Apigenin attenuates patulin-induced apoptosis in HEK293 cells by modulating ROS-mediated mitochondrial dysfunction and caspase signal pathway

Comparative analysis of whole plant, flower and root extracts of Chamomilla recutita L. and characteristic pure compounds reveals differential anti-inflammatory effects on human T cells

Introduction

Chronic inflammation is a hallmark of chronic wounds and inflammatory skin diseases. Due to a hyperactive and prolonged inflammation triggered by proinflammatory immune cells, transitioning to the repair and healing phase is halted. T cells may exacerbate the proinflammatory milieu by secreting proinflammatory cytokines. Chamomilla recutita L. (chamomile) has been suggested for use in several inflammatory diseases, implying a capability to modulate T cells. Here, we have characterized and compared the effects of differently prepared chamomile extracts and characteristic pure compounds on the T cell redox milieu as well as on the migration, activation, proliferation, and cytokine production of primary human T cells.

Methods

Phytochemical analysis of the extracts was carried out by LC-MS/MS. Primary human T cells from peripheral blood (PBTs) were pretreated with aqueous or hydroethanolic chamomile extracts or pure compounds. Subsequently, the effects on intracellular ROS levels, SDF-1α induced T cell migration, T cell activation, proliferation, and cytokine production after TCR/CD3 and CD28 costimulation were determined. Gene expression profiling was performed using nCounter analysis, followed by ingenuity pathway analysis, and validation at protein levels.

Results

The tested chamomile extracts and pure compounds differentially affected intracellular ROS levels, migration, and activation of T cells. Three out of five differently prepared extracts and two out of three pure compounds diminished T cell proliferation. In line with these findings, LC-MS/MS analysis revealed high heterogeneity of phytochemicals among the different extracts. nCounter based gene expression profiling identified several genes related to T cell functions associated with activation and differentiation to be downregulated. Most prominently, apigenin significantly reduced granzyme B induction and cytotoxic T cell activity.

Conclusion

Our results demonstrate an anti-inflammatory effect of chamomile- derived products on primary human T cells. These findings provide molecular explanations for the observed anti-inflammatory action of chamomile and imply a broader use of chamomile extracts in T cell driven chronic inflammatory diseases such as chronic wounds and inflammatory skin diseases. Importantly, the mode of extract preparation needs to be considered as the resulting different phytochemicals can result in differential effects on T cells.

Alzheimer, Parkinson, dementia, and phytochemicals: insight review

Alzheimer's, Parkinson's, and dementia are the leading neurodegenerative diseases that threaten the world with the aging population. Although the pathophysiology of each disease is unique, the steps to be taken to prevent diseases are similar. One of the changes that a person can make alone is to gain the habit of an antioxidant-rich diet. Phytochemicals known for their antioxidant properties have been reported to prevent neurodegenerative diseases in various studies. Phytochemicals with similar chemical structures are grouped. Accordingly, there are two main groups of phytochemicals, flavonoid and non-flavonoid. Various in vitro and in vivo studies on phytochemicals have proven neuroprotective effects by increasing cognitive function with their anti-inflammatory and antioxidant mechanisms. The purpose of this review is to summarize the in vitro and in vivo studies on phytochemicals with neuroprotective effects and to provide insight.

Methylseleninic acid induces apoptosis of human bladder cancer cells through the ROS-mediated mitochondrial pathway

As the most common selenium derivative, methylseleninic acid (MSA) has attracted wide attention. Its apoptotic induction ability and the possible molecular mechanism in human bladder cancer (BC) J82 and T24 cells were investigated in the present study. We found that the survival of J82 and T24 cells were inhibited in a dose-dependent manner after MSA treatment. Propidium iodide (PI) staining and Annexin V-fluorescein isothiocyanate/PI double staining clarified that MSA stocked cells at G2 /M phase and caused apoptosis in J82 and T24 cells. Further, typical morphological features of apoptotic cells were also observed. Accumulation of reactive oxygen species (ROS) and loss of mitochondrial membrane potential were also detected by dichlorodihydrofluorescein diacetate and Rhodamin123 staining. Meanwhile, pretreatment with N-acetylcysteine, an ROS scavenging agent, found that the apoptosis of BC cells induced by MSA was related to the production of ROS. Western blot analysis results showed that MSA interrupted Bax/Bcl-2 balance, stimulated cytochrome c release into the cytoplasm, activated caspase-9 and caspase-3, and finally induced the apoptosis of the BC cells. These findings demonstrated that MSA was able to induce apoptosis in J82 and T24 cells through ROS-mediated mitochondrial apoptosis.

Patulin Alters Insulin Signaling and Metabolic Flexibility in HepG2 and HEK293 Cells

Non-communicable diseases (NCDs) have risen rapidly worldwide, sparking interest in causative agents and pathways. Patulin (PAT), a xenobiotic found in fruit products contaminated by molds, is postulated to be diabetogenic in animals, but little is known about these effects in humans. This study examined the effects of PAT on the insulin signaling pathway and the pyruvate dehydrogenase complex (PDH). HEK293 and HepG2 cells were exposed to normal (5 mM) or high (25 mM) glucose levels, insulin (1.7 nM) and PAT (0.2 μM; 2.0 μM) for 24 h. The qPCR determined gene expression of key enzymes involved in carbohydrate metabolism while Western blotting assessed the effects of PAT on the insulin signaling pathway and Pyruvate Dehydrogenase (PDH) axis. Under hyperglycemic conditions, PAT stimulated glucose production pathways, caused defects in the insulin signaling pathway and impaired PDH activity. These trends under hyperglycemic conditions remained consistent in the presence of insulin. These findings are of importance, given that PAT is ingested with fruit and fruit products. Results suggest PAT exposure may be an initiating event in insulin resistance, alluding to an etiological role in the pathogenesis of type 2 diabetes and disorders of metabolism. This highlights the importance of both diet and food quality in addressing the causes of NCDs.

Deciphering the modulatory role of apigenin targeting oncogenic pathways in human cancers

Cancer is a complicated malignancy controlled by numerous intrinsic and extrinsic pathways. There has been a significant increase in interest in recent years in the elucidation of cancer treatments based on natural extracts that have fewer side effects. Numerous natural product-derived chemicals have been investigated for their anticancer effects in the search for an efficient chemotherapeutic method. Therefore, the rationale behind this review is to provide a detailed insights about the anticancerous potential of apigenin via modulating numerous cell signaling pathways. An ingestible plant-derived flavonoid called apigenin has been linked to numerous anticancerous potential in numerous experimental and biological studies. Apigenin has been reported to induce cell growth arrest and apoptotic induction by modulating multiple cell signaling pathways in a wider range of human tumors including those of the breast, lung, liver, skin, blood, colon, prostate, pancreatic, cervical, oral, and stomach. Oncogenic protein networks, abnormal cell signaling, and modulation of the apoptotic machinery are only a few examples of diverse molecular interactions and processes that have not yet been thoroughly addressed by scientific research. Thus, keeping this fact in mind, we tried to focus our review towards summarizing the apigenin-mediated modulation of oncogenic pathways in various malignancies that can be further utilized to develop a potent therapeutic alternative for the treatment of various cancers.

Mechanistic Approach for Protective Effect of ARA290, a Specific Ligand for the Erythropoietin/CD131 Heteroreceptor, against Cisplatin-Induced Nephrotoxicity, the Involvement of Apoptosis and Inflammation Pathways

ARA 290, an 11-amino acid linear nonhematopoietic peptide derived from the three-dimensional structure of helix B of the erythropoietin (EPO), interacts selectively with the innate repair receptor (IRR) that arbitrates tissue protection. The aim of this study was to investigate the protective effects of ARA290 against cisplatin-induced nephrotoxicity. For this purpose, HEK-293 and ACHN cells were treated with ARA290 (50-400 nM) and cisplatin (2.5 μM) in pretreatment condition. Then, cytotoxicity, genotoxicity, oxidative stress parameters (ROS, GPx, SOD, and MDA), and inflammatory markers (TNFα, IL6, and IL1β) were evaluated. Furthermore, apoptotic cell death was assessed via caspase-3 activity and tunnel assay. To determine the molecular mechanisms of the possible nephroprotective effects of ARA290, gene and protein expressions of TNFα, IL1β, IL6, Caspase-3, Bax, and Bcl2 were evaluated by real-time PCR and western blot assay, respectively. The findings indicated that ARA290 significantly reduced the DNA damage parameters of comet assay and the frequency of micronuclei induced by cisplatin. Besides, ARA290 improved cisplatin-induced oxidative stress by reducing MDA/ROS levels and enhancing antioxidant enzyme levels. In addition, reduced levels of pro-inflammatory cytokines indicated that cisplatin-induced renal inflammation was mitigated upon the treatment with ARA290. Besides, ARA290 ameliorates cisplatin-induced cell injury by antagonizing apoptosis. Furthermore, the molecular findings indicated that gene and protein levels of TNFα, IL1β, IL6, Caspase-3, and Bax were significantly decreased and gene and protein levels of Bcl2 significantly increased in the ARA290 plus cisplatin group compared with the cisplatin group. These findings revealed that ARA290 as a potent chemo-preventive agent exerted a protective effect on cisplatin-induced nephrotoxicity mostly through its anti-apoptotic, anti-inflammatory, and antioxidant potentials and also suggested that ARA290 might be a new therapeutic approach for patients with acute kidney injury.

The Mycotoxin Patulin Inhibits the Mitochondrial Carnitine/Acylcarnitine Carrier (SLC25A20) by Interaction with Cys136 Implications for Human Health

The effect of mycotoxin patulin (4-hydroxy-4H-furo [3,2c] pyran-2 [6H] -one) on the mitochondrial carnitine/acylcarnitine carrier (CAC, SLC25A20) was investigated. Transport function was measured as [³H]-carnitine_ex/carnitine_in antiport in proteoliposomes reconstituted with the native protein extracted from rat liver mitochondria or with the recombinant CAC over-expressed in E. coli. Patulin (PAT) inhibited both the mitochondrial native and recombinant transporters. The inhibition was not reversed by physiological and sulfhydryl-reducing reagents, such as glutathione (GSH) or dithioerythritol (DTE). The IC₅₀ derived from the dose-response analysis indicated that PAT inhibition was in the range of 50 µM both on the native and on rat and human recombinant protein. The kinetics process revealed a competitive type of inhibition. A substrate protection experiment confirmed that the interaction of PAT with the protein occurred within a protein region, including the substrate-binding area. The mechanism of inhibition was identified using the site-directed mutagenesis of CAC. No inhibition was observed on Cys mutants in which only the C136 residue was mutated. Mass spectrometry studies and in silico molecular modeling analysis corroborated the outcomes derived from the biochemical assays.

The effects of natural active substances in food on the toxicity of patulin

Patulin (PAT) is a mycotoxin, a secondary metabolite mainly produced by fungi of the genera Aspergillus, Byssochlamys, and Penicillium. Many studies have looked into the potential impacts of this mycotoxin due to its high risk. Researchers are currently doing a more in-depth investigation of and employing physical, chemical, and biological ways to remove PAT. However, existing technology cannot completely remove it, and the residual PAT will continue to pose a threat to human health. As a result, substances capable of reducing PAT toxicity need be discovered. According to previous studies, natural components in food could reduce the toxicity of PAT. This article will review the different types of active compounds and discus the detoxification processes, as well as give recommendations for decreasing the toxicity of PAT and future research directions.

Contamination, Detection and Control of Mycotoxins in Fruits and Vegetables

Mycotoxins are secondary metabolites produced by pathogenic fungi that colonize fruits and vegetables either during harvesting or during storage. Mycotoxin contamination in fruits and vegetables has been a major problem worldwide, which poses a serious threat to human and animal health through the food chain. This review systematically describes the major mycotoxigenic fungi and the produced mycotoxins in fruits and vegetables, analyzes recent mycotoxin detection technologies including chromatography coupled with detector (i.e., mass, ultraviolet, fluorescence, etc.) technology, electrochemical biosensors technology and immunological techniques, as well as summarizes the degradation and detoxification technologies of mycotoxins in fruits and vegetables, including physical, chemical and biological methods. The future prospect is also proposed to provide an overview and suggestions for future mycotoxin research directions.

Effects of Selenium Nanoparticles on Preventing Patulin-Induced Liver, Kidney and Gastrointestinal Damage

Patulin (PAT) is a toxic fungal metabolite, and oxidative damage was proved to be its important toxicity mechanism. Selenium nanoparticles (SeNPs) were prepared by reducing sodium selenite with chitosan as a stabilizer and used for preventing PAT-induced liver, kidney and gastrointestinal damage. SeNPs have good dispersibility, in vitro antioxidant activity, and are much less cytotoxic than sodium selenite. Cell culture studies indicated that SeNPs can effectively alleviate PAT-induced excessive production of intracellular ROS, the decline of glutathione peroxidase activity, and the suppression of cell viability. Evaluation of serum biochemical parameters, histopathology, oxidative stress biomarkers and activities of antioxidant enzymes in a mouse model showed that pre-treatment with SeNPs (2 mg Se/kg body weight) could ameliorate PAT-induced oxidative damage to the liver and kidneys of mice, but PAT-induced gastrointestinal oxidative damage and barrier dysfunction were not recovered by SeNPs, possibly because the toxin doses suffered by the gastrointestinal as the first exposed tissues exceeded the regulatory capacity of SeNPs. These results suggested that a combination of other strategies may be required to completely block PAT toxicity.

miR-27b inhibition contributes to cytotoxicity in patulin-exposed HEK293 cells

Patulin (PAT) is a mycotoxin produced by Penicillium and other fungi that contaminate fruit. PAT targets the kidney and is associated with nephrotoxicity. Micro-RNAs (miRNA) may offer new insights into PAT-induced nephrotoxicity. Cytochrome P₄₅₀ family 1, subfamily B, polypeptide 1 (CYP1B1), involved in metabolism of dietary toxins is negatively regulated by miR-27b and linked with the nuclear factor kappa B (NF-κB) pathway and peroxisome proliferator activated receptor gamma (PPARɣ) in renal fibrosis. This study investigated the effects of PAT on miR-27b, CYP1B1, PPARɣ and cytotoxicity in human kidney (HEK293) cells. HEK293 cells were exposed to PAT (2.5 μM, 24h). Protein expression of CYP1B1, PPARɣ, NF-κB (p65), pNF-κB (p65) (phospho-Ser563) and cleaved PARP-1 was quantified using western blotting. QPCR evaluated mRNA levels of CYP1B1, IL-6, miR-27b, OGG1, mtDNA, TFAM and UCP2. Mitochondrial membrane potential and phosphatidylserine (PS) externalization was evaluated by flow cytometry while levels of ATP and caspase -9, -8, -3/7 activity was measured using luminometry. PAT significantly decreased miR-27b levels (p = 0.0014) and increased CYP1B1 mRNA (p = 0.0015) and protein (p = 0.0013) levels. PPARɣ protein expression was significantly increased (p = 0.0002) and associated with decreased NF-κB activation (p = 0.0273) and IL-6 mRNA levels (p = 0.0265). Finally, PAT significantly compromised mitochondrial repair mechanisms and increased apoptotic biomarkers. PAT altered miR-27b levels and PPARɣ, with associated changes to NF-κB activation, downstream IL-6 and CYP1B1 expression. These results show that PAT impairs detoxification mechanisms leading to mitochondrial damage and apoptosis. In conclusion, PAT altered the epigenetic environment and impaired detoxification processes, supporting a mechanism for nephrotoxic outcomes.

Potential nephroprotective phytochemicals: Mechanism and future prospects

ETHNOPHARMACOLOGICAL RELEVANCE

Kidney disease (KD) is one of the serious health issues, which causes worrisome morbidity and economic burden. Therapeutic strategies are available however majority of them are associated with severe adverse effects and poor patient compliance and adherence. This explorative article was undertaken to provide a holistic review of known nephroprotective (NP) phytoconstituents along with their research-based evidences on mechanism, sources, and clinical trials that may play essential role in prevention and cure of KD.

AIM OF THE STUDY

The present systematic review aimed to provide in-depth and better evidences of the global burden of KD, phytoconstituents as NP with emphasis on mechanism of action both in vitro and in vivo, their wide biological sources as well as their clinical efficacy in management of kidney disease and its related disorders.

MATERIAL AND METHODS

Comprehensive information was searched systematically from electronic databases, namely, PubMed, Sciencedirect, Wiley, Scopus, Google scholar and Springer until February 2021 to find relevant data for publication on phytoconstituents with nephroprotective potential.

RESULTS

In total, 24,327 articles were screened in first search for "phytoconstituents and medicinal plants for nephroprotection and kidney disorder". On the basis of exclusion and inclusion criteria, 24,091 were excluded. Only 236 papers were spotted to have superlative quality data, which is appropriate under titles and sub-titles of the present review. The phytoconstituents having multiple research evidence along with wide number of medicinal plants sources and mechanism reported for nephroprotection have been selected and reviewed.

CONCLUSION

This review, based on pre-clinical and clinical data of NP phytoconstituents, provides scientific-basis for the rational discovery, development and utilization of these upcoming treatment practices. Further,-more clinical studies are warranted to improve the pharmacodynamic and pharmacokinetic understanding of phytoconstituents. Also, more specific evaluation for natural sources is needed.

Antiproliferative and Mitochondrial Protective Effects of Apigenin in an Oxygen-Induced Retinopathy In Vivo Mouse Model

Purpose: To investigate the effects of a common dietary flavonoid apigenin on retinal endothelial cell proliferation, retinal morphological structure, and apoptotic cell death in an oxygen-induced retinopathy (OIR) mouse model to evaluate the possibility of the use of apigenin in the treatment of ocular neovascular diseases (ONDs). Methods: Ninety-six newborn C57BL/6J mice were included. Eight groups were randomized, each including 12 mice. Two negative control groups were kept in room air: the first without any injection and the second received intravitreal (IV) dimethyl sulfoxide (DMSO), which is the solvent we used. The OIR groups were exposed to 75% ± 2% oxygen from postnatal days (PD) 7 to 12. On PD 12, the mice were randomly assigned to 6 groups: 2 OIR control groups (1 received no injection, 1 received IV-DMSO), 2 IV-apigenin groups (10 and 20 μg/mL), and 2 intraperitoneal (IP)-apigenin groups (10 and 20 mg/kg). We quantified retinal endothelial cell proliferation by counting neovascular tufts in cross-sections and examined histological and ultrastructural changes through light and electron microscopy. We evaluated apoptosis by terminal deoxynucleotidyl transferase-mediated nick end-labeling (TUNEL). Results: We detected a significant increase in endothelial cell proliferation in the OIR groups. Groups receiving apigenin, both IP and IV, had significant decreases in endothelial cells, atypical mitochondrion count, and apoptotic cells compared with the groups receiving no injections. None of the apigenin-injected groups revealed cystic degeneration or cell loss. Conclusions: Apigenin suppresses neovascularization, has antiapoptotic and antioxidative effects in an OIR mouse model, and can be considered a promising agent for treating OND. Clinical trial (Project number: DA15/19).

Functionality of apigenin as a potent antioxidant with emphasis on bioavailability, metabolism, action mechanism and in vitro and in vivo studies: A review

Numerous diseases such as cancer, diabetes, cardiovascular, neurodegenerative diseases, etc. are linked with overproduction of reactive oxygen species (ROS) and oxidative stress. Apigenin (5,7,4'-trihydroxyflavone) is a widely distributed flavonoid, responsible for antioxidant potential and chelating redox active metals. Being present as glycosides or polymers, the apigenin degrades to variable amount in the digestive tract; during processing, its activity is also reduced due to high temperature or Fe/Cu addition. Although its metabolism remains elusive, enteric absorption occurs sufficiently to reduce plasma indices of oxidant status. Delayed clearance in plasma and slow liver decomposition enhance its systematic bioavailability. Antioxidant mechanism of apigenin includes: oxidant enzymes inhibition, modulation of redox signaling pathways (NF-kB, Nrf2, MAPK, and P13/Akt), reinforcing enzymatic and nonenzymatic antioxidant, metal chelation, and free radical scavenging. DPPH, ORAC, ABTS, and FRAP are the major in vitro methods for determining the antioxidant potential of apigenin, whereas its protective effects in whole and living cells of animals are examined using in vivo studies. Due to limited information on antioxidant potential of apigenin, its in vitro and in vivo antioxidant effects are, therefore, discussed with action mechanism and interaction with the signaling pathways. This paper concludes that apigenin is a potent antioxidant compound to overcome the difficulties related to oxidative stress and other chronic diseases.

The effect of ochratoxin A on cytotoxicity and glucose metabolism in human esophageal epithelium Het-1A cells

Ochratoxin A (OTA) is a widespread mycotoxin worldwide that causes major health risks. The esophageal epithelium is unavoidably exposed to food contaminated OTA after ingestion. Yet, few studies have involved in the putative effects of OTA on the cytotoxicity and glucose metabolism responses on esophageal epithelial cells. In this in vitro study, we aimed to investigate the effects of OTA on esophageal epithelial cell intracellular apoptosis, oxidative stress, DNA damage, mitochondrial function and glucose metabolism. Human esophageal epithelial Het-1A cells were exposed to 2.5, 5 or 10 μM OTA for 24 h. The results showed that OTA decreased cell viability and concomitantly increased apoptosis-related indices, reactive oxygen species generation, oxidative DNA damage, mitochondrial dysfunction and mitochondrial apoptotic pathway activation. In addition, OTA switched the glucose metabolism of Het-1A cells from oxidative phosphorylation towards glycolysis by decreasing the expression of tricarboxylic acid cycle-associated enzymes such as α-ketoglutarate dehydrogenase and isocitrate dehydrogenase 1 and by increasing pyruvate dehydrogenase kinase 1 expression. The data indicated that cell apoptosis, oxidative damage, mitochondrial dysfunction and glucose metabolism perturbation might play pivotal roles in the mechanism of OTA-induced esophageal toxicity.

Patulin in food: A mycotoxin concern for human health and its management strategies

The mycotoxin patulin is primarily produced as a secondary metabolite by numerous fungal species and predominantly by Aspergillus, Byssochlamys, and Penicillium species. It is generally associated with fungal infected food materials. Penicillium expansum is considered the only fungal species liable for patulin contamination in pome fruits, especially in apples and apple-based products. This toxin in food poses serious health concerns and economic threat, which has aroused the need to adopt effective detection and mitigation strategies. Understanding its origin sources and biosynthetic mechanism stands essential for efficiently designing a management strategy against this fungal contamination. This review aims to present an updated outline of the sources of patulin occurrence in different foods and their biosynthetic mechanisms. It further provides information regarding the detrimental effects of patulin on human and agriculture as well as its effective detection, management, and control strategies.

Involvement of NADPH oxidase in patulin-induced oxidative damage and cytotoxicity in HEK293 cells

Patulin (PAT) is a kind of mycotoxins that commonly found in decayed fruits and their products. Our previous studies have shown that PAT induced cell apoptosis and the overproduction of reactive oxygen species (ROS) in human embryonic kidney (HEK293) cells. The present study aimed to further investigate the functional role of NADPH oxidase, one of the main cellular sources of ROS, in PAT-induced apoptosis and oxidative damage in HEK293 cells. We demonstrated that the protein and mRNA expression levels of NADPH oxidase catalytic subunit NOX2 and regulatory subunit p47phox were up-regulated under PAT stress. Inhibiting of NADPH oxidase with the specific antagonist diphenyleneiodonium (DPI) suppressed cytotoxicity and apoptosis induced by PAT as evidenced by the increase of cell viability, the decrease of LDH release and the inhibition of caspase activities. Furthermore, DPI re-established mitochondrial membrane potential (MMP) and enhanced cellular ATP content. Importantly, DPI supplementation elevated endogenous GSH contents as well as the ratio of GSH/GSSG. Meanwhile, the antioxidant-enzyme activities of GPx, GR, CAT and SOD were significantly promoted. Collectively, our results suggested that NADPH oxidase played a critical role in PAT-induced nephrotoxicity, and inhibition of NADPH oxidase by DPI attenuated cell injury and apoptosis via regulation of oxidative damage.

Apocynin attenuates patulin-induced cytotoxicity through reduction of oxidation stress and apoptosis in HEK293cells

Patulin (PAT) is a natural mycotoxin that commonly contaminates fruits and their derivative products and has been proven to induce cytotoxicity and oxidative damage in renal cells. In the present study, we aimed to evaluate the effect of apocynin, a potent phenolic antioxidant isolated from plants, on PAT-induced cell injury in human embryonic kidney (HEK293) cells. Compared with 7.5 μM PAT treatment alone, 10 μM apocynin co-treatment elevated cell viability, alleviated lactate dehydrogenase release and reduced caspase activities. Furthermore, apocynin inhibited reactive oxygen species overproduction, re-established mitochondria membrane potential and elevated intracellular ATP content. In addition, the results showed that apocynin aggrandized reduced glutathione (GSH) content, reduced oxidized glutathione (GSSG) content, raised the GSH/GSSG ratio and elevated superoxide dismutase, catalase, glutathione reductase, and glutathione peroxidase activities. Collectively, results of the study clearly show that apocynin supplement may serve as an alternative intervention to protect HEK293 cells against cytotoxicity induced by PAT through reduction of oxidation stress and apoptosis.

A novel acid polysaccharide from Boletus edulis: extraction, characteristics and antitumor activities in vitro

A novel cold-water-soluble polysaccharide (BEP), with a molecular weight of 6.0 × 10⁶ Da, was isolated from Boletus edulis. BEP consists of galactose, glucose, xylose, mannose, glucuronic, and galacturonic acid in a ratio of 0.34:0.28:0.28:2.57:1.00:0.44. The IR results showed that BEP was an acid polysaccharide, containing α-type and β-type glucoside bonds. MTT assay showed BEP could inhibit cell proliferation significantly. Morphological observation demonstrated that BEP-treated MDA-MB-231 and Ca761 cells exhibited typical apoptotic morphological features. Flow cytometry analysis revealed that BEP caused mitochondrial membrane potential collapse. Annexin V-FITC/PI staining indicated that BEP induced apoptosis of MDA-MB-231 and Ca761 cells through cell block in S phase and G₀/G₁ phase, respectively. Western blot results showed that BEP could increase the Bax/Bcl-2 ratios, promote the release of cytochrome C, and activate the expression of caspase-3 and caspase-9 in MDA-MB-231 and Ca761 cells. In conclusion, our results demonstrated that BEP could inhibit the proliferation of breast cancer cells and induce apoptosis through mitochondrial pathways.

Patulin suppresses α1-adrenergic receptor expression in HEK293 cells

Patulin (PAT) is a common mycotoxin contaminant of apple products linked to impaired metabolic and kidney function. Adenosine monophosphate activated protein kinase (AMPK), abundantly expressed in the kidney, intercedes metabolic changes and renal injury. The alpha-1-adrenergic receptors (α₁-AR) facilitate Epinephrine (Epi)-mediated AMPK activation, linking metabolism and kidney function. Preliminary molecular docking experiments examined potential interactions and AMPK-gamma subunit 3 (PRKAG3). The effect of PAT exposure (0.2-2.5 µM; 24 h) on the AMPK pathway and α₁-AR was then investigated in HEK293 human kidney cells. AMPK agonist Epi determined direct effects on the α₁-AR, metformin was used as an activator for AMPK, while buthionine sulphoximine (BSO) and N-acetyl cysteine (NAC) assessed GSH inhibition and supplementation respectively. ADRA1A and ADRA1D expression was determined by qPCR. α₁-AR, ERK1/2/MAPK and PI3K/Akt protein expression was assessed using western blotting. PAT (1 µM) decreased α₁-AR protein and mRNA and altered downstream signalling. This was consistent in cells stimulated with Epi and metformin. BSO potentiated the observed effect on α₁-AR while NAC ameliorated these effects. Molecular docking studies performed on Human ADRA1A and PRKAG3 indicated direct interactions with PAT. This study is the first to show PAT modulates the AMPK pathway and α₁-AR, supporting a mechanism of kidney injury.

Transcriptomic and Proteomic Analysis Reveals Mechanisms of Patulin-Induced Cell Toxicity in Human Embryonic Kidney Cells

Patulin (PAT) is a natural mycotoxin that commonly contaminates fruits and fruit-based products. Previous work indicated that PAT-induced apoptosis in which reactive oxygen species (ROS) are involved in human embryonic kidney (HEK293) cells. To uncover novel aspects of the possible mechanism of PAT nephrotoxicity, the transcriptome and proteome profiles were investigated using the digital gene expression (DGE) and isobaric tags for relative and absolute quantitation (iTRAQ) proteomic approaches. A total of 127 genes and 85 proteins were found to express differentially in response to 5 μM PAT for 10 h in HEK293 cells. The most dramatic changes of expression were noticed with genes or proteins related to apoptosis, oxidative phosphorylation ribosome and cell cycle. Especially, the activation of caspase 3, UQCR11, active transport form and endocytosis appeared to be crucial in PAT kidney cytotoxicity. PAT also seemed to be associated with cancer and neuropathic disease as pathways associated with carcinogenesis, Alzheimer’s disease and Parkinson’s disease were induced. Overall, this study served to uncover overall insights associated with signaling pathway that modulated the PAT toxicity mechanism.

Data-Independent Acquisition-Based Quantitative Proteomic Analysis Reveals the Protective Effect of Apigenin on Palmitate-Induced Lipotoxicity in Human Aortic Endothelial Cells

The ingestion of excessive free fatty acid could induce lipotoxicity in tissues and then lead to the initiation of many metabolism diseases. In this work, the protective effect of apigenin on palmitate-induced lipotoxicity in human aortic endothelial cells (HAEC) was investigated. Compared with 150 μM palmitate treatment alone, pretreatment with 10 μM apigenin for 6 h significantly increased the cell viability from 71.55 ± 3.62 to 91.06 ± 4.30% and improved mitochondrial membrane potential to the normal level (101.62 ± 11.72% of control). In addition, the production of nitric oxide was markedly elevated by apigenin cotreatment from 7.10 ± 3.95 to 94.20 ± 21.86%. The data-independent acquisition-based proteomic approach was used to study the protective mechanism, and the results revealed that 242 proteins were differently expressed in cells treated with palmitate and 93 proteins were reversed after apigenin supplementation. Apigenin realized its protective function mainly via regulating pathways such as IL-17, TNF, Fox O, cell adhesion, and endoplasmic reticulum protein processing. Collectively, these data demonstrated that apigenin supplement may serve as an alternative nutritional intervention to protect HAEC against lipotoxicity.

Apigenin attenuates Aluminum phosphide-induced cytotoxicity via reducing mitochondrial/Lysosomal damages and oxidative stress in rat Cardiomyocytes

Apigenin, is a natural compound that found in high amounts in vegetables and fruits. This natural flavone has shown strong cardioprotective effects in animal and clinical studies. Due to cardioprotective effects of apigenin in previous studies, we hypothesized that apigenin protects isolated cardiomyocytes from aluminum phosphide(AlP)-induced toxicity as the most common disturbances after exposure with this agent. By using of biochemical and flowcytometry techniques; cell viability, reactive oxygen species (ROS) generation, mitochondria membrane potential (MMP), lysosomal membrane integrity, malondialdehyde (MDA) and oxidized/reduced glutathione (GSH/GSSG) content were measured in rat heart isolated cardiomyocytes. Our results showed that the administration of apigenin (5-100 μM) efficiently decreased (P < .05) cytotoxicity, oxidative, lysosomal and mitochondrial damages induced by AlP (20 μg/ml) in isolated cardiomyocytes. Taken together, apigenin protected the cardiomyocytes against AlP toxicity via the protection of mitochondria and lysosome mediated by its antioxidant properties.

The role of mitochondria in sterigmatocystin-induced apoptosis on SH-SY5Y cells

Mitochondria are cellular organelles involved in many crucial functions, such as generation of energy (ATP) and initiation of apoptosis. The aim of the present study was to evaluate the role of mitochondria in the toxicity induced by sterigmatocystin (STE), a mycotoxin produced by fungi of the genus Aspergillus, on SH-SY5Y cells. Our results showed that STE exposure decreased cell viability in a time- and concentration-dependent manner by MTT assay and caused mitochondrial dysfunction, as highlighted by the increase of STE cytotoxicity in cells forced to rely on mitochondrial oxidative phosphorylation. Furthermore, intracellular ATP depletion and increased mitochondrial reactive oxygen species were also observed. Since mitochondria play a pivotal role in apoptosis, the induction of this process in response to STE exposure was decided to study. Our results showed an increase in apoptotic cell population by flow cytometry, further confirmed by the up-regulation of the expression levels of the pro-apoptotic genes Bax and Casp-3 and the down-regulation of the anti-apoptotic gene Bcl-2 by qPCR technique. Taken together, our results provide novel insights in the signalling pathways of the cell death process induced by STE in SH-SY5Y cells, highlighting the key role played by mitochondria in STE toxicity.

Apigenin induces apoptosis and counteracts cisplatin-induced chemoresistance via Mcl-1 in ovarian cancer cells

Ovarian cancer (OC) is one of the prominent causes of mortality in female patients diagnosed with gynecologic malignancies. While it has previously been demonstrated that apigenin inhibits cell growth in colon and breast cancer cells, the effect of apigenin in OC cells is not fully understood. Therefore, the aim of the present study was to investigate the impact of apigenin on cell death and resistance to cisplatin in OC cells. It was found that apigenin inhibited proliferation, hindered cell cycle progression and promoted SKOV3 cell apoptosis. Moreover, these effects were also observed in cisplatin-resistant SKOV3/DDP cells. Furthermore, apigenin reduced the mitochondrial transmembrane potential, and elevated the ratios of cleaved caspase-3/caspase-3 and Bax/Bcl-2 in the two cell types. Reverse transcription-quantitative PCR and western blotting results demonstrated that apigenin significantly downregulated Mcl-1 at the transcriptional and translational levels in SKOV3 and SKOV3/DDP cells, which was responsible for its cytotoxic functions and chemosensitizing effects. Collectively, the present results identified the impact of apigenin on OC cell death and resistance to cisplatin, and the potential molecular mechanisms. However, additional studies are required to further elucidate the underlying mechanisms.

Does low concentration mycotoxin exposure induce toxicity in HepG2 cells through oxidative stress?

The purpose of this study was to determine whether exposure to low concentrations of deoxynivalenol (DON), T-2 toxin (T-2) and patulin (PAT) in a human hepatocellular carcinoma cell line (HepG2) exerts toxic effects through mechanisms related to oxidative stress, and how cells deal with such exposure. Cell viability was determined by the MTT and protein content (PC) assays over 24, 48 and 72 h. The IC₅₀ values detected ranged from >10 to 2.53 ± 0.21 μM (DON), 0.050 ± 0.025 to 0.034 ± 0.007 μM (T-2) and 2.66 ± 0.66 to 1.17 ± 0.21 µM (PAT). The key players in oxidative stress are the generation of reactive oxygen species (ROS), lipid peroxidation (LPO) and mitochondrial membrane potential (MMP) dysfunction. The results obtained showed that PAT, DON and T-2 did not significantly increase LPO or ROS production with respect to the controls. Moreover, PAT and DON did not alter MMP, though T-2 increased MMP at the higher concentrations tested (17 and 34 nM). In conclusion, the exposure of HepG2 cells to nontoxic concentrations of T-2 condition them against subsequent cellular oxidative conditions induced by even higher concentrations of mycotoxin.

Metformin enhances the sensitivity of colorectal cancer cells to cisplatin through ROS-mediated PI3K/Akt signaling pathway

Metformin and cisplatin have been widely studied as antitumor agents. However, the effect of metformin combined with cisplatin has not been investigated in colorectal cancer (CRC) cells. This study was aimed to explore the effect of metformin or/and cisplatin on cell viability, apoptosis, and the related signaling pathways in CRC SW480 and SW620 cells. We found that metformin or cisplatin inhibited cell viability of SW480 and SW620 cells in a concentration- and time-dependent manner. Furthermore, metformin combined with cisplatin obviously inhibited cell viability, decreased colony formation, induced apoptosis, mediated cleavage of caspase-9, caspase-3 and PARP, activated mitochondrial membrane potential, downregulated Mcl-1 and Bcl-2 expression, upregulated Bak and Bax expression, and increased reactive oxygen species (ROS) production, compared to the individual agent in SW480 and SW620 cells, which were attenuated by N-acetyl-L-cysteine (NAC), a ROS scavenger. Moreover, NAC could recover the downregulation of p-PI3K and p-Akt treated with combination of metformin and cisplatin, which subsequently activated the PI3K/Akt signaling pathway. Taken together, our results demonstrated that metformin enhanced the sensitivity of CRC cells to cisplatin through ROS-mediated PI3K/Akt signaling pathway.

Antitumor effects of seleno-β-lactoglobulin on human breast cancer MCF-7 and MDA-MB-231 cells in vitro

Seleno-β-lactoglobulin (Se-β-Lg) was synthesized using seleninic acid, an organoselenium compound, and β-lactoglobulin (β-Lg), an important component of milk. Previously, we have studied the effects of Se-β-Lg on hepatocellular carcinoma and gastric cancer cells. In this study, we investigated the antitumor effects of Se-β-Lg and its potential mechanisms of action against human breast cancer cells (MCF-7 and MDA-MB-231). The results showed that the half-maximal inhibitory concentrations (IC50) of Se-β-Lg were 40.84 μg/mL for MCF-7 cells and 46.04 μg/mL for MDA-MB-231 cells at 24 h, while the compound showed no cytotoxicity to normal breast cells. The involvement of reactive oxygen species (ROS) in the activation of the apoptotic signaling pathway by Se-β-Lg was demonstrated by the incubation of cells with 80 μg/mL Se-β-Lg and determination of the rates of apoptosis and intracellular ROS levels after the addition of 10 mM N-acetyl-l-cysteine, a ROS inhibitor. Our findings revealed highly potent anticancer activities of Se-β-Lg against breast cancer cells and suggested that the compound may be used as a chemopreventive agent for breast cancer. Furthermore, we thoroughly elucidated the antitumor mechanism of Se-β-Lg.

The characteristics, occurrence, and toxicological effects of patulin

Mycotoxins are the secondary metabolites secreted by different types of fungi to which humans can get exposed mainly via ingestion. Patulin (C₇H₆O₄) is a polyketide lactone produced by various fungal specifies, including Penicillium expansum as the main producer. P. expansum can infect different fruits and vegetables yet it has preference to apples in which they cause blue rot. Therefore, apples and apple-based food products are the main source of Patulin exposure for humans. Patulin was first identified in 1943 under the name of tercinin as a possible antimicrobial agent. Although it is categorized as a non-carcinogen, Patulin has been linked, in the last decades, to neurological, gastrointestinal, and immunological adverse effects, mainly causing liver and kidney damages. In this review, the characteristics of and possible human exposure pathways to Patulin are discussed. Various surveillance and toxicity studies on the levels of Patulin in various food products and effects of Patulin on cells and animal models have been documented as well. Importance of epidemiological studies and a summary of the possible toxicity mechanisms are highlighted with a case study. The commonly used control methods as described in the literature are also discussed to guide future researchers to focus on mitigating mycotoxins contamination in the food industry.

Apigenin Protects the Brain against Ischemia/Reperfusion Injury via Caveolin-1/VEGF In Vitro and In Vivo

Apigenin is a natural flavonoid found in several dietary plant foods as vegetables and fruits. To investigate potential anti-ischemia/reperfusion injury properties of apigenin in vitro, cell proliferation assay, tube formation, cell migration, apoptosis, and autophagy were performed in human brain microvascular endothelial cells (HBMVECs) after oxygen-glucose deprivation/reoxygenation (OGD/R). The effect of apigenin was also explored in rats after middle cerebral artery occlusion/reperfusion (MCAO/R) via neurobehavioral scores, pathological examination, and measurement of markers involved in ischemia/reperfusion injury. Data in vitro indicated that apigenin could prompt cell proliferation, tube formation, and cell migration while inhibiting apoptosis and autophagy by affecting Caveolin-1/VEGF, Bcl-2, Caspase-3, Beclin-1, and mTOR expression. Results in vivo showed that apigenin significantly reduced neurobehavioral scores and volume of cerebral infarction while prompting vascular endothelial cell proliferation by upregulating VEGFR2/CD34 double-labeling endothelial progenitor cell (EPC) number and affecting Caveolin-1, VEGF, and eNOS expression in brain tissue of MCAO/R rats. All the data suggested that apigenin may be protective for the brain against ischemia/reperfusion injury by alleviating apoptosis and autophagy, promoting cell proliferation in HBMVECs of OGD/R, and attenuating brain damage and improved neurological function in rats of MCAO/R through the Caveolin-1/VEGF pathway.

Glutathione Reduction of Patulin-Evoked Cytotoxicity in HEK293 Cells by the Prevention of Oxidative Damage and the Mitochondrial Apoptotic Pathway

Patulin (PAT) is a mycotoxin frequently detected in moldy fruits and fruit products. This study investigated the protective role of glutathione (GSH), an antioxidant agent, against PAT-induced cytotoxicity and its potential mechanisms in HEK293 cells. The obtained results showed that the addition of GSH significantly increased cell viability and decreased apoptosis induced by PAT. Additionally, GSH decreased intracellular ROS and mitochondrial ROS overproduction, suppressed the decline of the mitochondrial membrane potential, and maintained cellular ATP contents. GSH prevented the impairment of mitochondrial oxidative-phosphorylation system and, especially, enhanced the mRNA and protein levels of electron-transport-chain complex III (UQCRC2) and complex V (ATP5, ATP6 and ATP8). Furthermore, GSH increased endogenous GSH contents; enhanced the antioxidant-enzyme activities of SOD, CAT, GR, and GPx; and modulated oxidative damage. These results suggest that GSH reduces PAT-induced cytotoxicity via inhibition of oxidative damage and the mitochondrial apoptotic pathway in HEK293 cells.

Anti-Oxidative and Anti-Apoptotic Effects of Apigenin on Number of Viable and Apoptotic Blastomeres, Zona Pellucida Thickness and Hatching Rate of Mouse Embryos

Background

Apigenin is a plant-derived compound belonging to the flavonoids category and bears protective effects on different cells. The aim of this study was to evaluate the effect of apigenin on the number of viable and apoptotic blastomeres, the zona pellucida (ZP) thickness and hatching rate of pre-implantation mouse embryos exposed to H₂O₂ and actinomycin D.

Materials and Methods

In this experimental study, 420 two-cell embryos were randomly divided into six groups: i. Control, ii. Apigenin, iii. H₂O₂ , iv. Apigenin+H₂O₂ , v. Actinomycin D, and vi. Apigenin+Actinomycin D. The percentage of blastocysts and hatched blastocysts was calculated. Blastocyst ZP thickness was also measured. In addition, viable blastomeres quantity was counted by Hoechst and propidium iodide staining and the number of apoptotic blastomeres was counted by TUNEL assay.

Results

The results of viable and apoptotic blastomeres quantity, the ZP thickness, and the percentage of blastocysts and hatched blastocysts were significantly more favorable in the apigenin group, rather than the control group (P<0.05). The results of the apigenin+H₂O₂ group were significantly more favorable than the H₂O₂ group (P<0.05); and the results of apigenin+actinomycin D group were significantly more favorable than actinomycin D group (P<0.05).

Conclusion

The results suggest that apigenin may protect mouse embryos against H₂O₂ and actinomycin D. So that it increases the number of viable blastomeres and decreases the number of apoptotic blastomeres, which may cause expanding the blastocysts, thinning of the ZP thickness and increasing the rate of hatching in mouse embryos.

Mycotoxins and oxidative stress: where are we?

Mycotoxins are the most common contaminants of food and feed worldwide and are considered an important risk factor for human and animal health. Oxidative stress occurs in cells when the concentration of reactive oxygen species exceeds the cell’s antioxidant capacity. Oxidative stress causes DNA damage, enhances lipid peroxidation, protein damage and cell death. This review addresses the toxicity of the major mycotoxins, especially aflatoxin B1, deoxynivalenol, nivalenol, T-2 toxin, fumonisin B1, ochratoxin, patulin and zearalenone, in relation to oxidative stress. It summarises the data associated with oxidative stress as a plausible mechanism for mycotoxin-induced toxicity. Given the contamination caused by mycotoxins worldwide, the protective effects of a variety of natural compounds due to their antioxidant capacities have been evaluated. We review data on the ability of vitamins, flavonoids, crocin, curcumin, green tea, lycopene, phytic acid, L-carnitine, melatonin, minerals and mixtures of anti-oxidants to mitigate the toxic effect of mycotoxins associated with oxidative stress.

Protective effects of Artemisia campestris extract against gastric acid reflux-induced esophageal mucosa injuries

Artemisia campestris L. has been widely used in alternative medicine to treat digestive system diseases, particularly gastroesophageal disorders. In the present investigation, we studied the putative protective effect of Artemisia campestris aqueous extract (ACAE) against gastro-esophageal reflux (GER)-induced esophagitis in rats. The experimental ophagitis was induced by the ligation of the pylorus as well as the junction between the forestomach and the corpus. We firstly found that ACAE administration at 100, 200 and 400 mg/kg, b.w., p.o. significantly protected GER-induced macroscopic and histological injuries in the esophagus tissue. Our extract also counteracted GER-induced esophagus lipoperoxidation, restored the depletion of antioxidant enzyme activities such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) as well as thiol groups levels. Furthermore, we showed that acute GER provoked an increase in esophagus mucosa hydrogen peroxide (H₂O₂), free iron and calcium levels, whereas ACAE treatment reversed all GER-induced intracellular mediators' disturbances. In conclusion, we suggested that ACAE had potent protective effects against esophagitis due, in part, to its antioxidant properties as well as its opposite effect on some intracellular mediators.