Esculetin ameliorates insulin resistance and type 2 diabetic nephropathy through reversal of histone H3 acetylation and H2A lysine 119 monoubiquitination

Chinese botanical drugs targeting mitophagy to alleviate diabetic kidney disease, a comprehensive review

Diabetic kidney disease (DKD) is one of the chronic microvascular complications caused by diabetes, which is characterized by persistent albuminuria and/or progressive decline of estimated glomerular filtration rate (eGFR), and has been the major cause of dialysis around the world. At present, although the treatments for DKD including lifestyle modification, glycemic control and even using of Sodium-glucose cotransporter 2 (SGLT2) inhibitors can relieve kidney damage caused to a certain extent, there is still a lack of effective treatment schemes that can prevent DKD progressing to ESRD. It is urgent to find new complementary and effective therapeutic agents. Growing animal researches have shown that mitophagy makes a great difference to the pathogenesis of DKD, therefore, exploration of new drugs that target the restoration of mitophagy maybe a potential perspective treatment for DKD. The use of Chinese botanical drugs (CBD) has been identified to be an effective treatment option for DKD. There is growing concern on the molecular mechanism of CBD for treatment of DKD by regulating mitophagy. In this review, we highlight the current findings regarding the function of mitophagy in the pathological damages and progression of DKD and summarize the contributions of CBD that ameliorate renal injuries in DKD by interfering with mitophagy, which will help us further explain the mechanism of CBD in treatment for DKD and explore potential therapeutic strategies for DKD.

Network pharmacology combined with molecular docking and dynamics to assess the synergism of esculetin and phloretin against acute kidney injury-diabetes comorbidity

Acute kidney injury (AKI) is a global health concern with high incidence and mortality, where diabetes further worsens the condition. The available treatment options are not uniformly effective against the complex pathogenesis of AKI-diabetes comorbidity. Hence, combination therapies based on the multicomponent, multitarget approach can tackle more than one pathomechanism and can aid in AKI-diabetes comorbidity management. This study aimed to investigate the therapeutic potential of esculetin and phloretin combination against AKI-diabetes comorbidity by network pharmacology followed by validation by molecular docking and dynamics. The curative targets for diabetes, AKI, esculetin, and phloretin were obtained from DisGeNET, GeneCards, SwissTargetPrediction database. Further, the protein-protein interaction of the potential targets of esculetin and phloretin against AKI-diabetes comorbidity was investigated using the STRING database. Gene ontology and pathway enrichment analysis were performed with the help of the DAVID and KEGG databases, followed by network construction and analysis via Cytoscape. Molecular docking and dynamic simulations were performed to validate the targets of esculetin and phloretin against AKI-diabetes comorbidity. We obtained 6341 targets for AKI-diabetes comorbidity. Further, a total of 54 and 44 targets of esculetin and phloretin against AKI-diabetes comorbidity were retrieved. The top 10 targets for esculetin selected based on the degree value were AKR1B1, DAO, ESR1, PLK1, CA3, CA2, CCNE1, PRKN, HDAC2, and MAOA. Similarly, phloretin's 10 key targets were ACHE, CDK1, MAPK14, APP, CDK5R1, CCNE1, MAOA, MAOB, HDAC6, and PRKN. These targets were enriched in 58 pathways involved in the pathophysiology of AKI-diabetes comorbidity. Further, esculetin and phloretin showed an excellent binding affinity for these critical targets. The findings of this study suggest that esculetin and phloretin combination as a multicomponent multitarget therapy has the potential to prevent AKI-diabetes comorbidity.

Renoprotective effect of esculetin against ischemic acute kidney injury-diabetic comorbidity

Mitophagy maintains cellular homeostasis by eliminating damaged mitochondria. Accumulated damaged mitochondria can lead to oxidative stress and cell death. Induction of the PINK1/Parkin-mediated mitophagy is reported to be renoprotective in acute kidney injury (AKI). Esculetin, a naturally available coumarin, has shown protective action against diabetic complications. However, its effect on AKI-diabetes comorbidity has not been explored yet. Therefore, we aimed to investigate the renoprotective effect of esculetin against AKI under diabetic conditions via regulating PINK1/Parkin-mediated mitophagy. For this, type 1 diabetic male Wistar rats were treated with two doses of esculetin (50 and 100 mg/kg/day orally) for five days followed by AKI induction by bilateral ischemic-reperfusion injury (IRI). NRK-52E cells grown in high glucose were exposed to sodium azide (10 mM) for induction of hypoxia/reperfusion injury (HRI) in-vitro. Esculetin (50 µM) treatment for 24 h was given to the cells before HRI. The in-vitro samples were utilized for cell viability and ΔΨm assay, immunoblotting, and immunofluorescence. Rats' plasma, urine, and kidney samples were collected for biochemical analysis, histopathology, and western blotting. Our results showed a significant decrease in kidney injury-specific markers and increased expression of mitophagy markers (PINK1 and Parkin) with esculetin treatment. Moreover, esculetin prevented the HRI and hyperglycemia-induced decrease in ΔΨm and autophagosome marker. Also, esculetin therapy reduced oxidative stress via increased Nrf2 and Keap1 expression. Esculetin attenuated AKI under diabetic condition by preventing mitochondrial dysfunction via inducing PINK1/Parkin-mediated mitophagy, suggesting its potential as an effective therapy for preventing AKI-diabetes comorbidity.

Nutraceuticals and network pharmacology approach for acute kidney injury: A review from the drug discovery aspect

Acute kidney injury (AKI) has become a global health issue, with ~12 million reports yearly, resulting in a persistent increase in morbidity and mortality rates. AKI pathophysiology is multifactorial involving oxidative stress, mitochondrial dysfunction, epigenetic modifications, inflammation, and eventually, cell death. Hence, therapies able to target multiple pathomechanisms can aid in AKI management. To change the drug discovery framework from "one drug, one target" to "multicomponent, multitarget," network pharmacology is evolving as a next-generation research approach. Researchers have used the network pharmacology approach to predict the role of nutraceuticals against different ailments including AKI. Nutraceuticals (herbal products, isolated nutrients, and dietary supplements) belong to the pioneering category of natural products and have shown protective action against AKI. Nutraceuticals have recently drawn attention because of their ability to provide physiological benefits with less toxic effects. This review emphasizes the nutraceuticals that exhibited renoprotection against AKI and can be used either as monotherapy or adjuvant with conventional therapies to boost their effectiveness and lessen the adverse effects. Additionally, the study sheds light on the application of network pharmacology as a cost-effective and time-saving approach for the therapeutic target prediction of nutraceuticals against AKI.

Therapeutic Potential of Phenolic Compounds in Medicinal Plants-Natural Health Products for Human Health

Phenolic compounds and flavonoids are potential substitutes for bioactive agents in pharmaceutical and medicinal sections to promote human health and prevent and cure different diseases. The most common flavonoids found in nature are anthocyanins, flavones, flavanones, flavonols, flavanonols, isoflavones, and other sub-classes. The impacts of plant flavonoids and other phenolics on human health promoting and diseases curing and preventing are antioxidant effects, antibacterial impacts, cardioprotective effects, anticancer impacts, immune system promoting, anti-inflammatory effects, and skin protective effects from UV radiation. This work aims to provide an overview of phenolic compounds and flavonoids as potential and important sources of pharmaceutical and medical application according to recently published studies, as well as some interesting directions for future research. The keyword searches for flavonoids, phenolics, isoflavones, tannins, coumarins, lignans, quinones, xanthones, curcuminoids, stilbenes, cucurmin, phenylethanoids, and secoiridoids medicinal plant were performed by using Web of Science, Scopus, Google scholar, and PubMed. Phenolic acids contain a carboxylic acid group in addition to the basic phenolic structure and are mainly divided into hydroxybenzoic and hydroxycinnamic acids. Hydroxybenzoic acids are based on a C6-C1 skeleton and are often found bound to small organic acids, glycosyl moieties, or cell structural components. Common hydroxybenzoic acids include gallic, syringic, protocatechuic, p-hydroxybenzoic, vanillic, gentistic, and salicylic acids. Hydroxycinnamic acids are based on a C6-C3 skeleton and are also often bound to other molecules such as quinic acid and glucose. The main hydroxycinnamic acids are caffeic, p-coumaric, ferulic, and sinapic acids.

Targeting epigenetic regulators for treating diabetic nephropathy

Diabetes is accompanied by the worsening of kidney functions. The reasons for kidney dysfunction mainly include high blood pressure (BP), high blood sugar levels, and genetic makeup. Vascular complications are the leading cause of the end-stage renal disorder (ESRD) and death of diabetic patients. Epigenetics has emerged as a new area to explain the inheritance of non-mendelian conditions like diabetic kidney diseases. Aberrant post-translational histone modifications (PTHMs), DNA methylation (DNAme), and miRNA constitute major epigenetic mechanisms that progress diabetic nephropathy (DN). Increased blood sugar levels alter PTHMs, DNAme, and miRNA in kidney cells results in aberrant gene expression that causes fibrosis, accumulation of extracellular matrix (ECM), increase in reactive oxygen species (ROS), and renal injuries. Histone acetylation (HAc) and histone deacetylation (HDAC) are the most studied epigenetic modifications with implications in the occurrence of kidney disorders. miRNAs induced by hyperglycemia in renal cells are also responsible for ECM accumulation and dysfunction of the glomerulus. In this review, we highlight the role of epigenetic modifications in DN progression and current strategies employed to ameliorate DN.

Pharmacologically Active Phytomolecules Isolated from Traditional Antidiabetic Plants and Their Therapeutic Role for the Management of Diabetes Mellitus

Diabetes mellitus is a chronic complication that affects people of all ages. The increased prevalence of diabetes worldwide has led to the development of several synthetic drugs to tackle this health problem. Such drugs, although effective as antihyperglycemic agents, are accompanied by various side effects, costly, and inaccessible to the majority of people living in underdeveloped countries. Medicinal plants have been used traditionally throughout the ages to treat various ailments due to their availability and safe nature. Medicinal plants are a rich source of phytochemicals that possess several health benefits. As diabetes continues to become prevalent, health care practitioners are considering plant-based medicines as a potential source of antidiabetic drugs due to their high potency and fewer side effects. To better understand the mechanism of action of medicinal plants, their active phytoconstituents are being isolated and investigated thoroughly. In this review article, we have focused on pharmacologically active phytomolecules isolated from medicinal plants presenting antidiabetic activity and the role they play in the treatment and management of diabetes. These natural compounds may represent as good candidates for a novel therapeutic approach and/or effective and alternative therapies for diabetes.

Inhibition of endoplasmic reticulum stress combined with activation of angiotensin-converting enzyme 2: novel approach for the prevention of endothelial dysfunction in type 1 diabetic rats

Persistent hyperglycemia in type 1 diabetes triggers numerous signaling pathways, which may prove deleterious to the endothelium. As hyperglycemia damages the endothelial layer via multiple signaling pathways, including enhanced oxidative stress, downregulation of angiotensin-converting enzyme 2 signaling, and exacerbation of endoplasmic reticulum (ER) stress, it becomes difficult to prevent injury using monotherapy. Thus, the present study was conceived to evaluate the combined effect of ER stress inhibition along with angiotensin-converting enzyme 2 activation, two major contributors to hyperglycemia-induced endothelial dysfunction, in preventing endothelial dysfunction associated with type 1 diabetes. Streptozotocin-induced diabetic animals were treated with either diminazene aceturate (5 mg·kg-1 per day, p.o.) or tauroursodeoxycholic acid, sodium salt (200 mg·kg-1 per day i.p.), or both for 4 weeks. Endothelial dysfunction was evaluated using vasoreactivity assay, where acetylcholine-induced relaxation was assessed in phenylephrine pre-contracted rings. Combination therapy significantly improved vascular relaxation when compared with diabetic control as well as monotherapy. Restoration of nitrite levels along with prevention of collagen led to improved vasodilatation. Moreover, there was an overall reduction in aortic oxidative stress. We conclude that by simultaneously inhibiting ER stress and activating angiotensin-converting enzyme 2 deleterious effects of hyperglycemia on endothelium were significantly alleviated. This could serve as a novel strategy for the prevention of endothelial dysfunction.

Antidiabetic Effects of Arginyl-Fructosyl-Glucose, a Nonsaponin Fraction from Ginseng Processing in Streptozotocin-Induced Type 2 Diabetic Mice through Regulating the PI3K/AKT/GSK-3β and Bcl-2/Bax Signaling Pathways

Streptozotocin- (STZ-) induced type 2 diabetes mellitus (T2DM) caused insulin secretion disorder and hyperglycemia, further causing tissue and organ damage. In recent years, studies on ginseng (Panax ginseng C. A. Meyer) and its saponins (Ginsenosides) have proved to possess antidiabetic pharmacological activities, but the mechanism of nonsaponins on STZ-induced T2DM is still unclear. Arginyl-fructosyl-glucose (AFG) is a representative nonsaponin component produced in the processing of red ginseng. The present study was designed to assess the possible healing consequence of AFG on STZ-induced T2DM in mice and also to explore its fundamental molecular contrivances. T2DM-related indexes, fasting blood glucose levels, and body weight, histological changes, biochemical considerations, biomarkers, the mRNA countenance intensities of inflammatory facts, and variations in correlated protein manifestation in adipose tissue and liver tissue were calculated. Consequences specified that AFG usage successfully amends STZ-induced insulin conflict and liver grievance in T2DM. Systematically, AFG action diminished STZ-induced oxidative stress and inflammatory responses in the liver. In addition, we demonstrated that AFG also attenuates apoptosis and insulin secretion disorders in T2DM by adjusting the PI3K/AKT/GSK3β signaling pathway. At the end, these discoveries recommend that AFG averts the development of T2DM through numerous types of machinery and proposes that AFG can also be used in order to treat T2DM in the future.

Histone Acetylation Regulates Natriuretic Peptides and Neprilysin Gene Expressions in Diabetic Cardiomyopathy and Nephropathy

BACKGROUND

Natriuretic peptide system (NPS) alterations are involved in pathogenesis of diabetic cardiomyopathy (DCM) and nephropathy (DN), however its epigenetic regulation is still unclear. Interestingly, histone acetylation epigenetically regulates neprilysin expression in Alzheimer's disease.

OBJECTIVES

The present study was aimed at delineating role of histone acetylation in regulation of NPS in DCM and DN.

METHODS

Streptozotocin (55 mg/kg, i.p.)-induced diabetic male Wistar rats were used to mimic pathogenesis of DCM and DN. After haemodynamic measurements, all the rat's plasma, heart and kidney were collected for biochemistry, ELISA, protein isolation and western blotting, RT-PCR and chromatin immunoprecipitation (ChIP) assay.

RESULTS

Diabetic rats heart and kidney exhibited activation of NF-κB and TGF-β signalling with increased histone acetyl transferases (PCAF/CBP) expressions and augmented H2AK5Ac, H2BK5Ac, H3K18Ac, and H4K8Ac levels. ChIP assay results showed increased enrichment of H3K18Ac and H2BK5Ac at Nppa, Nppb (Heart) and Mme promoter (Heart/Kidney) in diabetic rats. Enrichment of H2AK5Ac was augmented on Nppa and Mme promoters in diabetic heart, while it remained unchanged on Nppb promoter in heart and Mme promoter in kidney.

CONCLUSION

Augmented histone acetylation at promoter regions of NPS gene(s), at least in a part, is responsible for increased expressions of ANP, BNP and NEP in diabetic heart and kidney. Hence, histone acetylation inhibitors can be considered as novel therapeutic targets against DCM and DN.

Diabetic nephropathy: The regulatory interplay between epigenetics and microRNAs

Diabetic nephropathy (DN) is still one of the leading causes of end-stage renal disease despite the emergence of different therapies to counter the metabolic, hemodynamic and fibrotic pathways, implicating a prominent role of genetic and epigenetic factors in its progression. Epigenetics is the study of changes in the expression of genes which may be inheritable and does not involve a change in the genome sequence. Thrust areas of epigenetic research are DNA methylation and histone modifications. Noncoding RNAs (ncRNAs), particularly microRNAs (miRNAs) control the expression of genes via post-transcriptional mechanisms. However, the regulation by epigenetic mechanisms and miRNAs are not completely distinct. A number of emerging reports have revealed the interplay between epigenetic machinery and miRNA expression, particularly in cancer. Further research has proved that a feedback loop exists between miRNA expression and epigenetic regulation in disorders including DN. Studies showed that different miRNAs (miR-200, miR-29 etc.) were found to be regulated by epigenetic mechanisms viz. DNA methylation and histone modifications. Conversely, miRNAs (miR-301, miR-449 etc.) themselves modulated levels of DNA methyltranferases (DNMTs) and Histone deacetylases (HDACs), enzymes vital to epigenetic modifications. With already few FDA approved epigenetic -modulating drugs (Vorinostat, Decitabine) in the market and miRNA therapeutic drugs under clinical trial it becomes imperative to analyze the possible interaction between the two classes of drugs in the modulation of a disease process. The purpose of this review is to articulate the interplay between miRNA expression and epigenetic modifications with a particular focus on its impact on the development and progression of DN.