Baicalein Alleviates Liver Oxidative Stress and Apoptosis Induced by High-Level Glucose through the Activation of the PERK/Nrf2 Signaling Pathway

Research progress and advances in endoplasmic reticulum stress regulation of acute kidney injury

Acute kidney injury (AKI) is a common and severe clinical disorder in which endoplasmic reticulum (ER) stress plays an important regulatory role. In this review, we summarize the research progress on the relationship between ER stress and AKI. It emphasizes the importance of maintaining a balance between promoting and protecting ER stress during AKI and highlights the potential of ER stress-targeted drugs as a new therapeutic approach for AKI. The article also discusses the need for developing drugs that target ER stress effectively while avoiding adverse effects on normal cells and tissues. The review concludes that with a more comprehensive understanding of ER stress mechanisms and advancements in research techniques, more effective treatment options for AKI can be developed in the future.

Nrf2/Keap1/ARE regulation by plant secondary metabolites: a new horizon in brain tumor management

Brain cancer is regarded as one of the most life-threatening forms of cancer worldwide. Oxidative stress acts to derange normal brain homeostasis, thus is involved in carcinogenesis in brain. The Nrf2/Keap1/ARE pathway is an important signaling cascade responsible for the maintenance of redox homeostasis, and regulation of anti-inflammatory and anticancer activities by multiple downstream pathways. Interestingly, Nrf2 plays a somewhat, contradictory role in cancers, including brain cancer. Nrf2 has traditionally been regarded as a tumor suppressor since its cytoprotective functions are considered to be the principle cellular defense mechanism against exogenous and endogenous insults, such as xenobiotics and oxidative stress. However, hyperactivation of the Nrf2 pathway supports the survival of normal as well as malignant cells, protecting them against oxidative stress, and therapeutic agents. Plants possess a pool of secondary metabolites with potential chemotherapeutic/chemopreventive actions. Modulation of Nrf2/ARE and downstream activities in a Keap1-dependant manner, with the aid of plant-derived secondary metabolites exhibits promise in the management of brain tumors. Current article highlights the effects of Nrf2/Keap1/ARE cascade on brain tumors, and the potential role of secondary metabolites regarding the management of the same.

The Molecular Mechanism of Radix Paeoniae Rubra.-Cortex Moutan. Herb Pair in the Treatment of Atherosclerosis: A Work Based on Network Pharmacology and In Vitro Experiments

Radix Paeoniae Rubra. (Chishao, RPR) and Cortex Moutan. (Mudanpi, CM) are a pair of traditional Chinese medicines that play an important role in the treatment of atherosclerosis (AS). The main objective of this study was to identify potential synergetic function and underlying mechanisms of RPR-CM in the treatment of AS. The main active ingredients, targets of RPR-CM and AS-related genes were obtained from public databases. A Venn diagram was utilized to screen the common targets of RPR-CM in treating AS. The protein-protein interaction network was established based on STRING database. Biological functions and pathways of potential targets were analyzed through Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses. Cytoscape was used to construct the drug-compound-target-signal pathway network. Molecular docking was performed to verify the binding ability of the bioactive ingredients and the target proteins. The endothelial inflammation model was constructed with human umbilical vein endothelial cells stimulated with ox-LDL, and the function of RPR-CM in treating AS was verified by CCK-8 assay, enzyme-linked immunosorbent assay, and qPCR. In this study, 12 active components and 401 potential target genes of RPR-CM were identified, among which quercetin, kaempferol and baicalein were considered to be the main active components. A total of 1903 AS-related genes were identified through public databases and four GEO datasets (GSE57691, GSE72633, GSE6088 and GSE199819). There are 113 common target genes of RPR-CM in treating AS. PPI network analysis identified 17 genes in cluster 1 as the core targets. Bioinformatics analysis showed that RPR-CM in AS treatment was associated with multiple downstream biological processes and signal pathways. PTGS2, JUN, CASP3, TNF, IL1B, IL6, FOS, STAT1 were identified as the core targets of RPR-CM, and molecular docking showed that the main bioactive components of RPR-CM had good binding ability with the core targets. RPR-CM extract significantly inhibited the levels of inflammatory factors TNF-α, IL-6, IL-1β, MCP-1, VCAM-1 and ICAM-1 in HUVECs, and inhibited endothelial inflammation. This study revealed the active ingredients of RPR-CM, and identified the key downstream targets and signaling pathways in the treatment of AS, providing theoretical basis for the application of RPR-CM in prevention and treatment of AS.

Environment-relevant concentrations of cadmium induces necroptosis and inflammation; baicalein maintains gill homeostasis through suppressing ROS/ER stress signaling in common carps (Cyprinus carpio L.)

Cadmium (Cd) is a major contaminant in natural environments and exerts adverse effects on aquatic biota at low concentrations. Gill is as vital respiratory organ and may cause pollutants to enter fish during gas exchange. Baicalein (BAI), as a kind of flavonoids, possess antioxidant properties through inactivating free radicals. To confirm the potential effects and approaches of BAI addition in maintaining the gill stability, 90 common carps (Cyprinus carpio L.) were selected and randomly divided into water environment exposure group (0.22 mg/L Cd) and/or feed added with 0.10 g/kg BAI for 30 days. The analysis of ion content in serum showed that Cd exposure disturbed ion homeostasis, and BAI could reduce serum Cd concentration. The histopathological results of gills showed that Cd exposure caused gill tissue lesions and structural damage, and BAI feeding effectively alleviated this damage. In addition, BAI could enhance antioxidant activity and activate Nrf2/HO-1 axis, thereby reducing oxidative stress and endoplasmic reticulum (ER) stress. Moreover, BAI lightened cytokine imbalance, inflammatory response, and necroptosis. Overall, the results indicated that BAI feeding could maintain gill homeostasis against Cd poisoning via the ROS/ER stress signaling. This trial revealed the properties of BAI resistance to metal Cd in aquaculture and partially elucidated its mechanism.

Network Pharmacology, Molecular Docking Analysis and Molecular Dynamics Simulation of Scutellaria baicalensis in the Treatment of Liver Fibrosis

BACKGROUND

Traditional Chinese medicine Scutellaria Baicalensis (SB), one of the clinical firstline heat-clearing drugs, has obvious symptomatic advantages for hepatic fibrosis with dampness-heat stasis as its syndrome. We aim to predict and validate the potential mechanism of Scutellaria baicalensis active ingredients against liver fibrosis more scientifically and effectively.

METHODS

The underlying mechanism of Scutellaria baicalensis in inhibiting hepatic fibrosis was studied by applying network pharmacology, molecular docking and molecular dynamics simulation. Expression levels of markers in activated Hepatic Stellate Cells (HSC) after administration of three Scutellaria baicalensis extracts were determined by Western blot and Real-time PCR, respectively, in order to verify the anti-fibrosis effect of the active ingredients Results: There are 164 common targets of drugs and diseases screened and 115 signaling pathways obtained, which were mainly associated with protein phosphorylation, senescence and negative regulation of the apoptotic process. Western blot and Real-time PCR showed that Scutellaria baicalensis extracts could reduce the expression of HSC activation markers, and Oroxylin A had the strongest inhibitory effect on it. Molecular docking results showed that Oroxylin A had high binding activity to target proteins. Molecular dynamics simulation demonstrates promising stability of the Oroxylin A-AKT1 complex over the simulated MD time of 200 ns.

CONCLUSION

Scutellaria baicalensis active ingredients may inhibit HSC proliferation, reduce the generation of pro-inflammatory factors and block the anti-inflammatory effect of inflammatory signal transduction by inducing HSC apoptosis and senescence, thus achieving the effect of anti-fibrosis.

Associations of CKIP-1 and LOX-1 polymorphisms with the risk of type 2 diabetes mellitus with hypertension among Chinese adults

AIMS

Type 2 diabetes mellitus (T2DM) and hypertension are common high-incidence diseases, closely related, and have common pathogenic basis such as oxidative stress. Casein kinase 2 interacting protein-1 (CKIP-1) and low-density lipoprotein receptor (LOX-1) are considered to be important factors affect the level of oxidative stress in the body. The main purpose of this study was to explore the relationship between CKIP-1 (rs6693817 A > T, rs2306235 C > G) and LOX-1 (rs1050283 G > A, rs11053646 C > G) polymorphisms and the risk of hypertension and diabetes, and try to find new candidate genes for diabetes and diabetes with hypertension etiology in Chinese population.

METHODS

574 T2DM patients and 597 controls frequently matched by age and sex were selected for genotyping of CKIP-1 (rs6693817 A > T, rs2306235 C > G) and LOX-1 gene (rs1050283 G > A, rs11053646 C > G). Logistic regression was used to analyze the correlation between different genotypes and the risk of T2DM and T2DM with hypertension, and the results were expressed as odds ratio (OR) and 95% confidence interval (95% CI).

RESULTS

We found that the risk of T2DM in the AA + AT genotype of rs6693817 was higher than that in the TT genotype in Chinese population (OR = 1.318, 95%CI: 1.011-1.717, P = 0.041), and the difference was still significant after adjustment (OR = 1.370, 95%CI: 1.043-1.799, Padjusted = 0.024), the difference of heterozygotes (AT vs TT: OR = 1.374, 95%CI: 1.026-1.840, Padjusted = 0.033) was statistically significant. But after Bonferroni correction, the significance of the above sites disappeared. And rs6693817 was associated with the risk of T2DM combined with hypertension before and after adjustment in dominant model (OR = 1.424, 95% CI: 1.038-1.954, P = 0.028; OR = 1.460, 95% CI: 1.057-2.015, Padjusted = 0.021, respectively) and in heterozygote model (OR = 1.499, 95% CI: 1.069-2.102, P = 0.019; OR = 1.562, 95% CI: 1.106-2.207, Padjusted = 0.011, respectively). However, only the statistical significance of the heterozygous model remained after Bonferroni correction. rs2306235, rs1050283 and rs11053646 were not significantly correlated with T2DM and T2DM combined with hypertension risk (P > 0.05).

CONCLUSIONS

The results suggest that CKIP-1 rs6693817 is related to the susceptibility of Chinese people to T2DM with hypertension, providing a new genetic target for the treatment of diabetes with hypertension with in the future.

Dietary flavonoids prevent diabetes through epigenetic regulation: advance and challenge

The pathophysiology of diabetes has been studied extensively in various countries, but effective prevention and treatment methods are still insufficient. In recent years, epigenetics has received increasing attention from researchers in exploring the etiology and treatment of diabetes. DNA methylation, histone modifications, and non-coding RNAs play critical roles in the occurrence, maintenance, and progression of diabetes and its complications. Therefore, preventing or reversing the epigenetic alterations that occur during the development of diabetes may reduce the individual and societal burden of the disease. Dietary flavonoids serve as natural epigenetic modulators for the discovery of biomarkers for diabetes prevention and the development of alternative therapies. However, there is limited knowledge about the potential beneficial effects of flavonoids on the epigenetics of diabetes. In this review, the multidimensional epigenetic effects of different flavonoid subtypes in diabetes were summarized. Furthermore, it was discussed that parental flavonoid diets might reduce diabetes incidence in offspring, which represent a promising opportunity to prevent diabetes in the future. Future work will depend on exploring anti-diabetic effects of different flavonoids with different epigenetic regulation mechanisms and clinical trials.Highlights• "Epigenetic therapy" could reduce the burden of diabetic patients• "Epigenetic diet" ameliorates diabetes• Targeting epigenetic regulations by dietary flavonoids in the diabetes prevention• Dietary flavonoids prevent diabetes via transgenerational epigenetic inheritance.

Protective effect of solanesol in glucose-induced hepatocyte injury: Mechanistic insights on oxidative stress and mitochondrial preservation

Solanesol is a tetra sesquiterpene enol with various biological activities. Modern medical studies have confirmed that solanesol has the function of lipid antioxidation and scavenges free radicals. This study aimed to investigate the protective effect of solanesol against oxidative damage induced by high glucose on human normal hepatocytes (L-02 cells) and its possible mechanism. The results showed that solanesol could effectively improve the decrease of cell viability induced by high glucose, decrease the contents of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) in the extracellular medium, increased the enzyme activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT), balanced the level of reactive oxygen species (ROS) in cells, inhibited lipid peroxidation of all kinds of biological membranes, and restored mitochondrial membrane potential (MMP). In addition, Solanesol also inhibited the expression of Keap1, promoted the nuclear translocation of Nrf2 by hydrogen bonding with Nrf2, and activated the expression of downstream antioxidant factors NQO1 and HO-1. Altogether, these findings suggest that solanesol may be a potential protectant against diabetic liver injury.

The great potential of flavonoids as candidate drugs for NAFLD

Non-alcoholic fatty liver disease (NAFLD) has a global prevalence of approximately 25 % and is associated with high morbidity and high mortality. NAFLD is a leading cause of cirrhosis and hepatocellular carcinoma. Its pathophysiology is complex and still poorly understood, and there are no drugs used in the clinic to specifically treat NAFLD. Its pathogenesis involves the accumulation of excess lipids in the liver, leading to lipid metabolism disorders and inflammation. Phytochemicals with the potential to prevent or treat excess lipid accumulation have recently received increasing attention, as they are potentially more suitable for long-term use than are traditional therapeutic compounds. In this review, we summarize the classification, biochemical properties, and biological functions of flavonoids and how they are used in the treatment of NAFLD. Highlighting the roles and pharmacological uses of these compounds will be of importance for enhancing the prevention and treatment of NAFLD.

Nrf2-Mediated Pathway Activated by Prunus spinosa L. (Rosaceae) Fruit Extract: Bioinformatics Analyses and Experimental Validation

In our previous studies, Prunus spinosa fruit (PSF) ethanol extract was showed to exert antioxidant, antimicrobial, anti-inflammatory and wound healing activities. In the present study, an integrated bioinformatics analysis combined with experimental validation was carried out to investigate the biological mechanism(s) that are responsible for the reported PSF beneficial effects as an antioxidant during a pro-inflammatory TLR4 insult. Bioinformatics analysis using miRNet 2.0 was carried out to address which biological process(es) the extract could be involved in. In addition, Chemprop was employed to identify the key targets of nuclear receptor (NR) signaling and stress response (SR) pathways potentially modulated. The miRNet analysis suggested that the PSF extract mostly activates the biological process of cellular senescence. The Chemprop analysis predicted three possible targets for nine phytochemicals found in the extract: (i) ARE signaling, (ii) mitochondrial membrane potential (MMP) and (iii) p53 SR pathways. The PSF extract antioxidant effect was also experimentally validated in vitro using the human monocyte U937 cell line. Our findings showed that Nrf2 is modulated by the extract with a consequent reduction of the oxidative stress level. This was confirmed by a strong decrease in the amount of reactive oxygen species (ROS) observed in the PSF-treated cells subjected to lipopolysaccharide (LPS) (6 h treatment, 1 µg/mL). No visible effects were observed on p53 and MMP modulation.

Baicalein alleviates TNF-α-induced apoptosis of human nucleus pulposus cells through PI3K/AKT signaling pathway

BACKGROUND

Nucleus pulposus (NP) cell apoptosis contributed to disc degeneration. Baicalein, a natural steroid saponin, has been demonstrated to have anti-inflammatory, antiapoptotic, and antioxidative effects in various diseases. However, little is known about the roles of baicalein in intervertebral disc degeneration.

METHODS

To evaluate the roles of baicalein in disc degeneration and its specific mechanism, human NP cells were incubated with TNF-α and various concentrations of baicalein. Cell viability, extracellular matrix protein expression, catabolic factors, degree of apoptosis, inflammatory factors, and related signaling pathways were evaluated by western blotting, fluorescence immunostaining, TUNEL staining, and reverse transcription PCR.

RESULTS

Baicalein inhibited TNF-α-activated apoptotic signaling and catabolic activity in NP cells. Baicalein promoted PI3K/Akt signaling and attenuated the level of apoptosis-related markers in TNF-α-stimulated human NP cells.

CONCLUSION

Our work provides that baicalein attenuates TNF-α-activated apoptosis in human NP cells through promoting the PI3K/Akt pathway, indicating that baicalein is a new potential candidate for clinical therapy to attenuate disc degeneration.

New aphidicolane diterpenoids with glucose consumption promoting and cell viability enhancing activities from Scoparia dulcis

Two new aphidicolane diterpenoids, termed Scopadulinol A (1) and B (2), were obtained from whole plants of Scoparia dulcis. Their structures were elucidated by applying various spectroscopic techniques, including 1D- and 2D-NMR and HR-ESI-MS. The absolute configurations of 1 and 2 were determined by applying the calculated electronic circular dichroism (ECD). In addition, both compounds were tested for their effects on glucose consumption in HL-7702 cells and on palmitic acid (PA) induced viability in MIN6 cells at different concentrations. The results showed that they significantly promoted glucose consumption and attenuated the PA-induced decrease of cell viability. Additionally, 2 was tested to determine whether it could activate AMP-activated protein kinase (AMPK), but it showed no such effect at the tested dosage. These results indicated that the new compounds might promote glucose consumption through other pathways but not by activating AMPK. Collectively, we highlighted the isolation of two new aphidicolane diterpenoids from S. dulcis and found that they could promote glucose consumption and attenuate PA-induced decrease of cell viability.

Endoplasmic reticulum as a therapeutic target in type 2 diabetes: Role of phytochemicals

Type 2 diabetes mellitus (T2DM) is a metabolic disorders characterized by insulin resistance and β-cell dysfunction with an increasing worldwide incidence. Several studies have revealed that long-term glucotoxicity results in β-cell failure and death through induction of endoplasmic reticulum (ER) stress. Owing to the chronic progression of T2DM and the low effectiveness of antidiabetic drugs in long-term use, medicinal plants and their secondary metabolites seem to be the promising alternatives. Here we have provided a comprehensive review regarding the role of phytochemicals to alleviate ER stress in T2DM. Ginsenoside compound K, baicalein, quercetin, isopulegol, kaempferol, liquiritigenin, aspalathin, and tyrosol have demonstrated remarkable improvement of T2DM via modulation of ER stress. Arctigenin and total glycosides of peony have been shown to be effective in the treatment of diabetic retinopathy through modulation of ER stress. The effectiveness of grape seed proanthocyanidins and wolfberry is also shown in the relief of diabetic neuropathy and retinopathy. Resveratrol is involved in the prevention of atherosclerosis via ER stress modulation. Taken together, the data described herein revealed the capability of herbal constituents to prevent different complications of T2DM via a decrease in ER stress which open new doors to the treatment of diabetes.

Flavonoids' Dual Benefits in Gastrointestinal Cancer and Diabetes: A Potential Treatment on the Horizon?

Diabetes and gastrointestinal cancers (GI) are global health conditions with a massive burden on patients' lives worldwide. The development of both conditions is influenced by several factors, such as diet, genetics, environment, and infection, which shows a potential link between them. Flavonoids are naturally occurring phenolic compounds present in fruits and vegetables. Once ingested, unabsorbed flavonoids reaching the colon undergo enzymatic modification by the gut microbiome to facilitate absorption and produce ring fission products. The metabolized flavonoids exert antidiabetic and anti-GI cancer properties, targeting major impaired pathways such as apoptosis and cellular proliferation in both conditions, suggesting the potentially dual effects of flavonoids on diabetes and GI cancers. This review summarizes the current knowledge on the impact of flavonoids on diabetes and GI cancers in four significant pathways. It also addresses the synergistic effects of selected flavonoids on both conditions. While this is an intriguing approach, more studies are required to better understand the mechanism of how flavonoids can influence the same impaired pathways with different outcomes depending on the disease.

Mechanism and Active Components of Qingre Lidan Tablets Alleviate Intrahepatic Cholestasis by Activating the Farnesoid X Receptor

Background

Qingre Lidan tablets (QLTs) are a compound preparation of Chinese medicine that have long been used clinically to treat poor bile circulation caused by the inflammation and obstruction of the gallbladder and bile duct and to relieve jaundice and other symptoms. However, its material basis and mechanism are still unclear. The purpose of this study was to investigate the mechanism and active components of QLTs for treating intrahepatic cholestasis (IHC) in rat models.

Methods

In vivo experiments verified the effect of QLTs on alpha-naphthyl isothiocyanate (ANIT)-induced IHC models in rats. The mRNA and protein expression levels of farnesoid X receptor (FXR), bile salt export pump (BSEP), and multidrug-associated protein 2 (MRP2) in the rat liver were detected. UPLC/Q-TOF-MS was used to separate and identify the monomers in QLTs, and a dual-luciferase reporter assay was used to select effective the monomers that stimulate FXR. Among the selected monomers, baicalein was used as a representative to verify the effect on rat IHC models.

Results

QLTs and baicalein significantly reduced the serum biochemical indicators reflecting the changes in liver function among IHC rats and remitted the ANIT-induced liver histopathological changes. The expression levels of FXR, BSEP, and MRP2 in the liver were significantly increased after QLT treatment in a dose-dependent manner. Moreover, six types of active components that activate FXR were selected in QLTs, namely baicalein, wogonin, baicalein II, emodin, dibutyl phthalate, and diisooctyl phthalate.

Conclusions

QLTs and the active component, baicalein, can alleviate IHC in model rats.

Regulation of Cell Signaling Pathways and Non-Coding RNAs by Baicalein in Different Cancers

Landmark discoveries in molecular oncology have provided a wide-angle overview of the heterogenous and therapeutically challenging nature of cancer. The power of modern ‘omics’ technologies has enabled researchers to deeply and comprehensively characterize molecular mechanisms underlying cellular functions. Interestingly, high-throughput technologies have opened new horizons for the design and scientific fool-proof evaluation of the pharmacological properties of targeted chemical compounds to tactfully control the activities of the oncogenic protein networks. Groundbreaking discoveries have galvanized the expansion of the repertoire of available pharmacopoeia to therapeutically target a myriad of deregulated oncogenic pathways. Natural product research has undergone substantial broadening, and many of the drugs which constitute the backbone of modern pharmaceuticals have been derived from the natural cornucopia. Baicalein has gradually gained attention because of its unique ability to target different oncogenic signal transduction cascades in various cancers. We have partitioned this review into different sub-sections to provide a broader snapshot of the oncogenic pathways regulated by baicalein. In this review, we summarize baicalein-mediated targeting of WNT/β-catenin, AKT/mTOR, JAK/STAT, MAPK, and NOTCH pathways. We also critically analyze how baicalein regulates non-coding RNAs (microRNAs and long non-coding RNAs) in different cancers. Finally, we conceptually interpret baicalein-mediated inhibition of primary and secondary growths in xenografted mice.

Role of baicalin as a potential therapeutic agent in hepatobiliary and gastrointestinal disorders: A review

Baicalin is a natural bioactive compound derived from Scutellaria baicalensis, which is extensively used in traditional Chinese medicine. A literature survey demonstrated the broad spectrum of health benefits of baicalin such as antioxidant, anticancer, anti-inflammatory, antimicrobial, cardio-protective, hepatoprotective, renal protective, and neuroprotective properties. Baicalin is hydrolyzed to its metabolite baicalein by the action of gut microbiota, which is further reconverted to baicalin via phase 2 metabolism in the liver. Many studies have suggested that baicalin exhibits therapeutic potential against several types of hepatic disorders including hepatic fibrosis, xenobiotic-induced liver injury, fatty liver disease, viral hepatitis, cholestasis, ulcerative colitis, hepatocellular and colorectal cancer. During in vitro and in vivo examinations, it has been observed that baicalin showed a protective role against liver and gut-associated abnormalities by modifying several signaling pathways such as nuclear factor-kappa B, transforming growth factor beta 1/SMAD3, sirtuin 1, p38/mitogen-activated protein kinase/Janus kinase, and calcium/calmodulin-dependent protein kinase kinaseβ/adenosine monophosphate-activated protein kinase/acetyl-coenzyme A carboxylase pathways. Furthermore, baicalin also regulates the expression of fibrotic genes such as smooth muscle actin, connective tissue growth factor, β-catenin, and inflammatory cytokines such as interferon gamma, interleukin-6 (IL-6), tumor necrosis factor-alpha, and IL-1β, and attenuates the production of apoptotic proteins such as caspase-3, caspase-9 and B-cell lymphoma 2. However, due to its low solubility and poor bioavailability, widespread therapeutic applications of baicalin still remain a challenge. This review summarized the hepatic and gastrointestinal protective attributes of baicalin with an emphasis on the molecular mechanisms that regulate the interaction of baicalin with the gut microbiota.

Baicalein inhibits macrophage lipid accumulation and inflammatory response by activating the PPARγ/LXRα pathway

Lipid accumulation and inflammatory response are two major risk factors for atherosclerosis. Baicalein, a phenolic flavonoid widely used in East Asian countries, possesses a potential atheroprotective activity. However, the underlying mechanisms remain elusive. This study was performed to explore the impact of baicalein on lipid accumulation and inflammatory response in THP-1 macrophage-derived foam cells. Our results showed that baicalein up-regulated the expression of ATP binding cassette transporter A1 (ABCA1), ABCG1, liver X receptor α (LXRα), and peroxisome proliferator-activated receptor γ (PPARγ), promoted cholesterol efflux, and inhibited lipid accumulation. Administration of baicalein also reduced the expression and secretion of TNF-α, IL-1β, and IL-6. Knockdown of LXRα or PPARγ with siRNAs abrogated the effects of baicalein on ABCA1 and ABCG1 expression, cholesterol efflux, lipid accumulation as well as pro-inflammatory cytokine release. In summary, these findings suggest that baicalein exerts a beneficial effect on macrophage lipid accumulation and inflammatory response by activating the PPARγ/LXRα signaling pathway.

Scutellaria baicalensis and its constituents baicalin and baicalein as antidotes or protective agents against chemical toxicities: a comprehensive review

Scutellaria baicalensis (SB), also known as the Chinese skullcap, has a long history of being used in Chinese medicine to treat a variety of conditions ranging from microbial infections to metabolic syndrome and malignancies. Numerous studies have reported that treatment with total SB extract or two main flavonoids found in its root and leaves, baicalin (BA) and baicalein (BE), can prevent or alleviate the detrimental toxic effects of exposure to various chemical compounds. It has been shown that BA and BE are generally behind the protective effects of SB against toxicants. This paper aimed to review the protective and therapeutic effects of SB and its main components BA and BE against chemical compounds that can cause intoxication after acute or chronic exposure and seriously affect different vital organs including the brain, heart, liver, and kidneys. In this review paper, we had a look into a total of 221 in vitro and in vivo studies from 1995 to 2021 from the scientific databases PubMed, Scopus, and Web of Science which reported protective or therapeutic effects of BA, BE, or SB against drugs and chemicals that one might be exposed to on a professional or accidental basis and compounds that are primarily used to simulate disease models. In conclusion, the protective effects of SB and its flavonoids can be mainly attributed to increase in antioxidants enzymes, inhibition of lipid peroxidation, reduction of inflammatory cytokines, and suppression of apoptosis pathway.

Ferroptosis and ferritinophagy in diabetes complications

BACKGROUND

With long-term metabolic malfunction, diabetes can cause serious damage to whole-body tissue and organs, resulting in a variety of complications. Therefore, it is particularly important to further explore the pathogenesis of diabetes complications and develop drugs for prevention and treatment. In recent years, different from apoptosis and necrosis, ferroptosis has been recognized as a new regulatory mode of cell death and involves the regulation of nuclear receptor coactivator 4 (NCOA4)-mediated ferritinophagy. Evidence shows that ferroptosis and ferritinophagy play a significant role in the occurrence and development of diabetes complications.

SCOPE OF REVIEW

we systematically review the current understanding of ferroptosis and ferritinophagy, focusing on their potential mechanisms, connection, and regulation, discuss their involvement in diabetes complications, and consider emerging therapeutic opportunities and the associated challenges with future prospects.

MAJOR CONCLUSIONS

In summary, ferroptosis and ferritinophagy are worthy targets for the treatment of diabetes complications, but their complete molecular mechanism and pathophysiological process still require further study.

Redox Activity of Flavonoids: Impact on Human Health, Therapeutics, and Chemical Safety

The cost-effectiveness of presently used therapies is a problem in overall redox-based management, which is posing a significant financial burden on communities across the world. As a result, sophisticated treatment models that provide notions of predictive diagnoses followed by targeted preventive therapies adapted to individual patient profiles are gaining global acclaim as being beneficial to patients, the healthcare sector, and society as a whole. In this context, natural flavonoids were considered due to their multifaceted antioxidant, anti-inflammatory, and anticancer effects as well as their low toxicity and ease of availability. The aim of this review is to focus on the capacity of flavonoids to modulate the responsiveness of various diseases and ailments associated with redox toxicity. The review will also focus on the flavonoids' pathway-based redox activity and the advancement of redox-based therapies as well as flavonoids' antioxidant characteristics and their influence on human health, therapeutics, and chemical safety. Research findings indicated that flavonoids significantly exhibit various redox-based therapeutic responses against several diseases such as inflammatory, neurodegenerative, cardiovascular, and hepatic diseases and various types of cancer by activating the Nrf2/Keap1 transcription system, suppressing the nuclear factor κB (NF-κB)/IκB kinase inflammatory pathway, abrogating the function of the Hsp90/Hsf1 complex, inhibiting the PTEN/PI3K/Akt pathway, and preventing mitochondrial dysfunction. Some flavonoids, especially genistein, apigenin, amentoflavone, baicalein, quercetin, licochalcone A, and biochanin A, play a potential role in redox regulation. Conclusions of this review on the antioxidant aspects of flavonoids highlight the medicinal and folk values of these compounds against oxidative stress and various diseases and ailments. In short, treatment with flavonoids could be a novel therapeutic invention in clinical trials, as we hope.

Baicalein pre-treatment alleviates hepatic ischemia/reperfusion injury in mice by regulating the Nrf2/ARE pathway

Hepatic ischemia-reperfusion injury (HIRI) is caused by blood flow recovery following ischemia. Baicalein (BAI), a natural antioxidant used in traditional Chinese medicine, eliminates excessive free radicals and protects the structure of the cell membrane. However, its protective mechanism against HIRI is still unclear. The present study investigated underlying mechanism using a mouse HIRI model. Liver injury was evaluated using serum levels of alanine aminotransferase and aspartate aminotransferase, and hematoxylin-eosin staining was performed to evaluate the pathological changes in liver tissue. Apoptosis of hepatocytes was detected by TUNEL staining. The expression levels of reactive oxygen species (ROS), malondialdehyde (MDA) and superoxide dismutase (SOD) in the liver were detected to evaluate oxidative stress. Western blotting was performed to assess expression levels of nuclear factor E2-related factor 2 (Nrf2)/antioxidant response elements (ARE) pathway proteins in liver tissue. BAI pre-treatment significantly decreased elevation of serum aminotransferase levels induced by IR and alleviated histological damage to the liver. BAI decreased production of ROS and MDA in liver tissue induced by IR and increased the activity of SOD. At the same time, BAI inhibited apoptosis of liver cells induced by oxidative stress. Furthermore, BAI promoted the translocation of Nrf2 into the nucleus and increased the expression of total heme oxygenase-1 and NAD(P)H dehydrogenase quinone-1. The Nrf2 inhibitor ML385 reversed the protective effect of BAI on HIRI. These results indicated that BAI served a protective effect in HIRI by regulating the Nrf2/ARE pathway.

Baicalein Enhances the Effect of Acarbose on the Improvement of Nonalcoholic Fatty Liver Disease Associated with Prediabetes via the Inhibition of De Novo Lipogenesis

Prediabetes is a prevalent metabolic disorder with multiple complications, including nonalcoholic fatty liver disease (NAFLD). In this study, we investigated the combinatorial effect of baicalein, a dietary flavonoid abundant in multiple edible plants, and acarbose on prediabetes-associated NAFLD. Baicalein and its metabolites inhibited de novo lipogenesis (DNL), thereby decreasing lipid accumulation and hepatokine secretion in oleic acid-induced hepatocytes. Carbohydrate restriction, which mimicked the effect of acarbose, led to comparable results. The combinatorial effect of baicalein and acarbose was further verified in prediabetic mice with NAFLD. Through the 16-week intervention, baicalein and acarbose inhibited DNL and improved glucose tolerance, oxidative stress, liver histology, and hepatokine secretion, thereby ameliorating insulin resistance and NAFLD. Our study demonstrated that baicalein enhanced the effect of acarbose on improving NAFLD and explored the underlying multitarget mechanism, laying a theoretical foundation for the development of flavonoid dietary supplements for the simultaneous improvement of NAFLD and prediabetes.

Effect of Gegen Qinlian Decoction on Hepatic Gluconeogenesis in ZDF Rats with Type 2 Diabetes Mellitus Based on the Farnesol X Receptor/Ceramide Signaling Pathway Regulating Mitochondrial Metabolism and Endoplasmic Reticulum Stress

Background

Type 2 diabetes mellitus (T2DM) is a kind of disorder of glucose and lipid metabolism with the main clinical manifestation of long‐term higher blood glucose level than the normal value. Farnesol X receptor (FXR)/ceramide signaling pathway plays an important role in regulating cholesterol metabolism, lipid homeostasis, and the absorption of fat and vitamins in diet. Gegen Qinlian Decoction (GQD) is a classical herbal formula, which has a good clinical therapeutic effect on diabetes-related metabolic syndrome.

Objective

To investigate the effect of Gegen Qinlian Decoction (GQD) on hepatic gluconeogenesis in obese T2DM rats based on the FXR/ceramide signaling pathway regulating mitochondrial metabolism and endoplasmic reticulum stress (ERS).

Methods

ZDF (fa/fa) rats were fed with high-fat diet to establish the T2DM model; GQD was given to T2DM model rats by gavage; changes of the general state and body weight of rats were recorded; fasting blood glucose was detected; blood insulin, blood ceramide, glycosylated hemoglobin in blood, acetyl CoA in liver mitochondria, and bile salt lyase in intestinal tissue were detected by ELISA. The content of T-β-MCA in blood was detected by LC-MS; the content of glycogen in liver tissue was detected by PAS staining; the expression of FXR, Sptlc2, and Smpd3 in ileum tissue, P-PERK, ATF6α, GRP78 BIP, and P-IRE1 in the liver, and CS and PC protein in liver mitochondria was detected by immunohistochemistry and western blot assay. The mRNA expression levels of FXR, Sptlc2, and Smpd3 in the ileum, PERK, ATF6α, GRP78 BIP, and IRE1 in the liver, and CS and PC in liver mitochondria were detected by qRT-PCR.

Results

GQD can improve the general state of T2DM rats, slow down their weight gain, reduce the levels of fasting blood glucose, fasting insulin, glycosylated hemoglobin, blood ceramide, bile salt hydrolase in intestinal tissue, and acetyl CoA in liver mitochondria of T2DM rats, and increase the contents of liver glycogen and T-β-MCA in blood of T2DM rats. At the molecular level, GQD can inhibit the expression levels of FXR, Sptlc2, and Smpd3 in the ileum of T2DM rats and the protein and mRNA expression levels of oxidative stress-related factors in the liver. At the same time, GQD can increase the expression of CS and reduce the expression of PC in liver mitochondria of T2DM rats.

Conclusion

GQD can inhibit the FXR/ceramide signaling pathway, regulate endoplasmic reticulum stress, enhance the CS activity of liver mitochondria, reduce the acetyl CoA level and PC activity of liver mitochondria, inhibit hepatic gluconeogenesis, protect islet β-cells, and control blood glucose.

Effects of Traditional Chinese Medication-Based Bioactive Compounds on Cellular and Molecular Mechanisms of Oxidative Stress

The oxidative stress reaction is the imbalance between oxidation and antioxidation in the body, resulting in excessive production of oxygen free radicals in the body that cannot be removed, leading to excessive oxidation of the body, and causing damage to cells and tissues. A large number of studies have shown that oxidative stress is involved in the pathological process of many diseases, so inhibiting oxidative stress, that is, antioxidation, is of great significance for the treatment of diseases. Studies have shown that many traditional Chinese medications contain antioxidant active bioactive compounds, but the mechanisms of those compounds are different and complicated. Therefore, by summarizing the literature on antioxidant activity of traditional Chinese medication-based bioactive compounds in recent years, our review systematically elaborates the main antioxidant bioactive compounds contained in traditional Chinese medication and their mechanisms, so as to provide references for the subsequent research.

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.

Pharmacological properties of baicalin on liver diseases: a narrative review

Baicalin is the main active component of Scutellaria baicalensis, widely used in traditional Chinese medicine thanks to its various pharmacological effects, such as anti-tumor, anti-inflammatory, and antibacterial properties, as well as cardiovascular, hepatic, and renal protective effect. Recently, the protective effects of baicalin on liver disease have received much more attention. Several studies showed that baicalin protects against several types of liver diseases including viral hepatitis, fatty liver disease, xenobiotic induced liver injury, cholestatic liver injury, and hepatocellular carcinoma, with a variety of pharmacological mechanisms. A comprehensive understanding of the mechanism of baicalin can provide a valuable reference for its clinical use, but up to now, no narrative review is available that summarizes the pharmacological effects of baicalin to clarify its potential use in the treatment of liver diseases. Therefore, this review summarizes the progress of baicalin research and the underlying mechanism in the treatment of various liver diseases, to promote further research and its clinical application.

Regulation of Nrf2/ARE Pathway by Dietary Flavonoids: A Friend or Foe for Cancer Management?

The nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) pathway is an important cell signaling mechanism in maintaining redox homeostasis in humans. The role of dietary flavonoids in activating Nrf2/ARE in relation to cancer chemoprevention or cancer promotion is not well established. Here we summarize the dual effects of flavonoids in cancer chemoprevention and cancer promotion with respect to the regulation of the Nrf2/ARE pathway, while underlying the possible cellular mechanisms. Luteolin, apigenin, quercetin, myricetin, rutin, naringenin, epicatechin, and genistein activate the Nrf2/ARE pathway in both normal and cancer cells. The hormetic effect of flavonoids has been observed due to their antioxidant or prooxidant activity, depending on the concentrations. Reported in vitro and in vivo investigations suggest that the activation of the Nrf2/ARE pathway by either endogenous or exogenous stimuli under normal physiological conditions contributes to redox homeostasis, which may provide a mechanism for cancer chemoprevention. However, some flavonoids, such as luteolin, apigenin, myricetin, quercetin, naringenin, epicatechin, genistein, and daidzein, at low concentrations (1.5 to 20 µM) facilitate cancer cell growth and proliferation in vitro. Paradoxically, some flavonoids, including luteolin, apigenin, and chrysin, inhibit the Nrf2/ARE pathway in vitro. Therefore, even though flavonoids play a major role in cancer chemoprevention, due to their possible inducement of cancer cell growth, the effects of dietary flavonoids on cancer pathophysiology in patients or appropriate experimental animal models should be investigated systematically.

Apigetrin ameliorates streptozotocin-induced pancreatic β-cell damages via attenuating endoplasmic reticulum stress

The pathogenesis of diabetes is associated with dysfunction of pancreatic β-cells. To ameliorate the β-cell dysfunction, it has propelled great interest to search pharmacological agents from natural plants. This study explored the protective effect of apigetrin, a flavonoid present in natural plants, against streptozotocin (STZ)-induced cell damages in RINm5F cells and the potential mechanisms. Apigetrin was found to inhibit the elevation of intracellular reactive oxygen species levels, restore the impairment of antioxidant enzymes, and recover the disruption of redox homeostasis in the STZ-treated pancreatic β-cells. Moreover, treatment of apigetrin significantly suppressed the STZ-induced apoptosis in the analysis of apoptotic sub-G₁ population and the protein expressions of cleaved poly(ADP-ribose) polymerase and caspase-3. Furthermore, apigetrin attenuated STZ-induced endoplasmic reticulum (ER) stress, indicated by the reduction of ER stress biomarkers, including overloading of mitochondrial calcium, increase in glucose-regulated protein 78, phosphorylation of protein kinase RNA-like ER kinase and its downstream eukaryotic initiation factor 2α, cleavage of activating transcription factor 6 and caspase-12, up-regulation of CCAAT/enhancer binding protein homologous protein, and induction of spliced X-box binding protein 1. Additionally, pretreatment with 4-phenylbutyric acid, a classic ER stress inhibitor, augmented these beneficial effects of apigetrin. In conclusion, these results demonstrated that apigetrin could improve the STZ-induced pancreatic β-cell damages via mitigation of oxidative stress and ER stress and supported the application of apigetrin to developing the novel therapeutics of diabetes.