Eriodictyol inhibits high glucose-induced extracellular matrix accumulation, oxidative stress, and inflammation in human glomerular mesangial cells

pH responsive fabrication of PVA-stabilized selenium nano formulation encapsulated with luteolin to reduce diabetic ureteral injury by decreasing NLRP3 inflammasome via Nrf2/ARE signaling

Diabetic ureteral injury (DUI) is a condition characterized by damage to the ureter, causing functional and morphological changes in the urinary system, which have a significant impact on a quality of life and requires appropriate medical treatment. The present study describes to novel design of luteolin (LT), a type of natural flavonoid, encapsulated selenium nanoparticles (Se NPs) to attain therapeutic potential for DUI. The physico-chemical characterizations of prepared Se NPs have benefitted zeta potential (-18 mV) and particle size (10-50 nm). In vitro assays were demonstrated the potential of LT-SeNPs by HEK 293 cells stimulated by STZ for DUI. Cytotoxicity assays on HEK 293 and NIH-3T3 showed >90% cell viability, which demonstrates the suitability of the nanoformulation for DUI treatment. The LT-SeNPs significantly inhibits the NLRP3 inflammasome through Nrf2/ARE pathway, which benefits for DUI treatment. The developed LT-SeNPs could be an effective formulation for the DUI therapy.

Toll-like receptors in inflammatory bowel disease: A review of the role of phytochemicals

BACKGROUND

Inflammatory bowel disease (IBD) is a chronic inflammation within the gastrointestinal tract with a remarkable impact on patients' quality of life. Toll-like receptors (TLR), as a key contributor of immune system in inflammation, has a critical role in the pathogenesis of IBD and thus, can be a suitable target of therapeutic agents. Medicinal plants have long been considered as a source of bioactive agents for different diseases, including IBD.

PURPOSE

This review discusses current state of the art on the role of plant-derived compounds for the management of IBD with a focus on TLRs.

METHODS

Electronic database including PubMed, Web of Science, and Scopus were searched up to January 2023 and all studies in which anticolitis effects of a phytochemical was assessed via modulation of TLRs were considered.

RESULTS

Different categories of phytochemicals, including flavonoids, lignans, alkaloids, terpenes, saccharides, and saponins have demonstrated modulatory effects on TLR in different animal and cell models of bowel inflammation. Flavonoids were the most studied phytochemicals amongst others. Also, TLR4 was the most important type of TLRs which were modulated by phytochemicals. Other mechanisms such as inhibition of pro-inflammatory cytokines, nuclear factor-κB pathway, nitric oxide synthesis pathway, cyclooxygenase-2, lipid peroxidation, as well as induction of endogenous antioxidant defense mechanisms were also reported for phytochemicals in various IBD models.

CONCLUSION

Taken together, a growing body of pre-clinical evidence support the efficacy of herbal compounds for the treatment of IBD via modulation of TLRs. Future clinical studies are recommended to assess the safety and efficacy of these compounds in human.

Bu-Shen-Tian-Jing formulas alleviate the mitochondrial damage induced by oxidative stress in ovarian granulosa cells exposed to DEHP through the HDAC3-HSP90AA pathway

CONTEXT

di-(2-Ethylhexyl) phthalate (DEHP) has potential reproductive toxicity. Bu-Shen-Tian-Jing formulations (BSTJFs) are beneficial for female reproductive capacity. However, BSTJF2 has much lower cytotoxicity than BSTJF1.

OBJECTIVE

To investigate the effects of BSTJFs on ovarian granulosa cells exposed to DEHP and determine the potential molecular mechanisms.

METHODS AND MATERIALS

Human granulosa-like tumor cell line (KGN) cells were divided into control, DEHP, BSTJF1 and BSTJF2 groups. The DEHP group were given 1 μM DEHP for 24 h. They were then given BSTJF1 at 200 μg/mL or BSTJF2 at 100 μg/mL for 24 h. The control group was treated with the same concentration of DMSO (0.1%). Oxidative stress and mitochondrial function were measured. The mRNA and protein expression levels of HDAC3 and HSP90AA were determined. Integrative network pharmacology analysis of BSTJF2 was also performed.

RESULTS

DEHP (1 μM) significantly suppressed the proliferation of KGN cells by 17%, significantly increased ROS levels by 28% and MDA levels by 47%, significantly decreased MMP levels by 22% and mtDNA copy by 30%. DEHP significantly increased protein expression of HDAC3 by 21%and HSP90AA by 64%. All these changes were significantly reversed by BSTJFs. Integrative network pharmacology analysis revealed HSP90AA was a key target (degree = 8). Both RGFP966 and BSTJF2 significantly reversed the increased expression of HDAC3 and HSP90AA, attenuated oxidative stress, and mitochondrial damage which were induced by DEHP.

CONCLUSION

BSTJFs might have therapeutic potential on oxidative stress and mitochondrial damage through the HDAC3/HSP90AA pathway which encourages further clinical trials.

Protective effect of eriodictyol against hyperglycemia-induced diabetic nephropathy in rats entails antioxidant and anti-inflammatory effects mediated by activating Nrf2

The pathogenesis of diabetic nephropathy (DN) involves cellular activation of oxidative stress and inflammation. Eriodictyol is a citrus-derived flavonoid with multiple pharmacological and protective effects in various conditions. The protective role of Eriodictyol against diabetes and diabetic nephropathy is less investigated. The current research aimed to explore the role of eriodictyol in protecting against DN prompted by streptozotocin in male rats and investigate some possible mechanisms of action. Diabetes was brought about in rats by an i.p injection of a lone dose (65 mg/kg). Five groups of rats were included (n = 8 each) as control (non-diabetic), eriodictyol (20 mg/kg, orally), STZ-diabetic, STZ + eriodictyol (20 mg/kg, orally), and STZ + eriodictyol (20 mg/kg, orally) + ML385 (30 µg/kg, i.p.). Kidney histology and the levels of some markers of kidney function, renal oxidative stress, and renal inflammation were analyzed in all groups of rats. Treatment with eriodictyol prevented the damage in the renal glomeruli and tubules and reduced renal immune cell infiltration in STZ-treated animals. It also spiked urinary creatinine excretion and reduced urine volume and urinary levels of albumin, monocyte chemoattractant protein 1 (MCP-1), urinary kidney injury molecule-1 (KIM-1), and nephrin in these diabetic rats. In addition, eriodictyol stimulated the nuclear protein accumulation of Nrf2 and boosted the expression of superoxide dismutase (SOD), glutathione (GSH), heme oxygenase-1 (HO-1), and catalase (CAT) in the diabetic rat kidneys. In concomitance, it reduced the nuclear levels of NF-κB and levels of interleukine-6 (IL-6), malondialdehyde (MDA), and tumor necrosis factor-α (TNF-α) and attenuated the reduction in renal ATP levels and the increase in the mitochondria transition pore opening (mtTPT). However, the administration of eriodictyol did not affect rats' body weights and fasting glucose and insulin levels but significantly reduced serum levels of cholesterol, triglycerides, LDL-c, and oxidized LDL-c (ox-LDL-c). In conclusion, eriodictyol prevents STZ-induced nephropathy by a hypolipidemic effect and concomitant antioxidant and anti-inflammatory effects mediated by activating Nrf2/NF-κB/antioxidant axis.

Oxidative stress and inflammation in diabetic nephropathy: role of polyphenols

Diabetic nephropathy (DN) often leads to end-stage renal disease. Oxidative stress demonstrates a crucial act in the onset and progression of DN, which triggers various pathological processes while promoting the activation of inflammation and forming a vicious oxidative stress-inflammation cycle that induces podocyte injury, extracellular matrix accumulation, glomerulosclerosis, epithelial-mesenchymal transition, renal tubular atrophy, and proteinuria. Conventional treatments for DN have limited efficacy. Polyphenols, as antioxidants, are widely used in DN with multiple targets and fewer adverse effects. This review reveals the oxidative stress and oxidative stress-associated inflammation in DN that led to pathological damage to renal cells, including podocytes, endothelial cells, mesangial cells, and renal tubular epithelial cells. It demonstrates the potent antioxidant and anti-inflammatory properties by targeting Nrf2, SIRT1, HMGB1, NF-κB, and NLRP3 of polyphenols, including quercetin, resveratrol, curcumin, and phenolic acid. However, there remains a long way to a comprehensive understanding of molecular mechanisms and applications for the clinical therapy of polyphenols.

Mechanisms of ferroptosis in Alzheimer's disease and therapeutic effects of natural plant products: A review

Neurodegenerative diseases, such as Alzheimer's disease (AD), are characterized by massive loss of specific neurons. It is a progressive disabling, severe and fatal complex disease. Due to its complex pathogenesis and limitations of clinical treatment strategies, it poses a serious medical challenge and medical burden worldwide. The pathogenesis of AD is not clear, and its potential biological mechanisms include aggregation of soluble amyloid to form insoluble amyloid plaques, abnormal phosphorylation of tau protein and formation of intracellular neurofibrillary tangles (NFT), neuroinflammation, ferroptosis, oxidative stress and metal ion disorders. Among them, ferroptosis is a newly discovered programmed cell death induced by iron-dependent lipid peroxidation and reactive oxygen species. Recent studies have shown that ferroptosis is closely related to AD, but the mechanism remains unclear. It may be induced by iron metabolism, amino acid metabolism and lipid metabolism affecting the accumulation of iron ions. Some iron chelating agents (deferoxamine, deferiprone), chloroiodohydroxyquine and its derivatives, antioxidants (vitamin E, lipoic acid, selenium), chloroiodohydroxyquine and its derivatives Fer-1, tet, etc. have been shown in animal studies to be effective in AD and exert neuroprotective effects. This review summarizes the mechanism of ferroptosis in AD and the regulation of natural plant products on ferroptosis in AD, in order to provide reference information for future research on the development of ferroptosis inhibitors.

A natural products solution to diabetic nephropathy therapy

Diabetic nephropathy is one of the most common complications in diabetes. It has been shown to be the leading cause of end-stage renal disease. However, due to their complex pathological mechanisms, effective therapeutic drugs other than angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), which have been used for 20 years, have not been developed so far. Recent studies have shown that diabetic nephropathy is characterized by multiple signalling pathways and multiple targets, including inflammation, apoptosis, pyroptosis, autophagy, oxidative stress, endoplasmic reticulum stress and their interactions. It definitely exacerbates the difficulty of therapy, but at the same time it also brings out the chance for natural products treatment. In the most recent two decades, a large number of natural products have displayed their potential in preclinical studies and a few compounds are under invetigation in clinical trials. Hence, many compounds targeting these singals have been emerged as a comprehensive blueprint for treating strategy of diabetic nephropathy. This review focuses on the cellular and molecular mechanisms of natural prouducts that alleviate this condition, including preclinical studies and clinical trials, which will provide new insights into the treatment of diabetic nephropathy and suggest novel ideas for new drug development.

Citrus nutraceutical eriocitrin and its metabolites are partial agonists of peroxisome proliferator-activated receptor gamma (PPARγ): a molecular docking and molecular dynamics study

Peroxisome proliferator-activated receptor gamma (PPARγ) agonists are potent insulin sensitizers in treating type 2 diabetes. Despite being very effective in the fight against diabetes-mediated complications, PPARγ agonists are accompanied by severe side effects leading to complicated health problems, making the discovery of novel safe ligands highly pertinent. A significant intense research effort is in progress to explore the PPARγ activating potential of a wide range of natural compounds. Lemon (Citrus limon) contains various bioactive flavonoids, and eriocitrin is the major flavonoid. It possesses substantial antioxidant and anticancer, lipid-lowering activities and prevents obesity-associated metabolic diseases. Eriocitrin is metabolized to eriodictyol in the intestine, and the absorbed eriodictyol undergoes conversion to numerous metabolites in vivo. It is unclear if eriocitrin or its metabolites are responsible for their beneficial effects. We have used molecular docking, ADMET properties, drug-likeness score and molecular dynamics simulation study to find if eriocitrin and its metabolites are potent binders for PPARγ. Docking studies revealed that eriocitrin binds to PPARγ with the highest binding energy, but ADMET properties and in vivo studies show that the bioavailability of eriocitrin is very poor. Molecular dynamics studies were carried out to validate the docking results, and multiple parameters like RMSD, RMSF, Radius of gyration, SASA, hydrogen bond analysis, interaction energy, principal component analysis, Gibbs free energy and MM-PBSA were calculated. Based on our studies, eriodictyol, eriodictyol 7-O-glucuronide, eriodictyol 3'-O-glucuronide, homoeriodictyol and homoeriodictyol 7-O-glucuronide which are metabolites of eriocitrin appear to be potent partial agonists of PPARγ under physiological conditions.Communicated by Ramaswamy H. Sarma.

Eriodictyol Suppresses Porphyromonas gingivalis-Induced Reactive Oxygen Species Production by Gingival Keratinocytes and the Inflammatory Response of Macrophages

Porphyromonas gingivalis is a key pathogen of periodontitis, an inflammatory disease that affects the tooth-supporting tissues. The aim of the present study was to investigate the effects of the flavanone eriodictyol on P. gingivalis-induced reactive oxygen species (ROS) production by gingival keratinocytes and the inflammatory response of macrophages. Porphyromonas gingivalis and H2O2 acted synergistically to induce ROS production by keratinocytes. The presence of eriodictyol significantly attenuated ROS production in a dose-dependent manner. We used a macrophage model to show that eriodictyol decreases the secretion of IL-1β, IL-6, IL-8, and TNF-α induced by P. gingivalis. Evidence has been brought that this anti-inflammatory property of eriodictyol may be related to its ability to prevent the activation of the NF-κB signaling pathway by P. gingivalis. This periodontal pathogen was also found to be a potent inducer of matrix metalloproteinase (MMP) production by macrophages, including MMP-2, MMP-8, and MMP-9. Eriodictyol dose-dependently inhibited the production of all three MMPs. Lastly, eriodictyol inhibited the catalytic activity of both MMP-9 and P. gingivalis collagenase. In conclusion, eriodictyol may be a potential therapeutic agent for preventing and/or treating periodontal disease due to its antioxidant, anti-inflammatory, and anti-proteinase properties.

Eriodictyol ameliorates cognitive dysfunction in APP/PS1 mice by inhibiting ferroptosis via vitamin D receptor-mediated Nrf2 activation

Background

Alzheimer’s disease (AD) is the most common type of neurodegenerative disease in the contemporary era, and it is still clinically incurable. Eriodictyol, a natural flavonoid compound that is mainly present in citrus fruits and some Chinese herbal medicines, has been reported to exert anti-inflammatory, antioxidant, anticancer and neuroprotective effects. However, few studies have examined the anti-AD effect and molecular mechanism of eriodictyol.

Methods

APP/PS1 mice were treated with eriodictyol and the cognitive function of mice was assessed using behavioral tests. The level of amyloid-β (Aβ) aggregation and hyperphosphorylation of Tau in the mouse brain were detected by preforming a histological analysis and Western blotting. HT-22 cells induced by amyloid-β peptide (1–42) (Aβ_1–42) oligomers were treated with eriodictyol, after which cell viability was determined and the production of p-Tau was tested using Western blotting. Then, the characteristics of ferroptosis, including iron aggregation, lipid peroxidation and the expression of glutathione peroxidase type 4 (GPX4), were determined both in vivo and in vitro using Fe straining, Western blotting and qPCR assays. Additionally, the expression level of vitamin D receptor (VDR) and the nuclear factor erythroid 2-related factor 2/heme oxygenase-1 (Nrf2/HO-1) signaling pathway were tested using Western blotting and qPCR assays. Afterward, HT-22 cells with VDR knockout were used to explore the potential mechanisms, and the relationship between VDR and Nrf2 was further assessed by performing a coimmunoprecipitation assay and bioinformatics analysis.

Results

Eriodictyol obviously ameliorated cognitive deficits in APP/PS1 mice, and suppressed Aβ aggregation and Tau phosphorylation in the brains of APP/PS1 mice. Moreover, eriodictyol inhibited Tau hyperphosphorylation and neurotoxicity in HT-22 cells induced by Aβ_1–42 oligomer. Furthermore, eriodictyol exerted an antiferroptosis effect both in vivo and in vitro, and its mechanism may be associated with the activation of the Nrf2/HO-1 signaling pathway. Additionally, further experiments explained that the activation of Nrf2/HO-1 signaling pathway by eriodictyol treatment mediated by VDR.

Conclusions

Eriodictyol alleviated memory impairment and AD-like pathological changes by activating the Nrf2/HO-1 signaling pathway through a mechanism mediated by VDR, which provides a new possibility for the treatment of AD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10020-022-00442-3.

The role of flavonoids in inhibiting IL-6 and inflammatory arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease that primarily affects the synovial joints. RA has well-known clinical manifestations and can cause progressive disability and premature death along with socioeconomic burdens. Interleukin-6 (IL-6) has been implicated in the pathology of RA where it can stimulate pannus formation, osteoclastogenesis, and oxidative stress. Flavonoids are plant metabolites with beneficial pharmacological effects, including anti-inflammatory, antioxidant, antidiabetic, anticancer, and others. Flavonoids are polyphenolic compounds found in a variety of plants, vegetables, and fruits. Many flavonoids have demonstrated anti-arthritic activity mediated mainly through the suppression of pro-inflammatory cytokines. This review thoroughly discusses the accumulate data on the role of flavonoids on IL-6 in RA.

microRNA-15b-5p shuttled by mesenchymal stem cell-derived extracellular vesicles protects podocytes from diabetic nephropathy via downregulation of VEGF/PDK4 axis

Diabetic nephropathy (DN) is a severe complication of diabetes lethal for end-stage renal disease, with less treatment methodologies and uncertain pathogenesis. In the current study, we determined the role of mesenchymal stem cells (MSCs)-derived extracellular vesicles (EVs) containing microRNA (miR)-15b-5p in DN. After extraction and identification of MSC-derived EVs, mouse podocyte line MPC5 was selected to establish an in vitro high-glucose (HG) cell model, where expression of miR-15b-5p, pyruvate dehydrogenase kinase 4 (PDK4) and VEGFA expression in tissues and cells were determined. The loss- and gain- function assays were conducted to determine the roles of miR-15b-5p, PDK4 and VEGFA. MPC5 cells were then co-cultured with MSC-derived EVs and their biological behaviors were detected by Western blot, CCK-8 assay, and flow cytometry. The binding relationship between miR-15b-5p and PDK43 by dual luciferase reporter gene assay. The expression of miR-15b-5p was downregulated in podocytes under HG environment, but highly expressed in mouse MSCs-derived EVs. EVs-derived miR-15b-5p could protect MPC5 cell apoptosis and inflammation. miR-15b-5p inhibited the expression of PDK4 by directly bound to the 3'UTR region of PDK4 gene. miR-15b-5p inhibits VEGF expression by binding to PDK4. Inhibition of PDK4 decreased VEGFA expression and reduced apoptosis and inflammation. Collectively, miR-15b-5p shuttled by MSC-derived EV can play protective roles in HG-induced mouse podocyte injury, possibly by targeting PDK4 and decreasing the VEGFA expression.

Eriodictyol attenuates TNBS-induced ulcerative colitis through repressing TLR4/NF-kB signaling pathway in rats

Ulcerative colitis (UC) is a chronic disease characterized by mucosal and submucosal inflammation, which has a low cure rate and is prone to relapse, due to the immune imbalance of the body. Inhibition of inflammation-related pathways can delay the progression of UC. Toll-like receptor 4 (TLR4) pathway is considered to be one of the important signaling pathways involved in colon inflammation. Eriodictyol (EDT) is a natural flavonoid widely distributed in foodborne plants. EDT plays an important role in the regulation of inflammation and related signaling pathways. However, whether EDT plays a role in UC remains unknown. Herein, we established a TNBS induced animal model of enteritis in Wistar rats. Our data confirmed the establishment of TNBS induced animal model of enteritis and the administration Eriodictyol in Wistar rats. EDT treatment alleviated TNBS-induced intestinal tissue injury in rats. We further found that EDT reduced MPO expression and regulated the cytokine parameters in TNBS-induced intestinal tissues of rats. The levels of TNF-α, IL-1β, IL-6, IL-10, IL-2, and IL-12 were also affected by the treatment of EDT. EDT also affected SOD, CAT, GSH-Px, and MDA level in rats with colitis. Moreover, EDT regulated TNBS-induced TLR4/NF-κB pathway activation, therefore inhibiting the progression of UC. Our results suggest that EDT could be a potential therapeutic agent for UC.

Flavonoids on diabetic nephropathy: advances and therapeutic opportunities

With the advances in biomedical technologies, natural products have attracted substantial public attention in the area of drug discovery. Flavonoids are a class of active natural products with a wide range of pharmacological effects that are used for the treatment of several diseases, in particular chronic metabolic diseases. Diabetic nephropathy is a complication of diabetes with a particularly complicated pathological mechanism that affects at least 30% of diabetic patients and represents a great burden on public health. A large number of studies have shown that flavonoids can alleviate diabetic nephropathy. This review systematically summarizes the use of common flavonoids for the treatment of diabetic nephropathy. We found that flavonoids play a therapeutic role in diabetic nephropathy mainly by regulating oxidative stress and inflammation. Nrf-2/GSH, ROS production, HO-1, TGF-β1 and AGEs/RAGE are involved in the process of oxidative stress regulation. Quercetin, apigenin, baicalin, luteolin, hesperidin, genistein, proanthocyanidin and eriodictyol were found to be capable of alleviating oxidative stress related to the aforementioned factors. Regarding inflammatory responses, IL-1, IL-6β, TNF-α, SIRT1, NF-κB, and TGF-β1/smad are thought to be essential. Quercetin, kaempferol, myricetin, rutin, genistein, proanthocyanidin and eriodictyol were confirmed to influence the above targets. As a result, flavonoids promote podocyte autophagy and inhibit the overactivity of RAAS by suppressing the upstream oxidative stress and inflammatory pathways, ultimately alleviating DN. The above results indicate that flavonoids are promising drugs for the treatment of diabetic nephropathy. However, due to deficiencies in the effect of flavonoids on metabolic processes and their lack of structural stability in the body, further research is required to address these issues.

Integrated transcriptomic and metabolomic analysis provides insight into the regulation of leaf senescence in rice

Leaf senescence is one of the most precisely modulated developmental process and affects various agronomic traits of rice. Anti-senescence rice varieties are important for breeding application. However, little is known about the mechanisms underlying the metabolic regulatory process of leaf senescence in rice. In this study, we performed transcriptomic and metabolomic analyses of the flag leaves in Yuenong Simiao (YN) and YB, two indica rice cultivars that differ in terms of their leaf senescence. We found 8524 genes/204 metabolites were differentially expressed/accumulated in YN at 30 days after flowering (DAF) compared to 0 DAF, and 8799 genes/205 metabolites were differentially expressed in YB at 30 DAF compared to 0 DAF. Integrative analyses showed that a set of genes and metabolites involved in flavonoid pathway were significantly enriched. We identified that relative accumulation of PHENYLALANINE AMMONIA-LYASE (PAL), CINNAMATE 4-HYDROXYLASE (C4H), 4-COUMAROYL-COA LIGASE (4CL), CHALCONE SYNTHASE (CHS) and CHALCONE ISOMERASE (CHI) in YN30/0 was higher than that in YB30/0. Three flavonoid derivatives, including phloretin, luteolin and eriodictyol, showed lower abundances in YB than in YN at 30 DAF. We further revealed a MYB transcription factor, which is encoded by OsR498G0101613100 gene, could suppress the expression of CHI and CHS. Our results suggested a comprehensive analysis of leaf senescence in a view of transcriptome and metabolome and would contribute to exploring the molecular mechanism of leaf senescence in rice.

Eriodictyol Attenuates MCAO-Induced Brain Injury and Neurological Deficits via Reversing the Autophagy Dysfunction

The present study was designed to investigate the protective effect of eriodictyol on MCAO-induced brain injury and its regulation of neural function and to explore the mechanism of its regulation of autophagy in rats. Brain injury was induced by middle cerebral artery occlusion (MCAO) in adult rats and pretreated with eriodictyol (low dose: 20 mg/kg; medium dose: 40 mg/kg; high dose: 80 mg/kg) or saline. Rats in the treatment group had a smaller volume of infarction and improved neurological outcome and reduced the latency to the platform, increased the time spent in the correct quadrant compared to MCAO rats pretreated with saline. ELISA kits results confirmed that eriodictyol reduced the inflammatory response induced by MCAO. The results of apoptosis and proliferation by Nissl staining and immunofluorescence detection indicated that eriodictyol could inhibit apoptosis and promote the proliferation in MCAO rats. The expressions of LC3, ATG5, p62, and Beclin1 were used to evaluate the autophagy, as well as the reversal of the autophagy activator (rapamycin) on the neuroprotective effect of eriodictyol, which suggested that the protective effect of eriodictyol on brain injury may be related to the inhibition of autophagy. In summary, we, therefore, suggested that eriodictyol could reduce the inflammation response of brain injury and inhibit neuroapoptosis, directly affecting autophagy to alleviate brain injury. It will provide theoretical support for eriodictyol in the treatment of ischemic stroke.

Chemical composition and pharmacological mechanism of ephedra-glycyrrhiza drug pair against coronavirus disease 2019 (COVID-19)

Traditional Chinese medicine (TCM) had demonstrated effectiveness in the prevention and control of COVID-19. Statistics showed that Ephedra and Glycyrrhiza were frequently used in the treatment of COVID-19. We hypothesized that the Ephedra-Glycyrrhiza drug pair is a potential choice for the treatment of COVID-19. Here, 112 active compounds were identified from Ephedra-Glycyrrhiza via network pharmacology approach. Ephedra-Glycyrrhiza pair enrichment analysis demonstrated that these compounds might participate in the cAMP, PI3K-Akt, JAK-STAT and chemokine signaling pathways, which had a high correlation with respiratory, nervous, blood circulation and digestive system-related diseases. Pathway analysis between Ephedra-Glycyrrhiza and COVID-19 showed that the key targets were TNF-α, IL2, FOS, ALB, and PTGS2. They might control PI3K-Akt signaling pathway to exert immune regulation, organ protection and antiviral effects. Molecular docking results showed that the active compounds from the Ephedra-Glycyrrhiza pair bound well to COVID-19 related targets, including the main protease (Mpro, also called 3CLpro), the spike protein (S protein), and the angiotensin-converting enzyme 2 (ACE2). The Molecular dynamics simulation was analyzed for the stability and flexibility of the complex. In conclusion, our study elucidated the potential pharmacological mechanism of Ephedra-Glycyrrhiza in the treatment of COVID-19 through multiple targets and pathways.

Anti-inflammatory phytochemicals for the treatment of diabetes and its complications: Lessons learned and future promise

Diabetes mellitus (type 1 and type 2) and its various complications continue to place a huge burden on global medical resources, despite the availability of numerous drugs that successfully lower blood glucose levels. The major challenging issue in diabetes management is the prevention of various complications that remain the leading cause of diabetes-related mortality. Moreover, the limited long-term durability of monotherapy and undesirable side effects of currently used anti-diabetic drugs underlie the urgent need for novel therapeutic approaches. Phytochemicals represent a rich source of plant-derived molecules that are of pivotal importance to the identification of compounds with therapeutic potential. In this review, we aim to discuss recent advances in the identification of a large array of phytochemicals with immense potential in the management of diabetes and its complications. Given that metabolic inflammation has been established as a key pathophysiological event that drives the progression of diabetes, we focus on the protective effects of representative phytochemicals in metabolic inflammation. This paper also discusses the potential of phytochemicals in the development of new drugs that target the inflammation in the management of diabetes and its complications.

Pharmacological Activity of Eriodictyol: The Major Natural Polyphenolic Flavanone

Eriodictyol is a flavonoid that belongs to a subclass of flavanones and is widespread in citrus fruits, vegetables, and medicinally important plants. Eriodictyol has been anticipated to explain the method of its activity via multiple cellular signaling cascades. Eriodictyol is an effective natural drug source to maintain higher health standards due to its excellent therapeutic roles in neuroprotection, cardioprotective activity, hepatoprotective activity, antidiabetes and obesity, and skin protection and having highly analgesic, antioxidant, and anti-inflammatory effects, antipyretic and antinociceptive actions, antitumor activity, and much more. This review aims to highlight the modes of action of eriodictyol against various diseases via multiple cellular signaling pathways.

Loganin alleviates macrophage infiltration and activation by inhibiting the MCP-1/CCR2 axis in diabetic nephropathy

BACKGROUND/AIMS

The theory of inflammation is one of the important theories in the pathogenesis of diabetic nephropathy (DN). We herein aimed to explore whether loganin affected macrophage infiltration and activation upon diabetic nephropathy (DN) by a spontaneous DN mice and a co-culture system of glomerular mesangial cells (GMCs) and macrophage cells (RAW264.7) which was induced by advanced glycation end products (AGEs).

METHODS AND KEY FINDINGS

Loganin showed remarkable capacity on protecting renal from damage by mitigating diabetic symptoms, improving the histomorphology of the kidney, decreasing the expression of extracellular matrix such as FN, COL-IV and TGF-β, reversing the production of IL-12 and IL-10 and decreasing the number of infiltrating macrophages in the kidney. Moreover, loganin showed markedly effects by suppressing iNOS and CD16/32 expressions (M1 markers), increasing Arg-1 and CD206 expressions (M2 markers), which were the phenotypic transformation of macrophage. These effects may be attributed to the inhibition of the receptor for AGEs (RAGE) /monocyte chemotactic protein-1 (MCP-1)/CC chemokine receptor 2 (CCR2) signaling pathway, with significantly down-regulated expressions of RAGE, MCP-1 and CCR2 by loganin. Loganin further decreased MCP-1 secretion when RAGE was silenced, which means other target was involved in regulating the MCP-1 expression. While loganin combinated with the inhibitor of CCR2 exerted stronger anti-inhibition effects of iNOS expression, suggesting that CCR2 was the target of loganin in regulating the activation of macrophages.

SIGNIFICANCE

Loganin could ameliorate DN kidney damage by inhibiting macrophage infiltration and activation via the MCP-1/CCR2 signaling pathway in DN.

LncRNA CTBP1-AS2 alleviates high glucose-induced oxidative stress, ECM accumulation, and inflammation in diabetic nephropathy via miR-155-5p/FOXO1 axis

BACKGROUND

This study aimed to investigate the involvement of lncRNA CTBP1-AS2 in the progression of diabetic nephropathy (DN) by affecting high glucose (HG)-induced human glomerular mesangial cells (HGMCs).

METHODS

HGMCs were selected for the establishment of cell injury induced by HG. The expression of CTBP1-AS2, miR-155-5p and FOXO1 was detected by real-time PCR and western blotting. The target association between miR-155-5p and CTBP1-AS2 or FOXO1 was confirmed by dual-luciferase reporter assays. Cell proliferation and oxidative stress were revealed by CCK-8 colorimetry, and the measurement of reactive oxygen species (ROS) and the activities of antioxidant enzymes. Extracellular matrix (ECM) protein accumulation and the production of inflammatory cytokines were investigated by western blotting and ELISA.

RESULTS

The expression of CTBP1-AS2 was downregulated, and miR-155-5p was highly expressed in peripheral blood of DN patients and HG-treated HGMCs. Further investigation revealed that CTBP1-AS2 overexpression inhibited proliferation, oxidative stress, ECM accumulation and inflammatory response in HG-induced HGMCs. Mechanical analysis revealed that CTBP1-AS2 regulated FOXO1 expression via sponging miR-155-5p. Rescue experiments demonstrated that miR-155-5p overexpression or FOXO1 inhibition reversed the effects of CTBP1-AS2 in HG-stimulated HGMCs.

CONCLUSION

Taken together, this study revealed CTBP1-AS2 attenuated HG-induced HGMC proliferation, oxidative stress, ECM accumulation, and inflammation through miR-155-5p/FOXO1 signaling.

Transcriptomic Analysis Reveals the Protection of Astragaloside IV against Diabetic Nephropathy by Modulating Inflammation

Background

Diabetic nephropathy (DN) is one of the leading causes of end-stage kidney disease. Recently, there is no specific drug available to block the kidney damage. Astragaloside IV (AS-IV) is a major active component of Astragalus membranaceus (Fisch) Bge and has been demonstrated to benefit the kidney functions. This study explores the potential pharmacological action of AS-IV in DN of rats.

Methods

Male Sprague-Dawley rats were fed with high-fat diet and injected with streptozotocin to induce diabetes. The diabetic rats were randomized and treated with vehicle or AS-IV (80 mg/kg) daily by gavage for 12 weeks as the DN or AS-IV group, respectively. The normal control rats were fed with normal chow and injected with vehicles (n = 8 per group). These rats were monitored for diabetes- and kidney function-related measures. The expression profiles of gene mRNA transcripts in the kidney tissues were analyzed by RNA-seq and quantitative RT-PCR. The levels of advanced glycation end products (AGEs), IL-1β, and IL-18 in the serum samples and kidney tissues were quantified by ELISA. The levels of collagen IV (COL-4) and fibronectin (FN) expression in kidney tissues were examined by immunohistochemistry and Western blot.

Results

In comparison with the DN group, AS-IV treatment significantly reduced blood glucose levels, food and water consumption, 24 h urine, renal index values, 24 h urine total proteins, blood urea nitrogen (BUN) levels, and creatinine clearance rates (CCR), accompanied by minimizing the DN-induced early kidney damages, fibrosis, and microstructural changes. Furthermore, AS-IV treatment significantly modulated the DN-altered gene transcription profiles in the kidney of rats, particularly for inflammation-related genes, including the nucleotide-binding oligomerization domain-like receptor signaling, which was validated by quantitative RT-PCR. AS-IV treatment significantly decreased the levels of serum and kidney AGEs, IL-1β, and IL-18 expression and fibrosis indexes in the kidney of rats.

Conclusion

AS-IV treatment ameliorated the severity of DN by inhibiting inflammation-related gene expression in the kidney of rats.

The pharmacological and biological roles of eriodictyol

Eriodictyol is a flavonoid in the flavanones subclass. It is abundantly present in a wide range of medicinal plants, citrus fruits, and vegetables that are considered to have potential health importance. Having the considerable medicinal properties, eriodictyol has been predicted to clarify the mode of action in various cellular and molecular pathways. Evidence for the existing therapeutic roles of eriodictyol includes antioxidant, anti-inflammatory, anti-cancer, neuroprotective, cardioprotective, anti-diabetic, anti-obesity, hepatoprotective, and miscellaneous. Therefore, this review aims to present the recent evidence regarding the mechanisms of action of eriodictyol in different signaling pathways in a specific disease condition. In view of the immense therapeutic effects, eriodictyol may serve as a potential drug source to enhance community health standards.

HMGB1 mediates lipopolysaccharide-induced inflammation via interacting with GPX4 in colon cancer cells

Background

Inflammation is one of a main reason for colon cancer progression and poor prognosis. The high-mobility group box-1 (HMGB1) and glutathione peroxidase 4 (GPX4) are responsible for inflammation, but the relationship between HMGB1 and GPX4 remains unknown about inflammation in colon cancer.

Methods

RT-qPCR was carried out to investigate the expression of IL1β, IL6 and TNFα in colon cancer cells stimulated with LPS or siHMGB1. To observe the relationship between HMGB1, GPX4 and inflammation or ROS, Western blot assays were adopted. Pull-down, CoIP and immunohistochemistry assays were performed to further investigate the molecular mechanisms of HMGB1 and GPX4 in colon cancer.

Results

We report that HMGB1 mediates lipopolysaccharide (LPS)-induced inflammation in colon cancer cells. Mechanistically, acetylated HMGB1 interacts with GPX4, negatively regulating GPX4 activity. Furthermore, by utilizing siHMGB1 and its inhibitor, our discoveries demonstrate that HMGB1 knockdown can inhibit inflammation and reactive oxygen species (ROS) accumulation via NF-kB.

Conclusion

Collectively, our findings first demonstrate that acetylated HMGB1 can interact with GPX4, leading to inflammation, and providing therapeutic strategies targeting HMGB1 and GPX4 for colon cancer.

NADPH oxidase: A membrane-bound enzyme and its inhibitors in diabetic complications

The human body has a mechanism for balancing the generation and neutralization of reactive oxygen species. The body is exposed to many agents that are responsible for the generation of reactive oxygen/nitrogen species, which leads to disruption of the balance between generation of these species and oxidative stress defence mechanisms. Diabetes is a chronic pathological condition associated with prolonged hyperglycaemia. Prolonged elevation of level of glucose in the blood leads to the generation of reactive oxygen species. This generation of reactive oxygen species is responsible for the development of diabetic vasculopathy, which includes micro- and macrovascular diabetic complications. Nicotinamide adenine dinucleotide phosphate oxidase (NOX) is a membrane-bound enzyme responsible for the development of reactive oxygen species in hyperglycaemia. Phosphorylation of the cytosolic components of NOX, such as p47phox, p67phox, and RAC-1, in hyperglycaemia is one of the important causes of conversion of oxygen to reactive oxygen. Overexpression of NOX in pathological conditions is associated with activation of aldose reductase, advanced glycation end products, protein kinase C and the hexosamine pathway. In addition, NOX also promotes the activation of inflammatory cytokines, such as TGF-β, TNF-α, NF-kβ, IL-6, and IL-18, the activation of endothelial growth factors, such as VEGF and FGF, hyperlipidaemia, and the deposition of collagen. Thus, overexpression of NOX is linked to the development of diabetic complications. The present review focuses on the role of NOX, its associated pathways, and various NOX inhibitors in the management and treatment of diabetic complications, such as diabetic nephropathy, retinopathy, neuropathy and cardiomyopathy.

Inhibition of NADPH Oxidase 5 (NOX5) Suppresses High Glucose-Induced Oxidative Stress, Inflammation and Extracellular Matrix Accumulation in Human Glomerular Mesangial Cells

Background

The aim of this study was to explore the effects of NADPH oxidase 5 (NOX5) in high glucose-stimulated human glomerular mesangial cells (HMCs).

Material/Methods

Cells were cultured under normal glucose (NG) or high glucose (HG) conditions. Then, NOX5 siRNA was transfected into HG-treated HMCs. A Cell Counting Kit-8 assay, colony formation assay and 5-ethynyl-20-deoxyuridine (EDU) incorporation assay were applied to measure cell proliferative ability. In addition, the levels of oxidative stress factors including reactive oxygen species (ROS), malonaldehyde (MDA), NADPH, superoxide dismutase (SOD), and glutathione peroxidase (GSH-PX), inflammatory cytokines including tumor necrosis factor-alpha (TNF-α), interleukin (IL)-6, IL-1β, and monocyte chemoattractant protein-1 (MCP-1) in HMCs were detected by kits. Moreover, the expression of TLR4/NF-κB signaling and extracellular matrix (ECM) associated genes were evaluated by western blotting.

Results

The results revealed that the NOX5 was overexpressed in HG-treated HMCs. Silencing of NOX5 decreased proliferation of HMCs induced by HG. And NOX5 silencing alleviated the production of MDA and NADPH accompanied by an increase of SOD and GSH-PX levels. Additionally, the contents of TNF-α, IL-6, IL-1β, and MCP-1 were reduced after transfection with NOX5 siRNA. Furthermore, silencing of NOX5 deceased the expression of collagen I, collagen IV, TGF-β1, and fibronectin induced by HG stimulation. TLR4, MyD88, and phospho-NF-κB p65 expression were downregulated notably in NOX5 silencing group.

Conclusions

Taken together, these findings demonstrated that inhibition of NOX5 attenuated HG-induced HMCs oxidative stress, inflammation, and ECM accumulation, suggesting that NOX5 may serve as a potential therapeutic target for diabetic nephropathy (DN) treatment.