.05 or P<0.01).

CONCLUSION

ZZD exhibited beneficial effects on the intestinal system of STC mice and alleviated intestinal inflammation and oxidative stress via activating SIRT1/FoxO1 antioxidant signaling pathway in the colon.

Food-derived cyanidin-3-O-glucoside alleviates oxidative stress: evidence from the islet cell line and diabetic db/db mice

Type 2 diabetes mellitus is a disease associated with an oxidative milieu that often leads to adverse health outcomes. Multiple anthocyanins have been reported to possess outstanding antioxidant activity, however, their effects on hyperglycemia-related oxidative stress remain elusive. In the present study, cyanidin-3-O-glucoside (C3G), a typical anthocyanin with various widely accepted health benefits, was applied to alleviate oxidative stress in pancreas islets under the conditions of hyperglycemia. Firstly, significantly decreased mitochondrial membrane potential (MMP) and antioxidant enzymes, as well as increased reactive oxygen species (ROS) and O₂^- levels, were detected after exposure to a series of concentrations of high glucose (HG) and palmitic acid (PA), which manifested oxidative stress triggered by mitochondrial damage. To evaluate the antioxidant effect of C3G in vitro, the islet cell line NIT-1 was used, and results proved that C3G could effectively relieve cellular oxidative stress induced by HG and PA. Furthermore, we found that the antioxidant effect of C3G was achieved by activating mitophagy via the PINK1-PARKIN signaling pathway. More importantly, an autophagy inhibitor chloroquine (CQ) was added to verify our findings at the protein level, and we observed the co-localization of mitochondria and lysosomes, which may form autophagolysosomes to clean damaged mitochondria. Immediately afterwards, more studies were conducted on pancreatic islets of diabetic db/db mice to verify the antioxidant effect of C3G discovered in islet cells. Along with the decline in fasting blood glucose, the oxidative stress in pancreas islets was successfully alleviated in diabetic db/db mice after supplementation with C3G. This was demonstrated by increased levels of ROS, and the impaired activities of anti-oxidative enzymes superoxide dismutase (SOD) and catalase (CAT) were partly reversed by C3G intervention. Our study has provided evidence for the alleviation effect of C3G against oxidative stress in pancreas islets, which may provide enlightenment for improving the health situation of diabetic patients in the future.

Empagliflozin alleviates ethanol-induced cardiomyocyte injury through inhibition of mitochondrial apoptosis via a SIRT1/PTEN/Akt pathway

Ethanol-induced myocardial injury involves multiple pathophysiological processes including apoptosis. Empagliflozin (EMPA), is a novel hypoglycaemic drug which possesses multiple pharmacologically relevant protective effects, including anti-apoptotic, anti-inflammatory and antioxidant effects. However, whether EMPA treatment has a protective effect on ethanol-induced myocardial injury has not been assessed, to the best of our knowledge. Therefore, the aim of this study was to determine the effect of EMPA treatment on ethanol-induced myocardial injury and the underlying mechanism. An ethanol-induced myocardial injury model was established by culturing H9c2 cells treated with 200 mmol/L ethanol for 24 hours, and additional groups of ethanol treated cells were also treated with EMPA with or without SIRT1 inhibitors prior to ethanol treatment. Cell viability and apoptosis were assessed using a CCK-8 assay and flow cytometry, respectively. The expression of apoptosis-related proteins was assessed using western blotting. The results showed that EMPA pretreatment resulted in increased cell viability and a decrease in LDH activity. Moreover, EMPA pretreatment significantly reduced apoptosis of cardiomyocytes, and reduced the expression of cleaved caspase 3. Furthermore, EMPA increased the expression of SIRT1, increased the phosphorylation levels of Akt, and reduced the expression of PTEN. EMPA also reduced ethanol-induced mitochondrial apoptosis, increasing the Bcl-2/Bax ratio and the mitochondrial membrane potential. However, the cardioprotective effects of EMPA were abrogated when cells were pretreated with a SIRT1 inhibitor. In conclusion, EMPA can alleviate ethanol-induced myocardial injury by inhibiting mitochondrial apoptosis via the SIRT1/PTEN/Akt pathway. Therefore, EMPA may be a novel target for treatment of ethanol-induced myocardial injury.

Differential effects of arsenic species on Nrf2 and Bach1 nuclear localization in cultured hepatocytes

Arsenic is a ubiquitous metalloid element present in both inorganic and organic forms in the environment. The liver is considered to be a primary organ of arsenic biotransformation and methylation, as well as the main target of arsenic toxicity. Studies have confirmed that Chang human hepatocytes have an efficient arsenic methylating capacity. Our previous studies have proven that arsenite activates nuclear factor erythroid 2-related factor 2 (Nrf2) pathway in hepatocytes. This study aimed to explore the activation of the Nrf2 pathway upon treatment of arsenic in various forms, including inorganic and organic arsenic. Our results showed that inorganic arsenic-both As₂O₃ and Na₂HAsO₄ significantly induced the expression of Nrf2 protein and mRNA, enhanced the transcription activity of Nrf2, and induced the expression of downstream target genes. These results confirmed the inorganic arsenic-induced Nrf2 pathway activation in hepatocytes. Although all arsenic chemicals used in the study induced Nrf2 protein accumulation, the organic arsenic C₂H₇AsO₂ did not affect the expression of Nrf2 downstream genes which were elevated by inorganic arsenic exposures. Through qRT-PCR and Nrf2 luciferase reporter assays, we further confirmed that C₂H₇AsO₂ neither increased Nrf2 mRNA level nor activated the Nrf2 transcription activity. Mechanistically, our results confirmed inorganic arsenic-induced both the nuclear import of Nrf2 and export of Bach1 (BTB and CNC homology 1), which is an Nrf2 transcriptional repressor, while organic arsenic only induced Nrf2 translocation. The unique pattern of Nrf2 regulation by organic arsenic underlines the critical role of Nrf2 and Bach1 in the arsenic toxicology.

Piceatannol protects against cerebral ischemia/reperfusion‑induced apoptosis and oxidative stress via the Sirt1/FoxO1 signaling pathway

Reperfusion is a critical therapeutic intervention used following acute ischemic stroke; however, it may cause cerebral ischemia/reperfusion injury (CIRI) and aggravate brain damage. Piceatannol (Pic), a hydroxylated analog of resveratrol, has been reported to exhibit anti‑inflammatory effects. However, the detailed molecular mechanisms and its effects on CIRI have not been sufficiently assessed, and, to the best of our knowledge, current methods of prevention of CIRI are limited. The aim of the present study was to investigate the effects of Pic on improving neurological function in a mouse model of CIRI. For the animal experiments, 8‑week‑old C57BL/6 mice were raised and randomly grouped, and an in vivo model of CIRI was established. Mice were administered a low (10 mg/kg/day) or high‑dose (20 mg/kg/d) of Pic 1 h after CIRI orally and once daily for the next 6 days. Neurological dysfunction was assessed using a modified neurological severity score and a rotarod test 1 week after CIRI establishment, and the cognitive status of the mice was assessed using a Morris water maze. Hematoxylin and eosin staining was used to evaluate the histopathological changes. The expression levels of sirtuin 1 (Sirt1), FoxO1, cleaved caspase‑3 (CC‑3), Bax and Bcl‑2 were measured using western blotting. Intracellular reactive oxygen species (ROS) generation, antioxidant enzymes [superoxide dismutase, glutathione (GSH) peroxidase and catalase] and non‑enzymatic antioxidants (GSH) were also detected using spectrophotometry. After inhibition of the Sirt1/FoxO1 pathway, a TUNEL assay was used for the detection of apoptotic cells in vitro and in vivo. The co‑localization of neuron‑specific nuclear protein and CC‑3 was assessing using immunofluorescent staining. Pic improved neurological functions and ameliorated hippocampal neuronal pathology following CIRI. In addition, the expression levels of CC‑3 and Bax and intracellular ROS levels were increased, while levels of antioxidant and non‑enzymatic enzymes were decreased in the mouse model of CIRI. Low and high doses of Pic significantly decreased ROS production and the expression levels of apoptosis‑related proteins, but increased antioxidant enzyme levels. However, a high‑dose of Pic did not result in increased levels of non‑enzymatic enzymes. Furthermore, low and high doses of Pic treatment significantly activated the Sirt1/FoxO1 pathway. Following inhibition of the Sirt1/FoxO1 pathway, the percentage of TUNEL‑positive cells and expression of CC‑3 were increased, and CC‑3 was enriched in neurons. The antioxidant effects of Pic were blocked by inhibition of Sirt1 in vitro and in vivo. In conclusion, these results suggested that Pic may exert a neuroprotective effect against in hippocampal neurons via the Sirt1/FoxO1 pathway.

The ameliorating effects of anthocyanins on the cross-linked signaling pathways of cancer dysregulated metabolism

Cancer cells underlie the dysregulated metabolism of carbohydrate, lipid and protein and thereby, employ interconnected cross-linked signaling pathways to supply adequate energy for growth and related biosynthetic procedures. In the present study, a comprehensive review of cancer metabolism and anthocyanin's effect was conducted using the existing electronic databases, including Medline, PubMed, Scopus, and Web of Science, as well as related articles in the field. Such keywords as "cancer", and "cancer metabolism" in the title/abstract/keyword and all the "anthocyanins" in the whole text were used. Data were collected without time restriction until February 2020. The results indicated the involvement of several signaling pathways, including inflammatory PI3K/Akt/mTOR pathway, Bax/Bcl-2/caspases as apoptosis modulators, and NF-κB/Nrf2 as oxidative stress mediators in the cancer dysregulated metabolism. Compelling studies have shown that targeting these pathways, as critical hallmarks of cancer, plays a critical role in combating cancer dysregulated metabolism. The complexity of cancer metabolism signaling pathways, along with toxicity, high costs, and resistance to conventional drugs urge the need to investigate novel multi-target agents. Increasing evidence has introduced plant-derived secondary metabolites as hopeful anticancer candidates which target multiple dysregulated cross-linked pathways of cancer metabolism. Amongst these metabolites, anthocyanins have demonstrated positive anticancer effects by targeting inflammation, oxidative stress, and apoptotic signaling pathways. The current study revealed the cross-linked signaling pathways of cancer metabolism, as well as the promising pharmacological mechanisms of anthocyanins in targeting the aforementioned signaling mediators. To overcome the pharmacokinetic limitations of anthocyanins in cancer treatment, their interactions with gut microbiota and the need to develop related nano-formulations were also considered.

Pathogenesis, Early Diagnosis, and Therapeutic Management of Alcoholic Liver Disease

Alcoholic liver disease (ALD) refers to the damages to the liver and its functions due to alcohol overconsumption. It consists of fatty liver/steatosis, alcoholic hepatitis, steatohepatitis, chronic hepatitis with liver fibrosis or cirrhosis, and hepatocellular carcinoma. However, the mechanisms behind the pathogenesis of alcoholic liver disease are extremely complicated due to the involvement of immune cells, adipose tissues, and genetic diversity. Clinically, the diagnosis of ALD is not yet well developed. Therefore, the number of patients in advanced stages has increased due to the failure of proper early detection and treatment. At present, abstinence and nutritional therapy remain the conventional therapeutic interventions for ALD. Moreover, the therapies which target the TNF receptor superfamily, hormones, antioxidant signals, and MicroRNAs are used as treatments for ALD. In particular, mesenchymal stem cells (MSCs) are gaining attention as a potential therapeutic target of ALD. Therefore, in this review, we have summarized the current understandings of the pathogenesis and diagnosis of ALD. Moreover, we also discuss the various existing treatment strategies while focusing on promising therapeutic approaches for ALD.

Effects of nutrient and bioactive food components on Alzheimer's disease and epigenetic

Alzheimer's disease (AD) is the most common form of dementia in the elderly and is a chronic neurodegenerative disease that is becoming widespread. For this reason, in recent years factors affecting the development, progression and cognitive function of the AD have been emphasized. Nutrients and other bioactive nutrients are among the factors that are effective in AD. In particular, vitamins A, C and E, vitamins B₁, B₆ and B₁₂, folate, magnesium, choline, inositol, anthocyanins, isoflavones etc. nutrients and bioactive nutrients are known to be effective in the development of AD. Nutrients and nutrient components may also have an epigenetic effect on AD. At the same time, nutrients and bioactive food components slow down the progression of the disease. For this reason, the effect of nutrients and food components on AD was examined in this review.

Silencing of HJURP induces dysregulation of cell cycle and ROS metabolism in bladder cancer cells via PPARγ-SIRT1 feedback loop

Holliday Junction Recognition Protein (HJURP) is a centromeric histone chaperone involving in de novo histone H3 variant CenH3 (CENP-A) recruitment. Our transcriptome and in vivo study revealed that HJURP is significantly upregulated in bladder cancer (BCa) tissues at both mRNA and protein levels. Knockdown of HJURP inhibited proliferation and viability of BCa cell lines revealed by CCK-8, colony formation and Ki-67-staining assays, and induced apoptosis and reactive oxygen species (ROS) production, as well as triggered cell cycle arrest at G0/G1 phase possibly via loss of CENP-A. Interestingly, in the HJURP-reduced BCa cells the levels of PPARγ and acetylated-p53 were increased, while the ratio of phosphorylated/total SIRT1 protein was decreased. Moreover, after treatment of the BCa cells using PPARγ antagonist (GW9662) and SIRT1 agonist (resveratrol, RSV) respectively, thee phenotypes of cell cycle arrest, increased ROS production and inhibited proliferation rate were all rescued. Taken together, our results suggested that HJURP might regulate proliferation and apoptosis via the PPARγ-SIRT1 negative feedback loop in BCa cells.

Study of acetylcholinesterase activity and apoptosis in SH-SY5Y cells and mice exposed to ethanol

Ethanol is one of the most commonly abused psychotropic substances with deleterious effects on the central nervous system. Ethanol exposure during development results in the loss of neurons in brain regions and when exposed to ethanol cultured cells undergo apoptosis. To date no information is available on whether abnormally high AChE activity is characteristic of apoptosis in animals exposed to ethanol. The aims of the present study were to determine whether induction of AChE activity is associated with ethanol-induced apoptosis and to explore the mechanism of enhanced AChE activity induced by ethanol. For this purpose, in vitro and in vivo experiments were performed. AChE activity was quantified by spectrophotometry and apoptosis by flow cytometer in SH-SY5Y cells exposed to ethanol. The results showed that cells treated with 500mM ethanol for 24h had a 9-fold increase in apoptotic cells and a 6-fold increase in AChE activity compared with controls. Mice exposed acutely to 200μl of 20% ethanol daily on days 1-4 had elevated AChE activity in plasma on days 3-7. On day 4, plasma AChE activity was 2.4-fold higher than pretreatment activity. More apoptotic cells were found in the brains of treated mice compared to controls. Cells in brain sections that were positive in the TUNEL assay stained for AChE activity. In conclusion, AChE activity and apoptosis were induced in SH-SY5Y cells and mice treated with ethanol, which may indicate that increased AChE may related to apoptosis induced by ethanol. Unusually high AChE activity may be an effect marker of exposure to ethanol. The relationship between AChE and apoptosis might represent a novel mechanism of ethanol-associated neuronal injury.

Effects of anthocyanins on the prevention and treatment of cancer

Anthocyanins are a class of water-soluble flavonoids, which show a range of pharmacological effects, such as prevention of cardiovascular disease, obesity control and antitumour activity. Their potential antitumour effects are reported to be based on a wide variety of biological activities including antioxidant; anti-inflammation; anti-mutagenesis; induction of differentiation; inhibiting proliferation by modulating signal transduction pathways, inducing cell cycle arrest and stimulating apoptosis or autophagy of cancer cells; anti-invasion; anti-metastasis; reversing drug resistance of cancer cells and increasing their sensitivity to chemotherapy. In this review, the latest progress on the anticancer activities of anthocyanins and the underlying molecular mechanisms is summarized using data from basic research in vitro and in vivo, from clinical trials and taking into account theory and practice.

LINKED ARTICLES

This article is part of a themed section on Principles of Pharmacological Research of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.11/issuetoc.

Cyanidin-3-O-glucoside: Physical-Chemistry, Foodomics and Health Effects

Anthocyanins (ACNs) are plant secondary metabolites from the flavonoid family. Red to blue fruits are major dietary sources of ACNs (up to 1 g/100 g FW), being cyanidin-3-O-glucoside (Cy3G) one of the most widely distributed. Cy3G confers a red hue to fruits, but its content in raspberries and strawberries is low. It has a good radical scavenging capacity (RSC) against superoxide but not hydroxyl radicals, and its oxidative potential is pH-dependent (58 mV/pH unit). After intake, Cy3G can be metabolized (phases I, II) by oral epithelial cells, absorbed by the gastric epithelium (1%-10%) and it is gut-transformed (phase II &amp; microbial metabolism), reaching the bloodstream (<1%) and urine (about 0.02%) in low amounts. In humans and Caco-2 cells, Cy3G's major metabolites are protocatechuic acid and phloroglucinaldehyde which are also subjected to entero-hepatic recycling, although caffeic acid and peonidin-3-glucoside seem to be strictly produced in the large bowel and renal tissues. Solid evidence supports Cy3G's bioactivity as DNA-RSC, gastro protective, anti-inflammatory, anti-thrombotic chemo-preventive and as an epigenetic factor, exerting protection against Helicobacter pylori infection, age-related diseases, type 2 diabetes, cardiovascular disease, metabolic syndrome and oral cancer. Most relevant mechanisms include RSC, epigenetic action, competitive protein-binding and enzyme inhibition. These and other novel aspects on Cy3G's physical-chemistry, foodomics, and health effects are discussed.

The combination of blueberry juice and probiotics reduces apoptosis of alcoholic fatty liver of mice by affecting SIRT1 pathway

Purpose

To explore the effects of the combination of blueberry juice and probiotics on the apoptosis of alcoholic fatty liver disease (AFLD).

Methods

Healthy C57BL/6J mice were used in the control group (CG). AFLD mice models were established with Lieber–DeCarli ethanol diet and evenly assigned to six groups with different treatments: MG (model), SI (SIRT1 [sirtuin type 1] small interfering RNA [siRNA]), BJ (blueberry juice), BJSI (blueberry juice and SIRT1 siRNA), BJP (blueberry juice and probiotics), and BJPSI (blueberry juice, probiotics, and SIRT1 siRNA). Hepatic tissue was observed using hematoxylin and eosin (HE) and Oil Red O (ORO) staining. Biochemical indexes of the blood serum were analyzed. The levels of SIRT1, caspase-3, forkhead box protein O1 (FOXO1), FasL (tumor necrosis factor ligand superfamily member 6), BAX, and Bcl-2 were measured by reverse transcription-polymerase chain reaction and Western blotting.

Results

HE and ORO staining showed that the hepatocytes were heavily destroyed with large lipid droplets in MG and SI groups, while the severity was reduced in the CG, BJ, and BJP groups (P<0.05). The levels of superoxide dismutase (SOD), reduced glutathione (GSH), and high-density lipoprotein-cholesterol (HDL-C) were increased in BJ and BJP groups when compared with the model group (P<0.05). In contrast, the levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT), total triglycerides (TGs), total cholesterol, low-density lipoprotein-cholesterol (LDL-C), and malondialdehyde (MDA) were lower in BJ and BJP groups than in the model group (P<0.05). The level of SIRT1 was increased, while the levels of FOXO1, phosphorylated FOXO1, acetylated FOXO1, FasL, caspase-3, BAX, and Bcl-2 were decreased in CG, BJ, and BJP groups (P<0.05). Meanwhile, SIRT1 silence resulted in increase of the levels of FOXO1, phosphorylated FOXO1, acetylated FOXO1, FasL, caspase-3, BAX, and Bcl-2.

Conclusion

The combination of blueberry juice and probiotics reduces apoptosis in AFLD by suppressing FOXO1, phosphorylated FOXO1, acetylated FOXO1, FasL, caspase-3, BAX, and Bcl-2 via the upregulation of SIRT1.