Apoptotic effects of genistein, biochanin-A and apigenin on LNCaP and PC-3 cells by p21 through transcriptional inhibition of polo-like kinase-1

Cellular and Molecular Mechanisms Modulated by Genistein in Cancer

Genistein (4',5,7-trihydroxyisoflavone) is a phytoestrogen belonging to a subclass of natural flavonoids that exhibits a wide range of pharmacological functions, including antioxidant and anti-inflammatory properties. These characteristics make genistein a valuable phytochemical compound for the prevention and/or treatment of cancer. Genistein effectively inhibits tumor growth and dissemination by modulating key cellular mechanisms. This includes the suppression of angiogenesis, the inhibition of epithelial-mesenchymal transition, and the regulation of cancer stem cell proliferation. These effects are mediated through pivotal signaling pathways such as JAK/STAT, PI3K/Akt/mTOR, MAPK/ERK, NF-κB, and Wnt/β-catenin. Moreover, genistein interferes with the function of specific cyclin/CDK complexes and modulates the activation of Bcl-2/Bax and caspases, playing a critical role in halting tumor cell division and promoting apoptosis. The aim of this review is to discuss in detail the key cellular and molecular mechanisms underlying the pleiotropic anticancer effects of this flavonoid.

The Pros and Cons of Estrogens in Prostate Cancer: An Update with a Focus on Phytoestrogens

The role of estrogens in prostate cancer (PCa) is shrouded in mystery, with its actions going from angelic to devilish. The findings by Huggins and Hodges establishing PCa as a hormone-sensitive cancer have provided the basis for using estrogens in therapy. However, despite the clinical efficacy in suppressing tumor growth and the panoply of experimental evidence describing its anticarcinogenic effects, estrogens were abolished from PCa treatment because of the adverse secondary effects. Notwithstanding, research work over the years has continued investigating the effects of estrogens, reporting their pros and cons in prostate carcinogenesis. In contrast with the beneficial therapeutic effects, many reports have implicated estrogens in the disruption of prostate cell fate and tissue homeostasis. On the other hand, epidemiological data demonstrating the lower incidence of PCa in Eastern countries associated with a higher consumption of phytoestrogens support the beneficial role of estrogens in counteracting cancer development. Many studies have investigated the effects of phytoestrogens and the underlying mechanisms of action, which may contribute to developing safe estrogen-based anti-PCa therapies. This review compiles the existing data on the anti- and protumorigenic actions of estrogens and summarizes the anticancer effects of several phytoestrogens, highlighting their promising features in PCa treatment.

Apigenin: Molecular Mechanisms and Therapeutic Potential against Cancer Spreading

Due to its propensity to metastasize, cancer remains one of the leading causes of death worldwide. Thanks in part to their intrinsic low cytotoxicity, the effects of the flavonoid family in the prevention and treatment of various human cancers, both in vitro and in vivo, have received increasing attention in recent years. It is well documented that Apigenin (4',5,7-trihydroxyflavone), among other flavonoids, is able to modulate key signaling molecules involved in the initiation of cancer cell proliferation, invasion, and metastasis, including JAK/STAT, PI3K/Akt/mTOR, MAPK/ERK, NF-κB, and Wnt/β-catenin pathways, as well as the oncogenic non-coding RNA network. Based on these premises, the aim of this review is to emphasize some of the key events through which Apigenin suppresses cancer proliferation, focusing specifically on its ability to target key molecular pathways involved in angiogenesis, epithelial-to-mesenchymal transition (EMT), maintenance of cancer stem cells (CSCs), cell cycle arrest, and cancer cell death.

Comprehensive exploration of Biochanin A as an oncotherapeutics potential in the treatment of multivarious cancers with molecular insights

Cancer is considered a leading cause of mortality. This rising cancer death rate and several existing limitations like side effects, poor efficacies, and high cost of the present chemotherapeutic agents have increased the demand for more potent and alternative cancer treatments. This review elucidated a brief overview of Biochanin A (BCA) and its potentiality on various cancers with details of anticancer mechanism. According to our review, a number of studies including in silico, in vitro, pre-clinical, and clinical trials have tested to evaluate the efficacy of BCA. This compound is effective against 15 types of cancer, including breast, cervical, colorectal, gastric, glioblastoma, liver, lung, melanoma, oral, osteosarcoma, ovarian, pancreatic, pharynx, prostate, and umbilical vein cancer. The general anticancer activities of this compound are mediated via several molecular processes, including regulation of apoptosis, cell proliferation, metastasis and angiogenesis, signaling, enzymatic pathways, and other mechanisms. Targeting both therapeutic and oncogenic proteins, as well as different pathways, makes up the molecular mechanism underlying the anticancer action. Many signaling networks and their components, such as EFGR, PI3K/Akt/mTOR, MAPK, MMP-2, MMP-9, PARP, Caspase-3/8/9, Bax, Bcl2, PDL-1, NF-κB, TNF-α, IL-6, JAK, STAT3, VEGFR, VEGF, c-MY, Cyclin B1, D1, E1 and CDKs, Snail, and E-cadherin proteins, can be regulated in cancer cells by BCA. Such kind of anticancer properties of BCA could be a result of its correct structural chemistry. The use of BCA-based therapies as nano-carriers for the delivery of chemotherapeutic medicines has the potential to be very effective. This natural compound synergises with other natural compounds and standard drugs, including sorafenib, 5-fluorouracil, temozolomide, doxorubicin, apigenin, and genistein. Moreover, proper use of this compound can reverse multidrug resistance through numerous mechanisms. BCA has better drug-likeness and pharmacokinetic properties and is nontoxic (eye, liver, kidney, skin, cardio) in human bodies. As having a wide range of cancer-fighting mechanisms, synergistic effects, and good pharmacokinetic properties, BCA can be used as a supplementary food until standard drugs are available at pharma markets.

Effect of Apigenin on Neurodegenerative Diseases

Neurodegenerative diseases (NDDs), such as Alzheimer's and Parkinson's, are the most frequent age-related illnesses affecting millions worldwide. No effective medication for NDDs is known to date and current disease management approaches include neuroprotection strategies with the hope of maintaining and improving the function of neurons. Such strategies will not provide a cure on their own but are likely to delay disease progression by reducing the production of neurotoxic chemicals such as reactive oxygen species (ROS) and related inflammatory chemicals. Natural compounds such as flavonoids that provide neuroprotection via numerous mechanisms have attracted much attention in recent years. This review discusses evidence from different research models and clinical trials on the therapeutic potential of one promising flavonoid, apigenin, and how it can be helpful for NDDs in the future prospects. We have also discussed its chemistry, mechanism of action, and possible benefits in various examples of NDDs.

Mechanisms Behind the Pharmacological Application of Biochanin-A: A review

This review was aimed at summarizing the cellular and molecular mechanisms behind the various pharmacological actions of biochanin-A. Many studies have been reported claiming its application in cancers, metabolic disorders, airway hyperresponsiveness, cardiac disorders, neurological disorders, etc. With regard to hormone-dependent cancers like breast, prostate, and other malignancies like pancreatic, colon, lung, osteosarcoma, glioma that has limited treatment options, biochanin-A revealed agreeable results in arresting cancer development. Biochanin-A has also shown therapeutic benefits when administered for neurological disorders, diabetes, hyperlipidaemia, and other chronic diseases/disorders. Isoflavones are considered phenomenal due to their high efficiency in modifying the physiological functions of the human body. Biochanin-A is one among the prominent isoflavones found in soy (glycine max), red clover (Trifolium pratense), and alfalfa sprouts, etc., with proven potency in modulating vital cellular mechanisms in various diseases. It has been popular for ages among menopausal women in controlling symptoms. In view of the multi-targeted functions of biochanin-A, it is essential to summarize it's mechanism of action in various disorders. The safety and efficacy of biochanin-A needs to be established in clinical trials involving human subjects. Biochanin-A might be able to modify various systems of the human body like the cardiovascular system, CNS, respiratory system, etc. It has shown a remarkable effect on hormonal cancers and other cancers. Many types of research on biochanin-A, particularly in breast, lung, colon, prostate, and pancreatic cancers, have shown a positive impact. Through modulating oxidative stress, SIRT-1 expression, PPAR gamma receptors, and other multiple mechanisms biochanin-A produces anti-diabetic action. The diverse molecular mechanistic pathways involved in the pharmacological ability of biochanin-A indicate that it is a very promising molecule and can play a major impact in modifying several physiological functions.

Inflammation in Prostate Cancer: Exploring the Promising Role of Phenolic Compounds as an Innovative Therapeutic Approach

Prostate cancer (PCa) remains a significant global health concern, being a major cause of cancer morbidity and mortality worldwide. Furthermore, profound understanding of the disease is needed. Prostate inflammation caused by external or genetic factors is a central player in prostate carcinogenesis. However, the mechanisms underlying inflammation-driven PCa remain poorly understood. This review dissects the diagnosis methods for PCa and the pathophysiological mechanisms underlying the disease, clarifying the dynamic interplay between inflammation and leukocytes in promoting tumour development and spread. It provides updates on recent advances in elucidating and treating prostate carcinogenesis, and opens new insights for the use of bioactive compounds in PCa. Polyphenols, with their noteworthy antioxidant and anti-inflammatory properties, along with their synergistic potential when combined with conventional treatments, offer promising prospects for innovative therapeutic strategies. Evidence from the use of polyphenols and polyphenol-based nanoparticles in PCa revealed their positive effects in controlling tumour growth, proliferation, and metastasis. By consolidating the diverse features of PCa research, this review aims to contribute to increased understanding of the disease and stimulate further research into the role of polyphenols and polyphenol-based nanoparticles in its management.

A comprehensive view on the apigenin impact on colorectal cancer: Focusing on cellular and molecular mechanisms

Colon cancer (CC) is one of the most common and deadly cancers worldwide. Oncologists are facing challenges such as development of drug resistance and lack of suitable drug options for CC treatment. Flavonoids are a group of natural compounds found in fruits, vegetables, and other plant-based foods. According to research, they have a potential role in the prevention and treatment of cancer. Apigenin is a flavonoid that is present in many fruits and vegetables. It has been used as a natural antioxidant for a long time and has been considered due to its anticancer effects and low toxicity. The results of this review study show that apigenin has potential anticancer effects on CC cells through various mechanisms. In this comprehensive review, we present the cellular targets and signaling pathways of apigenin indicated to date in in vivo and in vitro CC models. Among the most important modulated pathways, Wnt/β-catenin, PI3K/AKT/mTOR, MAPK/ERK, JNK, STAT3, Bcl-xL and Mcl-1, PKM2, and NF-kB have been described. Furthermore, apigenin suppresses the cell cycle in G2/M phase in CC cells. In CC cells, apigenin-induced apoptosis is increased by inhibiting the formation of autophagy. According to the results of this study, apigenin appears to have the potential to be a promising agent for CC therapy, but more research is required in the field of pharmacology and pharmacokinetics to establish the apigenin effects and its dosage for clinical studies.

MKK4 Inhibitors-Recent Development Status and Therapeutic Potential

MKK4 (mitogen-activated protein kinase kinase 4; also referred to as MEK4) is a dual-specificity protein kinase that phosphorylates and regulates both JNK (c-Jun N-terminal kinase) and p38 MAPK (p38 mitogen-activated protein kinase) signaling pathways and therefore has a great impact on cell proliferation, differentiation and apoptosis. Overexpression of MKK4 has been associated with aggressive cancer types, including metastatic prostate and ovarian cancer and triple-negative breast cancer. In addition, MKK4 has been identified as a key regulator in liver regeneration. Therefore, MKK4 is a promising target both for cancer therapeutics and for the treatment of liver-associated diseases, offering an alternative to liver transplantation. The recent reports on new inhibitors, as well as the formation of a startup company investigating an inhibitor in clinical trials, show the importance and interest of MKK4 in drug discovery. In this review, we highlight the significance of MKK4 in cancer development and other diseases, as well as its unique role in liver regeneration. Furthermore, we present the most recent progress in MKK4 drug discovery and future challenges in the development of MKK4-targeting drugs.

Evaluation of Hypoglycemic Activity and Sub-Acute Toxicity of the Novel Biochanin A–Chromium(III) Complex

The novel biochanin A–chromium(III) complex was synthesized by chelating chromium with biochanin A (BCA). The structure of the complex was determined and the complex ([CrBCA3]) was composed of chromium(III) and three ligands, and the chromium content was 55 μg/mg. The hypoglycemic activity of the complex was studied in db/db mice and C57 mice. The sub-acute toxicity test of the complex was carried out by the maximum limit method in KM mice. The hypoglycemic activity showed that the complex could reduce the weight of db/db mice and lower the fasting blood glucose and random blood glucose levels. The complex also improved the organ index, oral glucose tolerance test (OGTT) and insulin tolerance test (ITT) results of db/db mice, and some of the indicators were similar to those of the positive control group after treatment with the complex. The histopathology study showed significant improvements in the liver, kidney, pancreas and skeletal muscle compared with the diabetes model group. The complex also showed a significant improvement in serum biochemical indices and antioxidant enzyme activities, as well as glycogen levels. The sub-acute toxicity study showed that the complex did not cause death or any dangerous symptoms during the study. In addition, the sub-acute toxicity study showed that the complex had no significant effect on the serum biochemical indices, antioxidant capacity and organs of normal mice. This study showed that [CrBCA3] had good hypoglycemic activity in vivo and had no sub-acute toxicity. This work provides an important reference for the development of functional hypoglycemic foods or drugs.

Activity of isoflavone biochanin A in chronic experimental toxoplasmosis: impact on inflammation

Toxoplasma gondii is a worldwide prevalent parasite. The infection has been linked to variable inflammatory effects including neuroinflammation. Biochanin A (BCA) is an isoflavone, known for its anti-inflammatory and anti-oxidative properties. In this study, we examined the effect of BCA on the brain and liver inflammatory lesions in a murine model with chronic toxoplasmosis. Mice were divided in to six groups: non-infected control, non-infected BCA-treated, and four infected groups with Toxoplasmagondii Me49-type II cystogenic strain: infected control, BCA (50 mg/kg/day)-treated, combined BCA/cotrimoxazole-treated and cotrimoxazole (370 mg/kg/day) alone-treated. Gene expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and inducible nitric oxide synthase (iNOS) was evaluated by quantitative real-time PCR in the brain and liver tissues. In the infected control group, an upregulation of TNF-α and IL-1β mRNA expression levels was found. However, a downregulation of iNOS expression was detected in the brain of infected control mice. In both BCA- and combined-treated groups, the brain and liver tissues showed significantly reduced inflammatory lesions compared to the infected control mice with inhibited TNF-α and IL-1β mRNA levels. The iNOS expression levels in the brain tissues of BCA group were significantly higher than the levels of the infected control group. BCA alone or combined significantly reduced T. gondii cyst count in the brain tissues. In conclusion, the anti-inflammatory activity of BCA was demonstrated in the brain tissues of mice with chronic toxoplasmosis with decreased TNF-α and IL-1β expression levels and increased iNOS expression levels.

The effect of apigenin and chemotherapy combination treatments on apoptosis-related genes and proteins in acute leukaemia cell lines

Apigenin is a dietary polyphenol found abundantly in fruit and vegetables, which sensitizes leukaemia cells to topoisomerase inhibitor agents (e.g., etoposide), and alkylating agents (e.g., cyclophosphamide), reducing ATP levels and inducing apoptosis; whilst being protective to control haematopoietic stem cells. This study analysed the expression profiles of intrinsic and extrinsic apoptosis-related genes and proteins to help elucidate the mechanisms of action of apigenin when used in combination with etoposide or cyclophosphamide in lymphoid and myeloid leukaemia cell lines (Jurkat and THP-1). Expression of apoptosis-related genes were measured using a TaqMan® Human Apoptosis Array and the StepOne Plus RT-qPCR System, whilst apoptosis-related proteins were determined using a protein profiler™-human apoptosis array and the LI-COR Odyssey^R Infrared Imaging System. Apigenin when combined with etoposide or cyclophosphamide-induced apoptosis via the mitochondrial pathway, increasing the expression of pro-apoptotic cytochrome c, SMAC/DIABLO, and HTRA2/OMI, which promoted caspase-9 and -3 activation. Targeting anti-apoptotic and/or pro-apoptotic members of the apoptotic pathways is a promising strategy to induce cancer cell death and improve sensitivity to chemotherapy agents. Here the apoptotic pathways induced by apigenin in combination with etoposide or cyclophosphamide were identified within human leukaemia cell lines, such applications could provide combination therapies for the treatment of leukaemia.

Protective Roles of Apigenin Against Cardiometabolic Diseases: A Systematic Review

Apigenin is a flavonoid with antioxidant, anti-inflammatory, and anti-apoptotic activity. In this study, the potential effects of apigenin on cardiometabolic diseases were investigated in vivo and in vitro. Potential signaling networks in different cell types induced by apigenin were identified, suggesting that the molecular mechanisms of apigenin in cardiometabolic diseases vary with cell types. Additionally, the mechanisms of apigenin-induced biological response in different cardiometabolic diseases were analyzed, including obesity, diabetes, hypertension and cardiovascular diseases. This review provides novel insights into the potential role of apigenin in cardiometabolic diseases.

Role of Induced Programmed Cell Death in the Chemopreventive Potential of Apigenin

The flavonoid apigenin (4′,5,7-trihydroxyflavone), which is one of the most widely distributed phytochemicals in the plant kingdom, is one of the most thoroughly investigated phenolic components. Previous studies have attributed the physiological effects of apigenin to its anti-allergic, antibacterial, antidiabetic, anti-inflammatory, antioxidant, antiviral, and blood-pressure-lowering properties, and its documented anticancer properties have been attributed to the induction of apoptosis and autophagy, the inhibition of inflammation, angiogenesis, and cell proliferation, and the regulation of cellular responses to oxidative stress and DNA damage. The most well-known mechanism for the compound’s anticancer effects in human cancer cell lines is apoptosis, followed by autophagy, and studies have also reported that apigenin induces novel cell death mechanisms, such as necroptosis and ferroptosis. Therefore, the aim of this paper is to review the therapeutic potential of apigenin as a chemopreventive agent, as well as the roles of programmed cell death mechanisms in the compound’s chemopreventive properties.

Biochanin-A: A Bioactive Natural Product with Versatile Therapeutic Perspectives

BACKGROUND

Biochanin-A (5,7 dihydroxy 4 methoxy isoflavone) is a phytochemical phytoestrogen that is highly effective against various diseases. Biochanin-A is a nutritional and dietary isoflavonoid naturally present in red clover, chickpea, soybeans and other herbs. Biochanin- A possesses numerous biological activities.

OBJECTIVE

The study focused on collective data of therapeutic activities of Biochanin-A.

METHODS

According to the literature, biochanin-A revealed a range of activities starting from chemoprevention, by hindering cell growth, activation of tumor cell death, hampering metastasis, angiogenic action, cell cycle regulation, neuroprotection, by controlling microglial activation, balancing antioxidants, elevating the neurochemicals, suppressing BACE-1, NADPH oxidase hindrance to inflammation, by mitigating the MAPK and NF- κB, discharge of inflammatory markers, upregulating the PPAR-γ, improving the function of heme oxygenase-1, erythroid 2 nuclear factors, detoxifying the oxygen radicals and stimulating the superoxide dismutase action, and controlling its production of transcription factors. Against pathogens, biochanin-A acts by dephosphorylating tyrosine kinase proteins, obstructing gram-negative bacteria, suppressing the development of cytokines from viruses, and improving the action of a neuraminidase cleavage of caspase-3, and acts as an efflux pump inhibitor. In metabolic disorders, biochanin-A acts by encouraging transcriptional initiation and inhibition, activating estrogen receptors, and increasing the activity of differentiation, autophagy, inflammation, and blood glucose metabolism.

CONCLUSION

Therefore, biochanin-A could be used as a therapeutic drug for various pathological conditions and treatments in human beings.

In Vitro Evaluation of Antioxidant and Anticancer Activity of Lemongrass (Cymbopogon citratus (D.C.) Stapf)

Cancer is considered a multifactorial disease and its development could be associated with several factors, for example, rotenone exposition. Unfortunately, many cancers are resistant to chemotherapy, as cervical cancer. Regarding this, lemongrass is a remarkable natural product that presents antioxidant and anticancer activities, which could show therapeutic action against rotenone and cervical cancer. Thus, this study aimed to investigate the antioxidant and anticancer action of lemongrass. An in vitro study was conducted using VERO (kidney cells) and SiHa cell lines (cervical cancer cells). VERO cells were exposed to rotenone and lemongrass extract for 24 and 72 h. While SiHa cells were exposed to lemongrass isolated and associated to chemotherapy, 5-fluorouracil, during 24 and 48 h. After, levels of viability, proliferation, and oxidative metabolism were determined. The results showed that lemongrass presents antioxidant activity on VERO cells by increasing cell viability and proliferation and decreasing oxidative stress caused by rotenone. Moreover, lemongrass showed anticancer activity by decreasing cell viability and increasing oxidative stress parameters on SiHa. Besides, lemongrass had no alteration in the chemotherapy activity. Therefore, this study revealed that lemongrass presents antioxidant and anticancer activity since it can protect against the cytotoxicity of rotenone and reduce the cell viability of cervical cancer.

An In Vitro-In Vivo Evaluation of the Antiproliferative and Antiangiogenic Effect of Flavone Apigenin against SK-MEL-24 Human Melanoma Cell Line

One of the most important class of natural compounds with successful preclinical results in the management of cancer is the flavonoids. Due to the plethora of biological activities, apigenin (4',5,7 trihydroxyflavone) is a main representant of the flavone subclass. Although the antiproliferative and antiangiogenic effects of apigenin were studied on a significant number of human and murine melanoma cell lines, in order to complete the data existing in the literature, the aim of this study is to evaluate the in vitro effect of apigenin on SK-MEL-24 human melanoma cell line as well as in vivo on tumor angiogenesis using the aforementioned cell line on the chorioallantoic membrane assay. Results have shown that in the range of tested doses, the phytocompound presents significant antiproliferative, cytotoxic, and antimigratory potential at 30 μM, respectively, 60 μM. Moreover, the phytocompound in both tested concentrations limited melanoma cell growth and migration and induced a reduced angiogenic reaction limiting melanoma cell development.

Phytochemicals in Chemoprevention: A Cost-Effective Complementary Approach

Cancer is one of the leading causes of death across the world. Although conventional cancer treatments such as chemotherapy and radiotherapy have effectively decreased cancer progression, they come with many dose-limiting side-effects. Phytochemicals that naturally occur in spices, fruits, vegetables, grains, legumes, and other common foods are surprisingly effective complements to conventional cancer treatments. These biologically active compounds demonstrate anticancer effects via cell signaling pathway interference in cancerous cells. In addition, phytochemicals protect non-cancerous cells from chemotherapy-induced side-effects. This paper addresses the not only the potential of phytochemicals quercetin, isoflavones, curcumin, catechins, and hesperidin in terms of cancer treatment and protection against side-effects of chemotherapy, but also methods for increasing phytochemical bioavailability.

Eupatilin Inhibits the Proliferation and Migration of Prostate Cancer Cells through Modulation of PTEN and NF-κB Signaling

BACKGROUND

Despite advances in the treatment of prostate cancer, side effects and the risks of developing drug resistance require new therapeutic agents. Eupatilin is a secondary metabolite of Artemisia asiatica and has shown potential anti-tumor activity in some cancers, but its potential in prostate cancer treatment has not yet been evaluated.

OBJECTIVE

The aim of the study was to investigate the effectiveness of eupatilin on prostate cancer cell proliferation and migration.

METHODS

Human prostate cancer PC3 and LNCaP cells were exposed to eupatilin and its efficacy on cell survival was determined by the MTT test. Apoptosis and cell cycle phases were evaluated by an image-based cytometer. Cell migration and invasion were evaluated by wound healing and matrigel migration assays; the expression of mRNA and protein was assessed by RT-qPCR and Western blot, respectively.

RESULTS

Eupatilin time- and dose-dependently reduced the viability of prostate cancer cells. Exposure of PC3 cells to 12.5μM-50μM eupatilin resulted in apoptosis by upregulating the expression of caspase 3, Bax and cytochrome c. Annexin V assessment also confirmed that eupatilin causes apoptosis. The treatment significantly upregulated the mRNA expression of p53, p21, and p27, causing cell cycle arrest in the G1 phase. Administration of eupatilin inhibited migration and invasion of the cells by downregulating the expression of Twist, Slug and MMP-2, -7. In addition, the agent increased protein expression of tumor suppressor PTEN, while transcription factor NF-κB expression was reduced.

CONCLUSION

Eupatilin strongly prevents the proliferation of prostate cancer cells, and suppresses migration and invasion. Due to its therapeutic potential, the clinical use of eupatilin in prostate cancer should also be supported by in vivo studies.

Rationalizing the therapeutic potential of apigenin against cancer

BACKGROUND

Despite the remarkable advances made in the diagnosis and treatment of cancer during the past couple of decades, it remains the second largest cause of mortality in the world, killing approximately 9.6 million people annually. The major challenges in the treatment of the advanced stage of this disease are the development of chemoresistance, severe adverse effects of the drugs, and high treatment cost. Therefore, the development of drugs that are safe, efficacious, and cost-effective remains a 'Holy Grail' in cancer research. However, the research over the past four decades shed light on the cancer-preventive and therapeutic potential of natural products and their underlying mechanism of action. Apigenin is one such compound, which is known to be safe and has significant potential in the prevention and therapy of this disease.

AIM

To assess the literature available on the potential of apigenin and its analogs in modulating the key molecular targets leading to the prevention and treatment of different types of cancer.

METHOD

A comprehensive literature search has been carried out on PubMed for obtaining information related to the sources and analogs, chemistry and biosynthesis, physicochemical properties, biological activities, bioavailability and toxicity of apigenin.

KEY FINDINGS

The literature search resulted in many in vitro, in vivo and a few cohort studies that evidenced the effectiveness of apigenin and its analogs in modulating important molecular targets and signaling pathways such as PI3K/AKT/mTOR, JAK/STAT, NF-κB, MAPK/ERK, Wnt/β-catenin, etc., which play a crucial role in the development and progression of cancer. In addition, apigenin was also shown to inhibit chemoresistance and radioresistance and make cancer cells sensitive to these agents. Reports have further revealed the safety of the compound and the adaptation of nanotechnological approaches for improving its bioavailability.

SIGNIFICANCE

Hence, the present review recapitulates the properties of apigenin and its pharmacological activities against different types of cancer, which warrant further investigation in clinical settings.

Reverted effect of mesenchymal stem cells in glioblastoma treated with agathisflavone and its selective antitumoral effect on cell viability, migration, and differentiation via STAT3

Glioblastoma is the most lethal tumor of the central nervous system, presenting a very poor prognostic, with a survival around 16 months. The interaction of mesenchymal stem cells and tumor cells has been studied, showing a bias in their role favoring or going against aggressiveness. Natural products such as flavonoids have showed their anticancer properties and the synergic potential with the activation of microenvironment cells to inhibit tumor progression. Agathisflavone is a flavonoid studied in neurodegenerative diseases and cancer. The present study investigated the effect of flavonoid in the viability of heterogeneous glioblastoma (GBM) cells considering a coculture or conditioned medium of mesenchymal stem cells (MSCs) effect, as well as the dose-dependent effect of this flavonoid in tumor migration and differentiation via STAT3. Agathisflavone (3-10 μM) induced dose-dependent toxicity to GL-15 and U373 human GBM cells, since 24 h after treatments. It was not toxic to human MSC but modified the pattern of interaction with GBM cells. Agathisflavone also inhibited migration and increased differentiation of human GBM cells, associated with the reduction on the expression of STAT3. These results demonstrate that the flavonoid agathisflavone had a direct anti-glioma effect. However, could be observed its effect in MSCs response that may have an impact in controlling GBM growth and aggressiveness, an important factor to consider for new therapies.

Revisiting prostate cancer metabolism: From metabolites to disease and therapy

Prostate cancer (PCa), one of the most commonly diagnosed cancers worldwide, still presents important unmet clinical needs concerning treatment. In the last years, the metabolic reprogramming and the specificities of tumor cells emerged as an exciting field for cancer therapy. The unique features of PCa cells metabolism, and the activation of specific metabolic pathways, propelled the use of metabolic inhibitors for treatment. The present work revises the knowledge of PCa metabolism and the metabolic alterations that underlie the development and progression of the disease. A focus is given to the role of bioenergetic sources, namely, glucose, lipids, and glutamine sustaining PCa cell survival and growth. Moreover, it is described as the action of oncogenes/tumor suppressors and sex steroid hormones in the metabolic reprogramming of PCa. Finally, the status of PCa treatment based on the inhibition of metabolic pathways is presented. Globally, this review updates the landscape of PCa metabolism, highlighting the critical metabolic alterations that could have a clinical and therapeutic interest.

Biochanin A: A novel bioactive multifunctional compound from nature

Natural products (NPs) will continue to serve humans as matchless source of novel drug leads and an inspiration for the synthesis of non-natural drugs. As our scientific understanding of 'nature' is rapidly expanding, it would be worthwhile to illuminate the pharmacological distinctions of NPs to the scientific community and the public. Flavonoids have long fascinated scientists with their remarkable structural diversity as well as biological functions. Consequently, this review aims to shed light on the sources and pharmacological significance of a dietary isoflavone, biochanin A, which has been recently emerged as a multitargeted and multifunctional guardian of human health. Biochanin A possesses anti-inflammatory, anticancer, neuroprotective, antioxidant, anti-microbial, and hepatoprotective properties. It combats cancer development by inducing apoptosis, inhibition of metastasis and arresting cell cycle via targeting several deregulated signaling pathways of cancer. It fights inflammation by blocking the expression and activity of pro-inflammatory cytokines via modulation of NF-κB and MAPKs. Biochanin A acts as a neuroprotective agent by inhibiting microglial activation and apoptosis of neurons. As biochanin A has potential to modulate several biological networks, thus, it can be anticipated that this therapeutically potent compound might serve as a novel lead for drug development in the near future.

Apigenin as an anticancer agent

Apigenin is an edible plant-derived flavonoid that has been reported as an anticancer agent in several experimental and biological studies. It exhibits cell growth arrest and apoptosis in different types of tumors such as breast, lung, liver, skin, blood, colon, prostate, pancreatic, cervical, oral, and stomach, by modulating several signaling pathways. Apigenin induces apoptosis by the activation of extrinsic caspase-dependent pathway by upregulating the mRNA expressions of caspase-3, caspase-8, and TNF-α. It induces intrinsic apoptosis pathway as evidenced by the induction of cytochrome c, Bax, and caspase-3, while caspase-8, TNF-α, and B-cell lymphoma 2 levels remained unchanged in human prostate cancer PC-3 cells. Apigenin treatment leads to significant downregulation of matrix metallopeptidases-2, -9, Snail, and Slug, suppressing invasion. The expressions of NF-κB p105/p50, PI3K, Akt, and the phosphorylation of p-Akt decreases after treatment with apigenin. However, apigenin-mediated treatment significantly reduces pluripotency marker Oct3/4 protein expression which might be associated with the downregulation of PI3K/Akt/NF-κB signaling.

Molecular mechanisms of plant steroids and study of their interaction with nuclear receptors in prostate cancer cells

Plant hormone brassinosteroids (BRs) have multiple important functions in plants. They have also been found to exhibit anti-tumor, anti-angiogenic and anti-proliferative activity. The experimental part of this article describes the effects of BR biosynthetic precursors on prostate cancer cells. The experiments were performed with LNCaP and DU-145 prostate cancer cell lines. These were cultivated and treated with tested BRs in different concentrations and time intervals. The tested compounds were found to affect cell viability, nuclear receptor expression, cell cycle and apoptosis in the tumor cells. IC₅₀ concentrations were determined based on MTT test and the two most active compounds (cathasterone and 6-oxocampestanol) were used in the next experiments. Cathasterone was the most effective of all tested compounds and effectively inhibited integrity of cell spheres. It was found that both BRs had no significant effect on the cell cycle in LNCaP at IC₅₀ concentration, while in DU-145 a significant block in G₀/G₁ phase after the BR treatment was observed. The effect of BRs on the nuclear steroid receptors was manifested by changes in their expression and localization. BRs demonstrated their significant effect on prostate cancer cells and the compounds have potential used in anticancer drug research and cancer treatment.

Molecular Targets of Genistein and Its Related Flavonoids to Exert Anticancer Effects

Increased health awareness among the public has highlighted the health benefits of dietary supplements including flavonoids. As flavonoids target several critical factors to exert a variety of biological effects, studies to identify their target-specific effects have been conducted. Herein, we discuss the basic structures of flavonoids and their anticancer activities in relation to the specific biological targets acted upon by these flavonoids. Flavonoids target several signaling pathways involved in apoptosis, cell cycle arrest, mitogen-activated protein kinase (MAPK), phosphoinositide 3-kinase (PI3K)/AKT kinase, and metastasis. Polo-like kinase 1 (PLK1) has been recognized as a valuable target in cancer treatment due to the prognostic implication of PLK1 in cancer patients and its clinical relevance between the overexpression of PLK1 and the reduced survival rates of several carcinoma patients. Recent studies suggest that several flavonoids, including genistein directly inhibit PLK1 inhibitory activity. Later, we focus on the anticancer effects of genistein through inhibition of PLK1.

Androgen receptor and soy isoflavones in prostate cancer

Androgens and androgen receptor (AR) play a critical role not only in normal prostate development, but also in prostate cancer. For that reason, androgen deprivation therapy (ADT) is the primary treatment for prostate cancer. However, the majority of patients develop castration-resistant prostate cancer, which eventually leads to mortality. Novel therapeutic approaches, including dietary changes, have been explored. Soy isoflavones have become a focus of interest because of their positive health benefits on numerous diseases, particularly hormone-related cancers, including prostate and breast cancers. An important strategy for the prevention and/or treatment of prostate cancer might thus be the action of soy isoflavones on the AR signaling pathway. The current review article provides a detailed overview of the anticancer potential of soy isoflavones (genistein, daidzein and glycitein), as mediated by their effect on AR.

Apigenin, a dietary flavonoid, induces apoptosis, DNA damage, and oxidative stress in human breast cancer MCF-7 and MDA MB-231 cells

Apigenin is found in several dietary plant foods such as vegetables and fruits. To investigate potential anticancer properties of apigenin on human breast cancer, ER-positive MCF-7 and triple-negative MDA MB-231 cells were used. Moreover, toxicological safety of apigenin towards normal cells was evaluated in human lymphocytes. Cytotoxicity of apigenin towards cancer cells was evaluated by MTT assay whereas further genotoxic and oxidative stress parameters were measured by comet and lipid peroxidation assays, respectively. In order to examine the type of cell death induced by apigenin, several biomarkers were used. Toxicological safety towards normal cells was evaluated by cell viability and comet assays. After the treatment with apigenin, we observed changes in cell morphology in a dose- (10 to 100 μM) and time-dependent manner. Moreover, apigenin caused cell death in both cell lines leading to significant toxicity and dominantly to apoptosis. Furthermore, apigenin proved to be genotoxic towards the selected cancer cells with a potential to induce oxidative damage to lipids. Of great importance is that no significant cytogenotoxic effects were detected in normal cells. The observed cytogenotoxic and pro-cell death activities of apigenin coupled with its low toxicity towards normal cells indicate that this natural product could be used as a future anticancer modality. Therefore, further analysis to determine the exact mechanism of action and in vivo studies on animal models are warranted.

Kinase-targeted cancer therapies: progress, challenges and future directions

The human genome encodes 538 protein kinases that transfer a γ-phosphate group from ATP to serine, threonine, or tyrosine residues. Many of these kinases are associated with human cancer initiation and progression. The recent development of small-molecule kinase inhibitors for the treatment of diverse types of cancer has proven successful in clinical therapy. Significantly, protein kinases are the second most targeted group of drug targets, after the G-protein-coupled receptors. Since the development of the first protein kinase inhibitor, in the early 1980s, 37 kinase inhibitors have received FDA approval for treatment of malignancies such as breast and lung cancer. Furthermore, about 150 kinase-targeted drugs are in clinical phase trials, and many kinase-specific inhibitors are in the preclinical stage of drug development. Nevertheless, many factors confound the clinical efficacy of these molecules. Specific tumor genetics, tumor microenvironment, drug resistance, and pharmacogenomics determine how useful a compound will be in the treatment of a given cancer. This review provides an overview of kinase-targeted drug discovery and development in relation to oncology and highlights the challenges and future potential for kinase-targeted cancer therapies.

The co-treatment of metformin with flavone synergistically induces apoptosis through inhibition of PI3K/AKT pathway in breast cancer cells

Metformin, a widely used antidiabetic drug, exhibits anticancer effects which are mediated by the phosphatidylinositol 3-kinase (PI3K)/serine/threonine kinase (AKT) signaling pathway. However, its use in anticancer therapy combined with other natural products remains unclear. Flavone as the core structure of flavonoids has been demonstrated to induce cell apoptosis without causing serious side effect. Murine double minute X (MDMX) inhibits tumor suppressor gene p53 whose function is associated with the PI3K/AKT pathway. The results presented herein revealed that the combination of metformin and flavone significantly inhibited cell viability, and increased apoptosis of human breast cancer cells compared with metformin or flavone alone. The combination decreased the protein expression of MDMX, activated p53 through the PI3K/AKT signaling pathway, regulated p53 downstream target genes Bcl-2 apoptosis regulator, BCL2 associated X apoptosis regulator and cleaved caspase3, subsequently inducing apoptosis in MDA-MB-231 and MCF-7 breast cancer cells. These results indicated that dietary flavone may potentiate breast cancer cell apoptosis induced by metformin, and PI3K/AKT is involved in regulating MDMX/p53 signaling. This data suggests that dietary supplementary of flavone is a promising strategy for metformin mediated anticancer effects.

Anti-proliferative activity of biochanin A in human osteosarcoma cells via mitochondrial-involved apoptosis

Biochanin A is a major isoflavone in red clover and a potent chemopreventive agent against cancer. However, the effects of biochanin A on human osteosarcoma cells have never been clarified. This study investigated the anti-proliferative potential of biochanin A in osteosarcoma cells. The results indicate that biochanin A inhibited cell growth and colony formation in a dose-dependent manner with a minimal toxicity to normal cells. The combination of doxorubicin and biochanin A could synergistically inhibit osteosarcoma cell growth. The cytotoxic effect of biochanin A via the induction of apoptosis as evidenced by formation of apoptotic bodies, externalization of phosphatidylserine, accumulation of sub-G₁ phase cells, caspase 3 activation, and cleavage of PARP. Apoptosis was associated with loss of the mitochondrial membrane potential, release of cytochrome c, caspase 9 activation, increased Bax expression, and reduced Bcl-2 and Bcl-X_L expression. Pre-treatment with a caspase-9 specific inhibitor (Z-LEHD-FMK) partially attenuated cell death, suggesting involvement of the intrinsic mitochondrial apoptotic cascade. However, pre-treatment with the JNK inhibitor SP600125, the MEK inhibitor PD-98059, and the p38 MAPK inhibitor SB203580 or the antioxidants vitamin E, N-acetylcysteine, and glutathione failed to prevent biochanin A-induced cell death. Our results suggest that biochanin A inhibits cell growth and induces apoptosis in osteosarcoma cells by triggering activation of the intrinsic mitochondrial pathway and caspase-9 and -3 and increasing the Bax: Bcl-2/Bcl-X_L ratio.

Synthesis, Characterization, and Antioxidant Activities of Genistein, Biochanin A, and Their Analogues

A series of naturally occurring genistein(3)and biochanin A(4)compounds and their analogues were synthesized from phloroglucinol. The structures of all the synthesized compounds were established by the combined use ofHNMR1,CNMR13, IR spectral data, and mass spectrometry; their antioxidant activities were investigated. Most of the synthesized compounds show moderate-to-high activity; only two compounds exhibit no significant activity.

Effect of Genistein and 17-β Estradiol on the Viability and Apoptosis of Human Hepatocellular Carcinoma HepG2 cell line

Background:

One of the most lethal cancers is hepatocellular carcinoma (HCC). Genistein (GE) is a choice compound for treatment of certain types of cancer. Phytoestrogens are plant derivatives that bear a structural similarity to 17-β estradiol (E2) and act in a similar manner. They are a group of lipophillic plant compounds with tumorigenic and antitumorigenic effects. E2 has stimulatory and inhibitory effects on cancer cell lines. This study was designed to investigate the antiproliferative and apoptotic effects of GE and E2 on the HCC HepG2 cell line.

Materials and Methods:

HepG2 cells were cultured and treated with various concentrations of GE and E2 and then 3-[4, 5-dimethyl-2-thiazolyl]-2, 5-diphenyl-2H-tetrazolium bromideand flow cytometry assay were performed to determine cell viability and apoptosis.

Results:

GE and E2 induced apoptosis and inhibited cell growth significantly. Reduction of cell viability by 50% required 20 μM E2 for E2-treatment groups and 20 μMGE for GE-treatment groups. The percentage of the GE-treated apoptotic cells was reduced by about 35%, 42%, and 47% (P < 0.001) and that of E2-treated groups 34%, 39%, and 42% (P < 0.001) after 24, 48, and 72 h, respectively.

Conclusions:

Our experimental work clearly demonstrated that GE and E2 exhibited significant antiproliferative and apoptotic effects on human HCC HepG2 cells.

Sensitivity of TP53-Mutated Cancer Cells to the Phytoestrogen Genistein Is Associated With Direct Inhibition of Plk1 Activity

Polo-like kinase 1 (Plk1), a conserved Ser/Thr mitotic kinase, has been identified as a promising target for anticancer drug development because its overexpression is correlated with malignancy. Here, we found that genistein, an isoflavone, inhibits Plk1 kinase activity directly. Previously the mitotic disturbance phenomenon induced by treatment with genistein was not fully explained by its inhibitory effect on EGFR. In kinase profiling assays, it showed selectivity relative to a panel of kinases, including EGFR. Treatment with genistein induced cell death in a concentration-dependent manner in cancer cells from diverse tissue origins, but not in non-transformed cells such as hTERT-RPE or MCF10A cells. We also observed that genistein tended to be more selective against cancer cells with mutations in the TP53 gene. TP53-depeleted LNCaP and NCI-H460 cells using shRNA targeting human TP53 were more sensitive to cell death by treatment of genistein. Furthermore, genistein induced mitotic arrest by inhibiting Plk1 activity and, consequently, led to mitotic catastrophe and apoptosis. These data suggest that genistein may be a promising anticancer drug candidate due to its inhibitory activity against Plk1 as well as EGFR and effectiveness toward cancer cells, especially those with p53-mutation. J. Cell. Physiol. 232: 2818-2828, 2017. © 2016 Wiley Periodicals, Inc.

Biochanin A induces anticancer effects in SK-Mel-28 human malignant melanoma cells via induction of apoptosis, inhibition of cell invasion and modulation of NF-κB and MAPK signaling pathways

The present study aimed to investigate the antitumor activity of Biochanin A in SK-Mel-28 human malignant melanoma cells. An MTT assay was used to study the cytotoxic effects of Biochanin A. In vitro wound healing and invasion assays were used to investigate the effects on cell migration and invasion. Fluorescence microscopy using acridine orange/propidium iodide was used to study effects on cell morphology and apoptosis. Nuclear factor (NF)-κB and mitogen-activated protein kinase (MAPK) protein expression levels were determined by western blot analysis. The results indicated that Biochanin A significantly inhibited the growth of SK-Mel-28 cells in a dose and time dependent manner. Treatment of the cells with Biochanin A induced apoptosis in a dose dependent manner. Additionally, Biochanin A led to inhibition of cell migration and invasion in a dose-dependent manner and upregulated the expression of key proteins in the NF-κB and MAPK signaling pathways.

The flavonoid apigenin reduces prostate cancer CD44(+) stem cell survival and migration through PI3K/Akt/NF-κB signaling

AIMS

Cancer stem cells (CSCs) are involved in drug resistance, metastasis and recurrence of cancers. The efficacy of apigenin on cell survival, apoptosis, migration and stemness properties were analyzed in CSCs.

MAIN METHODS

Prostate CSCs (CD44(+)) were isolated from human prostate cancer (PCa) PC3 cells using a magnetic-activated cell sorting system. PC3 and CSCs were treated with various concentrations of apigenin, docetaxel and their combinations for 48h.

KEY FINDINGS

Apigenin dose dependently inhibited CSCs and PC3 cell survival, and this was accompanied with a significant increase of p21 and p27. Apigenin induced apoptosis via an extrinsic caspase-dependent pathway by upregulating the mRNA expressions of caspases-8, -3 and TNF-α, but failed to regulate the intrinsic pathway as determined by the Bax, cytochrome c (Cyt-c) and APAF-1 in CSCs. In contrary to CSCs, apigenin induced intrinsic apoptosis pathway as evidenced by the induction of Bax, Cyt-c and caspase-3 while caspase-8, TNF-α and Bcl-2 levels remained unchanged in PC3 cells. The flavonoid strongly suppressed the migration rate of CSCs compared to untreated cells. Significant downregulation of matrix metallopeptidases-2, -9, Snail and Slug exhibits the ability of apigenin treatment to suppress invasion. The expressions of NF-κB p105/p50, PI3K, Akt and the phosphorylation of pAkt were decreased after apigenin treatment. Moreover, apigenin treatment significantly reduced pluripotency marker Oct3/4 protein expression which might be associated with the down-regulation of PI3K/Akt/NF-κB signaling.

SIGNIFICANCE

Our data indicated that, apigenin could be a useful compound to prevent proliferation and migration of cancer cells as well as CSCs.

Flavones inhibit breast cancer proliferation through the Akt/FOXO3a signaling pathway

BACKGROUND

Flavones found in plants display various biological activities, including anti-allergic, anti-viral, anti-inflammatory, anti-oxidation, and anti-tumor effects. In this study, we investigated the anti-tumor effects of flavone, apigenin and luteolin on human breast cancer cells.

METHODS

The anti-cancer activity of flavone, apigenin and luteolin was investigated using the MTS assay. Apoptosis was analyzed by Hoechst 33342 staining, flow cytometry and western blot. Cell migration was determined using the culture inserts and xCELLigence real-time cell analyzer instrument equipped with a CIM-plate 16. Real-time quantitative PCR and western blot were used to determine the signaling pathway elicited by flavone, apigenin and luteolin.

RESULTS

Flavone, apigenin and luteolin showed potent inhibitory effects on the proliferation of Hs578T, MDA-MB-231 and MCF-7 breast cancer cells in a concentration and time-dependent manner. The ability of flavone, apigenin and luteolin to inhibit the growth of breast cancer cells through apoptosis was confirmed by Hoechst33342 staining and the induction of sub-G1 phase of the cell cycle. Flavone, apigenin and luteolin induced forkhead box O3 (FOXO3a) expression by inhibiting Phosphoinositide 3-kinase (PI3K) and protein kinase B (PKB)/Akt. This subsequently elevated the expression of FOXO3a target genes, including the Cyclin-dependent kinase inhibitors p21Cip1 (p21) and p27kip1 (p27), which increased the levels of activated poly(ADP) polymerase (PARP) and cytochrome c.

CONCLUSION

Taken together, these data demonstrated that flavone, apigenin and luteolin induced cell cycle arrest and apoptosis in breast cancer cells through inhibiting PI3K/Akt activation and increasing FOXO3a activation, which suggest that flavone, apigenin and luteolin will be the potential leads for the preventing and treating of breast cancer.

Inhibitory Effect of Genistein on PLC/PRF5 Hepatocellular Carcinoma Cell Line

BACKGROUND

Natural compounds including flavonoids like genistein (GE) are able to inhibit cell proliferation and induce apoptosis. GE is the main representative of these groups. GE inhibits carcinogenic tumors such as colon, stomach, lung, and pancreas tumors. The aim of the present study was to analyze the apoptotic effect of GE in the hepatocellular carcinoma (HCC) PLC/PRF5 cell line.

METHODS

Cells were treated with various doses of GE (1, 5, 10, 25, 50, 75, and 100 μM/L) at different times (24, 48, and 72 h) and the MTT assay was commonly used. Furthermore, cells were treated with single dose of GE (25 μM) at different times and flow cytometry was performed.

RESULTS

GE inhibited the growth of liver cancer cells significantly with a time- and dose-dependent manner. The percentage of living cells in GE treatment groups with a concentration of 25 μM at different times were 53, 48 and 47%, respectively (P < 0.001). Result of flow cytometry demonstrated that GE at a 25 μM concentration induces apoptosis significantly in a time-dependent manner. The percentage of apoptotic cells at different times were 44, 56, and 60%, respectively (P < 0.001).

CONCLUSIONS

GE can significantly inhibit the growth of HCC cells and plays a significant role in apoptosis of this cell line.

Anticancer potential of the histone deacetylase inhibitor-like effects of flavones, a subclass of polyphenolic compounds: a review

Cancer is characterized by the uncontrolled division of cells, followed by their invasion to other tissues. These kinds of cellular abnormalities arise as a result of the accumulation of genetic mutations or epigenetic alterations. Targeting genetic mutations by drugs is a conventional treatment approach. Nowadays, the development and use of epigenetic drugs are burgeoning, owing to the advancements in epigenetic research. The therapeutic intervention of cancer development by histone deacetylase inhibitors (HDACIs) holds promise for helping to control the disease, but their nonspecific functions impose certain side effects. Therefore, the search for more HDACIs becomes essential. Plentiful literature on the versatility of dietary components including flavones, a class of the flavonoid group, has already established these compounds to be better anticancer agents. The present review focuses on the significance of flavones with regard to their HDACI-mimicking effects as suggested by the recent evidences. The review also proposes an in-depth screening of flavones in future studies, in the hope that flavones may provide a better alternative to synthetic HDACIs.

Effects of flavonoids on expression of genes involved in cell cycle regulation and DNA replication in human fibroblasts

Flavonoids have been studied as potential agents in medicine for many years. Among them, genistein was found to be active in various biological systems, mainly in prevention of cancer. Our recent work supported the idea that genistein also impacts multiple cellular processes in healthy fibroblasts; however, its effects on cell cycle-related pathways remained to be elucidated. Thus, in this work, high throughput screening with microarrays coupled to real-time quantitative Reverse Transcription PCR analyses was employed to study the changes in expression of key genes associated with cell cycle regulation and/or DNA replication in response to genistein, kaempferol, daidzein, and mixtures of genistein and either kaempferol or daidzein. Among them, genistein was found as the most significantly modulating, in a time- and dose-dependent manner, compound of activity of studied genes, whose products are involved in different phases of the cell cycle and/or in regulatory processes important for DNA replication and cell growth. It considerably reduced the efficiency of expression of genes coding for MCM2-7 and MCM10 helicases, as well as some other proteins involved in the S phase control. In addition, genistein caused cell cycle arrest in the G2/M phase, which was accompanied by activation of CDKN1A, CDKN1C, CDKN2A, CDKN2B, CDKN2C, and GADD45A genes, as well as down-regulation of several mRNAs specific for this stage, demonstrated by transcriptomic assessments. We believe that studies described in this paper will be helpful in elucidating molecular mechanisms of action of genistein as modulator of cell cycle and inhibitor of DNA replication in humans.