The involvement of p62-Keap1-Nrf2 antioxidative signaling pathway and JNK in the protection of natural flavonoid quercetin against hepatotoxicity

Hypoxia and ferroptosis

Ferroptosis is a novel, iron-dependent cell death characterized by the excessive accumulation of ferroptosis lipid peroxides ultimately leading to oxidative damage to the cell membrane. Iron, lipid, amino acid metabolism, and other signaling pathways all control ferroptosis. Numerous bodily tissues experience hypoxia under normal and pathological circumstances. Tissue cells can adjust to these changes by activating the hypoxia-inducible factor (HIF) signaling pathway and other mechanisms in response to the hypoxic environment. In recent years, there has been increasing evidence that hypoxia and ferroptosis are closely linked, and that hypoxia can regulate ferroptosis in specific cells and conditions through different pathways. In this paper, we review the possible positive and negative regulatory mechanisms of ferroptosis by hypoxia-inducible factors, as well as ferroptosis-associated ischemic diseases, with the intention of delivering novel therapeutic avenues for the defense and management of hypoxic illnesses linked to ferroptosis.

Therapeutic Potential of Brassica oleracea and Raphanus sativus Aqueous Extracts on a Prediabetic Rat Model

Type 2 diabetes (T2D) is a serious health problem, and its prevalence is expected to increase worldwide in the years ahead. Cruciferous vegetables such as Brassica oleracea var. capitata L. (green cabbage) and Raphanus sativus L. (radish) have therapeutic properties that can be used to support the treatment of T2D. This study evaluated the effect of B. oleracea (BAE) and R. sativus (RAE) aqueous extracts on zoometric parameters, glycemic profiles, and pancreas and liver in prediabetic rats induced by a high-sucrose diet (HSD). BAE and RAE were administered to male HSD-induced Wistar rats (n = 35) at 5 and 10 mg/kg doses for 5 weeks. Zoometric and biochemical changes were measured, and then the pancreas and liver histological preparations were analyzed to observe the protective effect. BAE decreased feed intake and weight gain. Both extracts decreased fasting glucose and insulin levels compared with control (not treated), although not significantly (P > .05). The extracts significantly (P < .05) reduced homeostatic model assessment for insulin resistance, homeostasis model assessment of β-cell function, and glucose intolerance, similar to metformin control. In addition, minor damage occurred in the pancreas and liver. The results indicated that BAE and RAE decreased weight gain, improved glucose regulation, and protected the pancreas and liver in HSD rats. Therefore, they have multiple therapeutical properties and may be helpful in the prevention of T2D.

New perspectives on the therapeutic potential of quercetin in non-communicable diseases: Targeting Nrf2 to counteract oxidative stress and inflammation

Non-communicable diseases (NCDs), including cardiovascular diseases, cancer, metabolic diseases, and skeletal diseases, pose significant challenges to public health worldwide. The complex pathogenesis of these diseases is closely linked to oxidative stress and inflammatory damage. Nuclear factor erythroid 2-related factor 2 (Nrf2), a critical transcription factor, plays an important role in regulating antioxidant and anti-inflammatory responses to protect the cells from oxidative damage and inflammation-mediated injury. Therefore, Nrf2-targeting therapies hold promise for preventing and treating NCDs. Quercetin (Que) is a widely available flavonoid that has significant antioxidant and anti-inflammatory properties. It modulates the Nrf2 signaling pathway to ameliorate oxidative stress and inflammation. Que modulates mitochondrial function, apoptosis, autophagy, and cell damage biomarkers to regulate oxidative stress and inflammation, highlighting its efficacy as a therapeutic agent against NCDs. Here, we discussed, for the first time, the close association between NCD pathogenesis and the Nrf2 signaling pathway, involved in neurodegenerative diseases (NDDs), cardiovascular disease, cancers, organ damage, and bone damage. Furthermore, we reviewed the availability, pharmacokinetics, pharmaceutics, and therapeutic applications of Que in treating NCDs. In addition, we focused on the challenges and prospects for its clinical use. Que represents a promising candidate for the treatment of NCDs due to its Nrf2-targeting properties.

The Nrf2/HO-1 pathway participates in the antiapoptotic and anti-inflammatory effects of platelet-rich plasma in the treatment of osteoarthritis

INTRODUCTION

We aimed to explore the molecular mechanisms through which platelet-rich plasma (PRP) attenuates osteoarthritis (OA)-induced pain, apoptosis, and inflammation.

METHODS

An in vivo model of OA was established by injuring rats using the anterior cruciate ligament transection method, whereas an in vitro model was generated by exposing chondrocytes to interleukin (IL)-1β. Both models were then treated with PRP.

RESULTS

In both the in vivo and in vitro models, OA led to the suppression of the nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway, whereas treatment with PRP reactivated this molecular axis. Inhibition of the Nrf2/HO-1 pathway using the Nrf2 inhibitor brusatol or through Nrf2 gene silencing counteracted the effects of PRP in reducing the tenderness and thermal pain thresholds of OA rats. Additionally, PRP reduced the mRNA expression of IL-1β, IL-6, tumor necrosis factor-alpha (TNF-α), and matrix metallopeptidase 13 (MMP-13) and the protein expression of B-cell lymphoma 2 (Bcl-2), Bcl-2 associated X-protein (Bax), and caspase-3. Furthermore, inflammation and apoptosis were induced by brusatol treatment or Nrf2 silencing. Additionally, in the in vitro model, PRP treatment increased the proliferation of chondrocytes and attenuated their inflammatory response and apoptosis, effects that were abrogated by Nrf2 depletion.

CONCLUSIONS

The Nrf2/HO-1 pathway participates in the PRP-mediated attenuation of OA development by suppressing inflammation and apoptosis.

The combined analysis of transcriptomics and metabolomics reveals the mechanisms by which dietary quercetin regulates growth and immunity in Penaeus vannamei

As a potent antioxidant, the flavonoid compound quercetin (QUE) has been widely used in the farming of aquatic animals. However, there are fewer reports of the beneficial effects, especially in improving immunity of Penaeus vannamei by QUE. The aim of this study was to investigate the effects of dietary QUE on growth, apoptosis, antioxidant and immunity of P. vannamei. It also explored the potential mechanisms of QUE in improving the growth and immunity of P. vannamei. P. vannamei were fed diets with QUE for 60 days. The results revealed that QUE (0.5 or 1.0 g/kg) ameliorated the growth, and the expressions of genes related to apoptosis, antioxidant, and immunity. The differentially expressed genes (DEGs) and differential metabolites (DMs) obtained through transcriptomics and metabolomics, respectively, enriched in pathways related to nutritional metabolism such as lipid metabolism, amino acid metabolism, and carbohydrate metabolism. After QUE addition, especially at 0.5 g/kg, DEGs were enriched into the functions of response to stimulus and antioxidant activity, and the pathways of HIF-1 signaling pathway, C-type lectin receptor signaling pathway, Toll-like receptor signaling pathway, and FoxO signaling pathway. In conclusion, dietary QUE can ameliorate growth, apoptosis, antioxidant and immunity of P. vannamei, the appropriate addition amount was 0.5 g/kg rather than 1.0 g/kg. Regulations of QUE on nutrient metabolism and immune-related pathways, and bioactive metabolites, were important factors for improving the aforementioned abilities in P. vannamei.

Therapeutic implications of quercetin and its derived-products in COVID-19 protection and prophylactic

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel human coronavirus, which has triggered a global pandemic of the coronavirus infectious disease 2019 (COVID-19). Outbreaks of emerging infectious diseases continue to challenge human health worldwide. The virus conquers human cells through the angiotensin-converting enzyme 2 receptor-driven pathway by mostly targeting the human respiratory tract. Quercetin is a natural flavonoid widely represented in the plant kingdom. Cumulative evidence has demonstrated that quercetin and its derivatives have various pharmacological properties including anti-cancer, anti-hypertension, anti-hyperlipidemia, anti-hyperglycemia, anti-microbial, antiviral, neuroprotective, and cardio-protective effects, because it is a potential treatment for severe inflammation and acute respiratory distress syndrome. Furthermore, it is the main life-threatening condition in patients with COVID-19. This article provides a comprehensive review of the primary literature on the predictable effectiveness of quercetin and its derivatives docked to multi-target of SARS-CoV-2 and host cells via in silico and some of validation through in vitro, in vivo, and clinically to fight SARS-CoV-2 infections, contribute to the reduction of inflammation, which suggests the preventive and therapeutic latency of quercetin and its derived-products against COVID-19 pandemic, multisystem inflammatory syndromes (MIS), and long-COVID.

Exploring the therapeutic potential of quercetin: A focus on its sirtuin-mediated benefits

As the global population ages, preventing lifestyle- and aging-related diseases is increasing, necessitating the search for safe and affordable therapeutic interventions. Among nutraceuticals, quercetin, a flavonoid ubiquitously present in various plants, has garnered considerable interest. This review aimed to collate and analyze existing literature on the therapeutic potentials of quercetin, especially its interactions with SIRTs and its clinical applicability based on its bioavailability and safety. This narrative review was based on a literature survey spanning from 2015 to 2023 using PUBMED. The keywords and MeSH terms used were: "quercetin" AND "bioavailability" OR "metabolism" OR "metabolites" as well as "quercetin" AND "SIRTuin" OR "SIRT*" AND "cellular effects" OR "pathway" OR "signaling" OR "neuroprotective" OR "cardioprotective" OR "nephroprotective" OR "antiatherosclerosis" OR "diabetes" OR "antidiabetic" OR "dyslipidemia" AND "mice" OR "rats". Quercetin demonstrates multiple therapeutic activities, including neuroprotective, cardioprotective, and anti-atherosclerotic effects. Its antioxidant, anti-inflammatory, antiviral, and immunomodulatory properties are well-established. At a molecular level, it majorly interacts with SIRTs, particularly SIRT1 and SIRT6, and modulates numerous signaling pathways, contributing to its therapeutic effects. These pathways play roles in reducing oxidative stress, inflammation, autophagy regulation, mitochondrial biogenesis, glucose utilization, fatty acid oxidation, and genome stability. However, clinical trials on quercetin's effectiveness in humans are scarce. Quercetin exhibits a wide range of SIRT-mediated therapeutic effects. Despite the compelling preclinical data, more standardized clinical trials are needed to fully understand its therapeutic potential. Future research should focus on addressing its bioavailability and safety concerns.

Natural products as non-covalent and covalent modulators of the KEAP1/NRF2 pathway exerting antioxidant effects

By controlling several antioxidant and detoxifying genes at the transcriptional level, including NAD(P)H quinone oxidoreductase 1 (NQO1), multidrug resistance-associated proteins (MRPs), UDP-glucuronosyltransferase (UGT), glutamate-cysteine ligase catalytic (GCLC) and modifier (GCLM) subunits, glutathione S-transferase (GST), sulfiredoxin1 (SRXN1), and heme-oxygenase-1 (HMOX1), the KEAP1/NRF2 pathway plays a crucial role in the oxidative stress response. Accordingly, the discovery of modulators of this pathway, activating cellular signaling through NRF2, and targeting the antioxidant response element (ARE) genes is pivotal for the development of effective antioxidant agents. In this context, natural products could represent promising drug candidates for supplementation to provide antioxidant capacity to human cells. In recent decades, by coupling in silico and experimental methods, several natural products have been characterized to exert antioxidant effects by targeting the KEAP1/NRF2 pathway. In this review article, we analyze several natural products that were investigated experimentally and in silico for their ability to modulate KEAP1/NRF2 by non-covalent and covalent mechanisms. These latter represent the two main sections of this article. For each class of inhibitors, we reviewed their antioxidant effects and potential therapeutic applications, and where possible, we analyzed the structure-activity relationship (SAR). Moreover, the main computational techniques used for the most promising identified compounds are detailed in this survey, providing an updated view on the development of natural products as antioxidant agents.

Radix Astragali decoction improves liver regeneration by upregulating hepatic expression of aquaporin-9

BACKGROUND

The therapeutic efficacy of liver injuries heavily relies on the liver's remarkable regenerative capacity, necessitating the maintenance of glycose/lipids homeostasis and oxidative eustasis during the recovery process. Astragali Radix, an herbal tonic widely used in China and many other countries, is believed to have many positive effects, including immune stimulation, nourishing, antioxidant, liver protection, diuresis, anti-diabetes, anti-cancer and expectorant. Astragali Radix is widely integrated into hepatoprotective formulas as it is believed to facilitate liver regeneration. Nevertheless, the precise molecular pharmacological mechanisms underlying this hepatoprotective effect remain elusive.

PURPOSE

To investigate the improving effects of Astragali Radix on liver regeneration and the underlying mechanisms.

METHODS

A mouse model of 70% partial hepatectomy (PHx) was employed to investigate the impact of Radix Astragali decoction (HQD) on liver regeneration. HQD was orally administered for 7 days before the PHx procedure and throughout the experiment. N-acetylcysteine (NAC) was used as a positive control for liver regeneration. Liver regeneration was assessed by evaluating the liver-to-body weight ratio (LW/BW) and the expression of representative cell proliferation marker proteins. Oxidative stress and glucose metabolism were analyzed using biochemical assays, Western blotting, dihydroethidium (DHE) fluorescence, and periodic acid-Schiff (PAS) staining methods. To understand the role of AQP9 as a potential molecular target of HQD in promoting liver regeneration, td-Tomato-tagged AQP9 transgenic mice (AQP9-RFP) were employed to determine the expression pattern of AQP9 protein. AQP9 knockout mice (AQP9-/-) were used to assess the specific targeting of AQP9 in the promotion of liver regeneration by HQD.

RESULTS

HQD significantly upregulated hepatic AQP9 expression, alleviated liver injury and promoted liver regeneration in wild-type (AQP9+/+) mice after 70% PHx. However, the beneficial impact of HQD on liver regeneration was absent in AQP9 gene knockout (AQP9-/-) mice. Moreover, HQD facilitated the uptake of glycerol by hepatocytes, enhanced gluconeogenesis, and concurrently reduced H2O2 content and oxidative stress levels in AQP9+/+ but not AQP9-/- mouse livers. Additionally, main active substance of Radix Astragali, astragaloside IV (AS-IV) and cycloastragenol (CAG), demonstrated substantial upregulation of AQP9 expression and promoted liver regeneration in AQP9+/+ but not AQP9-/- mice.

CONCLUSION

This study is the first to demonstrate that Radix Astragali and its main active constituents (AS-IV and CAG) improve liver regeneration by upregulating the expression of AQP9 in hepatocytes to increase gluconeogenesis and reduce oxidative stress. The study revealed novel molecular pharmacological mechanisms of Radix Astragali and provided a promising therapeutic target of liver diseases.

Unveiling the therapeutic promise of natural products in alleviating drug-induced liver injury: Present advancements and future prospects

Drug-induced liver injury (DILI) refers to adverse reactions to small chemical compounds, biological agents, and medical products. These reactions can manifest as acute or chronic damage to the liver. From 1997 to 2016, eight drugs, including troglitazone, nefazodone, and lumiracoxib, were removed from the market due to their liver-damaging effects, which can cause diseases. We aimed to review the recent research on natural products and their bioactive components as hepatoprotective agents in mitigating DILI. Recent articles were fetched via searching the PubMed, PMC, Google Scholar, and Web of Science electronic databases from 2010 to January 2023 using relevant keywords such as "natural products," "acetaminophen," "antibiotics," "paracetamol," "DILI," "hepatoprotective," "drug-induced liver injury," "liver failure," and "mitigation." The studies reveal that the antituberculosis drug (acetaminophen) is the most frequent cause of DILI, and natural products have been largely explored in alleviating acetaminophen-induced liver injury. They exert significant hepatoprotective effects by preventing mitochondrial dysfunction and inflammation, inhibiting oxidative/nitrative stress, and macromolecular damage. Due to the bioavailability and dietary nature, using natural products alone or as an adjuvant with existing drugs is promising. To advance DILI management, it is crucial to conduct well-designed randomized clinical trials to evaluate natural products' efficacy and develop new molecules clinically. However, natural products are a promising solution for remedying drug-induced hepatotoxicity and lowering the risk of DILI.

Andrographolide attenuated MCT-induced HSOS via regulating NRF2-initiated mitochondrial biogenesis and antioxidant response

Hepatic sinusoidal obstruction syndrome (HSOS) is a death-dealing liver disease with a fatality rate of up to 67%. In the study present, we explored the efficacy of andrographolide (Andro), a diterpene lactone from Andrographis Herba, in ameliorating the monocrotaline (MCT)-induced HSOS and the underlying mechanism. The alleviation of Andro on MCT-induced rats HSOS was proved by biochemical index detection, electron microscope observation, and liver histological evaluation. Detection of hepatic ATP content, mitochondrial DNA (mtDNA) copy number, and protein expression of nuclear respiratory factor-1 (NRF1) and peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PPARGC1A) demonstrated that Andro strengthened mitochondrial biogenesis in livers from MCT-treated rats. Chromatin immunoprecipitation assay exhibited that Andro enhanced the occupation of nuclear factor erythroid 2-related factor 2 (NFE2L2, also known as NRF2) in the promoter regions of both PPARGC1A and NRF1. Andro also activated the NRF2-dependent anti-oxidative response and alleviated liver oxidative injury. In Nrf2 knock-out mice, MCT induced more severe liver damage, and Andro showed no alleviation in it. Furthermore, the Andro-activated mitochondrial biogenesis and anti-oxidative response were reduced in Nrf2 knock-out mice. Contrastingly, knocking out Kelch-like ECH-associated protein 1 (Keap1), a NRF2 repressor, reduced MCT-induced liver damage. Results from co-immunoprecipitation, molecular docking analysis, biotin-Andro pull-down, cellular thermal shift assay, and surface plasmon resonance assay showed that Andro hindered the NRF2-KEAP1 interaction via directly binding to KEAP1. In conclusion, our results revealed that NRF2-dependent liver mitochondrial biogenesis and anti-oxidative response were essential for the Andro-provided alleviation of the MCT-induced HSOS. Graphical Headlights: 1. Andro alleviated MCT-induced HSOS via activating antioxidative response and promoting mitochondrial biogenesis. 2. Andro-activated antioxidative response and mitochondrial biogenesis were NRF2-dependent. 3. Andro activated NRF2 via binding to KEAP1.

EGR1 is crucial for the chlorogenic acid-provided promotion on liver regeneration and repair after APAP-induced liver injury

Improper use of acetaminophen (APAP) will induce acute liver failure. This study is designed to investigate whether early growth response-1 (EGR1) participated in the promotion on liver repair and regeneration after APAP-induced hepatotoxicity provided by natural compound chlorogenic acid (CGA). APAP induced the nuclear accumulation of EGR1 in hepatocytes regulated by extracellular-regulated protein kinase (ERK)1/2. In Egr1 knockout (KO) mice, the liver damage caused by APAP (300 mg/kg) was more severe than in wild-type (WT) mice. Results of chromatin immunoprecipitation and sequencing (ChIP-Seq) manifested that EGR1 could bind to the promoter region in Becn1, Ccnd1, and Sqstm1 (p62) or the catalytic/modify subunit of glutamate-cysteine ligase (Gclc/Gclm). Autophagy formation and APAP-cysteine adduct (APAP-CYS) clearance were decreased in Egr1 KO mice administered with APAP. The EGR1 deletion reduced hepatic cyclin D1 expression at 6, 12, or 18 h post APAP administration. Meanwhile, the EGR1 deletion also decreased hepatic p62, Gclc and Gclm expression, GCL enzymatic activity, and glutathione (GSH) content and decreased nuclear factor erythroid 2-related factor 2 (Nrf2) activation and thus aggravated oxidative liver injury induced by APAP. CGA increased EGR1 nuclear accumulation; enhanced hepatic Ccnd1, p62, Gclc, and Gclm expression; and accelerated the liver regeneration and repair in APAP-intoxicated mice. In conclusion, EGR1 deficiency aggravated liver injury and obviously delayed liver regeneration post APAP-induced hepatotoxicity through inhibiting autophagy, enhancing liver oxidative injury, and retarding cell cycle progression, but CGA promoted the liver regeneration and repair in APAP-intoxicated mice via inducing EGR1 transcriptional activation.

Identification of antioxidant peptides targeting Keap1-Nrf2-ARE pathway from in vitro digestion of pork sausage with partial substitution of NaCl by KCl

The Kelch-like ECH-associated protein 1 (Keap1)-nuclear factor erythroid 2-related factor 2 (Nrf2)-antioxidant response elements (ARE) pathway is one of the most important cellular defense mechanisms against oxidative stress. This study focuses on finding antioxidant peptides from in vitro digestion products of pork sausage with partial substitution of NaCl by KCl by virtual screening. Six antioxidant peptides, LIVGFPAYGH, DWWGSTVR, WNSLLIR, IVGFPAYGH, FDNLWDQGL, and LRSPSWDPF, could activate the Keap1-Nrf2-ARE pathway and protect cells from oxidative stress. DWWGSTVR exhibits the most robust activity among them. Further studies indicated that DWWGSTVR could increase the expression of many antioxidant enzymes by enabling the transfer of Nrf2 from the cytoplasm to the nucleus. In summary, these six peptides are proven to be Nrf2 activators and could be used as functional foods to prevent and treat various oxidative stress-induced diseases.

The Mechanisms of Ferroptosis Under Hypoxia

Ferroptosis is a new form of programmed cell death, which is characterized by the iron-dependent accumulation of lipid peroxidation and increase of ROS, resulting in oxidative stress and cell death. Iron, lipid, and multiple signaling pathways precisely control the occurrence and implementation of ferroptosis. The pathways mainly include Nrf2/HO-1 signaling pathway, p62/Keap1/Nrf2 signaling pathway. Activating p62/Keap1/Nrf2 signaling pathway inhibits ferroptosis. Nrf2/HO-1 signaling pathway promotes ferroptosis. Furthermore, some factors also participate in the occurrence of ferroptosis under hypoxia, such as HIF-1, NCOA4, DMT1. Meanwhile, ferroptosis is related with hypoxia-related diseases, such as MIRI, cancers, and AKI. Accordingly, ferroptosis appears to be a therapeutic target for hypoxia-related diseases.

Molecular mechanism of caloric restriction mimetics-mediated neuroprotection of age-related neurodegenerative diseases: an emerging therapeutic approach

Aging-induced neurodegenerative diseases (NDs) are significantly increasing health problem worldwide. It has been well documented that oxidative stress is one of the potential causes of aging and age-related NDs. There are no drugs for the treatment of NDs, therefore there is an immediate necessity for the development of strategies/treatments either to prevent or cure age-related NDs. Caloric restriction (CR) and intermittent fasting have been considered as effective strategies in increasing the healthspan and lifespan, but it is difficult to adhere to these routines strictly, which has led to the development of calorie restriction mimetics (CRMs). CRMs are natural compounds that provide similar molecular and biochemical effects of CR, and activate autophagy process. CRMs have been reported to regulate redox signaling by enhancing the antioxidant defense systems through activation of the Nrf2 pathway, and inhibiting ROS generation through attenuation of mitochondrial dysfunction. Moreover, CRMs also regulate redox-sensitive signaling pathways such as the PI3K/Akt and MAPK pathways to promote neuronal cell survival. Here, we discuss the neuroprotective effects of various CRMs at molecular and cellular levels during aging of the brain. The CRMs are envisaged to become a cornerstone of the pharmaceutical arsenal against aging and age-related pathologies.

Progress in the mechanism of autophagy and traditional Chinese medicine herb involved in alcohol-related liver disease

Alcohol-related liver disease (ALD) is chronic liver damage caused by long-term heavy drinking with, extremely complicated pathogenesis. The current studies speculated that excessive alcohol and its metabolites are the major causes of liver cell toxicity. Autophagy is evolutionarily conserved in eukaryotes and aggravates alcoholic liver damage, through various mechanisms, such as cellular oxidative stress, inflammation, mitochondrial damage and lipid metabolism disorders. Therefore, autophagy plays an critical role in the occurrence and development of ALD. Some studies have shown that traditional Chinese medicine extracts improve the histological characteristics of ALD, as reflected in the improvement of oxidative stress and lipid droplet clearance, which might be achieved by inducing autophagy. This article reviews the mechanisms of quercetin, baicalin, glycycoumarin, salvianolic acid A, resveratrol, ginsenoside rg1, and dihydromyricetin inducing autophagy and their participation in the inhibition of ALD. The regulation of autophagy in ALD by these traditional Chinese medicine extracts provides novel ideas for the treatment of the disease; however, its molecular mechanism needs to be elucidated further.

A Mango Leaf Extract (Zynamite®) Combined with Quercetin Has Exercise-Mimetic Properties in Human Skeletal Muscle

Zynamite PX^®, a mango leaf extract combined with quercetin, enhances exercise performance by unknown molecular mechanisms. Twenty-five volunteers were assigned to a control (17 males) or supplementation group (8 males, receiving 140 mg of Zynamite^® + 140 mg quercetin/8 h for 2 days). Then, they performed incremental exercise to exhaustion (IE) followed by occlusion of the circulation in one leg for 60 s. Afterwards, the cuff was released, and a 30 s sprint was performed, followed by 90 s circulatory occlusion (same leg). Vastus lateralis muscle biopsies were obtained at baseline, 20 s after IE (occluded leg) and 10 s after Wingate (occluded leg), and bilaterally at 90 s and 30 min post exercise. Compared to the controls, the Zynamite PX^® group showed increased basal protein expression of Thr²⁸⁷-CaMKIIδ_D (2-fold, p = 0.007) and Ser⁹-GSK3β (1.3-fold, p = 0.005) and a non-significant increase of total NRF2 (1.7-fold, p = 0.099) and Ser⁴⁰-NRF2 (1.2-fold, p = 0.061). In the controls, there was upregulation with exercise and recovery of total NRF2, catalase, glutathione reductase, and Thr²⁸⁷-CaMKIIδ_D (1.2-2.9-fold, all p < 0.05), which was not observed in the Zynamite PX^® group. In conclusion, Zynamite PX^® elicits muscle signaling changes in resting skeletal muscle resembling those described for exercise training and partly abrogates the stress kinases responses to exercise as observed in trained muscles.

Regulation of Acetylation States by Nutrients in the Inhibition of Vascular Inflammation and Atherosclerosis

Atherosclerosis (AS) is a chronic metabolic disorder and primary cause of cardiovascular diseases, resulting in substantial morbidity and mortality worldwide. Initiated by endothelial cell stimulation, AS is characterized by arterial inflammation, lipid deposition, foam cell formation, and plaque development. Nutrients such as carotenoids, polyphenols, and vitamins can prevent the atherosclerotic process by modulating inflammation and metabolic disorders through the regulation of gene acetylation states mediated with histone deacetylases (HDACs). Nutrients can regulate AS-related epigenetic states via sirtuins (SIRTs) activation, specifically SIRT1 and SIRT3. Nutrient-driven alterations in the redox state and gene modulation in AS progression are linked to their protein deacetylating, anti-inflammatory, and antioxidant properties. Nutrients can also inhibit advanced oxidation protein product formation, reducing arterial intima-media thickness epigenetically. Nonetheless, knowledge gaps remain when it comes to understanding effective AS prevention through epigenetic regulation by nutrients. This work reviews and confirms the underlying mechanisms by which nutrients prevent arterial inflammation and AS, focusing on the epigenetic pathways that modify histones and non-histone proteins by regulating redox and acetylation states through HDACs such as SIRTs. These findings may serve as a foundation for developing potential therapeutic agents to prevent AS and cardiovascular diseases by employing nutrients based on epigenetic regulation.

Virtual Screening of Nrf2 Dietary-Derived Agonists and Safety by a New Deep-Learning Model and Verified In Vitro and In Vivo

Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is an essential regulatory target of antioxidants, but the lack of Nrf2 active site information has hindered discovery of new Nrf2 agonists from food-derived compounds by large-scale virtual screening. Two deep-learning models were separately trained to screen for Nrf2-agonists and safety. The trained models screened potentially active chemicals from approximately 70,000 dietary compounds within 5 min. Of the 169 potential Nrf2 agonists identified via deep-learning screening, 137 had not been reported before. Six compounds selected from the new Nrf2 agonists significantly increased (p < 0.05) the activity of Nrf2 on carbon tetrachloride (CCl₄)-intoxicated HepG2 cells (nicotiflorin (99.44 ± 18.5%), artemetin (97.91 ± 8.22%), daidzin (87.73 ± 3.77%), linonin (74.27 ± 5.73%), sinensetin (72.74 ± 10.41%), and tectoridin (77.78 ± 4.80%)), and their safety were demonstrated by an MTT assay. The safety and Nrf2 agonistic activity of nicotiflorin, artemetin, and daidzin were also reconfirm by a single-dose acute oral toxicity study and CCl₄-intoxicated rat assay.

Kaempferol prevents acetaminophen-induced liver injury by suppressing hepatocyte ferroptosis via Nrf2 pathway activation

Acetaminophen (APAP)-induced liver injury (AILI) has become a growing public health problem. Ferroptosis, an iron-dependent form of cell death associated with lipid peroxide accumulation, has been recently implicated in AILI. The activation of the Nrf2 signaling pathway is a potential therapy for AILI. Kaempferol (KA), a flavonoid widely existing in edible plants, has been reported to exert profound anti-inflammatory and antioxidant activities. This study aimed to investigate whether KA exerts anti-AILI effects via the Nrf2 signaling pathway. Mice were fasted for 22 h and injected intraperitoneally with APAP (250 mg kg^-1) to induce AILI. Mice were pre-injected intragastrically with KA for 2 h followed by APAP injection. The hepatic injury was observed by H&E staining. Biochemical parameters of the serum and liver were measured using kits. KA alleviated hepatic injury and inflammatory response in AILI mice and ameliorated APAP-induced hepatic iron overload and oxidative stress in mice. In addition, the protective effects of KA against APAP-induced hepatotoxicity were examined in L02 cells in vitro. Cell viability was assayed by the CCK8 assay. Mitochondrial reactive oxygen species (ROS) in L02 cells were detected by MitoSox fluorescence. KA reversed the APAP-induced decrease in cell viability and GSH levels and inhibited the accumulation of intracellular ROS. Furthermore, KA activated the Nrf2 pathway and upregulated Gpx4 in mouse livers and L02 cells to inhibit ferroptosis induced by APAP. Finally, molecular docking indicated the potential interaction of KA with Keap1. Taken together, KA ameliorated oxidative stress and ferroptosis-mediated AILI by activating Nrf2 signaling.

Characterization of tangeretin as an activator of nuclear factor erythroid 2-related factor 2/antioxidant response element pathway in HEK293T cells

Numerous studies have reported that tangeretin is a polymethoxylated flavone with a variety of biological activates, but little research has been done on the antioxidant mechanism of tangeretin. Hence, we investigated the effect of tangeretin on the nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) pathway and its potential molecular mechanisms by in vitro and in silico research. The results of molecular docking suggested that tangeretin bound at the top of the central pore of Kelch-like ECH-associated protein 1 (Keap1) Kelch domain, and the hydrophobic and hydrogen bond interactions contributed to their stable binding. Herein, the regulation of Nrf2-ARE pathway by tangeretin was explored in the human embryonic kidney cell line HEK293T, which is relatively easy to be transfected. Upon binding to tangeretin, Nrf2 translocated to the nucleus of HEK293T cells, which in turn activated the Nrf2-ARE pathway. Luciferase reporter gene analysis showed that tangeretin significantly induced ARE-mediated transcriptional activation. Real-time PCR and Western blot assays showed that tangeretin induced the gene and protein expressions of Nrf2-mediated targets, including heme oxygenase 1 (HO-1), nicotinamide adenine dinucleotide phosphate (NADPH) quinone dehydrogenase 1 (NQO1), and glutamate-cysteine ligase (GCLM). In addition, tangeretin could effectively scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals. In summary, tangeretin may be a potential antioxidant via activating the Nrf2-ARE pathway.

Feature Selection Assists BLSTM for the Ultrasensitive Detection of Bioflavonoids in Different Biological Matrices Based on the 3D Fluorescence Spectra of Gold Nanoclusters

Rapid and on-site qualitative and quantitative analysis of small molecules (including bioflavonoids) in biofluids are of great importance in biomedical applications. Herein, we have developed two deep learning models based on the 3D fluorescence spectra of gold nanoclusters as a single probe for rapid qualitative and quantitative analysis of eight bioflavonoids in serum. The results proved the efficiency and stability of the random forest-bidirectional long short-term memory (RF-BLSTM) model, which was used only with the most important features after deleting the unimportant features that might hinder the performance of the model in identifying the selected bioflavonoids in serum at very low concentrations. The optimized model achieves excellent overall accuracy (98-100%) in the qualitative analysis of the selected bioflavonoids. Next, the optimized model was transferred to quantify the selected bioflavonoids in serum at nanoscale concentrations. The transferred model achieved excellent accuracy, and the overall determination coefficient (R²) value range was 99-100%. Furthermore, the optimized model achieved excellent accuracies in other applications, including multiplex detection in serum and model applicability in urine. Also, LOD in serum at nanoscale concentration was considered. Therefore, this approach opens the window for qualitative and quantitative analysis of small molecules in biofluids at nanoscale concentrations, which may help in the rapid inclusion of sensor arrays in biomedical and other applications.

Integrating network pharmacology approach and experimental validation to reveal the alleviation of Shenkangning capsule on chronic nephritis

ETHNOPHARMACOLOGICAL RELEVANCE

Shenkangning (SKN), a Chinese patent medicine composed by eight Chinese medicinal herbs, is commonly applied to treat chronic glomerulonephritis (CGN) in clinic. However, its mechanism is still not clear now.

AIM OF THE STUDY

This study is designed to evaluate the SKN-provided alleviation on adriamycin (ADR)-induced nephropathy, to reveal its mechanism by integrating network pharmacology analysis and experimental evidences, and to further find the main drug that makes a major contribution to its efficacy.

MATERIALS AND METHODS

ADR was intravenously injected to mice to induce focal segmental glomerulosclerosis (FSGS). Renal histological evaluation was conducted. The level of urinary protein, and serum amounts of creatinine, urea nitrogen (BUN) and albumin were detected. The potential mechanisms were predicted by network pharmacology analysis and further validated by Real-time polymerase chain reaction (RT-PCR), Western-blot and enzyme-linked immunosorbent assay (ELISA).

RESULTS

SKN (1, 10 g/kg) improved ADR-induced nephropathy in mice. Network pharmacology results predicted that inflammation and oxidative stress were crucially involved in the SKN-provided amelioration on nephropathy. SKN reduced the activation of nuclear factor-κB (NF-κB) and the expression of some pro-inflammatory cytokines, and increased the activation of nuclear factor erythroid 2-related factor 2 (Nrf2) and the expression of its downstream genes in ADR-induced nephropathy in mice. Furthermore, SKN also restored the reduced expression of both podocin and synaptopodin, which are podocyte-associated proteins. Further results showed that the toxic drug Danfupian (DFP) had no contribution to the SKN-provided alleviation on ADR-induced nephropathy in mice. After integrating the results from evaluating anti-inflammation, anti-oxidant and anti-injury of podocytes in vitro and from comparing the activity of the whole SKN and SKN without Astragali Radix (Huangqi, HQ) in vivo, we found that HQ played a crucial contribution to the SKN-provided amelioration on ADR-induced nephropathy in mice.

CONCLUSION

SKN improved ADR-induced nephropathy through suppressing renal inflammation and oxidative stress injury via abrogating NF-κB activation and activating Nrf2 signaling pathway. HQ played a main contribution to the SKN-provided amelioration on ADR-induced nephropathy.

Isoginkgetin, a bioactive constituent from Ginkgo Biloba, protects against obesity-induced cardiomyopathy via enhancing Nrf2/ARE signaling

Obesity-induced metabolic cardiomyopathy (MC), characterized by lipotoxicity and excessive oxidative stress, emerges as the leading cause of heart failure in the obese patients. Yet, its therapy remains very limited. Here, we demonstrated that isoginkgetin (IGK), a bioactive biflavonoid isolated from medicinal herb Ginkgo Biloba, protected against obesity-induced cardiac diastolic dysfunction and adverse remodeling. Transcriptomics profiling revealed that IGK activated Nrf2 signaling in the heart tissues of the obese mice. Consistent with this observation, IGK treatment increased the nuclear translocation of Nrf2, which in turn trigger the activation of its downstream target genes (e. g. HO-1 and NQO1). In addition, IGK significantly rejuvenated mitochondrial defects in obese heart tissues as evidenced by enhancing mitochondrial respiratory capacity and resisting the collapse of mitochondrial potential and oxidative stress both in vitro and in vivo. Mechanistically, IGK stabilized Nrf2 protein via inhibiting the proteasomal degradation, independent of transcription regulation. Moreover, molecular docking and dynamics simulation assessment demonstrated a good binding mode between IGK and Nrf2/Keap1. Of note, the protective effects conferred by IGK against obesity-induced mitochondrial defects and cardiac dysfunction was compromised by Nrf2 gene silencing both in vitro and in vivo, consolidating a pivotal role of Nrf2 in IGK-elicited myocardial protection against MC. Thus, the present study identifies IGK as a promising drug candidate to alleviate obesity-induced oxidative stress and cardiomyocyte damage through Nrf2 activation, highlighting the therapeutic potential of IGK in ameliorating obesity-induced cardiomyopathy.

Sarmentosin promotes USP17 and regulates Nrf2-mediated mitophagy and cellular oxidative stress to alleviate APAP-induced acute liver failure

BACKGROUND

An overdose of acetaminophen (APAP), the main cause of acute liver failure (ALF), induces oxidative stress that ultimately causes mitochondrial impairment and hepatotoxicity. The nuclear factor erythroid 2-related factor 2 (Nrf2) was widely recognized as an anti-oxidative stress mechanism. The present study was aimed at investigating whether sarmentosin, extract from traditional Chinese medicine, protects the liver against APAP-induced injury via activating Nrf2 and subsequently decreasing oxidative stress.

METHODS

Male ICR mice were treated with sarmentosin oral administration for 1 week and injected APAP (300 mg/kg. i.p.) for acute liver injury model. The liver and serum of mice for histological and biochemistry analysis. AML12 and LO2 cells were used in vitro assays.

RESULTS

We found that sarmentosin moderately increased accumulation of Nrf2 via upregulating USP17-mediated ubiquitin inhibition at the early stage of hepatocytes damage. The Nrf2 separating from bonding protein Keap1 translocated into nucleus and activated downstream gene of antioxidants. Mitophagy, a unique autophagy can remove Reactive Oxygen Species (ROS) damaged mitochondria, was elevated in this progress to maintain mitochondria function and ROS homeostasis.

CONCLUSION

In summary, our research revealed that sarmentosin could alleviate APAP-induced liver acute injury through USP17-mediated Nrf2 overexpression and PINK1-dependent mitophagy.

Targeting NRF2 in Type 2 diabetes mellitus and depression: Efficacy of natural and synthetic compounds

Evidence supports a strong bidirectional association between depression and Type 2 diabetes mellitus (T2DM). The harmful impact of oxidative stress and chronic inflammation on the development of both disorders is widely accepted. Nuclear factor erythroid 2-related factor 2 (NRF2) is a pertinent target in disease management owing to its reputation as the master regulator of antioxidant responses. NRF2 influences the expression of various cytoprotective phase 2 antioxidant genes, which is hampered in both depression and T2DM. Through interaction and crosstalk with several signaling pathways, NRF2 endeavors to contain the widespread oxidative damage and persistent inflammation involved in the pathophysiology of depression and T2DM. NRF2 promotes the neuroprotective and insulin-sensitizing properties of its upstream and downstream targets, thereby interrupting and preventing disease advancement. Standard antidepressant and antidiabetic drugs may be powerful against these disorders, but unfortunately, they come bearing distressing side effects. Therefore, exploiting the therapeutic potential of NRF2 activators presents an exciting opportunity to manage such bidirectional and comorbid conditions.

7-deacetyl-gedunin suppresses proliferation of Human rheumatoid arthritis synovial fibroblast through activation of Nrf2/ARE signaling

BACKGROUND

Rheumatoid arthritis (RA) is an chronic autoimmune disease and characterized by high incidence. However, there is no effective therapies for RA. Therefore, it is urgent to discover new drugs for RA treatment. Nuclear factor erythroid 2 (NF-E2)-related factor (Nrf2) can effectively protect against arthritic inflammatory diseases through diverse stages, such as regulating redox balance, detoxification, metabolism and inflammation. Dimethyl fumarate (DMF), targets the Nrf2 pathway, was approved by FDA for the clinical treatment of multiple sclerosis (MS), which is another autoimmune disease. The latest report shown that DMF ameliorates complete Freund's adjuvant-induced arthritis in rats through activation of the Nrf2/HO-1 signaling pathway. Hence, Nrf2 serves as an important target for inflammation interference and oxidative stress of macrophages and RASFs in RA; therefore, it can be adopted as an effective therapeutic approach in the future. Rheumatoid arthritis synovial fibroblasts (RASFs) play crucial roles in the RA pathogenesis. Our results revealed that 7-deacetyl-gedunin (7-d-GDN), derived from fruits of Toona sinensis (A. Juss.) Roem, significantly inhibited RASFs proliferation in dose- and time- dependent manners and inhibited cell viability in MH7A cells, which is a kind of immortal cell line from joints of patients with RA. Additionally, 7-d-GDN remarkably down-regulated MMP-1/3/9/13 in RASFs, IL-6 and IL-33 in MH7A cells. Besides, 7-d-GDN sharply inhibited reactive oxygen species (ROS) in RASFs. Further mechanistic study demonstrated that 7-d-GDN induced heme oxygenase-1 (HO-1), NAD(P)H dehydrogenase quinone 1(NQO1), which all participated in suppressing of oxidative stress. Additionally, 7-d-GDN increased sequestosome 1 (SQSTM1, p62), causing down-regulating Kelch-like ECH-associated protein 1 (Keap1), which resulting in NF-E2-related factor 2 (Nrf2) cytoplasm accumulation and subsequently translocation into nucleus. Collectively, 7-d-GDN exerts the anti-inflammatory effect through regulating anti-oxidative enzymes via p62/ Nrf2/ARE signaling. All suggest that the potential of 7-d-GDN in suppression of inflammation, especially antagonizing RA severity. Our works support for drugs discovery in RA treatment.

Hepatotoxicity and renal toxicity induced by radiation and the protective effect of quercetin in male albino rats

PURPOSE

Although radiation is one of the basic methods commonly used in cancer treatment, it inevitably enters the field of treatment in healthy tissues and is adversely affected by the acute and chronic side effects of radiation. This study evaluated the possible protective effects of quercetin, an antioxidant agent, against liver and kidney damage in rats exposed to a whole-body single dose of radiation (10 Gy of gamma-ray).

MATERIALS AND METHODS

The study groups were formed as control, sham, quercetin, radiation, quercetin + radiation and radiation + quercetin using 60 male Wistar albino (200-250 g, 3 months old) rats, including 10 rats in each group. The gamma-ray provided by the Co60 teletherapy machine was given to the whole body as external irradiation. According to the groups, quercetin was administered to rats at 50 mg/kg/day via oral gavage before or after radiation administration. The rats were sacrificed the day after irradiation and the extracted tissue samples from all groups were compared histologically and immunohistochemically. DNA damage was determined by the neutral comet assay technique. Also, malondialdehyde (MDA) and glutathione peroxidase (GSH) were evaluated in liver and kidney tissues by the ELISA method.

RESULTS

Histopathological changes were observed altered morphology of liver and kidney tissues in the radiation groups. Sinusoidal dilatations, vacuolization, and hepatic parenchyma necrosis in the liver, while in kidneys, glomerular shrinkage, widened Bowman's space, tubular dilatation, and inflammation were evident. TNF-α, IL1-α, HIF1-α, and caspase 3 immunoreactivities in tissues were determined by immunohistochemistry. High caspase 3 positive cell number confirmed apoptosis, the comet parameters were decreased in the quercetin + radiation group. When compared to the control group, the exposure to radiation showed a marked elevation in MDA which was accompanied by high GSH. This damage was reduced in the quercetin + radiation group.

CONCLUSIONS

With the results obtained from the study; Quercetin is thought to have a protective potential against radiation-induced liver and kidney damage due to its radioprotective effect.

Dissecting the Crosstalk Between Nrf2 and NF-κB Response Pathways in Drug-Induced Toxicity

Nrf2 and NF-κB are important regulators of the response to oxidative stress and inflammation in the body. Previous pharmacological and genetic studies have confirmed crosstalk between the two. The deficiency of Nrf2 elevates the expression of NF-κB, leading to increased production of inflammatory factors, while NF-κB can affect the expression of downstream target genes by regulating the transcription and activity of Nrf2. At the same time, many therapeutic drug-induced organ toxicities, including hepatotoxicity, nephrotoxicity, cardiotoxicity, pulmonary toxicity, dermal toxicity, and neurotoxicity, have received increasing attention from researchers in clinical practice. Drug-induced organ injury can destroy body function, reduce the patients’ quality of life, and even threaten the lives of patients. Therefore, it is urgent to find protective drugs to ameliorate drug-induced injury. There is substantial evidence that protective medications can alleviate drug-induced organ toxicity by modulating both Nrf2 and NF-κB signaling pathways. Thus, it has become increasingly important to explore the crosstalk mechanism between Nrf2 and NF-κB in drug-induced toxicity. In this review, we summarize the potential molecular mechanisms of Nrf2 and NF-κB pathways and the important effects on adverse effects including toxic reactions and look forward to finding protective drugs that can target the crosstalk between the two.

Toosendanin and isotoosendanin suppress triple-negative breast cancer growth via inducing necrosis, apoptosis and autophagy

Toosendanin (TSN) and isotoosendanin (ITSN) are two natural triterpenoids isolated from Fructus Meliae Toosendan or Cortex Meliae. This study aims to observe the inhibition of TSN and ITSN on the growth of triple-negative breast cancer (TNBC) and the preliminary engaged mechanism. Cell viability assay showed that both TSN and ITSN had obvious cytotoxicity in a variety of tumor cells, and they had the best inhibitory effect on TNBC cells including MDA-MB-231, BT549 and 4T1. Propidium iodide (PI) staining results showed the increased number of necrotic MDA-MB-231 and 4T1 cells induced by TSN (20 nM) and ITSN (2.5 μM). Annexin V-FITC and PI double-staining results showed that TSN (20 nM) and ITSN (2.5 μM) induced cell apoptosis in both MDA-MB-231 and 4T1 cells. Moreover, TSN (20 nM) and ITSN (2.5 μM) induced the cleavage of pro-caspase-3 and pro-caspase-9, and decreased the expression of anti-apoptotic Bcl-xL in both MDA-MB-231 and 4T1 cells. Results from scanning electron microscope observation and detecting the expression of microtubule-associated protein 1 light chain 3B (LC3B) and Beclin 1 evidenced that TSN (20 nM) and ITSN (2.5 μM) induced autophagy in both MDA-MB-231 and 4T1 cells. TSN and ITSN decreased 4T1 xenograft tumor growth without inflicting toxicity on vital organs in mice. Collectively, this study shows that natural compound TSN and ITSN suppress TNBC growth via inducing necrosis, apoptosis and autophagy. TSN and ITSN could be promising drugs for TNBC treatment.

p62 works as a hub modulation in the ageing process

p62 (also known as SQSTM1) is widely used as a predictor of autophagic flux, a process that allows the degradation of harmful and unnecessary components through lysosomes to maintain protein homeostasis in cells. p62 is also a stress-induced scaffold protein that resists oxidative stress. The multiple domains in its structure allow it to be connected with a variety of vital signalling pathways, autophagy and the ubiquitin proteasome system (UPS), allowing p62 to play important roles in cell proliferation, apoptosis and survival. Recent studies have shown that p62 is also directly or indirectly involved in the ageing process. In this review, we summarize in detail the process by which p62 regulates ageing from multiple ageing-related signs with the aim of providing new insight for the study of p62 in ageing.

Nutritional and Bioactive Characterization of Sicana odorifera Naudim Vell. Seeds By-Products and Its Potential Hepatoprotective Properties in Swiss Albino Mice

The "Kurugua" (Sicana odorifera) is a native fruit that demonstrates attractive nutritional, coloring, flavoring, and antioxidant properties. The main by-products from the processing and consumption of kurugua fruit are epicarp and seeds. In this work, the properties of the seeds of S. odorifera were evaluated. The nutritional composition of the fruit seeds was determined through AOAC official methods and UHPLC-ESI-MS/MS profiling. The antioxidant activities were determined using in vitro methods, and the acute toxicity and hepatoprotective properties were investigated in Swiss albino mice. Quercetin derivatives and cucurbitacins were the main phytochemicals in the seeds' methanolic extract and demonstrated some biological activities. GC-MS analysis revealed the essential fatty acids linolenic and linoleic as the main compounds present in seeds oil. The methanolic extract significantly reduced the serum levels of glutamic-pyruvic transaminase (GPT) and glutamic-oxaloacetic transaminase (GOT) in mice with induced hepatotoxicity (GPT p < 0.05; GOT p < 0.001) at the minor concentration tested (100 mg/kg EMSo). The results suggest that the S. odorifera seeds as by-products show potential use as a source of phytochemicals and in the production of oils with application in food supplements and nutraceuticals. Their integral use could contribute to waste reduction from kurugua fruits processing within the food safety and environmental sustainability framework.

Chrysanthemi Flos extract alleviated acetaminophen-induced rat liver injury via inhibiting oxidative stress and apoptosis based on network pharmacology analysis

CONTEXT

Acetaminophen (APAP) overdose is the leading cause of drug-induced liver injury. Bianliang ziyu, a variety of Chrysanthemum morifolium Ramat. (Asteraceae), has potential hepatoprotective effect. However, the mechanism is not clear yet.

OBJECTIVE

To investigate the hepatoprotective activity and mechanism of Bianliang ziyu flower ethanol extract (BZE) on APAP-induced rats based on network pharmacology.

MATERIALS AND METHODS

Potential pathways of BZE were predicted by network pharmacology. Male Sprague-Dawley rats were pre-treated with BZE (110, 220 and 440 mg/kg, i.g.) for eight days, and then APAP (800 mg/kg, i.g.) was used to induce liver injury. After 24 h, serum and liver were collected for biochemical detection and western blot measurement.

RESULTS

Network pharmacology indicated that liver-protective effect of BZE was associated with its antioxidant and anti-apoptotic efficacy. APAP-induced liver pathological change was alleviated, and elevated serum AST and ALT were reduced by BZE (440 mg/kg) (from 66.45 to 22.64 U/L and from 59.59 to 17.49 U/L, respectively). BZE (440 mg/kg) reduced the ROS to 65.50%, and upregulated SOD and GSH by 212.92% and 175.38%, respectively. In addition, BZE (440 mg/kg) increased levels of p-AMPK, p-GSK3β, HO-1 and NQO1, ranging from 1.66- to 10.29-fold compared to APAP group, and promoted nuclear translocation of Nrf2. BZE also inhibited apoptosis induced by APAP through the PI3K-Akt pathway and restored the ability of mitochondrial biogenesis.

DISCUSSION AND CONCLUSIONS

Our study demonstrated that BZE protected rats from APAP-induced liver injury through antioxidant and anti-apoptotic pathways, suggesting BZE could be further developed as a potential liver-protecting agent.

Cabbage (Brassica oleracea var. capitata): A food with functional properties aimed to type 2 diabetes prevention and management

Type 2 diabetes mellitus (T2DM) is increasing the prevalence worldwide at an alarming rate, becoming a serious public health problem that mainly affects developing countries. Functional food research is currently of great interest because it contributes to developing nutritional therapy strategies for T2DM prevention and treatment. Bioactive compounds identified in some plant foods contribute to human health by mechanisms of action that exert biological effects on metabolic pathways involved in the development of T2DM. Hence, vegetables with high bioactive compounds content may be a source of functional value for the control of T2DM. Cabbages varieties (Brassica oleracea var. capitata) such as green (GCB), white (WCB), and red (RCB) are foods consumed (raw or cooked) and cultivated in different regions of the world. Scientific evidence shows that cabbage has multi-target effects on glucose homeostatic regulation due to its high content of bioactive compounds. It has also been shown to decrease damage to organs affected by T2DM complications, such as the liver and kidney. Additionally, it could contribute as a preventive by attenuating problems underlying the development of T2DM as oxidative stress and obesity. This review highlights the functional properties of cabbage varieties involved in glucose regulation and the main mechanisms of the action exerted by their bioactive compounds. In conclusion, cabbage is a valuable food that can be employed as part of nutritional therapy or functional ingredient aimed at the prevention and treatment of T2DM.

The potential effect of phytochemicals and herbal plant remedies for treating drug-induced hepatotoxicity: a review

Drug-induced liver injury significantly caused by synthetic drugs, and other xenobiotics contribute to clinical hepatic dysfunction, which has been a substantial challenge for both patients and physicians. Traditional medicines used as an alternative therapy because of their pharmacological benefits, less or no side effects, and enormous availability in nature. Phytochemicals are essential ingredients of plants that reduce necrotic cell death, restore the antioxidant defence mechanism, limit oxidative stress, and prevent the inflammation of tissue and dysfunction of the mitochondria. In this review, we principally focused on the potential effect of the herbal plants and their phytochemicals in treating drug-induced hepatotoxicity.

Metformin leads to accumulation of reactive oxygen species by inhibiting the NFE2L1 expression in human hepatocellular carcinoma cells

Metformin, as the first-line drug for the treatment of type 2 diabetes mellitus, has been shown to possess a capability to activate or inhibit the production of reactive oxygen species (ROS) in different ways. However, the detailed mechanisms of the opposite effect are poorly understood. Here we provide evidence that metformin induces accumulation of ROS by inhibiting the expression of a core antioxidant transcription factor nuclear factor erythroid 2 like 1 (NFE2L1/Nrf1) in human hepatocellular carcinoma HepG2 cells. In the present study, we originally found that the increased ROS induced by metformin was blunted in NFE2L1 knockdown cell line. Furtherly by examining the effects of metformin on endogenous and exogenous NFE2L1, we also found metformin could not only inhibit the transcription of NFE2L1 gene, but also promote the degradation of NFE2L1 protein at the post-transcriptional level, whereas this effect can be reversed by high glucose. The inhibitory effect of metformin on NFE2L1 was investigated to occur through the N-terminal domain (NTD) of NFE2L1 protein, and its downregulation by metformin was in an AMP-activated protein kinase (AMPK)-independent manner. But the activation of AMPK signaling pathway by metformin in NFE2L1 knockdown HepG2 cells is reversed, indicating that NFE2L1 may be an important regulator of AMPK signal. Altogether, this work provides a better understanding of the relationship between metformin and oxidative stress, and hence contributes to translational study of metformin through its hypoglycemic and tumor suppressive effects.

Flavonoid-rich fraction of Lasianthera africana leaves alleviates hepatotoxicity induced by carbon tetrachloride in Wistar rats

Lasianthera africana P. Beauv. (Icacinaceae) is a good source of natural antioxidants, having the potential to protect against oxidative stress-related diseases and complications. This study investigated the antioxidant, hepatoprotective and curative effects of flavonoid-rich fraction of L. africana leaves (LAFRF) against carbon tetrachloride-induced hepatotoxicity in Wistar rats. Phytochemical, nutrient content, and in vitro antioxidant activity of LAFRF were determined by standard methods. Fifty Wistar rats were randomized into 10 groups (n = 5). Groups 1 and 2 served as normal and CCl₄ controls, respectively. Groups 3A-6A constituted the protective study while groups 3B-6B represented the curative study. The effects of LAFRF at 3, 10, and 30 mg/kg body weight (b.w.) on lipid peroxidation, antioxidant status, liver enzymes activities, and histology of CCl₄-intoxicated rats were assessed. LAFRF total flavonoids (281.05 ± 7.44 mg QE/g), indicated LD₅₀ above 5000 mg/kg b.w., and scavenged ABTS*⁺ with an IC₅₀ of 5.05 ± 0.00 µg/mL relative to butylated hydroxytoluene (4.16 ± 0.00 µg/mL), and a concentration-dependent increase in total antioxidant capacity. Carbon tetrachloride (1 mL/kg) triggered significant (p < 0.05) increases in malonedialdehyde concentration (2.67 ± 0.21 mg/mL), with a corresponding decline in antioxidant status, and increases in alkaline phosphatase, alanine and aspartate aminotransferase activities (68.00 ± 9.59 IU/L, 79.60 ± 5.03 IU/L and 81.80 ± 3.96 IU/L), respectively. LAFRF significantly (p < 0.05) lowered lipid peroxidation levels, liver enzyme activities, increased antioxidant status, and improved hepatic histo-architecture of pre- and post LAFRF-treated rats. This demonstrates its high antioxidative, hepatoprotective and curative effects, indicating its potential for future drug development.

Polyphenols from Penthorum chinense Pursh. Attenuates high glucose-induced vascular inflammation through directly interacting with Keap1 protein

ETHNOPHARMACOLOGICAL RELEVANCE

Penthorum chinense Pursh is used for promoting diuresis and alleviating "heat"-associated disorders, which were considered to be related to diabetic in Traditional Chinese Medicine (TCM).

AIMS OF THIS STUDY

Here, we aimed to evaluate the ability and underlying mechanism of the ethyl acetate fraction of Penthorum chinense Pursh stems (PSE) to inhibit vascular inflammation in high glucose (HG)-induced human umbilical vein endothelial cells (HUVEC cells).

MATERIALS AND METHODS

HUVEC cells were pre-treated with PSE following HG treatment. The cell viability, mitochondrial membrane potential (MMP), lactate dehydrogenase (LDH) levels, reactive oxygen species (ROS) generation were analyzed. Inflammatory, and antioxidant,-related proteins were analyzed using western blotting. Molecular docking and drug affinity targeting experiments (DARTS) were utilized to analyze and verify the binding of the Keap1 protein and polyphenols of PSE.

RESULTS

HG can significantly increase the activity of lactic dehydrogenase (LDH), destroy the mitochondrial membrane potential (MMP), and promote the generation of reactive oxygen species (ROS), while PSE treatment reversed these changes. Mechanistically, PSE inhibited NF-κB and inflammatory cytokines activation induced by HG through activating the expression of Nrf2 and its downstream antioxidant proteins Heme oxygenase-1 (HO-1), NAD (P)H Quinone Dehydrogenase 1 (NQO1), Glutamate cysteine ligase catalytic subunit (GCLC), Glutamate-cysteine ligase modifier (GCLM). Further study indicated that PSE activated Nrf2 antioxidant pathway mainly by the binding of primary polyphenols from PSE and the Keap1 protein.

CONCLUSION

Taken together, the present data highlight the health benefits of polyphenols from Penthorum chinense Pursh. regarding diabetes, proving it to be an important source of health care products. Besides, binding of the Keap1 protein may be an effective strategy to activate Nrf2 antioxidant pathway and prevent diabetes.

Senolytic agent Quercetin ameliorates intervertebral disc degeneration via the Nrf2/NF-κB axis

OBJECTIVE

Intervertebral disc degeneration (IDD) represents major cause of low back pain. Quercetin (QUE) is one of the approved senolytic agents. In this study, we evaluated the protective effects of QUE on IDD development and its underlying mechanism.

METHODS

Effects of senolytic agent QUE on the viability of nucleus pulposus cells (NPCs) were measured by CCK-8 assays and EdU staining. The senescence associated secreted phenotype (SASP) factors expressions were measured by qPCR, western blot, and ELISA; and NF-κB pathway was detected by immunofluorescence and western blot. Molecular docking was applied to predict the interacting protein of QUE; while Nrf2 was knocked down by siRNAs to confirm its role in QUE regulated senescence phenotype. X-ray, MRI, Hematoxylin-Eosin and Safranin O-Fast green staining were performed to evaluate the therapeutic effects of QUE on IDD in the puncture-induced rat model.

RESULTS

In in vitro experiments, QUE inhibited SASP factors expression and senescence phenotype in IL-1β-treated NPCs. Mechanistically, QUE suppressed IL-1β induced activation of the NF-κB pathway cascades; it was also demonstrated in molecular docking and knock down studies that QUE might bind to Keap1-Nrf2 complex to suppress NF-κB pathway. In vivo, QUE ameliorated the IDD process in the puncture-induced rat model.

CONCLUSIONS

Together the present work suggests that QUE inhibits SASP factors expression and senescence phenotype in NPCs and ameliorates the progression of IDD via the Nrf2/NF-κB axis, which supports senolytic agent QUE as a potential therapeutic agent for the treatment of IDD.

Allyl isothiocyanate increases MRP1 expression in cigarette smoke extract-stimulated human bronchial epithelial cells via the JNK/Nrf2 pathway

Multidrug resistance-related protein 1 (MRP1) is involved in the biological transport of several molecules with diverse structural characteristics outside of the cell. In addition to its transport activity, MRP1 exhibits multiple defense mechanisms in vivo. MRP1 is highly expressed in normal lung tissues and plays a protective role in the process of chronic obstructive pulmonary disease. In the present study, human bronchial epithelial cells (16HBE14o-cells) were stimulated by cigarette smoke extract (CSE) in vitro to simulate a smoking environment. On this basis, the mechanism of Allyl isothiocyanate (AITC) administration on the expression of MRP1 in CSE-stimulated 16HBE14o-cells was investigated. The effects of CSE on the viability of 16 HBE14o-cells were investigated by an MTT assay. The changes in the mRNA expression levels of nuclear erythroid factor 2 (Nrf2) and MRP1 were investigated in CSE-stimulated 16HBE14o-cells using western blotting and reverse transcription quantitative PCR (RT-qPCR). Immunofluorescence analysis was used to detect Nrf2 nuclear translocation. Incubation of the cells with 5% CSE for 24 h had minor effects on cell viability and resulted in the activation of the JNK and p38MAPK signaling pathways. AITC activated the JNK pathway, inhibited the activation of the p38MAPK pathway in 16HBE14o-cells stimulated by 5% CSE and upregulated the expression levels of Nrf2 and MRP1 in a time-dependent manner. The upregulation of Nrf2, MRP1 and of Nrf2, and MRP1 mRNA expression levels in CSE-stimulated cells was inhibited by pretreatment with SP600125 (a JNK pathway inhibitor). Furthermore, the fluorescence intensity in the nucleus was significantly enhanced following AITC pretreatment and the analysis indicated nuclear translocation of Nrf2 in the cells. These results indicated that Nrf2 and MRP1 expression levels in CSE-stimulated cells were altered following AITC pretreatment. Thus demonstrating that the primary mechanism may be associated with activation of the JNK pathway, while the p38MAPK pathway may not be involved.

Quercetin Oxidation Metabolite Present in Onion Peel Protects Caco-2 Cells against the Oxidative Stress, NF-kB Activation, and Loss of Epithelial Barrier Function Induced by NSAIDs

The potential of 2-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxy-3(2H)-benzofuranone (BZF), a quercetin oxidation metabolite, and that of a BZF-rich onion peel aqueous extract (OAE) to protect Caco-2 monolayers against the oxidative stress (OS) and an increased permeability (IP) induced by five nonsteroidal anti-inflammatory drugs (NSAIDs) (indomethacin, diclofenac, piroxicam, ibuprofen, and metamizole) were investigated. Under identical OS conditions, the NSAIDs substantially differed in their ability to induce an IP and/or NF-kB activation. The OAE (100 nM BZF) protected in identical magnitude (84-86%) against OS but in a highly dissimilar manner against the IP (18-73%). While all NSAIDs activated NF-kB, the OAE prevented only that induced by indomethacin. Results reveal that the IP has no direct relationship with the OS and that with the exception of indomethacin, the prevention of NSAIDs-induced OS and/or NF-kB activation plays no fundamental role in the IP-protecting effect of OAE. These results warrant the in vivo evaluation of OAE against indomethacin-induced loss of intestinal barrier function.

Quercetin modulates NRF2 and NF-κB/TLR-4 pathways to protect against isoniazid- and rifampicin-induced hepatotoxicity in vivo

Isoniazid and rifampicin are crucial for treating tuberculosis (TB); however, they can cause severe hepatotoxicity leading to liver failure. Therapeutic options are limited and ineffective. We hypothesized that prophylaxis with quercetin attenuates isoniazid- and rifampicin-induced liver injury. We randomly divided Wistar rats into seven groups (n = 6). The animals received isoniazid and rifampicin or were co-treated with quercetin or silymarin for 28 days. The protective effect of quercetin was assessed using liver function tests and liver histology. Nuclear factor erythroid 2-related factor 2 (NRF2) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathways were explored to elucidate the mechanism of action. Quercetin co-administration prevented the elevation of alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP) and bilirubin compared with isoniazid and rifampicin treatment alone. In the histological analysis, we observed that quercetin prophylaxis lessened the severity of hepatic necrosis and inflammation compared with the anti-TB drug-treated group. Quercetin attenuated anti-TB drug-induced oxidative stress by increasing NRF2 activation and expression, boosting endogenous antioxidant levels. Additionally, quercetin blocked inflammatory mediators high mobility group box-1 (HMGB-1) and interferon γ (IFN-γ), inhibiting activation of the NF-κB/ toll like receptor 4 (TLR-4) axis. Quercetin protects against anti-TB liver injury by activating NRF2 and blocking NF-κB/TLR-4.

Phytochemical characterization and hepatoprotective effect of active fragment from Adhatoda vasica Nees. against tert-butyl hydroperoxide induced oxidative impairment via activating AMPK/p62/Nrf2 pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Adhatoda vasica Nees., which existed in a large; number of Tibetan medicine prescriptions for hepatopathy, used as an adjuvant to treat liver diseases.

HYPOTHESIS/PURPOSE

Oxidative stress is the key player in the development and progression of liver pathogenesis. In recent years, research is increasingly being focused on exploitation of the active components from medicinal plants to combat the liver oxidative injury. In our study, we aimed to screen the active principles from A. vasica and clarify whether they could relieve oxidative damage induced by tert-Butyl hydroperoxide (t-BHP) and its potential mechanism via activating AMPK/p62/Nrf2 pathway.

MATERIALS AND METHODS

Ultra performance liquid chromatography (UPLC) was adopted for analysis of chemical composition in the extracts. Furthermore, the antioxidant activity of the fractions was evaluated using DPPH, ABTS and reducing power assay. Along with this, the compounds in this fraction with highest antioxidant activity were analyzed using UPLC-MS. Based on this, the condition for extracting flavonoids of this subfraction was optimized via response surface method. CCK-8 assay was used to detect cell viability. Detection kits were used to measure the activity changes of AST, ALT, LDH and CAT as well as MDA and GSH levels induced by t-BHP. Detection of reactive oxygen species (ROS) production was used DCFH-DA probe. DAPI staining and flow cytometry was used to detect cell apoptosis. In terms of the mechanistic studies, the expression of proteins involved in AMPK/p62/Nrf2 pathway was measured using western blotting.

RESULTS

Eventually, 70% ethanol extract from leaf of A. vasica was chosen due to its highest active components compared with other extracts. Further, ethyl acetate fraction derived from 70% ethanol extract in A. vasica (AVEA) possess highest ability for scavenging DPPH and ABTS free radicals as well as strongest reducing power than other fractions. Chemical composition analysis showed that AVEA contained 17 compounds, including 1 quinazoline alkaloid, 12 flavonoid-C-glycosides and 4 flavonoid-O-glycosides. In addition, the conditions (ratio of solid-liquid 1:14, the concentration of ethanol 73%, and the temperature 65 °C) were selected to enrich the flavonoids in AVEA. Furthermore, AVEA could attenuate t-BHP induced hepatocyte damage via increasing the cell viability, restoring abnormal the activities of AST, ALT, LDH and CAT as well as the levels of MDA and GSH. ROS fluorescence intensity was reduced by AVEA. Meanwhile, it could inhibit the cell apoptosis of BRL 3 A cells, as evidenced by restoration of cell morphology and decreasing the number of apoptotic cells. Further mechanistic studies indicated AVEA could promote p-AMPK expression to further induce autophagy adaptor-p62 protein expression, which could autophagic degradation of Keap1, leading to Nrf2 release and translocation into nucleus to induce antioxidant genes (HO-1, NQO-1, GCLC and GCLM) expression.

CONCLUSION

In our study, AVEA was first to screen as the active fraction in A. vasica with alkaloids and abundant flavones. Moreover, the fraction potentiates its beneficial aspect by displaying the protective role on relieving t-BHP induced oxidative stress and activating AMPK/p62/Nrf2 pathway. AVEA helps maintain the redox homeostasis of hepatic cells and could be considered as an effective candidate against oxidative stress related liver disorders.

Active ingredients targeting Nrf2 in the Mongolian medicine Qiwei Putao powder: Systematic pharmacological prediction and validation for chronic obstructive pulmonary disease treatment

ETHNOPHARMACOLOGY RELEVANCE

Qiwei Putao powder (Uzhumu-7 in Mongolian) is a traditional Mongolian medicine, which has been widely used for alleviating cough and dyspnea, especially in aged individuals in both Inner Mongolia Autonomous Region and Xinjiang Uygur Autonomous Region of China. However, the active ingredients and exact pharmacological mechanism remain unclear.

MATERIALS AND METHODS

The protective effect of Qiwei Putao powder (QPP) on mice with cigarette smoke (CS)- and lipopolysaccharide (LPS)-induced chronic obstructive pulmonary disease (COPD) was assessed by histopathological hematoxylin and eosin staining, lung coefficient determination and measurement of cytokine levels. The bioactive ingredients and potential targets of the QPP were screened and detected with network pharmacology method and ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q/TOF-MS). The mechanism and efficacy of active ingredients were further validated in COPD mice with immunohistochemistry tests, cytokine level measurement and RT-PCR. The expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2) in the nucleus, interleukin (IL)-1β, superoxide dismutase (SOD), malondialdehyde (MDA) and tumor necrosis factor-alpha (TNF-α) were detected by enzyme-linked immunosorbent assay (ELISA) kits to evaluate oxidative stress and inflammatory conditions in vivo after treatment. The expression of Nrf2 and downstream genes was detected by RT-PCR.

RESULTS

QPP can alleviate pathological changes in the lung during COPD progression. Sixty-one bioactive molecules were identified in QPP, 42 candidate compounds present in UPLC-Q/TOF-MS and 30 predicted COPD-related targets were generated by in silico analysis. A therapeutic network was constructed with all potential targets to predict the preventive effects of the targets on respiratory disease as well as cardiovascular diseases, nervous system diseases, musculoskeletal diseases and bacterial infections. Targets related to inflammation, immunity and oxidative stress (prostaglandin-endoperoxide synthase 2, PTGS2; Nrf2; heat shock protein 90 alpha class A1, HSP90AA1; nitric oxide synthase, NOS2A; etc.) influenced COPD progression the most. We found that Nrf2 promotes a cell antioxidant response and is a key common target in the response to treatment with isoliquiritigenin (ISL), pterostilbene (PTE) and quercetin (QUE), the highly absorbed active ingredients in the formula. The data showed a strong synergistic protective role of these three molecules against the death of human type II alveolar adenocarcinoma (A549) cells through Nrf2 activation following H₂O₂ exposure and provide pharmacological mechanism of QPP in COPD treatment.

Quercetin alleviates Cadmium-induced autophagy inhibition via TFEB-dependent lysosomal restoration in primary proximal tubular cells

Autophagy dysregulation plays a pivotal role in cadmium (Cd)-induced nephrotoxicity. Quercetin (Qu), a flavonoid antioxidant with autophagy-enhancing effect, has protective effect on Cd-induced toxicity, but whether it can prevent Cd-induced nephrotoxicity via restoration of autophagy remains unknown. Here, primary rat proximal tubular (rPT) cells were exposed to Cd and/or Qu in vitro to clarify this issue. Data first showed that Cd-impaired autophagic flux was markedly alleviated by Qu, including decreased levels of autophagy marker proteins and recovery of autophagosome-lysosome fusion targeted for lysosomes. Meanwhile, Cd-induced lysosomal alkalization due to v-ATPases inhibition was prominently recovered by Qu. Accordingly, Qu enhanced Cd-diminished lysosomal degradation capacity and lysosome-related gene transcription levels. Notably, Qu improved Cd-inhibited TFEB nuclear translocation and its gene transcription level. Furthermore, data showed that the restoration of Cd-impaired autophagy-lysosome pathway and resultant alleviation of cytotoxicity by Qu are TFEB-dependent using TFEB gene silencing and overexpression technologies. In summary, these data provide novel evidences that the protective action of Qu against Cd-induced autophagy inhibition is attributed to its restoration of lysosomal dysfunction, which is dependent on TFEB.

Molecular Mechanisms Underlying Protective Role of Quercetin on Copper Sulfate-Induced Nephrotoxicity in Mice

Copper overload is an established cause of nephrotoxicity, but the precise molecular mechanism remains unknown. Our study aimed to investigate the molecular mechanism of copper sulfate (CuSO₄)-induced nephrotoxicity and the protective effect of the natural compound quercetin using a mouse model. Mice were orally administered CuSO₄ only (200 mg/kg per day), or co-administered CuSO₄ (200 mg/kg per day) plus quercetin (25, 50, or 100 mg/kg per day), or quercetin only (100 mg/kg per day), or vehicle for 28 days. The blood and kidneys were collected for the examination of serum biomarkers, oxidative stress biomarkers, changes in histopathology and gene and protein expression. Our results show that quercetin supplementation attenuates CuSO₄-induced renal dysfunction and tubular necrosis in a dose-dependent manner. Quercetin supplementation at 50 and 100 mg/kg significantly attenuated CuSO₄-induced oxidative damage. Quercetin supplementation also inhibited the activities of caspases-9 and-3, and the expression of p53 and Bax mRNAs. Furthermore, quercetin supplementation markedly activated the expression of Nrf2 and HO-1 mRNAs, but inhibited the expression of NF-κB, IL-1β, IL-6, and TNF-α mRNAs. In conclusion, our results revealed that quercetin supplementation could inhibit CuSO₄-induced nephrotoxicity in mice via the inhibition of mitochondrial apoptotic and NF-κB pathways and the activation of Nrf2/HO-1 pathway. Our study highlights quercetin as a potential candidate in treating copper overload-induced nephrotoxicity.

Hepatoprotective, antioxidant and, anti-inflammatory potentials of gallic acid in carbon tetrachloride-induced hepatic damage in Wistar rats

Gallic acid (GA) is a known phenolic compound with anti-inflammatory, antioxidant, and anti-cancer activities. The objective of this research is to evaluate the preventive role of GA against carbon tetrachloride (CCl4) induced liver fibrosis. Thirty-five (35) male Wistar rats were used in this study and were equally distributed into five groups (7 rats each). All groups were acclimatized for a week, Group I (control) rats were administered distilled water only. Group II rats were induced with a single dose of CCl4 (1.25 mL/kg in olive oil (1:1); IP) to cause hepatic damage, while Groups III, IV, and V, rats were intoxicated with CCl4. After 24 h the rats in groups III, IV, and V were given 50 mg/kg of silymarin, 50 mg/kg of GA, and 100 mg/kg of GA daily for one week respectively. Rats were sacrificed and fasting blood was estimated for biochemical analysis while the liver was excised for molecular studies. Results from this study revealed that GA significantly decreases serum hepatic enzymes, down-regulate the expression of pro-inflammatory cytokines, interleukin 1 beta (IL-1B), interleukin 6 (IL-6), cyclooxygenase 2 (COX 2), and tumor necrosis factor-alpha (TNF α), and up-regulate antioxidant gene expression (superoxide dismutase and catalase). The use of gallic acid as natural antioxidants can be promising in ameliorating liver diseases.

Protective effect of Pinot noir pomace extract against the cytotoxicity induced by polycyclic aromatic hydrocarbons on endothelial cells

Polycyclic Aromatic Hydrocarbons (PAHs) are pollutants found in the air generated mainly by the combustion of coal or biomass burning. Exposure to Polycyclic Aromatic Hydrocarbons is positively correlated with cardiovascular diseases. Phenolic compounds are widely found in the plant kingdom, and their availability from agri-food processing waste has led to an increased interest in their recovery. The production of large amounts of organic waste created by the wine industry has emphasized the valuation of these wastes to generate high-added-value by-products. The objective of this work was to investigate the protective effect of Pinot noir pomace extract on human endothelial cells against PAHs found in the polluted air of Temuco, Chile. The pomace extract was characterized by spectrophotometric analysis and high-performance liquid chromatography (HPLC). Results revealed the presence of 5 glycosylated anthocyanins and 9 low molecular weight polyphenols. Molecular docking indicated that cyanidin-3-glucoside (-9.2 kcal/mol) and quercetin (-9.6 kcal/mol) had the highest affinities for the Nrf2 binding site in the Keap1 protein, suggesting a possible competition with this transcription factor. Endothelial cells from the human umbilical vein were exposed to increasing concentrations of Phenanthrene, Fluoranthene, and Pyrene diluted in DMSO in a ratio of 3:1:1 (10 μM-200 μM). Viability through the MTS assay showed that 150 μM of PAHs was sufficient to reduce viability by 75% (p ˂ 0.0001). When the cells were pre-treated with 400 μg/ml of the extract, 150 μM of PAHs did not exert cell death (80% viability). Our preliminary results show that polyphenolic components found in Pinot noir pomace might have a beneficial effect as a protective agent.