Genistein Ameliorates Ischemia/Reperfusion-Induced Renal Injury in a SIRT1-Dependent Manner

N6-methyladenosine (m6A) methylation in kidney diseases: Mechanisms and therapeutic potential

The N6-methyladenosine (m6A) modification is regulated by methylases, commonly referred to as "writers," and demethylases, known as "erasers," leading to a dynamic and reversible process. Changes in m6A levels have been implicated in a wide range of cellular processes, including nuclear RNA export, mRNA metabolism, protein translation, and RNA splicing, establishing a strong correlation with various diseases. Both physiologically and pathologically, m6A methylation plays a critical role in the initiation and progression of kidney disease. The methylation of m6A may also facilitate the early diagnosis and treatment of kidney diseases, according to accumulating research. This review aims to provide a comprehensive overview of the potential role and mechanism of m6A methylation in kidney diseases, as well as its potential application in the treatment of such diseases. There will be a thorough examination of m6A methylation mechanisms, paying particular attention to the interplay between m6A writers, m6A erasers, and m6A readers. Furthermore, this paper will elucidate the interplay between various kidney diseases and m6A methylation, summarize the expression patterns of m6A in pathological kidney tissues, and discuss the potential therapeutic benefits of targeting m6A in the context of kidney diseases.

The potential renoprotective effect of Raloxifene in renal ischemia-reperfusion injury in a male rat model

Renal ischemia-reperfusion injury is caused by a temporary reduction in oxygen-carrying blood flow to the kidney, followed by reperfusion. During ischemia, kidney tissue damage induces overproduction of reactive oxygen species, which produces oxidative stress. The blood flow restoration during the reperfusion period causes further production of reactive oxygen species that ends with apoptosis and cell death. This study aimed to investigate the potential renoprotective effects of Raloxifene on bilateral renal ischemia-reperfusion injury in rats by looking into kidney function biomarkers, urea and creatinine, inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β). Additionally, antioxidant markers such as total antioxidant capacity (TAC) and the pro-apoptotic marker caspase-3 were assessed. Histopathological scores were also employed for evaluation. Our experimental design involved 20 rats divided into four groups: the sham group underwent median laparotomy without ischemia induction, the control group experienced bilateral renal ischemia for 30 minutes followed by 2 hours of reperfusion, the vehicle group received pretreatment with a mixture of corn oil and dimethyl sulfoxide (DMSO) before ischemia induction, and the Raloxifene-treated group was administered Raloxifene at a dose of 10 mg/kg before ischemia induction, followed by ischemia-reperfusion. Urea and creatinine, TNF-α, IL-1β, and caspase-3 in the Raloxifene group were significantly lower compared to the control and vehicle groups. On the other hand, TAC levels in the Raloxifene group were significantly higher than in the control and vehicle groups. This study concluded that Raloxifene had a renoprotective impact via multiple actions as an anti-inflammatory, anti-apoptotic, and antioxidant agent.

Atrazine Toxicity: The Possible Role of Natural Products for Effective Treatment

There are various herbicides which were used in the agriculture industry. Atrazine (ATZ) is a chlorinated triazine herbicide that consists of a ring structure, known as the triazine ring, along with a chlorine atom and five nitrogen atoms. ATZ is a water-soluble herbicide, which makes it capable of easily infiltrating into majority of the aquatic ecosystems. There are reports of toxic effects of ATZ on different systems of the body but, unfortunately, majority of these scientific reports were documented in animals. The herbicide was reported to enter the body through various routes. The toxicity of the herbicide can cause deleterious effects on the respiratory, reproductive, endocrine, central nervous system, gastrointestinal, and urinary systems of the human body. Alarmingly, few studies in industrial workers showed ATZ exposure leading to cancer. We embarked on the present review to discuss the mechanism of action of ATZ toxicity for which there is no specific antidote or drug. Evidence-based published literature on the effective use of natural products such as lycopene, curcumin, Panax ginseng, Spirulina platensis, Fucoidans, vitamin C, soyabeans, quercetin, L-carnitine, Telfairia occidentalis, vitamin E, Garcinia kola, melatonin, selenium, Isatis indigotica, polyphenols, Acacia nilotica, and Zingiber officinale were discussed in detail. In the absence of any particular allopathic drug, the present review may open the doors for future drug design involving the natural products and their active compounds.

Role of polyphenolic compounds and their nanoformulations: a comprehensive review on cross-talk between chronic kidney and cardiovascular diseases

Chronic kidney disease (CKD) affects a huge portion of the world's population and frequently leads to cardiovascular diseases (CVDs). It might be because of common risk factors between chronic kidney disease and cardiovascular diseases. Renal dysfunction caused by chronic kidney disease creates oxidative stress which in turn leads to cardiovascular diseases. Oxidative stress causes endothelial dysfunction and inflammation in heart which results in atherosclerosis. It ends in clogging of veins and arteries that causes cardiac stroke and myocardial infarction. To develop an innovative therapeutic approach and new drugs to treat these diseases, it is important to understand the pathophysiological mechanism behind the CKD and CVDs and their interrelationship. Natural phytoconstituents of plants such as polyphenolic compounds are well known for their medicinal value. Polyphenols are plant secondary metabolites with immense antioxidant properties, which can protect from free radical damage. Nowadays, polyphenols are generating a lot of buzz in the scientific community because of their potential health benefits especially in the case of heart and kidney diseases. This review provides a detailed account of the pathophysiological link between CKD and CVDs and the pharmacological potential of polyphenols and their nanoformulations in promoting cardiovascular and renal health.

Genistein attenuates renal ischemia-reperfusion injury via ADORA2A pathway

BACKGROUND

Studies have shown oxidative stress and apoptosis are the main pathogenic mechanisms of renal ischemia/reperfusion (IR) injury (IRI). Genistein, a polyphenolic non-steroidal compound, has been extensively explored in oxidative stress, inflammation and apoptosis. Our research aims to reveal the potential role of genistein on renal IRI and its potential molecular mechanism both in vivo and in vitro.

METHODS

In vivo experiments, mice were pretreated with or without genistein. Renal pathological changes and function, cell proliferation, oxidative stress and apoptosis were measured. In vitro experiments, overexpression of ADORA2A and knockout of ADORA2A cells were constructed. Cells proliferation, oxidative stress and apoptosis were analyzed.

RESULTS

Our results in vivo showed that the renal damage induced by IR was ameliorated by genistein pretreatment. Moreover, ADORA2A was activated by genistein, along with inhibition of oxidative stress and apoptosis. The results in vitro showed that genistein pretreatment and ADORA2A overexpression reversed the increase of apoptosis and oxidative stress in NRK-52E cells induced by H/R, while the knockdown of ADORA2A partially weakened this reversal from genistein treatment.

CONCLUSIONS

Our results demonstrated that genistein have a protective effect against renal IRI by inhibiting oxidative stress and apoptosis via activating ADORA2A, presenting its potential use for the treatment of renal IRI.

NEPHROPROTECTIVE EFFECT OF OLMESARTAN ON RENAL ISCHEMIA REPERFUSION INJURY IN MALE RATS: THE ROLE OF NRF2/HO-1 SIGNALING PATHWAY

OBJECTIVE

The aim: To investigate the Nephroprotective potential of Olmesartan in RIRI via modulation of the Nrf2/OH-1 signaling pathway.

PATIENTS AND METHODS

Materials and methods: Thirty male rats were equally divided into four groups. The sham group was exposed to surgical conditions without induction of RIRI. The control group was exposed to ischemia by clamping the renal pedicles for 30 min, followed by 2h of blood restoration. The vehicle-treated group was received dimethyl sulfoxide (DMSO) by intraperitoneal injection (IP) 30 min before clamping.

RESULTS

Results: Olmesartan-treated group was pretreated with Olmesartan a dose of 10 mg/kg IP; 30 min prior to induction of ischemia. Following 30 min of ischemia, the clamps were released and allowed to the reperfusion for 2 h. Blood samples were collected to examine the levels of serum urea and creatinine. Kidney tissue was used to measure the levels of cytokines (TNFα, IL6, MCP, BAX, BCL2 and isoprostane F2. Immunohistochemistry was used to assess the levels of Nrf2 and HO-1. Histological analyses were used to detect the tubular damage in the kidney.

CONCLUSION

Conclusions: The results showed that Olmesartan alleviates renal tissue damage through activating the antioxidant effect mediated by Nrf2 signaling.

Cellular senescence in ischemia/reperfusion injury

Ischemia/reperfusion (IR) injury, a main reason of mortality and morbidity worldwide, occurs in many organs and tissues. As a result of IR injury, senescent cells can accumulate in multiple organs. Increasing evidence shows that cellular senescence is the underlying mechanism that transforms an acute organ injury into a chronic one. Several recent studies suggest senescent cells can be targeted for the prevention or elimination of acute and chronic organ injury induced by IR. In this review, we concisely introduce the underlying mechanism and the pivotal role of premature senescence in the transition from acute to chronic IR injuries. Special focus is laid on recent advances in the mechanisms as well as on the basic and clinical research, targeting cellular senescence in multi-organ IR injuries. Besides, the potential directions in this field are discussed in the end. Together, the recent advances reviewed here will act as a comprehensive overview of the roles of cellular senescence in IR injury, which could be of great significance for the design of related studies, or as a guide for potential therapeutic target.

Effects of Genistein on Common Kidney Diseases

Genistein is a naturally occurring phytoestrogen (soy or soybean products) that is classified as an isoflavone, and its structure is similar to that of endogenous estrogens; therefore, genistein can exert an estrogen-like effect via estrogen receptors. Additionally, genistein is a tyrosine kinase inhibitor, which enables it to block abnormal cell growth and proliferation signals through the inhibition of tyrosine kinase. Genistein is also an angiogenesis inhibitor and an antioxidant. Genistein has effects on kidney cells, some of the kidney’s physiological functions, and a variety of kidney diseases. First, genistein exerts a protective effect on normal cells by reducing the inflammatory response, inhibiting apoptosis, inhibiting oxidative stress, inhibiting remodeling, etc., but after cell injury, the protective effect of genistein decreases or even has the opposite effect. Second, genistein can regulate renin intake to maintain blood pressure balance, regulate calcium uptake to regulate Ca²⁺ and Pi balances, and reduce vasodilation to promote diuresis. Third, genistein has beneficial effects on a variety of kidney diseases (including acute kidney disease, kidney cancer, and different chronic kidney diseases), such as reducing symptoms, delaying disease progression, and improving prognosis. Therefore, this paper reviews animal and human studies on the protective effects of genistein on the kidney in vivo and in vitro to provide a reference for clinical research in the future.

The Effect of Genistein on Anastomotic Healing in Intestinal Ischemia/Reperfusion Injury

INTRODUCTION

Genistein is a natural isoflavonoid and has several pharmacological effects, such as antioxidant, antitumor activity, and improvement of glucose metabolism. The safety of intestinal anastomosis after ischemia-reperfusion (I/R) injury is a critical issue for surgeons. This experimental study aimed to investigate the effects of genistein on anastomotic healing after intestinal I/R injury.

METHODS

A total of 36 male Wistar Albino rats were divided into four groups: control, I/R, genistein, and genistein + I/R. The control group received segmental ileal resection and ileoileal anastomosis. The I/R group received resection + anastomosis after intestinal I/R. The genistein group was administered subcutaneous injection of 1 mg/kg genistein 12 h and 1 h before the procedure and received ileal resection + anastomosis. The genistein + I/R group received I/R + ileal resection + anastomosis after genistein injection. Anastomotic bursting pressure, hydroxyproline, superoxide dismutase, and glutathione peroxidase levels and histopathological wound healing scores of all rats were measured on postoperative day 5.

RESULTS

The anastomotic bursting pressure was significantly higher in the genistein and genistein + I/R groups (P < 0.001). Genistein increased the hydroxyproline concentration and the superoxide dismutase and glutathione peroxidase levels in the intestinal anastomosis (P < 0.001). In histopathological assessment, the mean wound healing score was significantly higher in the genistein group than in the other groups (P < 0.001).

CONCLUSIONS

Genistein, with its anti-inflammatory and antioxidant properties, shows protective effects against increased oxidative stress after intestinal I/R injury and contributes positively to intestinal anastomotic healing.

Transcriptional progressive patterns from mild to severe renal ischemia/reperfusion-induced kidney injury in mice

The renal ischemia/reperfusion (I/R)-induced acute kidney injury incidence after nephron-sparing surgery for localized renal tumors is 20%, but the biological determinant process of postoperative acute kidney injury remains unclear. Using Gene Expression Omnibus database (GSE192883) and several bioinformatics analyses (discrete time points analysis, gene set enrichment analysis, dynamic network biomarker analysis, etc), combined with the establishment of the I/R model for verification, we identified three progressive patterns involving five core pathways confirmed using gene set enrichment analysis and six key genes (S100a10, Pcna, Abat, Kmo, Acadm, and Adhfe1) verified using quantitative polymerase chain reaction The dynamic network biomarker (DNB) subnetwork composite index value is the highest in the 22-min ischemia group, suggesting the transcriptome expression level fluctuated sharply in this group, which means 22-min ischemia is an critical warning point. This study illustrates the core molecular progressive patterns from mild to severe I/R kidney injury, laying the foundation for precautionary biomarkers and molecular intervention targets for exploration. In addition, the safe renal artery blocking time of nephron-sparing surgery that we currently accept may not be safe anymore.

Potential of Polyphenols to Restore SIRT1 and NAD+ Metabolism in Renal Disease

SIRT1 is an NAD⁺-dependent class III histone deacetylase that is abundantly expressed in the kidney, where it modulates gene expression, apoptosis, energy homeostasis, autophagy, acute stress responses, and mitochondrial biogenesis. Alterations in SIRT1 activity and NAD⁺ metabolism are frequently observed in acute and chronic kidney diseases of diverse origins, including obesity and diabetes. Nevertheless, in vitro and in vivo studies and clinical trials with humans show that the SIRT1-activating compounds derived from natural sources, such as polyphenols found in fruits, vegetables, and plants, including resveratrol, quercetin, and isoflavones, can prevent disease and be part of treatments for a wide variety of diseases. Here, we summarize the roles of SIRT1 and NAD⁺ metabolism in renal pathophysiology and provide an overview of polyphenols that have the potential to restore SIRT1 and NAD⁺ metabolism in renal diseases.

Calorie Restriction Protects against Contrast-Induced Nephropathy via SIRT1/GPX4 Activation

Calorie restriction (CR) extends lifespan and increases resistance to multiple forms of stress, including renal ischemia-reperfusion (I/R) injury. However, whether CR has protective effects on contrast-induced nephropathy (CIN) remains to be determined. In this study, we evaluated the therapeutic effects of CR on CIN and investigated the potential mechanisms. CIN was induced by the intravenous injection of iodinated contrast medium (CM) iopromide (1.8 g/kg) into Sprague Dawley rats with normal food intake or 40% reduced food intake, 4 weeks prior to iopromide administration. We found that CR was protective of CIN, assessed by renal structure and function. CM increased apoptosis, reactive oxygen species (ROS), and inflammation in the renal outer medulla, which were decreased by CR. The silent information regulator 1 (SIRT1) participated in the protective effect of CR on CIN, by upregulating glutathione peroxidase 4 (GPX4), a regulator of ferroptosis, because this protective effect was reversed by EX527, a specific SIRT1 antagonist. Our study showed that CR protected CIN via SIRT1/GPX4 activation. CR may be used to mitigate CIN.

Short-term supplementation of DHA-enriched phospholipids attenuates the nephrotoxicity of cisplatin without compromising its antitumor activity in mice

Cisplatin is one of the most effective chemotherapeutic agents used for the treatment of a wide variety of cancers. However, cisplatin has been associated with nephrotoxicity, which limits its application in clinical treatment. Various studies have indicated the protective effect of phospholipids against acute kidney injury. However, no study has focused on the different effects of phospholipids with different fatty acids on cisplatin-induced nephrotoxicity and on the combined effects of phospholipids and cisplatin in tumour-bearing mice. In the present study, the potential renoprotective effects of phospholipids with different fatty acids against cisplatin-induced nephrotoxicity were investigated by determining the serum biochemical index, renal histopathological changes, protein expression level and oxidative stress. The results showed that docosahexaenoic acid-enriched phospholipids (DHA-PL) and eicosapentaenoic acid-enriched phospholipids (EPA-PL) could alleviate cisplatin-induced nephrotoxicity by regulating the caspase signaling pathway, the SIRT1/PGC1α pathway, and the MAPK (mitogen-activated protein kinase) signaling pathway and by inhibiting oxidative stress. In particular, DHA-PL exhibited a better inhibitory effect on oxidative stress and apoptosis compared to EPA-PL. Furthermore, DHA-PL exhibited an additional effect with cisplatin on the survival of ascitic tumor-bearing mice. These findings suggested that DHA-PL are one kind of promising supplement for the alleviation of cisplatin-induced nephrotoxicity without compromising its antitumor activity.

Involvement of SIRT1 in amelioration of schistosomiasis-induced hepatic fibrosis by genistein

Previous study revealed that genistein alleviate the extent of hepatic fibrosis in schistosomiasis-infected mice, however, the potential mechanism is still incomplete. Present study was, therefore, carried out to investigate the underlying mechanism of ameliorating schistosomiasis-induced hepatic fibrosis by genistein. α-smooth muscle actin (α-SMA) expression, as a critical fibrotic marker, was markedly upregulated in Schistosoma japonicum (S. japonicum) egg-induced liver fibrosis, and gradually inhibited by genistein administration in infected mice. Contrary to the changes of α-SMA expression, hepatic SIRT1 expression and activity was greatly inhibited in mice upon S. japonicum infection, and the repression was reversed in liver tissues after receiving 25 mg/kg genistein. 50 mg/kg genistein treatment gave rise to the higher SIRT1 expression and activity than that of the control group. In hepatic stellate cells (HSCs), genistein (5, 10, 20 μM) treatment resulted in the increases of SIRT1 expression and activity in concentration-dependent manner. Moreover, to mimic the fibrogenesis in vivo, macrophage was treated with soluble egg antigen (SEA) to obtain macrophage-conditioned medium (MφCM), which was used to stimulate HSCs. Intriguingly, SIRT1 overexpression decreased fibrosis associated gene expression in HSCs exposed to MφCM or not. Additionally, MφCM gave rise to high levels of α-SMA and p-Smad3 and the increments were reversed upon genistein treatment in HSCs. Furthermore, EX527, SIRT1 specific inhibitor, abrogated the inhibitory effects of genistein on HSCs activation. Together, the results support the notion that the strong elevation of SIRT1 expression and activity may represent a potential mechanism of protection against schistosomiasis-induced hepatic fibrosis by genistein.

Current Perspectives on the Beneficial Effects of Soybean Isoflavones and Their Metabolites for Humans

Soybeans are rich in proteins and lipids and have become a staple part of the human diet. Besides their nutritional excellence, they have also been shown to contain various functional components, including isoflavones, and have consequently received increasing attention as a functional food item. Isoflavones are structurally similar to 17-β-estradiol and bind to estrogen receptors (ERα and ERβ). The estrogenic activity of isoflavones ranges from a hundredth to a thousandth of that of estrogen itself. Isoflavones play a role in regulating the effects of estrogen in the human body, depending on the situation. Thus, when estrogen is insufficient, isoflavones perform the functions of estrogen, and when estrogen is excessive, isoflavones block the estrogen receptors to which estrogen binds, thus acting as an estrogen antagonist. In particular, estrogen antagonistic activity is important in the breast, endometrium, and prostate, and such antagonistic activity suppresses cancer occurrence. Genistein, an isoflavone, has cancer-suppressing effects on estrogen receptor-positive (ER+) cancers, including breast cancer. It suppresses the function of enzymes such as tyrosine protein kinase, mitogen-activated kinase, and DNA polymerase II, thus inhibiting cell proliferation and inducing apoptosis. Genistein is the most biologically active and potent isoflavone candidate for cancer prevention. Furthermore, among the various physiological functions of isoflavones, they are best known for their antioxidant activities. S-Equol, a metabolite of genistein and daidzein, has strong antioxidative effects; however, the ability to metabolize daidzein into S-equol varies based on racial and individual differences. The antioxidant activity of isoflavones may be effective in preventing dementia by inhibiting the phosphorylation of Alzheimer's-related tau proteins. Genistein also reduces allergic responses by limiting the expression of mast cell IgE receptors, which are involved in allergic responses. In addition, they have been known to prevent and treat various diseases, including cardiovascular diseases, metabolic syndromes, osteoporosis, diabetes, brain-related diseases, high blood pressure, hyperlipidemia, obesity, and inflammation. Further, it also has positive effects on menstrual irregularity in non-menopausal women and relieving menopausal symptoms in middle-aged women. Recently, soybean consumption has shown steep increasing trend in Western countries where the intake was previously only 1/20-1/50 of that in Asian countries. In this review, I have dealt with the latest research trends that have shown substantial interest in the biological efficacy of isoflavones in humans and plants, and their related mechanisms.

Activators of SIRT1 in the kidney and protective effects of SIRT1 during acute kidney injury (AKI) (effect of SIRT1 activators on acute kidney injury)

Acute kidney injury (AKI) is a complex disorder and a clinical condition characterized by acute reduction in renal function. If AKI is not treated, it can lead to chronic kidney disease, which is associated with a high risk of death. SIRT1 (silent information regulator 1) is an NAD-dependent deacetylase. This enzyme is responsible for the processes of DNA repair or recombination, chromosomal stability, and gene transcription. This enzyme also plays a protective role in many diseases, including AKI. In this study, we review the mechanisms that mediate the protective effects of SIRT1 on AKI, including SIRT1 activators.

Regulatory mechanisms of Sesn2 and its role in multi-organ diseases

Sestrin2 (Sesn2) is a powerful anti-oxidant that can prevent acute and chronic diseases. The role of Sesn2 has been thoroughly reviewed in liver, nervous system, and immune system diseases. However, there is a limited number of reviews that have summarized the effects of Sesn2 in heart and vascular diseases, and very less literature-based information is available on involvement of Sesn2 in renal and respiratory pathologies. This review summarizes the latest research on Sesn2 in multi-organ stress responses, with a particular focus on the protective role of Sesn2 in cardiovascular, respiratory, and renal diseases, emphasizing the potential therapeutic benefit of targeting Sesn2 in stress-related diseases.

Genistein Ameliorates Renal Fibrosis Through Regulation Snail via m6A RNA Demethylase ALKBH5

Renal tubule-interstitial fibrosis is related to chronic kidney disease progression and a typical feature of the aging kidney. Epigenetic modifications of fibrosis-prone genes regulate the development of renal fibrosis. As a kind of “epigenetic diet”, soy isoflavone genistein was reported to have renal protective action and epigenetic-modulating effects. However, its renal protection role and underlying mechanisms are yet to be fully clarified. Herein, we showed that genistein exhibits a demonstrable anti-fibrotic effect on kidney in vivo UUO (unilateral ureteral occlusion) model and renal epithelial cells in vitro model. The mechanism is strongly associated with epithelial-to-mesenchymal transition and m6A RNA demethylase ALKBH5. Mouse fibrotic kidneys induced by UUO exhibited adverse expression of renal fibrosis-related proteins and significant increases in the total m6A level. As an eraser, ALKBH5 showed severer suppression in the renal fibrosis process. However, genistein pretreatment restored ALKBH5 loss remarkably and reduced renal fibrosis, abnormal protein, and inflammatory markers. The examination of possible mechanisms revealed that genistein promoted ALKBH5 and maybe induced the level of mRNA m6A methylation in some epithelial-to-mesenchymal transition-related transcription factors. We found snail was the critical regulator and critical for the protective role of genistein. To verify the relationship between ALKBH5 and snail, we generated knockdown and overexpression of ALKBH5 cells in vitro. ALKBH5 knockdown enhanced the mesenchymal phenotype marker α-smooth muscle actin and snail expression. In agreement, overexpression ALKBH5 increased epithelial adhesion molecule E-cadherin and reduced snail expression. In conclusion, genistein increased renal ALKBH5 expression in UUO-induced renal fibrosis and reduced RNA m6A levels and ameliorates renal damages.

Genistein protects against acetaminophen-induced liver toxicity through augmentation of SIRT1 with induction of Nrf2 signalling

Previous studies suggest that genistein protects liver from acetaminophen (APAP)-induced injury, however, the detailed mechanism of the process is still incompletely. Therefore, present study was to investigate the potential mechanism of the genistein mediated protection against APAP-induced hepatotoxicity. As shown, supplementation with 150 mg/kg genistein greatly alleviated the increase in serum alanine aminotransferase (ALT) activity, aspartate aminotransferase (AST) activity, hepatic malondialdehyde (MDA) contents, and reversed the decrease in hepatic GSH levels in response to overdose APAP. At the same time, hepatic SIRT1 protein and activity were markedly upregulated in mouse receiving genistein. However, the amelioration was almost abolished by the knockdown of hepatic SIRT1 expression using lentivirus carrying specific shRNA targeting SIRT1. These results were further validated by histopathology examination. Moreover, depletion of hepatic SIRT1 prevented the accumulation of Nrf2 in nucleus and the upregulation of the antioxidant gene expression in the presence of genistein and/or APAP. Concomitantly, the induced mRNA expression of UDP-glucuronosyltransferases (UGTs) by genistein was largely dependent on the SIRT1 expression and activity. Together, our results support the notion that the strong elevation of SIRT1 expression and activity may represent a potential mechanism of protection against APAP-induced liver injury by genistein.

Anti-Inflammatory and Antioxidative Properties of Isoflavones Provide Renal Protective Effects Distinct from Those of Dietary Soy Proteins against Diabetic Nephropathy

SCOPE

Dietary soy reportedly protects from diabetic nephropathy (DN), but its active components and mechanism of action remain unknown.

METHODS AND RESULTS

In this study, KKAy mice are fed three types of diet: Dietary soy isoflavones with soy protein (Soy-IP) diet, reduced isoflavones soy protein (RisoP), and oral administration of isoflavones aglycones (IsoAgc). Albuminuria and glycosuria are decreased only in the soy-IP group. The risoP group show reduced expansion of mesangial matrix and renal fibrosis, the IsoAgc group show renal anti-fibrotic and anti-inflammatory effects; however, these renal pathological changes are repressed in the soy-IP group, suggesting the distinct protective roles of soy protein or isoflavones in DN. The isoflavone genistein has a better inhibitory effect on the inflammatory response and cellular interactions in both mouse tubular cells and macrophages when exposed to high glucose and albumin (HGA). Genistein also represses HGA-induced activator protein 1 activation and reactive oxidases stress generation, accompanied by reduced NADPH oxidase (NOX) gene expression. Finally, diabetic mice show a decrease in lipid peroxidation levels in both plasma and urine, along with lower NOXs gene expression.

CONCLUSION

The data elucidate the detailed mechanism by which isoflavones inhibit renal inflammation and provide a potential practical adjunct therapy to restrict DN progression.

Inhibition of the SIRT1 signaling pathway exacerbates endoplasmic reticulum stress induced by renal ischemia/reperfusion injury in type 1 diabetic rats

The aim of the present study was to investigate whether the diabetic kidney is more susceptible to ischemia/reperfusion (I/R) injury, and identify the potential mechanisms involved. An animal model of type 1 diabetes was created by treating rats with streptozotocin (STZ). This model was then used, along with healthy controls, to investigate the effect of diabetes mellitus (DM) on renal I/R injury. After 45 min of ischemia and 24 h of reperfusion, kidney and serum samples were acquired and used to evaluate function and histopathological injury in the kidneys. Western blotting was also used to determine the expression levels of key proteins. Rats experiencing renal I/R exhibited significant characteristics of renal dysfunction, reduced levels of Sirtuin 1 (SIRT1) protein (a key signaling protein in the kidneys), increased endoplasmic reticulum stress (ERS) and pyroptosis. Furthermore, diabetic rats exhibited further reductions in the levels of SIRT1 in response to renal I/R injury and an increase in the levels of ERS. These effects were all alleviated by the administration of a SIRT1 agonist. The present analysis revealed that the SIRT1-mediated activation of ER stress and pyroptosis played a pivotal role in diabetic rats subjected to renal I/R injury. Downregulation of the SIRT1 signaling pathway were exacerbated in response to renal I/R injury-induced acute kidney injury (AKI). The present data indicated that DM enhanced ER stress and increased pyroptosis by downregulating the SIRT1 signaling pathway.

Renalase Attenuates Mouse Fatty Liver Ischemia/Reperfusion Injury through Mitigating Oxidative Stress and Mitochondrial Damage via Activating SIRT1

Liver ischemia/reperfusion (IR) injury is a severe complication of liver surgery. Moreover, nonalcoholic fatty liver disease (NAFLD) patients are particularly vulnerable to IR injury, with higher rates of postoperative morbidity and mortality after liver surgeries. Our previous study found that renalase (RNLS) was highly sensitive and responsive to oxidative stress, which may be a promising biomarker for the evaluation of the severity of liver IR injury. However, the role of RNLS in liver IR injury remains unclear. In the present study, we intensively explored the role and mechanism of RNLS in fatty liver IR injury in vivo and in vitro. C57BL/6 mice were divided into 2 groups feeding with high-fat diet (HFD) and control diet (CD), respectively. After 20 weeks' feeding, they were suffered from portal triad blockage and reflow to induce liver IR injury. Additionally, oleic acid (OA) and tert-butyl hydroperoxide (t-BHP) were used in vitro to induce steatotic hepatocytes and to simulate ROS burst and mimic cellular oxidative stress following portal triad blockage and reflow, respectively. Our data showed that RNLS was downregulated in fatty livers, and RNLS administration effectively attenuated IR injury by reducing ROS production and improving mitochondrial function through activating SIRT1. Additionally, the downregulation of RNLS in the fatty liver was mediated by a decrease of signal transduction and activator of transcription 3 (STAT3) expression under HFD conditions. These findings make RNLS a promising therapeutic strategy for the attenuation of liver IR injury.

A novel method for the highly efficient biotransformation of genistein from genistin using a high-speed counter-current chromatography bioreactor

Genistein, an important soybean isoflavone compound, has gained attention for its significant properties. Compared with the glycone form of genistin, low content of genistein limits the use in food and pharmaceutical fields. In this study, a novel bioreactor with high-speed counter-current chromatography (HSCCC) was built for the highly efficient biotransformation of genistein from genistin. The solvent system for the bioreactor was selected according to the K D values. The selected solvent system was evaluated by the enzyme activity of β-glucosidase. An ethyl acetate/buffer solution was selected as the preferred solvent system for the HSCCC bioreactor. Optimum reactor parameters were selected according to the retention of the stationary phase. The HSCCC bioreactor was operated using different flow rates, and 2.0 mL min-1 was chosen as the optimal flow rate with a conversion rate of over 90% within 24 h; the novel bioreactor easily immobilized and recycled the enzyme and could be applied in the preparation of genistein.

Genistein attenuates renal fibrosis in streptozotocin‑induced diabetic rats

The present study aimed to investigate the antifibrogenic effects of genistein (GEN) on the kidney in streptozotocin (STZ)-induced diabetic rats and to determine the associated mechanisms. Rats were randomized into four groups: Normal control (N), STZ (S), L (STZ + low-dose GEN) and H (STZ + high-dose GEN). After 8 weeks, the fasting blood glucose (FBG) level, the ratio of kidney weight to body weight (renal index), 24-h urine protein, blood urea nitrogen (BUN), serum creatinine (SCr), renal total antioxidant capacity (T-AOC), superoxide dismutase (SOD), lipid peroxidation (LPO), malondialdehyde (MDA) and hydroxyproline (Hyp) contents were measured. The histomorphology and ultrastructure of the kidney were also assessed. In addition, mRNA expression levels of transforming growth factor-β1 (TGF-β1) and protein expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), NAD(P)H:quinone oxidoreductase 1 (NQO1), TGF-β1, mothers against decapentaplegic homolog 3 (Smad3), phosphorylated (p)-Smad3 and collagen IV were estimated. Compared with group N, the levels of FBG, renal index, 24-h urine protein, BUN, SCr, LPO, MDA and Hyp were increased, whereas the levels of T-AOC and SOD were decreased in group S. The structure of renal tissue was damaged, and the expression of Nrf2, HO-1 and NQO1 were reduced, whereas the expression of TGF-β1, Smad3, p-Smad3 and collagen IV were increased in group S. Compared with group S, the aforementioned indices were improved in groups L and H. In conclusion, GEN exhibited reno-protective effects in diabetic rats and its mechanisms may be associated with the inhibition of oxidative stress by activating the Nrf2-HO-1/NQO1 pathway, and the alleviation of renal fibrosis by suppressing the TGF-β1/Smad3 pathway.

Effects of Polyphenol-Rich Foods on Human Health

Recent evidence has suggested that polyphenol-rich foods intake may be associated with decreased risk of chronic diseases. The Special Issue “Effects of Polyphenol-Rich Foods on Human Health” comprised 64 peer-reviewed papers on the most recent evidence regarding the dietary intake of polyphenols and polyphenol-rich foods, as well as their effect toward the prevention and treatment of non-communicable diseases. Original contributions and literature reviews demonstrated the potential protective effects of polyphenol-rich foods and their extracts toward cardiovascular diseases, certain cancers, and neurodegenerative diseases, mostly through anti-oxidant and chemo-preventive properties.

Isorhamnetin protects against hypoxia/reoxygenation-induced injure by attenuating apoptosis and oxidative stress in H9c2 cardiomyocytes

To unveil the possible protective role of isorhamnetin, an immediate 3'-O-methylated metabolite of quercetin, in cardiomyocyte under hypoxia/reoxygenation (H/R) condition and the underlying mechanisms involved, H9c2 cardiomyocytes were exposed to the vehicle or H/R for 6 h (2 h of hypoxia following by 4 h of reoxygenation) with isorhamnetin (0, 3, 6, 12, 25, 50 μM for 4 h prior to H/R exposure). Apoptosis was evaluated by TUNEL staining, flow cytometry analysis and western blot assay for cleaved caspase-3. Myocardial injure in vivo was determined by infarct size using TTC staining, histological damage using H&E staining and myocardial apoptosis. Here, we found that isorhamnetin dose-dependently protected H9c2 cardiomyocytes against H/R-induced injure, as evidenced by the reduction in lactate dehydrogenase (LDH) levels, increases in cell viability, superoxide dismutase (SOD) and catalase (CAT) activity, with the maximal effects at 25 μΜ. In addition, isorhamnetin treatment significantly inhibited apoptosis in H/R-induced H9c2 cardiomyocytes and ameliorated H/R-induced myocardial injure in vivo, concomitant with the upregulation of sirtuin 1 (SIRT1) expression. Mechanism studies demonstrated that isorhamnetin pretreatment remarkably abolished H/R-induced downregulation of Nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) expressions and upregulation of NADPH oxidase-2/4 (NOX-2/4) expressions in cardiomyocytes. However, SIRT1 inhibition (Sirtinol) not only inhibited isorhamnetin-induced Nrf2/HO-1 upregulation and NOX-2/4 downregulation, but also alleviated its anti-apoptotic effects. Taken together, these data indicate that isorhamnetin can exhibit positive effect on H/R-induced injure by attenuating apoptosis and oxidative stress in H9c2 cardiomyocytes, which is partly attributable to the upregulation of SIRT1 and Nrf2/HO-1-mediated antioxidant signaling pathway.

Soy isoflavone genistein attenuates lipopolysaccharide-induced cognitive impairments in the rat via exerting anti-oxidative and anti-inflammatory effects

Systemic inflammation during infectious disorders usually accompanies chronic complications including cognitive dysfunction. Neuroinflammation and cognitive deficit are also observed in some debilitating neurological disorders like Alzheimer's and Parkinson's diseases. Genistein is a soy isoflavone with multiple beneficial effects including anti-inflammatory, anti-oxidative, and protective properties. In this research study, the effect of genistein in prevention of lipopolysaccharide (LPS)-induced cognitive dysfunction was investigated. LPS was given i.p. (500 μg/kg/day) and genistein was orally given (10, 50, or 100 mg/kg) for one week. Findings showed that genistein could dose-dependently attenuate spatial recognition, discrimination, and memory deficits. Additionally, genistein treatment of LPS-challenged group lowered hippocampal level of malondialdehyde (MDA) and increased activity of superoxide dismutase (SOD) and catalase and glutathione (GSH) level. Furthermore, genistein ameliorated hippocampal acetylcholinesterase (AChE) activity in LPS-challenged rats. Furthermore, genistein administration to LPS-injected group lowered hippocampal level of interleukin 6 (IL-6), nuclear factor-kappaB (NF-κB) p65, toll-like receptor 4 (TLR4), tumor necrosis factor α (TNFα), cyclooxygenase-2 (COX2), inducible nitric oxide synthase (iNOS), glial fibrillary acidic protein (GFAP), and increased hippocampal level of antioxidant element nuclear factor (erythroid-derived 2)-like 2 (Nrf2). In conclusion, genistein alleviated LPS-induced cognitive dysfunctions and neural inflammation attenuation of oxidative stress and AChE activity and appropriate modulation of Nrf2/NF-κB/IL-6/TNFα/COX2/iNOS/TLR4/GFAP.