Analysis of the erythroid differentiation effect of flavonoid apigenin on K562 human chronic leukemia cells

Plant-derived inducers in tumor differentiation therapy:A systematic review

BACKGROUND

Differentiation therapy, a highly regarded treatment method in tumor research, aims to induce tumor cells to differentiate back to normal cells, deviating from the malignant pathway and returning to a benign state. Its development relies on the continuous discovery of efficient and low-toxic differentiation inducers, including plant-derived active components that offer significant biological utilization and therapeutic potential. For this reason, the exploration of plant-derived inducers, particularly in their application in differentiation therapy, holds great promise in advancing cancer treatment strategies toward more effective and safer alternatives.

PURPOSE

This paper aims to provide a valuable reference for researchers seeking to identify natural, efficient, and low-toxic differentiation inducers from plants and highlights a promising research direction for the application of differentiation therapy in malignant tumor treatment.

METHODS

For the collection of pertinent information, an extensive search was conducted across diverse literature and electronic databases, including PubMed, ScienceDirect, Wiley, ACS, CNKI, Springer, Taylor & Francis, Web of Science, Google Scholar, and Baidu Scholar. This comprehensive approach aimed to retrieve and include all relevant literature from 1985 to 2023. Primary keywords such as "Natural medicinal plant," "Differentiation therapy," and "Differentiation inducer" were utilized, supplemented by secondary search terms including "Cancer," "Tumor," "Herbal medicine," "Induced differentiation," and "Cancer treatment."

RESULTS

This study systematically evaluated the application of plant-derived inducers in tumor-induced differentiation therapy. Through extensive literature review, specific plant components with confirmed differentiation-inducing properties were identified. Furthermore, potential molecular mechanisms underlying this process were outlined, shedding light on the future development of differentiation therapy in cancer treatment.

CONCLUSION

Plant-derived active components exhibit substantial biological utility and therapeutic potential. Delving deeper into the research on these components as differentiation inducers holds promise for the selection of novel cancer drugs and the unveiling of novel pathways for cancer treatment. These results emphasize the importance of continued exploration and in-depth research into natural, efficient, and low-toxic differentiation inducers from plants, which could significantly advance cancer treatment strategies. Moreover, the highlighted research direction underscores the relevance of differentiation therapy in the context of malignant tumor treatment, indicating its potential as a safer and more effective alternative in cancer therapy.

Endoplasmic reticulum stress in pancreatic β-cell dysfunction: The potential therapeutic role of dietary flavonoids

Diabetes mellitus (DM) is a global health burden that is characterized by the loss or dysfunction of pancreatic β-cells. In pancreatic β-cells, endoplasmic reticulum (ER) stress is a fact of life that contributes to β-cell loss or dysfunction. Despite recent advances in research, the existing treatment approaches such as lifestyle modification and use of conventional therapeutics could not prevent the loss or dysfunction of pancreatic β-cells to abrogate the disease progression. Therefore, targeting ER stress and the consequent unfolded protein response (UPR) in pancreatic β-cells may be a potential therapeutic strategy for diabetes treatment. Dietary phytochemicals have therapeutic applications in human health owing to their broad spectrum of biochemical and pharmacological activities. Flavonoids, which are commonly obtained from fruits and vegetables worldwide, have shown promising prospects in alleviating ER stress. Dietary flavonoids including quercetin, kaempferol, myricetin, isorhamnetin, fisetin, icariin, apigenin, apigetrin, vitexin, baicalein, baicalin, nobiletin hesperidin, naringenin, epigallocatechin 3-O-gallate hesperidin (EGCG), tectorigenin, liquiritigenin, and acacetin have shown inhibitory effects on ER stress in pancreatic β-cells. Dietary flavonoids modulate ER stress signaling components, chaperone proteins, transcription factors, oxidative stress, autophagy, apoptosis, and inflammatory responses to exert their pharmacological effects on pancreatic β-cells ER stress. This review focuses on the role of dietary flavonoids as potential therapeutic adjuvants in preserving pancreatic β-cells from ER stress. Highlights of the underlying mechanisms of action are also presented as well as possible strategies for clinical translation in the management of DM.

Potential Cytoprotective and Regulatory Effects of Ergothioneine on Gene Expression of Proteins Involved in Erythroid Adaptation Mechanisms and Redox Pathways in K562 Cells

This study aimed to establish the importance of ergothioneine (ERT) in the erythroid adaptation mechanisms by appraising the expression levels of redox-related genes associated with the PI3K/AKT/FoxO3 and Nrf2-ARE pathways using K562 cells induced to erythroid differentiation and H₂O₂-oxidative stress. Cell viability and gene expression were evaluated. Two concentrations of ERT were assessed, 1 nM (C1) and 100 µM (C2), with and without stress induction (100 µM H₂O₂). Assessments were made in three periods of the cellular differentiation process (D0, D2, and D4). The C1 treatment promoted the induction of FOXO3 (D0 and 2), PSMB5, and 6 expressions (D4); C1 + H₂O₂ treatment showed the highest levels of NRF2 transcripts, KEAP1 (D0), YWHAQ (D2 and 4), PSMB5 (D2) and PSMB6 (D4); and C2 + H₂O₂ (D2) an increase in FOXO3 and MST1 expression, with a decrease of YWHAQ and NRF2 was observed. in C2 + H₂O₂ (D2) an increase in FOXO3 and MST1, with a decrease in YWHAQ and NRF2 was observed All ERT treatments increased gamma-globin expression. Statistical multivariate analyzes highlighted that the Nrf2-ARE pathway presented a greater contribution in the production of PRDX1, SOD1, CAT, and PSBM5 mRNAs, whereas the PI3K/AKT/FoxO3 pathway was associated with the PRDX2 and TRX transcripts. In conclusion, ERT presented a cytoprotective action through Nrf2 and FoxO3, with the latter seeming to contribute to erythroid proliferation/differentiation.

Chemical Constituents With Antiproliferative Activity From Pogostemon cablin (Blanco) Benth

Two new patchoulene sesquiterpenoid glycosides (1–2), a natural patchoulane-type sesquiterpenoid (3) and a natural cadinene-type sesquiterpenoid (4), were isolated from the aerial parts of Pogostemon cablin (Blanco) Benth., together with eleven known sesquiterpenoids (5–15) and eleven known flavonoids (16–26). Their chemical structures were elucidated on the basis of spectroscopic methods, including NMR, HRESIMS, IR, and CD spectroscopic data analysis, as well as chemical hydrolysis. The isolated compounds 1–13 and 15–26 were tested for inhibitory effects on the proliferation of HepG2 cancer cells. Among them, compounds 17 and 19 displayed anti-proliferative effects against HepG2 cells with IC₅₀ values of 25.59 and 2.30 μM, respectively. Furthermore, the flow cytometry analysis and Western blotting assays revealed that compound 19 significantly induced apoptosis of HepG2 cells by downregulating the ratio of Bcl-2/Bax and upregulating the expression of cleaved caspase-3 and cleaved caspase-9. Therefore, the potential pharmaceutical applications of P. cablin would be applied according to our study findings.

Hydrolyzed Flavonoids from Cyrtosperma johnstonii with Superior Antioxidant, Antiproliferative, and Anti-Inflammatory Potential for Cancer Prevention

Cyrtosperma johnstonii is one of the most interesting traditional medicines for cancer treatment. This study aimed to compare and combine the biological activities related to cancer prevention of the flavonoid glycosides rutin (RT) and isorhamnetin-3-o-rutinoside (IRR) and their hydrolysis products quercetin (QT) and isorhamnetin (IR) from C.johnstonii extract. ABTS and MTT assays were used to determine antioxidant activity and cytotoxicity against various cancer cells, as well as normal cells. Anti-inflammatory activities were measured by ELISA. The results showed that the antioxidant activities of the compounds decreased in the order of QT > IR > RT > IRR, while most leukemia cell lines were sensitive to QT and IR with low toxicity towards PBMCs. The reduction of IL-6 and IL-10 secretion by QT and IR was higher than that induced by RT and IRR. The combination of hydrolysis products (QT and IR) possessed a strong synergism in antioxidant, antiproliferative and anti-inflammatory effects, whereas the combination of flavonoid glycosides and their hydrolysis products revealed antagonism. These results suggest that the potential of the combination of hydrolyzed flavonoids from C. johnstonii can be considered as natural compounds for the prevention of cancer.

Research Progress of Natural Small-Molecule Compounds Related to Tumor Differentiation

Tumor differentiation is a therapeutic strategy aimed at reactivating the endogenous differentiation program of cancer cells and inducing cancer cells to mature and differentiate into other types of cells. It has been found that a variety of natural small-molecule drugs can induce tumor cell differentiation both in vitro and in vivo. Relevant molecules involved in the differentiation process may be potential therapeutic targets for tumor cells. Compared with synthetic drugs, natural small-molecule antitumor compounds have the characteristics of wide sources, structural diversity and low toxicity. In addition, natural drugs with structural modification and transformation have relatively concentrated targets and enhanced efficacy. Therefore, using natural small-molecule compounds to induce malignant cell differentiation represents a more targeted and potential low-toxicity means of tumor treatment. In this review, we focus on natural small-molecule compounds that induce differentiation of myeloid leukemia cells, osteoblasts and other malignant cells into functional cells by regulating signaling pathways and the expression of specific genes. We provide a reference for the subsequent development of natural small molecules for antitumor applications and promote the development of differentiation therapy.

Enhancement of bioavailability and bioactivity of diet-derived flavonoids by application of nanotechnology: a review

Flavonoids, which are a class of polyphenols widely existing in food and medicine, have enormous pharmacological effects. The functional properties of flavonoids are mainly distributed to their anti-oxidative, anticancer, and anti-inflammatoryeffects, etc. However, flavonoids' low bioavailability limits their clinical application, which is closely related to their intestinal absorption and metabolism. In addition, because of the short residence time of oral bioactive molecules in the stomach, low permeability and low solubility in the gastrointestinal tract, flavonoids are easy to be decomposed by the external environment and gastrointestinal tract after digestion. To tackle these obstacles, technological approaches like microencapsulation have been developed and applied for the formulation of flavonoid-enriched food products. In the light of these scientific advances, the objective of this review is to establish the structural requirements of flavonoids for appreciable anticancer, anti-inflammatory, and antioxidant effects, and elucidate a comprehensive mechanism that can explain their activity. Furthermore, the novelty in application of nanotechnology for the safe delivery of flavonoids in food matrices is discussed. After a literature on the flavonoids and their health attributes, the encapsulation methods and the coating materials are presented.

Luteolin and apigenin derived glycosides from Alphonsea elliptica abrogate LPS-induced inflammatory responses in human plasma

ETHNOPHARMACOLOGICAL RELEVANCE

Numerous Alphonsea species including Alphonsea elliptica (mempisang) leaves and fruits are indigenously used in inflammatory conditions such as postpartum swelling and rheumatism in southeast Asian countries. In our previous in-vitro findings, A. elliptica methanol extract exhibited platelet-activating factor inhibition, suggesting the presence of phyto-constituents with anti-inflammatory potential.

AIM OF THE STUDY

However, so far there is no literature available on the anti-inflammatory activity of this species. Henceforth, based on the above background and our previous laboratory findings, we hypothesize that phytoconstituents of A. elliptica could possess anti-inflammatory potential against inflammatory mediators including prostaglandin-E₂ (PGE₂), cyclooxegenase-2 (COX-2) and cytokines (IL-1β and IL-6).

MATERIALS AND METHODS

Vacuum and column chromatography techniques were employed for the isolation of phytoconstituents. The structure elucidation was carried out using HRESI-MS, ¹H and ¹³C-NMR analysis and compared with the published literature. For cytotoxicity analysis, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed on peripheral blood mononuclear cells. In-vitro anti-inflammatory activities were evaluated against the levels of PGE₂, COX-2, IL-1β and IL-6 in lipopolysaccharide (LPS)-induced human plasma using enzyme-linked immunosorbent assay and radioimmunoassay.

RESULTS

Unprecedentedly, chromatographic purification of methanolic leaves extract afforded five flavones namely vitexin, isovitexin, orientin, isoorientin, schaftoside with three flavanols; kaempferol, myricetin and rutin from A elliptica. In cell viability analysis, isolates did not present cytotoxicity up to 50 μM. In anti-inflammatory evaluation, orientin and isoorientin exhibited strong (≥70%), while isovitexin and vitexin produced strong to moderate (50-69%) PGE₂, COX-2, IL-1β and IL-6 inhibition at 25 and 50 μM. Isoorientin, orientin, isovitexin, and vitexin showed significant (p < 0.05) and concentration-dependent PGE₂ inhibition with IC₅₀ values (μM) of 11.40, 14.71, 17.70 and 20.58 against indomethacin (8.80). Furthermore, isoorientin, orientin, isovitexin, and vitexin produced significant concentration-dependent inhibition with IC₅₀ values (μM) of COX-2: 7.13, 9.51, 12.81, 16.61; IL-1β 4.80, 6.20, 10.85, 14.51; IL-6: 4.01, 5.90, 11.51 and 14.88 as compared to dexamethasone: 5.29, 2.93, 3.72, respectively (p < 0.05).

CONCLUSION

Conclusively, isolated phytoconstituents are reported for the first time from the A. elliptica. Moreover, isovitexin, vitexin orientin and isoorientin abrogated LPS-induced inflammatory responses in human plasma at non-cytotoxic concentrations.

Comprehensive transcriptome analysis of erythroid differentiation potential of olive leaf in haematopoietic stem cells

Anaemia is one of the leading causes of disability in young adults and is associated with increased morbidity and mortality in elderly. With a global target to reduce the disease burden of anaemia, recent researches focus on novel compounds with the ability to induce erythropoiesis and regulate iron homeostasis. We aimed to explore the biological events and potential polypharmacological effects of water-extracted olive leaf (WOL) on human bone marrow-derived haematopoietic stem cells (hHSCs) using a comprehensive gene expression analysis. HPLC analysis identifies six bioactive polyphenols in the WOL. Treatment with WOL for 12 days regulated gene expressions related to erythroid differentiation, oxygen homeostasis, iron homeostasis, haem metabolism and Hb biosynthesis in hHSCs. Functional clustering analysis reveals several major functions of WOL such as ribosomal biogenesis and mitochondrial translation machinery, glycolytic process, ATP biosynthesis and immune response. Additionally, the colonies of both primitive and mature erythroid progenitors, CFU-E and BFU-E, were significantly increased in WOL-treated hHSCs. The expressions of erythroid markers, CD47, glycophorin A (GYPA), and transferrin receptor (TFRC) and adult Hb subunits-HBA and HBB were also confirmed in immunofluorescent staining and flow cytometer analysis in WOL-treated hHSCs. It is well known that induction of lineage-specific differentiation, as well as the maturation of early haematopoietic precursors into fully mature erythrocytes, involves multiple simultaneous biological events and complex signalling networks. In this regard, our genome-wide transcriptome profiling with microarray study on WOL-treated hHSCs provides general insights into the multitarget prophylactic and/or therapeutic potential of WOL in anaemia and other haematological disorders.

The potential protective role of apigenin against oxidative damage induced by nickel oxide nanoparticles in liver and kidney of male Wistar rat, Rattus norvegicus

Nickel oxide nanoparticles (NiONPs) are involved in several applications but still have some adverse effects. Apigenin (APG) is a widespread natural product with antioxidative, anticancer, and anti-inflammatory properties. The present work aimed to study the protective role of APG against the NiONP-induced toxicity in male Wistar rats. Rats were randomly distributed to one control group and three treated groups. The treated groups were orally administered NiONPs (100 mg/kg) alone, APG (25 mg/kg) alone, or APG 1 h before NiONPs, once daily for 28 days. Blood, liver, and kidney were collected after 7, 14, and 28 days of administration for Ni accumulation, hematological, biochemical, histological, and transmission electron microscopy (TEM) investigations. As compared to the controls, the administration of NiONPs alone significantly elevated the levels of Ni, malondialdehyde, total cholesterol, low-density lipoprotein cholesterol, creatinine, urea, blood urea nitrogen, and the activity of alanine and aspartate aminotransferases as well as the count of white blood cells. Besides, marked reductions in the activity of superoxide dismutase, and the levels of glutathione, high-density lipoprotein cholesterol, total proteins, albumin, globulin, hemoglobin, packed cell volume, and red blood cell count were reported. Histologically, the liver and kidney of rats administered NiONPs alone showed remarkable disturbances. According to TEM, subcellular alterations were observed in the liver and kidney of rats administered NiONPs alone. In contrast, APG administering before NiONPs substantially alleviated all the studied parameters. In conclusion, APG can ameliorate the NiONP-induced hepatotoxicity and nephrotoxicity in male Wistar rats.

Bioassay-Guided Identification of the Antiproliferative Compounds of Cissus trifoliata and the Transcriptomic Effect of Resveratrol in Prostate Cancer Pc3 Cells

The bioassay-guided fractionation of a CHCl₃-MeOH extract from the stems of Cissus trifoliata identified an active fraction against PC3 prostate cancer cells. The treatment for 24 h showed an 80% reduction in cell viability (p ≤ 0.05) by a WST-1 assay at a concentration of 100 μg/mL. The HPLC-QTOF-MS analysis of the fraction showed the presence of coumaric and isoferulic acids, apigenin, kaempferol, chrysoeriol, naringenin, ursolic and betulinic acids, hexadecadienoic and octadecadienoic fatty acids, and the stilbene resveratrol. The exposure of PC3 cells to resveratrol (IC₂₅ = 23 μg/mL) for 24 h induced significant changes in 847 genes (Z-score ≥ ±2). The functional classification tool of the DAVID v6.8 platform indicates that the underlying molecular mechanisms against the proliferation of PC3 cells were associated (p ≤ 0.05) with the process of differentiation and metabolism. These findings provide experimental evidence suggesting the potential of C. trifoliata as a promising natural source of anticancer compounds.

Flavonoids, the compounds with anti-inflammatory and immunomodulatory properties, as promising tools in multiple sclerosis (MS) therapy: A systematic review of preclinical evidence

Multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE), an animal model of MS, are diseases resulting in neurological disabilities that are regarded as chronic, inflammatory, and autoimmune diseases of central nervous system (CNS). In this respect, the use of anti-inflammatory compounds including flavonoids, polyphenolic compounds abundantly found in vegetables and fruits, has proposed to combat MS to dampen the inflammation and thereby ameliorating the disease severity. The objective of this study was to clarify the probable therapeutic effect of flavonoids for treatment of MS. Therefore, only English published articles that reported the therapeutic effect of flavonoids alone or in combination with other anti-MS therapeutic agents on MS, were selected by searching scientific electronic databases including PubMed, Scopus and Web of Science. Evaluation of the selected researches (686) showed that a total of 13 studies were suitable to be included in this systematic review. Interestingly, all of the studies (11 studies concerning EAE and 2 studies concerning MS) reported positive outcomes for the therapeutic effect of flavonoids on EAE and MS. All flavonoid compounds which are mentioned herein could successfully decrease the maximum clinical score of EAE, which is particularly connected to the anti-inflammatory property of these compounds. The literature review clearly discloses that flavonoids alone or in combination with other anti-MS therapeutic agents can pave the way for improving MS therapeutic strategies.

Antiparasitic Effects of Selected Isoflavones on Flatworms

Medicinal plants have been successfully used in the ethno medicine for a wide range of diseases since ancient times. The research on natural products has allowed the discovery of biologically relevant compounds inspired by plant secondary metabolites, what contributed to the development of many chemotherapeutic drugs. Flavonoids represent a group of therapeutically very effective plant secondary metabolites and selected molecules were shown to exert also antiparasitic activity. This work summarizes the recent knowledge generated within past three decades about potential parasitocidal activities of several flavonoids with different chemical structures, particularly on medically important flatworms such as Schistosoma spp., Fasciola spp., Echinococcus spp., Raillietina spp., and model cestode Mesocestoides vogae. Here we focus on curcumin, genistein, quercetin and silymarin complex of flavonolignans. All of them possess a whole spectrum of biological activities on eukaryotic cells which have multi-therapeutic effects in various diseases. In vitro they can induce profound alterations in the tegumental architecture and its functions as well as their activity can significantly modulate or damage worm´s metabolism directly by interaction with enzymes or signaling molecules in dose-dependent manner. Moreover, they seem to differentially regulate the RNA activity in numbers of worm´s genes. This review suggests that examined flavonoids and their derivates are promising molecules for antiparasitic drug research. Due to lack of toxicity, isoflavons could be used directly for therapy, or as adjuvant therapy for diseases caused by medically important cestodes and trematodes.

Isolation and Biological Properties of the Natural Flavonoids Pectolinarin and Pectolinarigenin-A Review

Flavonoids are metabolites widely distributed in plants and commonly present in foods, such as fruits and vegetables. Pectolinarin, which belongs to the flavone subclass, has attracted considerable attention due to its presence in many medicinal plants. It has turned out to be a good biological agent especially due to its antioxidant, anti-inflammatory, antidiabetic, and antitumor activities, evaluated both in vitro and in vivo. Its aglycone, the metabolite pectolinarigenin, is also known for a series of biological properties including anti-inflammatory and antidiabetic effects. In the first overview on the two metabolites here presented, their collection, isolation and the results of their biological evaluation are reported.

Flavonoids and type 2 diabetes: Evidence of efficacy in clinical and animal studies and delivery strategies to enhance their therapeutic efficacy

Diabetes mellitus type 2 (T2DM) is a metabolic disorder develops due to the overproduction of free radicals where oxidative stress could contribute it. Possible factors are defective insulin signals, glucose oxidation, and degradation of glycated proteins as well as alteration in glutathione metabolism which induced hyperglycemia. Previous studies revealed a link between T2DM with oxidative stress, inflammation and insulin resistance which are assumed to be regulated by numerous cellular networks such as NF-κB, PI3K/Akt, MAPK, GSK3 and PPARγ. Flavonoids are ubiquitously present in the nature and classified according to their chemical structures for example, flavonols, flavones, flavan-3-ols, anthocyanidins, flavanones, and isoflavones. Flavonoids indicate poor bioavailability which could be improved by employing various nano-delivery systems against the occurrences of T2DM. These bioactive compounds exert versatile anti-diabetic activities via modulating targeted cellular signaling networks, thereby, improving glucose metabolism, α -glycosidase, and glucose transport or aldose reductase by carbohydrate metabolic pathway in pancreatic β-cells, hepatocytes, adipocytes and skeletal myofibres. Moreover, anti-diabetic properties of flavonoids also encounter diabetic related complications. This review article has designed to shed light on the anti-diabetic potential of flavonoids, contribution of oxidative stress, evidence of efficacy in clinical, cellular and animal studies and nano-delivery approaches to enhance their therapeutic efficacy. This article might give some new insights for therapeutic intervention against T2DM in near future.

Diosmin induces caspase-dependent apoptosis in human glioblastoma cells

Diosmin is a flavone glycoside clinically used as the main component of Daflon for the treatment of venous diseases. Several studies demonstrated that this natural compound can induce apoptosis in different tumors. However, isolated diosmin has not been studied regarding its effects on glioblastoma so far. Since glioblastoma is a highly lethal and fast-growing brain tumor, new therapeutic strategies are urgently needed. Herein, we evaluated the role of this flavonoid against glioblastoma cells using in vitro assays. Diosmin significantly reduced the viability of GBM95, GBM02, and U87MG glioblastoma cells, but not of healthy human astrocytes, as verified by MTT assay. Vimentin immunostaining showed that diosmin induced morphological changes in GBM95 and GBM02 cells, making them smaller and more polygonal. Diosmin did not inhibit GBM95 and GBM02 cell proliferation, but it caused DNA fragmentation, as verified by the TUNEL assay, and increased cleaved caspase-3 expression in these cells. In summary, diosmin is able to induce caspase-dependent apoptosis specifically in tumor cells and, therefore, could be considered a promising therapeutic compound against glioblastoma.

Evaluation of some genes and proteins involved in apoptosis on human chronic myeloid leukemia cells (K562 cells) by datura innoxia leaves aqueous extract

Datura innoxia (D. innoxia) has an extensive usage in traditional medicine and can also be used for intervention therapy in order to treat cancer. Despite of accomplishing some researches on D. innoxia mechanism, still our knowledge is very little about exact D. innoxia apoptotic mechanism on human chronic myeloid leukemia cells (K562 cells). This study purpose was to clarify the molecular mechanism of apoptosis, which was mediated by D. innoxia leaves aqueous extract in K562 cells. MTT assay and flow cytometry was applied in order to assess the viability and apoptosis induction of K562 cells and normal human lymphoid B cells in the D. innoxia presence. Finally, the expression of the apoptotic related genes (p53, BAX, BCL2, Caspases 3, 6, 7 and 9) were evaluated using quantitative Real-Time PCR. Western blot analysis was applied for assessing the protein expression. MTT results indicated that D. innoxia could inhibit the viability of K562 cells in a dose- and time-dependent manner. In parallel, D. innoxia inhibitory effect on normal human lymphoid B cells was lower in comparison with its effect on K562 cells at the same concentrations and same incubation time. Apoptosis induction in K562 cells after D. innoxia exposure was determined by flow cytometry. Apoptosis was activated by D. innoxia in K562 cells throughout increasing the expression of P53, BAX/BCL2 ratio, caspase 9, 3, 6, 7. Western blot analysis demonstrated significant increase in cleaved PARP-1 and cleaved caspase 3 in treated K562 cells with high D. innoxia leaves aqueous extract concentration. D. innoxia leaves trigger apoptosis in K562 cells throughout intrinsic apoptotic pathway.Communicated by Ramaswamy H. Sarma.

mTORC1 activity is essential for erythropoiesis and B cell lineage commitment

Mechanistic target of rapamycin (mTOR) is a serine/threonine protein kinase that mediates phosphoinositide-3-kinase (PI3K)/AKT signalling. This pathway is involved in a plethora of cellular functions including protein and lipid synthesis, cell migration, cell proliferation and apoptosis. In this study, we proposed to delineate the role of mTORC1 in haemopoietic lineage commitment using knock out (KO) mouse and cell line models. Mx1-cre and Vav-cre expression systems were used to specifically target Raptorfl/fl (mTORC1), either in all tissues upon poly(I:C) inoculation, or specifically in haemopoietic stem cells, respectively. Assessment of the role of mTORC1 during the early stages of development in Vav-cre+Raptorfl/fl mice, revealed that these mice do not survive post birth due to aberrations in erythropoiesis resulting from an arrest in development at the megakaryocyte-erythrocyte progenitor stage. Furthermore, Raptor-deficient mice exhibited a block in B cell lineage commitment. The essential role of Raptor (mTORC1) in erythrocyte and B lineage commitment was confirmed in adult Mx1-cre+Raptorfl/fl mice upon cre-recombinase induction. These studies were supported by results showing that the expression of key lineage commitment regulators, GATA1, GATA2 and PAX5 were dysregulated in the absence of mTORC1-mediated signals. The regulatory role of mTOR during erythropoiesis was confirmed in vitro by demonstrating a reduction of K562 cell differentiation towards RBCs in the presence of established mTOR inhibitors. While mTORC1 plays a fundamental role in promoting RBC development, we showed that mTORC2 has an opposing role, as Rictor-deficient progenitor cells exhibited an elevation in RBC colony formation ex vivo. Collectively, our data demonstrate a critical role played by mTORC1 in regulating the haemopoietic cell lineage commitment.

Flavonoids Isolated from Vitex grandifolia, an Underutilized Vegetable, Exert Monoamine A & B Inhibitory and Anti-inflammatory Effects and Their Structure-activity Relationship

Objectives

Vitex grandifolia belongs to family Lamiaceae; it consists of flowering plants and it is also called the mint family. The Yoruba people of southwest Nigeria called it "Oriri" or "Efo oriri". This plant is classified as an underutilized vegetable and little is known about its phytochemistry or its biological evaluations.

Materials and Methods

Methanol extracts of the dried leaves and stem of the plant were subjected to fractionation and isolation using vacuum layer and column chromatography methods. The structures of the compounds were elucidated using spectroscopic techniques including IR, 1D-, and 2D-NMR and by comparison with the data reported in the literature. They were evaluated in vitro for the inhibition of monoamine recombinant human MAO-A and -B and anti-inflammatory activities.

Results

Three known flavonoids were isolated from the methanolic extract of the leaves of V. grandifolia for the first time to the best of our knowledge, i.e. isoorientin (1), orientin (2), and isovitexin (3). Most of the isolated compounds showed selective inhibition of monoamine oxidase B, inhibition of MAO-B by isoorientin (1) and orientin (2) were 9-fold more potent (IC₅₀ (μg/mL) of 11.08 and 11.04) compared to the inhibition of MAO-A (IC₅₀ (μg/mL) of ˃100), while clorgyline and deprenyl were used as positive standards. The isolated flavonoids displayed good activity against the NF-ﭏb assay with IC₅₀ (μg/mL) of 8.9, 12, and 18. This study establishes a link between the structure and the biological activities on the basis of the different patterns of substitution, particularly the C2=C3 double bond and the position of glucose moiety.

Conclusion

This study is the first to establish the phytochemistry of the polar part of V. grandifolia and the anti-inflammatory and neuroprotective role of these isolated compounds.

Metal complexes of flavonoids: their synthesis, characterization and enhanced antioxidant and anticancer activities

Flavonoids are polyphenolic compounds of natural origin. They are extensively studied within drug discovery programs due to their wide ranging biological activities such as antimicrobial, antioxidant, antitumor, neuroprotective and cardioprotective properties. The ability of flavonoids to coordinate with metal atoms has provided new leads for drug discovery programs, with better pharmacological activities and clinical profiles than the parent flavonoids. In this review, the enhanced antioxidant and anticancer activities of flavonoid metal complexes versus the parent flavonoids are discussed. Possible mechanisms of action for the metal complexes, such as DNA binding and apoptosis induction, are also presented alongside an overview of the synthesis of the metal complexes, and the different techniques used for their characterization.

Prevention of Transcriptional γ-globin Gene Silencing by Inducing The Hereditary Persistence of Fetal Hemoglobin Point Mutation Using Chimeraplast-Mediated Gene Targeting

Objective

Hemoglobin F (HbF) augmentation is considered a clinically beneficial phenomenon in β-hemoglobinopathies. Prevention of γ-globin gene silencing, inspired by the hereditary persistence of fetal hemoglobin, may be a suitable strategy to upregulate HbF expression in these patients. Therefore, our objective was to assess the potential feasibility of induced -117 G→A substitution in HBG promoter in prevention of transcriptional silencing of the γ-globin.

Materials and Methods

In this experimental study, human peripheral blood-derived hematopoietic stem cells (HSCs) and the K562 cell line were differentiated to erythroid cells. Erythroid maturation was examined using cell morphology parameters and flow cytometry analysis of CD235a expression. A synthesised chimeraplast was transfected to differentiating cells. The efficiency of chimeraplast delivery into target cells was assessed by flow cytometry. Restriction-fragment length polymorphism and DNA sequencing verified oligonucleotide-directed mutagenesis. Gene conversion frequency and globin genes expression was quantified through Allele specific-quantitaive polymerase chain reaction (AS-qPCR) and quantitative-PCR respectively.

Results

Increase in CD235a-expressing cells along with observations made for different stages of erythroid maturation confirmed erythroid differentiation in HSCs and K562 cells. γ to β-globin gene switching was estimated to be on days 18-21 of HSC differentiation. Flow cytometry analysis showed that more than 70% of erythroid progenitor cells (EPCs) were transfected with the chimeraplast. The highest gene conversion efficiency was 7.2 and 11.1% in EPCs and K562 cells respectively. The induced mutation led to a 1.97-fold decrease in β/γ-globin gene expression in transfected EPCs at the experimental end point (day 28) whereas, due to the absence of β-globin gene expression following K562 differentiation, this rate was not evaluable.

Conclusion

Our results suggest the effectiveness of chimeraplasty in induction of the mutation of interest in both EPCs and K562 cells. We also demonstrate that the single nucleotide promoter variant was able to significantly inhibit γ-globin gene silencing during erythroid differentiation.

Plant flavone apigenin: An emerging anticancer agent

Research in cancer chemoprevention provides convincing evidence that increased intake of vegetables and fruits may reduce the risk of several human malignancies. Phytochemicals present therein provide beneficial anti-inflammatory and antioxidant properties that serve to improve the cellular microenvironment. Compounds known as flavonoids categorized anthocyanidins, flavonols, flavanones, flavonols, flavones, and isoflavones have shown considerable promise as chemopreventive agents. Apigenin (4', 5, 7-trihydroxyflavone), a major plant flavone, possessing antioxidant, anti-inflammatory, and anticancer properties affecting several molecular and cellular targets used to treat various human diseases. Epidemiologic and case-control studies have suggested apigenin reduces the risk of certain cancers. Studies demonstrate that apigenin retain potent therapeutic properties alone and/or increases the efficacy of several chemotherapeutic drugs in combination on a variety of human cancers. Apigenin's anticancer effects could also be due to its differential effects in causing minimal toxicity to normal cells with delayed plasma clearance and slow decomposition in liver increasing the systemic bioavailability in pharmacokinetic studies. Here we discuss the anticancer role of apigenin highlighting its potential activity as a chemopreventive and therapeutic agent. We also highlight the current caveats that preclude apigenin for its use in the human trials.

Bioactive flavonoids in medicinal plants: Structure, activity and biological fate

Flavonoids, a class of polyphenol secondary metabolites, are presented broadly in plants and diets. They are believed to have various bioactive effects including anti-viral, anti-inflammatory, cardioprotective, anti-diabetic, anti-cancer, anti-aging, etc. Their basic structures consist of C₆-C₃-C₆ rings with different substitution patterns to produce a series of subclass compounds, and correlations between chemical structures and bioactivities have been studied before. Given their poor bioavailability, however, information about associations between structure and biological fate is limited and urgently needed. This review therefore attempts to bring some order into relationships between structure, activity as well as pharmacokinetics of bioactive flavonoids.

Studies on the protective effect of the artichoke (Cynara scolymus) leaf extract against cadmium toxicity-induced oxidative stress, hepatorenal damage, and immunosuppressive and hematological disorders in rats

Our objective was to explore the protective effect of artichoke leaf extract (ALE) against cadmium (Cd) toxicity-induced oxidative organ damage in rats. Male albino Wistar rats were divided into four equal groups of eight animals each. The first group was assigned as a control. Groups 2-4 were orally administered with ALE (300 mg/kg bw), Cd (CdCl₂, 100 mg/L drinking water), and ALE plus Cd, respectively, daily for 4 weeks. After treatment with Cd, the liver and kidney malondialdehyde (MDA) increased significantly compared with the control rats. The sera interleukin (IL)-1β, tumor necrosis factor (TNF-α), and IL-10, liver transaminase, urea, creatinine, and peripheral neutrophil count were significantly increased in Cd-exposed rats compared to the control group. The reduced glutathione (GSH), glutathione peroxidase (GPX), superoxide dismutase (SOD), and catalase (CAT) decreased in the liver and kidney in Cd-exposed group. In combination treatment, Cd and ALE significantly improved immune response, an antioxidant system, and hepatorenal function with a significant decline in MDA. In conclusion, ALE ameliorates the immunosuppressive and hepatorenal oxidative injury stimulated by Cd in rats. These results suggest that artichoke has shown promising effects against adverse effects of Cd toxicity.

Natural and Synthetic Flavonoids: Structure-Activity Relationship and Chemotherapeutic Potential for the Treatment of Leukemia

Flavonoids and their derivatives are polyphenolic secondary metabolites with an extensive spectrum of pharmacological activities, including antioxidants, antitumor, anti-inflammatory, and antiviral activities. These flavonoids can also act as chemopreventive agents by their interaction with different proteins and can play a vital role in chemotherapy, suggesting a positive correlation between a lower risk of cancer and a flavonoid-rich diet. These agents interfere with the main hallmarks of cancer by various individual mechanisms, such as inhibition of cell growth and proliferation by arresting the cell cycle, induction of apoptosis and differentiation, or a combination of these mechanisms. This review is an effort to highlight the therapeutic potential of natural and synthetic flavonoids as anticancer agents in leukemia treatment with respect to the structure-activity relationship (SAR) and their molecular mechanisms. Induction of cell death mechanisms, production of reactive oxygen species, and drug resistance mechanisms, including p-glycoprotein efflux, are among the best-described effects triggered by the flavonoid polyphenol family.

Established Human Cell Lines as Models to Study Anti-leukemic Effects of Flavonoids

Despite the extensive work on pathological mechanisms and some recent advances in the treatment of different hematological malignancies, leukemia continues to present a significant challenge being frequently considered as incurable disease. Therefore, the development of novel therapeutic agents with high efficacy and low toxicity is urgently needed to improve the overall survival rate of patients. In this comprehensive review article, the current knowledge about the anticancer activities of flavonoids as plant secondary polyphenolic metabolites in the most commonly used human established leukemia cell lines (HL-60, NB4, KG1a, U937, THP-1, K562, Jurkat, CCRF- CEM, MOLT-3, and MOLT-4) is compiled, revealing clear anti-proliferative, pro-apoptotic, cell cycle arresting, and differentiation inducing effects for certain compounds. Considering the low toxicity of these substances in normal blood cells, the presented data show a great potential of flavonoids to be developed into novel anti-leukemia agents applicable also in the malignant cells resistant to the current conventional chemotherapeutic drugs.