The antioxidant effects of genistein are associated with AMP-activated protein kinase activation and PTEN induction in prostate cancer cells

Genistein: A promising phytoconstituent with reference to its bioactivities

Genistein, a potent phytoconstituent, has garnered significant attention for its diverse bioactivities, making it a subject of extensive research and exploration. This review delves into the multifaceted properties of genistein, encompassing its antioxidant and anticancer potential. Its ability to modulate various cellular pathways and interact with diverse molecular targets has positioned it as a promising candidate in the prevention and treatment of various diseases. This review provides a comprehensive examination of Genistein, covering its chemical properties, methods of isolation, synthesis, therapeutic attributes with regard to cancer management, and the proposed mechanisms of action as put forth by researchers.

The Use of Soy Isoflavones in the Treatment of Prostate Cancer: A Focus on the Cellular Effects

A possible link between diet and cancer has long been considered, with growing interest in phytochemicals. Soy isoflavones have been associated with a reduced risk of prostate cancer in Asian populations. Of the soy isoflavones, genistein and daidzein, in particular, have been studied, but recently, equol as a derivative has gained interest because it is more biologically potent. Different mechanisms of action have already been studied for the different isoflavones in multiple conditions, such as breast, gastrointestinal, and urogenital cancers. Many of these mechanisms of action could also be demonstrated in the prostate, both in vitro and in vivo. This review focuses on the known mechanisms of action at the cellular level and compares them between genistein, daidzein, and equol. These include androgen- and estrogen-mediated pathways, regulation of the cell cycle and cell proliferation, apoptosis, angiogenesis, and metastasis. In addition, antioxidant and anti-inflammatory effects and epigenetics are addressed.

Evaluating chemotherapeutic potential of soya-isoflavonoids against high penetrance genes in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is the most aggressive molecular subtype of breast cancer (BC) associated with a poor prognosis. Owing to the structural similarity with 17-β-estradiol, consumption of soya-isoflavonoids are associated with a reduced rate of hormone-receptive BC incidence, but their role in TNBC is not deciphered in detail. This present study thus aims to investigate the therapeutic binding dynamics of dietary soya-flavonoids with the six high penetrance (HP) receptors in TNBC, viz. BRCA1, BRCA2, PALB2, PTEN, STK11 and TP53. Out of the 14 soya-flavonoids screened based on ADMET descriptors and several other physicochemical, bioavailability, drug and lead-likeness properties, four hits were shortlisted (Daidzein, Genistein, Glycitein and Biochanin A). Docking and molecular dynamics (MD) simulation revealed Genistein as the most potential multi-target inhibitor of the six TNBC HP genes. Additionally, Genistein exhibited excellent binding specificity with PTEN, a potent mediator of the PI3K signaling pathway in TNBC. The binding interaction of PTEN and Genistein was further compared against a standardized FDA-approved chemotherapeutic inhibitor, Olaparib, computed through various MD trajectory analysis, principal component analysis and computation of free energy landscape. This study reveals a comparatively better binding dynamics of PTEN-Genistein than PTEN-Olaparib. With a significant global surge in biomarker-based precision therapeutics in oncology, the results of this exhaustive in-silico study thus encourage the prospect of validating PTEN as a druggable target of Genistein, a unique drug-receptor combination in the future.Communicated by Ramaswamy H. Sarma.

Genistein Protects against Acetaldehyde-Induced Oxidative Stress and Hepatocyte Injury in Chronic Alcohol-Fed Mice

Alcohol-related liver disease (ALD) is one of the most prevalent forms of liver disease in the world. Acetaldehyde, an intermediate product of alcohol catabolism, is a cause of liver injury caused by alcohol. This study was designed to evaluate the protective role and mechanism(s) of genistein against acetaldehyde-induced liver injury in the pathological process of ALD. We found that genistein administration significantly ameliorated alcohol-induced hepatic steatosis, injury, and inflammation in mice. Genistein supplementation markedly reversed hepatic oxidative stress, endoplasmic reticulum stress, mitochondrial dysfunction, and hepatocellular apoptosis in both alcohol-fed mice liver and acetaldehyde-treated hepatocytes. The mechanistic experiments revealed that the restoration of genistein administration rescued heme oxygenase-1 (HO-1) reduction at both transcriptional and protein levels in either alcohol-fed mice liver or acetaldehyde-treated hepatocytes, and the beneficial aspects derived from genistein were abolished in antioxidase heme oxygenase-1 (HO-1)-deficient hepatocytes. Moreover, we confirmed that genistein administration-restored hepatic nuclear factor erythroid 2-related factor 2 (NRF2), a key transcriptional regulator of HO-1, was involved in the protective role of genistein in ALD. This study demonstrated that genistein ameliorated acetaldehyde-induced oxidative stress and liver injury by restoring the hepatic NRF2-HO-1 signaling pathway in response to chronic alcohol consumption. Therefore, genistein may serve as a potential therapeutic choice for the treatment of ALD.

The role of AMPK in cancer metabolism and its impact on the immunomodulation of the tumor microenvironment

Adenosine monophosphate-activated protein kinase (AMPK) is a key metabolic sensor that is pivotal for the maintenance of cellular energy homeostasis. AMPK contributes to diverse metabolic and physiological effects besides its fundamental role in glucose and lipid metabolism. Aberrancy in AMPK signaling is one of the determining factors which lead to the development of chronic diseases such as obesity, inflammation, diabetes, and cancer. The activation of AMPK and its downstream signaling cascades orchestrate dynamic changes in the tumor cellular bioenergetics. It is well documented that AMPK possesses a suppressor role in the context of tumor development and progression by modulating the inflammatory and metabolic pathways. In addition, AMPK plays a central role in potentiating the phenotypic and functional reprogramming of various classes of immune cells which reside in the tumor microenvironment (TME). Furthermore, AMPK-mediated inflammatory responses facilitate the recruitment of certain types of immune cells to the TME, which impedes the development, progression, and metastasis of cancer. Thus, AMPK appears to play an important role in the regulation of anti-tumor immune response by regulating the metabolic plasticity of various immune cells. AMPK effectuates the metabolic modulation of anti-tumor immunity via nutrient regulation in the TME and by virtue of its molecular crosstalk with major immune checkpoints. Several studies including that from our lab emphasize on the role of AMPK in regulating the anticancer effects of several phytochemicals, which are potential anticancer drug candidates. The scope of this review encompasses the significance of the AMPK signaling in cancer metabolism and its influence on the key drivers of immune responses within the TME, with a special emphasis on the potential use of phytochemicals to target AMPK and combat cancer by modulating the tumor metabolism.

Crosstalk between xanthine oxidase (XO) inhibiting and cancer chemotherapeutic properties of comestible flavonoids- a comprehensive update

Gout is an inflammatory disease caused by metabolic disorder or genetic inheritance. People throughout the world are strongly dependent on ethnomedicine for the treatment of gout and some receive satisfactory curative treatment. The natural remedies as well as established drugs derived from natural sources or synthetically made exert their action by mechanisms that are closely associated with anticancer treatment mechanisms regarding inhibition of xanthine oxidase, feedback inhibition of de novo purine synthesis, depolymerization and disappearance of microtubule, inhibition of NF-ĸB activation, induction of TRAIL, promotion of apoptosis, and caspase activation and proteasome inhibition. Some anti-gout and anticancer novel compounds interact with same receptors for their action, e.g., colchicine and colchicine analogues. Dietary flavonoids, i.e., chrysin, kaempferol, quercetin, fisetin, pelargonidin, apigenin, luteolin, myricetin, isorhamnetin, phloretinetc etc. have comparable IC₅₀ values with established anti-gout drug and effective against both cancer and gout. Moreover, a noticeable number of newer anticancer compounds have already been isolated from plants that have been using by local traditional healers and herbal practitioners to treat gout. Therefore, the anti-gout plants might have greater potentiality to become selective candidates for screening of newer anticancer leads.

The Neuroprotective Potentiality of Flavonoids on Alzheimer's Disease

Alzheimer's disease (AD), due to its spread, has become a global health priority, and is characterized by senile dementia and progressive disability. The main cause of AD and other neurodegenerations (Huntington, Parkinson, Amyotrophic Lateral Sclerosis) are aggregated protein accumulation and oxidative damage. Recent research on secondary metabolites of plants such as polyphenols demonstrated that they may slow the progression of AD. The flavonoids' mechanism of action in AD involved the inhibition of acetylcholinesterase, butyrylcholinesterase, Tau protein aggregation, β-secretase, oxidative stress, inflammation, and apoptosis through modulation of signaling pathways which are implicated in cognitive and neuroprotective functions, such as ERK, PI3-kinase/Akt, NFKB, MAPKs, and endogenous antioxidant enzymatic systems. This review focuses on flavonoids and their role in AD, in terms of therapeutic potentiality for human health, antioxidant potential, and specific AD molecular targets.

Combinatorial approaches of nanotherapeutics for inflammatory pathway targeted therapy of prostate cancer

Prostate cancer (PC) is the most prevalent male urogenital cancer worldwide. PC patients presenting an advanced or metastatic cancer succumb to the disease, even after therapeutic interventions including radiotherapy, surgery, androgen deprivation therapy (ADT), and chemotherapy. One of the hallmarks of PC is evading immune surveillance and chronic inflammation, which is a major challenge towards designing effective therapeutic formulations against PC. Chronic inflammation in PC is often characterized by tumor microenvironment alterations, epithelial-mesenchymal transition and extracellular matrix modifications. The inflammatory events are modulated by reactive nitrogen and oxygen species, inflammatory cytokines and chemokines. Major signaling pathways in PC includes androgen receptor, PI3K and NF-κB pathways and targeting these inter-linked pathways poses a major therapeutic challenge. Notably, many conventional treatments are clinically unsuccessful, due to lack of targetability and poor bioavailability of the therapeutics, untoward toxicity and multidrug resistance. The past decade witnessed an advancement of nanotechnology as an excellent therapeutic paradigm for PC therapy. Modern nanovectorization strategies such as stimuli-responsive and active PC targeting carriers offer controlled release patterns and superior anti-cancer effects. The current review initially describes the classification, inflammatory triggers and major inflammatory pathways of PC, various PC treatment strategies and their limitations. Subsequently, recent advancement in combinatorial nanotherapeutic approaches, which target PC inflammatory pathways, and the mechanism of action are discussed. Besides, the current clinical status and prospects of PC homing nanovectorization, and major challenges to be addressed towards the advancement PC therapy are also addressed.

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.

Cytoprotective effect of genistein against dexamethasone-induced pancreatic β-cell apoptosis

Steroid-induced diabetes is a well-known metabolic side effect of long-term use of glucocorticoid (GC). Our group recently demonstrated dexamethasone-induced pancreatic β-cell apoptosis via upregulation of TRAIL and TRAIL death receptor (DR5). Genistein protects against pancreatic β-cell apoptosis induced by toxic agents. This study aimed to investigate the cytoprotective effect of genistein against dexamethasone-induced pancreatic β-cell apoptosis in cultured rat insulinoma (INS-1) cell line and in isolated mouse islets. In the absence of genistein, dexamethasone-induced pancreatic β-cell apoptosis was associated with upregulation of TRAIL, DR5, and superoxide production, but downregulation of TRAIL decoy receptor (DcR1). Dexamethasone also activated the expression of extrinsic and intrinsic apoptotic proteins, including Bax, NF-κB, caspase-8, and caspase-3, but suppressed the expression of the anti-apoptotic Bcl-2 protein. Combination treatment with dexamethasone and genistein protected against pancreatic β-cell apoptosis, and reduced the effects of dexamethasone on the expressions of TRAIL, DR5, DcR1, superoxide production, Bax, Bcl-2, NF-κB, caspase-8, and caspase-3. Moreover, combination treatment with dexamethasone and genistein reduced the expressions of TRAIL and DR5 in isolated mouse islets. The results of this study demonstrate the cytoprotective effect of genistein against dexamethasone-induced pancreatic β-cell apoptosis in both cell line and islets via reduced TRAIL and DR5 protein expression.

An overview of possible pivotal mechanisms of Genistein as a potential phytochemical against SARS-CoV-2 infection: A hypothesis

The Coronavirus Disease 2019 (COVID‐19) pandemic has been caused by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2). It is a global problem that humanity has not yet found a definitive solution for it. In this regard, a global effort has been done to find effective or potential adjuvant therapies in order to fight this infection. Genistein is a small, biologically active phytoestrogen flavonoid that is found in high amounts in soy and plants of the Fabaceae family. This important compound is known due to its anti‐cancer, anti‐inflammatory, and antioxidant effects. Additionally, protective effects of genistein have been reported in different pathological conditions through modulating intracellular pathways such as PI3K, Akt, mTOR, NF‐κB, PPARγ, AMPK, and Nrf2. Scientific evidence suggests that genistein could have a potential role to treat COVID‐19 through its anti‐inflammatory and anti‐oxidant effects. Furthermore, it appears to interfere with intracellular pathways involved in viral entry into the cell. This review provides a basis for further research and development of clinical applications of genistein as a potential alternative therapy to decrease inflammation and oxidative stress in COVID‐19 patients.

The Preparation of Gen-NH2-MCM-41@SA Nanoparticles and Their Anti-Rotavirus Effects

Genistein (Gen), a kind of natural isoflavone drug monomer with poor water solubility and low oral absorption, was incorporated into oral nanoparticles with a new mesoporous carrier material, NH₂-MCM-41, which was synthesized by copolycondensation. When the ratio of Gen to NH₂-MCM-41 was 1:0.5, the maximum adsorption capacity of Gen was 13.15%, the maximum drug loading was 12.65%, and the particle size of the whole core–shell structure was in the range of 370 nm–390 nm. The particles were characterized by a Malvern particle size scanning machine, XRD, Fourier transform infrared spectroscopy, scanning electron microscopy, and nitrogen adsorption and desorption. Finally, Gen-NH₂-MCM-41 was encapsulated by sodium alginate (SA), and the chimerism of this material, denoted as GEN-NH₂-MCM-41@SA, was investigated. In vitro release experiments showed that, after 5 h in artificial colon fluid (pH = 8.0), the cumulative release reached 99.56%. In addition, its anti-rotavirus (RV) effect showed that the maximum inhibition rate was 62.24% at a concentration of 30 μM in RV-infected Caco-2 cells, and it significantly reduced the diarrhea rate and diarrhea index in an RV-infected-neonatal mice model at a dose of 0.3 mg/g, which was better than the results of Gen. Ultimately, Gen-NH₂-MCM-41@SA was successfully prepared, which solves the problems of low solubility and poor absorption and provides an experimental basis for the application of Gen in the clinical treatment of RV infection.

Fermented Soy Drink (Q-CAN® PLUS) Induces Apoptosis and Reduces Viability of Cancer Cells

This study tested the ability of a fermented soy product to induce tumor cell toxicity and to assess if this was due to fermentation of soy, and to the genistein content. Four cancer cell lines were cultured without additive, with fermented soy (Q-CAN® PLUS), nonfermented soy, or genistein, and cell viability was examined at 24 h, 48 h, and 72 h. The sensitivity of the cell lines to apoptosis by Q-CAN PLUS was tested with the Annexin V assay. All cell lines demonstrated a dose and time response reduction in tumor cell viability with exposure to Q-CAN PLUS (IC50 at 24 h 3.8 mg/mL to 9 mg/mL). Unfermented soy did not show reduction in viability of any cell line within the same concentration range. The IC50 of genistein for each of the cell lines was significantly greater than for Q-CAN PLUS. All four tumor cell lines demonstrated apoptosis in response to Q-CAN PLUS. Q-CAN PLUS reduces viability and increases apoptosis of cancer cells in a concentration- and fermentation-dependent manner. Taking into consideration the IC50 of genistein and the concentration of genistein in Q-CAN PLUS, the genistein content of Q-CAN PLUS is not responsible for the majority reduction in tumor cell viability. This suggests that fermentation of soy results in the production of metabolites that reduce cancer cell viability and induce cellular apoptosis, and play a major role in addition to any effects produced by their genistein content.

The Cross-Talk between Polyphenols and the Target Enzymes Related to Oxidative Stress-Induced Thyroid Cancer

The most serious hallmark step of carcinogenesis is oxidative stress, which induces cell DNA damage. Although in normal conditions ROS are important second messengers, in pathological conditions such as cancer, due to imbalanced redox enzyme expression, oxidative stress can occur. Recent studies with firmly established evidence suggest an interdependence between oxidative stress and thyroid cancer based on thyroid hormone synthesis. Indeed, a reduced antioxidant defense system might play a part in several steps of progression in thyroid cancer. Based on studies that have been conducted previously, future drug designs for targeting enzymatic ROS sources, as a single agent or in combination, have to be tested. Polyphenols represent the potential for modulating biological events in thyroid cancer, including antioxidative activity. Targeting enzymatic ROS sources, without affecting the physiological redox state, might be an important purpose. As regards the underlying chemopreventive mechanisms of natural compounds that have been discussed in other cancer models, the confirmation of the influence of polyphenols on thyroid cancer is inconclusive and rarely available. Therefore, there is a need for further scientific investigations into the features of the antioxidative effects of polyphenols on thyroid cancer. The current review illustrates the association between some polyphenols and the key enzymes that take place in oxidation reactions in developing thyroid cancer cells. This review gives the main points of the enzymatic ROS sources act and redox signaling in normal physiological or pathological contexts and supplies a survey of the currently available modulators of TPO, LOX, NOX, DUOX, Nrf2, and LPO derived from polyphenols.

The multimodal action of genistein in Alzheimer's and other age-related diseases

Genistein is a phytoestrogen that, due to its structural similarity with estrogen, can both mimic and antagonize estrogen effects. Early analysis proved that at high concentrations, genistein inhibits breast cancer cell proliferation, thereby suggesting an anticancer activity. Since then, many discoveries have identified the genistein mechanism of action, including cell cycle arrest, apoptosis induction, as well as angiogenesis, and metastasis inhibition. In this review, we aim to discuss the multimodal action of genistein as an antioxidant, anti-inflammatory, anti-amyloid β, and autophagy promoter, which could be responsible for the genistein beneficial effect on Alzheimer's. Furthermore, we pinpoint the main signal transduction pathways that are known to be modulated by genistein. Genistein has thus several beneficial effects in several diseases, many of them associated with age, such as the above mentioned Alzheimer disease. Indeed, the beneficial effects of genistein for health promotion depend on each multimodality. In the context of geroscience, genistein has promising beneficial effects due to its multimodal action to treat age associated-diseases.

Genistein, a Potential Phytochemical against Breast Cancer Treatment-Insight into the Molecular Mechanisms

Breast cancer (BC) is one of the most common malignancies in women. Although widespread successful synthetic drugs are available, natural compounds can also be considered as significant anticancer agents for treating BC. Some natural compounds have similar effects as synthetic drugs with fewer side effects on normal cells. Therefore, we aimed to unravel and analyze several molecular mechanisms of genistein (GNT) against BC. GNT is a type of dietary phytoestrogen included in the flavonoid group with a similar structure to estrogen that might provide a strong alternative and complementary medicine to existing chemotherapeutic drugs. Previous research reported that GNT could target the estrogen receptor (ER) human epidermal growth factor receptor-2 (HER2) and several signaling molecules against multiple BC cell lines and sensitize cancer cell lines to this compound when used at an optimal inhibitory concentration. More specifically, GNT mediates the anticancer mechanism through apoptosis induction, arresting the cell cycle, inhibiting angiogenesis and metastasis, mammosphere formation, and targeting and suppressing tumor growth factors. Furthermore, it acts via upregulating tumor suppressor genes and downregulating oncogenes in vitro and animal model studies. In addition, this phytochemical synergistically reverses the resistance mechanism of standard chemotherapeutic drugs, increasing their efficacy against BC. Overall, in this review, we discuss several molecular interactions of GNT with numerous cellular targets in the BC model and show its anticancer activities alone and synergistically. We conclude that GNT can have favorable therapeutic advantages when standard drugs are not available in the pharma markets.

Supplementing Soy-Based Diet with Creatine in Rats: Implications for Cardiac Cell Signaling and Response to Doxorubicin

Nutritional habits can have a significant impact on cardiovascular health and disease. This may also apply to cardiotoxicity caused as a frequent side effect of chemotherapeutic drugs, such as doxorubicin (DXR). The aim of this work was to analyze if diet, in particular creatine (Cr) supplementation, can modulate cardiac biochemical (energy status, oxidative damage and antioxidant capacity, DNA integrity, cell signaling) and functional parameters at baseline and upon DXR treatment. Here, male Wistar rats were fed for 4 weeks with either standard rodent diet (NORMAL), soy-based diet (SOY), or Cr-supplemented soy-based diet (SOY + Cr). Hearts were either freeze-clamped in situ or following ex vivo Langendorff perfusion without or with 25 μM DXR and after recording cardiac function. The diets had distinct cardiac effects. Soy-based diet (SOY vs. NORMAL) did not alter cardiac performance but increased phosphorylation of acetyl-CoA carboxylase (ACC), indicating activation of rather pro-catabolic AMP-activated protein kinase (AMPK) signaling, consistent with increased ADP/ATP ratios and lower lipid peroxidation. Creatine addition to the soy-based diet (SOY + Cr vs. SOY) slightly increased left ventricular developed pressure (LVDP) and contractility dp/dt, as measured at baseline in perfused heart, and resulted in activation of the rather pro-anabolic protein kinases Akt and ERK. Challenging perfused heart with DXR, as analyzed across all nutritional regimens, deteriorated most cardiac functional parameters and also altered activation of the AMPK, ERK, and Akt signaling pathways. Despite partial reprogramming of cell signaling and metabolism in the rat heart, diet did not modify the functional response to supraclinical DXR concentrations in the used acute cardiotoxicity model. However, the long-term effect of these diets on cardiac sensitivity to chronic and clinically relevant DXR doses remains to be established.

Chemopreventive and hepatoprotective effects of genistein via inhibition of oxidative stress and the versican/PDGF/PKC signaling pathway in experimentally induced hepatocellular carcinoma in rats by thioacetamide

Objective

Genistein is a recognized isoflavone present in soybeans with antioxidant, anti-inflammatory, antiangiogenic and antitumor activities. This study aimed to test ability of genistein in modulating versican/platelet derived growth factor (PDGF) axis in HCC.

Methods

HCC was experimentally induced in male Sprague-Dawley rats then treated with 25 or 75 mg/kg genistein. Antioxidant activities of genistein was assessed by measuring the gene expression of Nrf2 and the hepatic levels of malondialdehyde (MDA), superoxide dismutase (SOD) and reduced glutathione. Expression of versican, PDGF, protein kinase C (PKC) and ERK-1 protein was assessed by Western blotting and immunostaining.

Results

HCC induced an elevation in oxidative stress, PDGF, versican, PKC and ERK protein expression levels. Genistein significantly reduced an HCC-induced increase in oxidative stress. Moreover, genistein dose-dependently reduced HCC-induced elevation of PDGF, versican, PKC and ERK protein expression levels. Moreover, genistein helped retain a normal hepatocyte structure and reduced fibrous tissue deposition, especially in high dose.

Conclusions

Genistein exerted antitumor and antioxidant effects and therefore suppress HCC development via inhibition of the PDGF/versican bidirectional axis, suppressing both ERK1 and PKC as downstream regulators. Therefore, genistein is a potential novel therapeutic candidate for improving the outcome of patients with HCC.

Genistein Prevents Hypoxia-Induced Cognitive Dysfunctions by Ameliorating Oxidative Stress and Inflammation in the Hippocampus

Genistein (GE), a plant-derived isoflavone, is a polyphenolic non-steroidal compound. Studies showed that GE possesses anti-cancer, anti-inflammatory, anti-microbial, anti-oxidant, and anti-apoptotic activities. However, the neuroprotective role of GE in amnesia has not been studied. This study aimed to evaluate the anti-amnesic potential of GE in a mice model of hypoxia-induced amnesia and to understand the underlying mechanism. Mice were exposed to hypoxia (10% O2) and administered vehicle or GE (10, 20, 30 mg/kg) orally for 28 days. Thereafter, Morris water maze (MWM), novel object recognition (NOR), and passive avoidance task (PAT) were performed to evaluate cognitive behavior. Next, we performed biochemical tests and gene expression analysis to uncover the mechanism underlying GE mode of action. Our results showed that GE-treatment ameliorated hypoxia-induced cognitive dysfunctions in mice. Further, GE-treatment suppressed the oxidative stress in the hippocampus of amnesic mice as evidenced by reduced lipid peroxidation, reduced nitrite and ROS levels, and increased levels of reduced glutathione (GSH) and increased total antioxidant capacity. GE treatment reduced the expression of pro-inflammatory cytokines TNFα, IL1β, IL6, and MCP-1 and increased the expression of anti-inflammatory cytokine IL10 in the hippocampus of amnesic mice. Finally, GE treatment enhanced the expression of neuroprotective genes including BDNF, CREB, CBP, and IGF1 in the hippocampus of amnesic mice. Altogether, our results showed that GE treatment prevents hypoxia-induced cognitive dysfunction in mice by reducing oxidative stress and suppressing neuroinflammation while increasing the expression of neuroprotective genes in the hippocampus.

Pueraria tuberosa: A Review on Traditional Uses, Pharmacology, and Phytochemistry

Pueraria tuberosa (Roxb. ex Willd.) DC. (Fabaceae), also known as Indian Kudzu (vidari kand), is a perennial herb distributed throughout India and other Asian countries. Traditionally, tuber and leaves of this plant have extensively been reported for nutritional and medicinal properties in Ayurveda as well as in Chinese traditional practices. The objective of the present review is to compile and update the published data on traditional uses, pharmacological potential, and phytochemistry of compounds isolated from the plant Pueraria tuberosa. P. tuberosa extracts and its purified compounds possess multiple activities such as anticancer, anticonvulsant, antidiabetic, antifertility, anti-inflammatory, antioxidant, anti-stress, antiulcerogenic, cardioprotective, hypolipidemic, hepatoprotective, immunomodulatory, nephroprotective, nootropic, neuroprotective, and wound healing. Tuber and leaf extracts of P. tuberosa contain several bioactive constituents such as puerarin, daidzein, genistein, quercetin, irisolidone, biochanin A, biochanin B, isoorientin, and mangiferin, which possess an extensive range of pharmacological activities. The extensive range of pharmacological properties of P. tuberosa provides opportunities for further investigation and presents a new approach for the treatment of ailments. Many phytochemicals have been identified and characterized from P. tuberosa; however, some of them are still unexplored, and there is no supporting data for their activities and exact mechanisms of action. Therefore, further investigations are warranted to unravel the mechanisms of action of individual constituents of this plant.

The Role of Isoflavones in Type 2 Diabetes Prevention and Treatment-A Narrative Review

Given the growing number of type 2 diabetic individuals and the substantial social and financial costs associated with diabetes management, every effort should be made to improve its prevention and treatment methods. There is an ongoing search for natural dietary compounds that could be used for this purpose. This narrative review focuses on the therapeutic potential of isoflavones in diabetes prevention and treatment. This review summarizes (i) the molecular mechanisms of isoflavones action that are critical to their anti-diabetic properties; (ii) preclinical (in vitro and in vivo) studies evaluating the influence of isoflavones on the function of key organs involved in the pathogenesis of diabetes; and (iii) epidemiological studies and clinical trials that assessed the effectiveness of isoflavones in the prevention and treatment of type 2 diabetes in humans. Apart from discussing the effects of isoflavones on the function of organs “classically” associated with the pathogenesis of diabetes (pancreas, liver, muscles, and adipose tissue), the impact of these compounds on other organs that contribute to the glucose homeostasis (gastrointestinal tract, kidneys, and brain) is also reviewed.

Isoorientin exerts a protective effect against 6-OHDA-induced neurotoxicity by activating the AMPK/AKT/Nrf2 signalling pathway

Parkinson's disease (PD) is a progressive neurodegenerative disorder that is closely associated with oxidative stress. Nuclear factor erythroid 2 related factor 2 (Nrf2) is a key transcription factor that regulates oxidative stress. Isoorientin (IOT), as a dietary C-glucosyl flavone derived from rooibos tea, cereals and legumes, is thought to possess multiple pharmacological activities; however, the protective effect of IOT against 6-hydroxydopamine (6-OHDA)-induced neurotoxicity in SH-SY5Y cells is still poorly understood. The present study focused on investigating whether IOT could ameliorate neurotoxicity and the underlying mechanisms. Our findings indicated that IOT significantly inhibited neurotoxicity reduced apoptotic cell numbers, reactive oxygen species (ROS) overproduction and mitochondrial membrane potential, and modulated the expression of apoptosis-related proteins, including Bcl-2, Bax and caspase-3, which were induced by 6-OHDA. Moreover, IOT also enhanced the expression of the GCLC, GCLM, HO-1, NQO1 and Trx-1 proteins, which mostly depends on the nuclear translation of Nrf2 and reduced expression of the Keap1 protein. IOT significantly increased the phosphorylation of AMPK, ERK, GSK3β, JNK, PI3K and AKT. In contrast, pretreatment with the inhibitors of AMPK and PI3K/AKT only suppressed the nuclear translocation of Nrf2. In addition, the expression of these proteins was effectively decreased by 6-OHDA, and this effect was reversed by IOT treatment. Importantly, the effect of IOT on improving 6-OHDA induced neurotoxicity was remarkably abrogated by the application of Nrf2 siRNA and, AMPK and PI3K/AKT inhibitors. In summary, IOT might play a protective role against 6-OHDA-induced neurotoxicity by inducing the expression of various antioxidant enzymes via the activation of the AMPK/AKT-Nrf2 signalling pathway.

Neuroinflammation in Alzheimer's Disease: Microglia, Molecular Participants and Therapeutic Choices

Alzheimer's disease is the world's most common dementing illness. It is pathologically characterized by β-amyloid accumulation, extracellular senile plaques and intracellular neurofibrillary tangles formation, and neuronal necrosis and apoptosis. Neuroinflammation has been widely recognized as a crucial process that participates in AD pathogenesis. In this review, we briefly summarized the involvement of microglia in the neuroinflammatory process of Alzheimer's disease. Its roles in the AD onset and progression are also discussed. Numerous molecules, including interleukins, tumor necrosis factor alpha, chemokines, inflammasomes, participate in the complex process of AD-related neuroinflammation and they are selectively discussed in this review. In the end of this paper from an inflammation- related perspective, we discussed some potential therapeutic choices.

Targeting Abdominal Obesity and Its Complications with Dietary Phytoestrogens

In the assessment of the health risk of an obese individual, both the amount of adipose tissue and its distribution and metabolic activity are essential. In adults, the distribution of adipose tissue differs in a gender-dependent manner and is regulated by sex steroids, especially estrogens. Estrogens affect adipocyte differentiation but are also involved in the regulation of the lipid metabolism, insulin resistance, and inflammatory activity of the adipose tissue. Their deficiency results in unfavorable changes in body composition and increases the risk of metabolic complications, which can be partially reversed by hormone replacement therapy. Therefore, the idea of the supplementation of estrogen-like compounds to counteract obesity and related complications is compelling. Phytoestrogens are natural plant-derived dietary compounds that resemble human estrogens in their chemical structure and biological activity. Supplementation with phytoestrogens may confer a range of beneficial effects. However, results of studies on the influence of phytoestrogens on body composition and prevalence of obesity are inconsistent. In this review, we present data from in vitro, animal, and human studies regarding the role of phytoestrogens in adipose tissue development and function in the context of their potential application in the prevention of visceral obesity and related complications.

Flavonoid Profile of the Genista tridentata L., a Species Used Traditionally to Treat Inflammatory Processes

Ethnopharmacological surveys on Portuguese flora reveal that Genista tridentata L. is a shrub used in traditional medicine for the treatment of various inflammation-related health problems, although scientific support of its benefits is still necessary. In order to establish the anti-inflammatory potential of G. tridentata and support its traditional use, ethanolic extracts of three sections of the plant (root, stem, and leaves) were subjected to in vitro evaluation of anti-inflammatory activity using lipopolysaccharide (LPS)-stimulates macrophages as an inflammation model. Simultaneously, we also aimed to establish the extracts' flavonoids profile. The ethanolic extracts, obtained by Soxhlet extraction, profile of the three sections confirmed their richness in flavonoids, being three prenylated flavonoids isolated and characterized in the root, including a new natural compound, the 3-methoxymundulin. The extracts from the three plant sections showed strong antioxidant activity at the cellular level and significantly inhibit the LPS-triggered NO production by downregulating Nos2 gene transcription and consequently iNOS expression. Additionally, root and stem extracts also decreased the LPS-induced transcription of the pro-inflammatory genes Il1b, Il6, and Ptgs2. Thus, the results support the anti-inflammatory properties attributed to G. tridentate preparations. Relevantly, the roots of the shrub, plant part not used, is an unexplored source of compounds with pharmacological and nutraceutical value.

Nanodelivery of Natural Antioxidants: An Anti-aging Perspective

The aging process is known to be associated with heightened oxidative stress and related systemic inflammation. Therefore, antioxidant supplementation is regarded as a promising strategy to combat aging and associated pathological conditions. Food-grade antioxidants from plant-derived extracts are the most common ingredients of these supplements. Phyto-bioactive compounds such as curcumin, resveratrol, catechins, quercetin are among the most commonly applied natural compounds used as potential modulators of the free radical-induced cellular damages. The therapeutic potential of these compounds is, however, restricted by their low bioavailability related to poor solubility, stability, and absorbance in gastrointestinal tract. Recently, novel nanotechnology-based systems were developed for therapeutic delivery of natural antioxidants with improved bioavailability and, consequently, efficacy in clinical practice. Such systems have provided many benefits in preclinical research over the conventional preparations, including superior solubility and stability, extended half-life, improved epithelium permeability and bioavailability, enhanced tissue targeting, and minimized side effects. The present review summarizes recent developments in nanodelivery of natural antioxidants and its application to combat pathological conditions associated with oxidative stress.

Anti-inflammatory Property of AMP-activated Protein Kinase

BACKGROUND

One of the many debated topics in inflammation research is whether this scenario is really an accelerated form of human wound healing and immunityboosting or a push towards autoimmune diseases. The answer requires a better understanding of the normal inflammatory process, including the molecular pathology underlying the possible outcomes. Exciting recent investigations regarding severe human inflammatory disorders and autoimmune conditions have implicated molecular changes that are also linked to normal immunity, such as triggering factors, switching on and off, the influence of other diseases and faulty stem cell homeostasis, in disease progression and development.

METHODS

We gathered around and collected recent online researches on immunity, inflammation, inflammatory disorders and AMPK. We basically searched PubMed, Scopus and Google Scholar to assemble the studies which were published since 2010.

RESULTS

Our findings suggested that inflammation and related disorders are on the verge and interfere in the treatment of other diseases. AMPK serves as a key component that prevents various kinds of inflammatory signaling. In addition, our table and hypothetical figures may open a new door in inflammation research, which could be a greater therapeutic target for controlling diabetes, obesity, insulin resistance and preventing autoimmune diseases.

CONCLUSION

The relationship between immunity and inflammation becomes easily apparent. Yet, the essence of inflammation turns out to be so startling that the theory may not be instantly established and many possible arguments are raised for its clearance. However, this study might be able to reveal some possible approaches where AMPK can reduce or prevent inflammatory disorders.

Molecular Mechanisms of Action of Genistein in Cancer: Recent Advances

Background: Genistein is one among the several other known isoflavones that is found in different soybeans and soy products. The chemical name of genistein is 4′,5,7-trihydroxyisoflavone. Genistein has drawn attention of scientific community because of its potential beneficial effects on human grave diseases, such as cancer. Mechanistic insight of genistein reveals its potential for apoptotic induction, cell cycle arrest, as well as antiangiogenic, antimetastatic, and anti-inflammatory effects.

Objective: The purpose of this review is to unravel and analyze various molecular mechanisms of genistein in diverse cancer models.

Data sources: English language literature was searched using various databases, such as PubMed, ScienceDirect, EBOSCOhost, Scopus, Web of Science, and Cochrane Library. Key words used in various combinations included genistein, cancer, anticancer, molecular mechanisms prevention, treatment, in vivo, in vitro, and clinical studies.

Study selection: Study selection was carried out strictly in accordance with the statement of Preferred Reporting Items for Systematic Reviews and Meta-analyses.

Data extraction: Four authors independently carried out the extraction of articles.

Data synthesis: One hundred one papers were found suitable for use in this review.

Conclusion: This review covers various molecular interactions of genistein with various cellular targets in cancer models. It will help the scientific community understand genistein and cancer biology and will provoke them to design novel therapeutic strategies.

Effectiveness of Genistein Supplementation on Metabolic Factors and Antioxidant Status in Postmenopausal Women With Type 2 Diabetes Mellitus

OBJECTIVES

The risk of type 2 diabetes mellitus (T2DM) increases in women after menopause. Genistein is known to modulate metabolic pathways. The aim of this study was to investigate the effects of genistein supplementation on metabolic parameters, oxidative stress and obesity values in postmenopausal women with T2DM.

METHODS

This randomized, double-blind, placebo-controlled clinical trial was conducted on 54 postmenopausal women 47 to 69 years of age with T2DM. The genistein group (n=28) was given 2 genistein capsules daily for 12 weeks. Each capsule contained 54 mg genistein. The placebo group (n=26) received 2 placebo capsules daily for the same period. Fasting blood samples, anthropometric measurements, dietary intakes and physical activity levels of subjects were collected at baseline and at the end of the trial. Data were analyzed by independent t test, paired t test and analysis of covariance.

RESULTS

Genistein supplementation significantly reduced serum levels of fasting blood glucose (FBS), glycated hemoglobin (A1C), serum triglyceride (TG) and malondialdehyde (MDA) and increased total antioxidant capacity (TAC) compared with the placebo group at the end of the study (p<0.05 for all). Serum high-density lipoprotein cholesterol and quantitative insulin sensitivity check index significantly increased within the genistein group. Changes in anthropometric indexes and other variables were not significant in any of the groups.

CONCLUSIONS

Genistein administration improved FBS, A1C, serum TG, TAC and MDA in postmenopausal women with T2DM and may be useful in the control of metabolic status and oxidative stress in these subjects.

Genistein protects against doxorubicin-induced cardiotoxicity through Nrf-2/HO-1 signaling in mice model

Doxorubicin (DOX)-induced cardiomyopathy is a lethal disease. DOX-induced cardiotoxic effects are attributed towards increased redox status and apoptotic signaling. In this study, we show that genistein offers protection against DOX-induced cardio toxicity in the mice model. DOX-mediated increase in serum cardiac troponin and redox markers (ROS, LPO, 4-hydroxynonenal-protein adducts [HNE] levels) was significantly reduced by genistein treatment. Significantly increased TNF-α, IL-6, IL-8 expressions during DOX-induced inflammatory responses were down regulated by genistein treatment. Further, we found that genistein regulated antioxidant response through increased Nrf-2, HO-1, NQO1 protein expressions. In addition, DOX downregulated survival proteins (p-Akt, Bcl-2) with concomitant upregulation in Erk (1/2), Bax and cleaved caspase-3 expressions. The apoptotic activation was significantly downregulated by genistein treatment through suppression of apoptosis. Altogether, these findings show that genistein protects against DOX-induced cardiotoxic effects through activation of Nrf-2/HO-1 signaling.

Recent progress on biocompatible nanocarrier-based genistein delivery systems in cancer therapy

Diets with naturally occuring chemopreventive agents are showing good potentials in serving dual purposes: firstly, for maintaining health, and secondly, for emerging as most puissant cost-effective strategy against chronic diseases like cancer. Genistein, one of the active soy isoflavone, is gaining attention due to its ability to impede carcinogenic processes by regulating wide range of associated molecules and signalling mechanisms. Epidemiologic and preclinical evidences suggest that sufficient consumption of soy-based food having genistein can be correlated to the reduction of cancer risk. However, certain adverse effects like poor oral bioavailability, low aqueous solubility and inefficient pharmacokinetics have pushed it down in the list of phytoconstituents currently undergoing successful clinical trials. In order to maximise the utilisation of therapeutic benefits of this phytoestrogen, suitable drug carrier designs are required. Recently, nanocarriers, mainly composed of polymeric materials, are progressively and innovatively exploited with the aim to improve pharmacokinetics and pharmacodynamics of genistein. Here, we have briefly reviewed (a) the targeted molecular mechanisms of geinstein, (b) nanopolymeric approaches opted so far in designing carriers and (c) the reasons behind their restricted clinical applications. Finally, some mechanism-based approaches are proposed presenting genistein as the future paradigm in cancer therapy.

Genistein and Ascorbic Acid Reduce Oxidative Stress-Derived DNA Damage Induced by the Antileishmanial Meglumine Antimoniate

Meglumine antimoniate (Glucantime) is a pentavalent antimonial used to treat leishmaniasis, despite its acknowledged toxic effects, such as its ability to cause oxidative damage to lipids and proteins. Recently, our group demonstrated that meglumine antimoniate causes oxidative stress-derived DNA damage. Knowing that antioxidants modulate reactive oxygen species, we evaluated the capacity of genistein and ascorbic acid for preventing genotoxicity caused by meglumine antimoniate. For that, mice (n = 5/group) received genistein (via gavage) in doses of 5, 10, and 20 mg/kg for three consecutive days. After this period, they were treated with 810 mg/kg meglumine antimoniate via intraperitoneal (i.p.) route. Furthermore, mice (n = 5/group) simultaneously received ascorbic acid (i.p.) in doses of 30, 60, and 120 mg/kg and 810 mg/kg meglumine antimoniate. We also conducted post- and pretreatment assays, in which animals received ascorbic acid (60 mg/kg) 24 h prior to or after receiving meglumine antimoniate. Genomic instability and mutagenicity were analyzed through conventional comet assay and enzymatic assay using formamide pyrimidine DNA glycosylase (Fpg) enzyme, as well as the micronucleus test, respectively. Meglumine antimoniate induced an increase in the DNA damage after digestion with Fpg, reinforcing its mutagenic potential by oxidizing DNA bases, which was prevented by genistein. Similarly, ascorbic acid was capable of reducing mutagenic effects in simultaneous treatment as well as in posttreatment. Therefore, our results demonstrate that both compounds are efficient in preventing mutations in mammalian cells treated with meglumine antimoniate.

Anti-tumour effects of beta-sitosterol are mediated by AMPK/PTEN/HSP90 axis in AGS human gastric adenocarcinoma cells and xenograft mouse models

We investigated the anti-cancer effects of beta-sitosterol (BS), a plant-derived sterol in AGS human gastric adenocarcinoma cells and xenograft mouse models. BS significantly reduced cell viability by inducing apoptosis in AGS adenocarcinoma cells. This was accompanied by the formation of apoptotic bodies, as detected by Annexin V, caspase 3/7 activity, and MitoPotential assay. BS stimulated phosphatase and tensin homolog (PTEN) and phospho-AMP-activated protein kinase (p-AMPK) expression. Pharmacological inhibitors or siRNA were used to further analyse the relationship between the two proteins. AMPK was found to represent a likely upstream regulator of PTEN. Additionally, two-dimensional gel electrophoresis was used to identify related proteins in the treatment of BS. The decrease of Hsp90 protein by BS was observed. Induction of PTEN protein and reduction of Hsp90 was mediated by AICAR, an AMPK activator, indicating that AMPK is necessary for PTEN and Hsp90 expression. Additionally, BS was found to be effective through the regulation of cancer biomarker. Furthermore, BS suppressed tumour growth without toxicity in the AGS xenograft mouse models-. Taken together, the present results demonstrate that BS exerts anti-cancer effects in AGS cells and xenograft mouse models by mediating AMPK, PTEN, and Hsp90.

The potential health effects of dietary phytoestrogens

Phytoestrogens are plant-derived dietary compounds with structural similarity to 17-β-oestradiol (E2), the primary female sex hormone. This structural similarity to E2 enables phytoestrogens to cause (anti)oestrogenic effects by binding to the oestrogen receptors. The aim of the present review is to present a state-of-the-art overview of the potential health effects of dietary phytoestrogens. Various beneficial health effects have been ascribed to phytoestrogens, such as a lowered risk of menopausal symptoms like hot flushes and osteoporosis, lowered risks of cardiovascular disease, obesity, metabolic syndrome and type 2 diabetes, brain function disorders, breast cancer, prostate cancer, bowel cancer and other cancers. In contrast to these beneficial health claims, the (anti)oestrogenic properties of phytoestrogens have also raised concerns since they might act as endocrine disruptors, indicating a potential to cause adverse health effects. The literature overview presented in this paper illustrates that several potential health benefits of phytoestrogens have been reported but that, given the data on potential adverse health effects, the current evidence on these beneficial health effects is not so obvious that they clearly outweigh the possible health risks. Furthermore, the data currently available are not sufficient to support a more refined (semi) quantitative risk-benefit analysis. This implies that a definite conclusion on possible beneficial health effects of phytoestrogens cannot be made.

LINKED ARTICLES

This article is part of a themed section on Principles of Pharmacological Research of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.11/issuetoc.

Effects of genistein supplementation on genome‑wide DNA methylation and gene expression in patients with localized prostate cancer

Epidemiological studies have shown that dietary compounds have significant effects on prostate carcinogenesis. Among dietary agents, genistein, the major isoflavone in soybean, is of particular interest because high consumption of soy products has been associated with a low incidence of prostate cancer, suggesting a preventive role of genistein in prostate cancer. In spite of numerous studies to understand the effects of genistein on prostate cancer, the mechanisms of action have not been fully elucidated. We investigated the differences in methylation and gene expression levels of prostate specimens from a clinical trial of genistein supplementation prior to prostatectomy using Illumina HumanMethylation450 and Illumina HumanHT-12 v4 Expression BeadChip Microarrays. The present study was a randomized, placebo-controlled, double-blind clinical trial on Norwegian patients who received 30 mg genistein or placebo capsules daily for 3–6 weeks before prostatectomy. Gene expression changes were validated by quantitative PCR (qPCR). Whole genome methylation and expression profiling identified differentially methylated sites and expressed genes between placebo and genistein groups. Differentially regulated genes were involved in developmental processes, stem cell markers, proliferation and transcriptional regulation. Enrichment analysis suggested overall reduction in MYC activity and increased PTEN activity in genistein-treated patients. These findings highlight the effects of genistein on global changes in gene expression in prostate cancer and its effects on molecular pathways involved in prostate tumorigenesis.

The Phytoestrogen Genistein Affects Breast Cancer Cells Treatment Depending on the ERα/ERβ Ratio

Genistein (GEN) is a phytoestrogen found in soybeans. GEN exerts its functions through its interaction with the estrogen receptors (ER), ERα and ERβ, and we previously reported that the ERα/ERβ ratio is an important factor to consider in GEN-treated breast cancer cells. The aim of this study was to investigate the effects of GEN in breast cancer cells with different ERα/ERβ ratio: MCF-7 (high ratio), T47D (low ratio), and MCF-7 overexpressing ERβ (MCF7 + ERβ) treated with cisplatin (CDDP), paclitaxel (PTX) or tamoxifen (TAM). Cell viability, ROS production, autophagy, apoptosis, antioxidant enzymes protein levels, and cell cycle were analyzed. GEN treatment provoked an increase in cell viability in MCF-7 cells and in the antioxidant enzymes protein levels in combination with the cytotoxic agents, decreasing ROS production (CDDP + GEN and TAM+GEN) and autophagy (TAM + GEN) or apoptosis (CDDP + GEN and TAM + GEN). Moreover GEN treatment enhanced the cell cycle S phase entry in CDDP+GEN- and TAM + GEN-treated MCF-7 cells and, in the case of CDDP + GEN, increased the proportion of cells in the G2/M phase and decreased it in the subG0 /G1 phase. Otherwise, in the T47D and MCF7 + ERβ cells the combination of GEN with cytotoxic treatments did not cause significant changes in these parameters, even TAM + GEN-treated T47D cells showed less cell viability due to an increment in the autophagy. In conclusion, GEN consumption may be counterproductive in those patients receiving anticancer treatment with a high ERα/ERβ ratio diagnosed breast cancer and it could be harmless or even beneficial in those patients with a lower ERα/ERβ ratio breast cancer cells.

Standardized LC×LC-ELSD Fractionation Procedure for the Identification of Minor Bioactives via the Enzymatic Screening of Natural Extracts

To identify natural bioactive compounds from complex mixtures such as plant extracts, efficient fractionation for biological screening is mandatory. In this context, a fully automated workflow based on two-dimensional liquid chromatography (2D-LC × LC) was developed, allowing for the production of hundreds of semipure fractions per extract. Moreover, the ELSD response was used for online sample weight estimation and automated concentration normalization for subsequent bioassays. To evaluate the efficiency of this protocol, an enzymatic assay was developed using AMP-activated protein kinase (AMPK). The activation of AMPK by nonactive extracts spiked with biochanin A, a known AMPK activator, was enhanced greatly when the fractionation workflow was applied compared to screening crude spiked extracts. The performance of the workflow was further evaluated on a red clover (Trifolium pratense) extract, which is a natural source of biochanin A. In this case, while the crude extract or 1D chromatography fractions failed to activate AMPK, semipure fractions containing biochanin A were readily localized when produced by the 2D-LC×LC-ELSD workflow. The automated fractionation methodology presented demonstrated high efficiency for the detection of bioactive compounds at low abundance in plant extracts for high-throughput screening. This procedure can be used routinely to populate natural product libraries for biological screening.

Bovine and soybean milk bioactive compounds: Effects on inflammatory response of human intestinal Caco-2 cells

In this study the effects of commercial bovine and soybean milks and their bioactive compounds, namely genistein, daidzein and equol, on the inflammatory responses induced by lipopolysaccharide (LPS) treatment of human intestinal Caco-2 cells were examined, in terms of nitric oxide (NO) release and inducible nitric oxide synthetase (iNOS) expression. Both milks and their bioactive compounds significantly inhibited, dose-dependently, the expression of iNOS mRNA and protein, resulting in a decreased NO production. The NF-κB activation in LPS-stimulated intestinal cells was also examined. In all cases we observed that cell pre-treatment before LPS activation inhibited the IkB phosphorylation. Accordingly, quantification of bioactive compounds by solid phase microextraction coupled with liquid chromatography has shown that they were absorbed, metabolized and released by Caco-2 cells in culture media. In conclusion, we demonstrated that milks and compounds tested are able to reduce LPS-induced inflammatory responses from intestinal cells, interfering with NF-kB dependent molecular mechanisms.

AMPK Facilitates Nuclear Accumulation of Nrf2 by Phosphorylating at Serine 550

Nrf2 (nuclear factor erythroid 2-related factor 2) is an antioxidant transcription factor. AMP-activated protein kinase (AMPK) functions as a central regulator of cell survival in response to stressful stimuli. Nrf2 should be coordinated with the cell survival pathway controlled by AMPK, but so far the mechanistic connections remain undefined. This study investigated the role of AMPK in Nrf2 trafficking and its activity regulation. A subnetwork integrating neighbor molecules suggested direct interaction between AMPK and Nrf2. In cells, AMPK activation caused nuclear accumulation of Nrf2. In the in vitro kinase and peptide competition assays, AMPK phosphorylated Nrf2 at the Ser558 residue (Ser550 in mouse) located in the canonical nuclear export signal. Nrf2 with an S550A mutation failed to be accumulated in the nucleus after AMPK activation. Leptomycin B, a nuclear export inhibitor, did not enhance nuclear accumulation of wild-type Nrf2 (WT-Nrf2) activated by AMPK or a phospho-Ser550-mimetic Nrf2 mutant, corroborating the finding that AMPK facilitated nuclear accumulation of Nrf2, probably by inhibiting nuclear export. Activated glycogen synthase kinase 3β (GSK3β) diminished the basal nuclear level of Myc-S550A-Nrf2. Taking the data collectively, AMPK phosphorylates Nrf2 at the Ser550 residue, which, in conjunction with AMPK-mediated GSK3β inhibition, promotes nuclear accumulation of Nrf2 for antioxidant response element (ARE)-driven gene transactivation.

Innovative Soaking and Grinding Methods and Cooking Affect the Retention of Isoflavones, Antioxidant and Antiproliferative Properties in Soymilk Prepared from Black Soybean

This study's objective was to characterize the effect of traditional and 3 newly devised (soaking+grinding) methods combined with cooking on the content and composition of phenolic substances, antioxidant, and antiproliferative properties of soymilk prepared from black soybean. Phenolic substances and antioxidant profile were characterized and antiproliferation of prostate cancer DU145 cells was conducted using a cell culture assay. Results indicated Grinding Method 4 produced significantly (P < 0.05) higher total phenolic content (TPC), total flavonoid content (TFC), condensed tannin content (CTC), and total isoflavone content in both raw and cooked black soymilk as compared to Method 1. Cooking soymilk reduced 23% to 38% of total phenolic substances. Raw black soymilk produced by Method 4 displayed the highest antioxidant capability, which was determined using ORAC, FRAP, and DPPH assays, and a higher antiprostate cell proliferation ability. Cooking only slightly reduced the potency to inhibit DU145 prostate cancer cells as IC50 value was increased from the average of about 4.0 mg/mL of raw soymilk extracts to 5.5 mg/mL of cooked soymilk extracts of all grinding methods. Overall, total isoflavone content was the only component that was negatively correlated with IC50 value (r = -0.93, P < 0.05) which indicates the ability to inhibit prostate cancer cell is associated with the increase in total isoflavone content, not with any other phenolic substances or antioxidant properties.

Genistein-induced LKB1-AMPK activation inhibits senescence of VSMC through autophagy induction

Genistein, the primary isoflavone from soy products, enhances antioxidant enzyme activities and inhibits tyrosine kinase. However, the mechanisms underlying genistein-induced autophagy are not yet completely understood. Autophagy refers to a regulated cellular process for the lysosomal-dependent turnover of organelles and proteins. During starvation or nutrient deficiency, autophagy provides an endogenous mechanism for prolonging survival. Here, we investigated whether genistein exerts autophagic effects through the activation of LKB1-AMPK signaling in VSMCs. Genistein dose- and time-dependently increased the phosphorylation of LKB1 and AMPK in VSMCs. LKB1 and AMPK induced autophagy through the downregulation of mTOR in VSMCs. Genistein-induced autophagy was inhibited in dominant-negative AMPK-transfected cells, whereas it was accelerated in cells transfected with the constitutively active form of AMPK. Increased autophagosome activity was confirmed by a concentration-dependent increase in LC3-II formation on Western blots and by increased perinuclear LC3-II puncta in genistein-treated VSMCs. Furthermore, genistein-induced autophagy attenuated adriamycin-induced SA-b-gal staining. These results suggest that genistein-dependent autophagy diminishes VSMC senescence and genistein may attenuate the VSMC senescence via an LKB1-AMPK-dependent mechanism.

The Role of Soy Phytoestrogens on Genetic and Epigenetic Mechanisms of Prostate Cancer

Soy phytoestrogens are dietary components with considerable effects on reducing the incidence of prostate cancer. Epidemiological studies demonstrated that occurrence of prostate cancer is relatively low in Asia and Southern Europe, a status associated with consuming of soy isoflavones, such as genistein, daidzein, and glycitein. Soy phytoestrogens exert their activity on molecular mechanisms, including cell-cycle control, induction of apoptosis, inhibition of angiogenesis, and metastasis. In addition, they have antioxidant activity and show regulatory effect on the expression of genes involved in DNA damage and repair. Furthermore, the epigenetic regulation of gene expression can be modified by soy phytoestrogens. They show regulatory effects on gene activity by altering DNA methylation and/or histone modification patterns. In this chapter, we discuss the role of soy phytoestrogens on the genetic and epigenetic mechanisms of prostate cancer. We attempt to provide further insight in order to understand the underlying mechanisms of protective effects of soy phytoestrogens in preventing prostate cancer.

Genistein ameliorates cardiac inflammation and oxidative stress in streptozotocin-induced diabetic cardiomyopathy in rats

The present study was undertaken to evaluate the protective effects of genistein against cardiac inflammation and oxidative stress in streptozotocin (STZ) (45 mg/kg body weight)-induced diabetic rats. genistein (300 mg/kg/day) was administered orally for 24 weeks to STZ-induced diabetic rats. The effects of genistein on blood glucose, % glycosylated hemoglobin (HbA1c), C-reactive protein, tumor necrosis factor (TNF- α), transforming growth factor (TGF-β1), and total antioxidant were studied. Ultrastructural and histopathological assessment of injury were also undertaken using transmission electron microscope. STZ-induced diabetes resulted in significant increase in the levels of blood glucose, HbA1c, C-reactive protein, TNF- α and TGF-β1, and a decline in total antioxidant reserve of the myocardium. Administration of genistein to diabetic rats resulted in a decrease in blood glucose (p < 0.001), % HbA1c (p < 0.0001), C-reactive protein (p < 0.001), and expression of TNF- α (p < 0.001) and TGF-β1 (p < 0.0001) proteins. In addition, genistein treatment results in augmentation of total antioxidant (p < 0.01) reserve of the hearts. The above findings were supported by histological as well as immunohistochemical localization of NF-κB (p65) in the heart. Genistein treatment ameliorated the ultrastructural degenerative changes in the cardiac tissues as compared to the diabetic control. The result demonstrates that genistein restored the integrity of the diabetic myocardium by virtue of its anti-inflammatory and antioxidant effects.