Natural Flavone Research Articles

Doxorubicin cardiomyopathy is ameliorated by acacetin via Sirt1-mediated activation of AMPK/Nrf2 signal molecules.

Doxorubicin cardiotoxicity is frequently reported in patients undergoing chemotherapy. The present study investigates whether cardiomyopathy induced by doxorubicin can be improved by the natural flavone acacetin in a mouse model and uncovers the potential molecular mechanism using cultured rat cardiomyoblasts. It was found that the cardiac dysfunction and myocardial fibrosis induced by doxorubicin were significantly improved by acacetin in mice with impaired Nrf2/HO‐1 and Sirt1/pAMPK molecules, which is reversed by acacetin treatment. Doxorubicin decreased cell viability and increased ROS production in rat cardiomyoblasts; these effects are significantly countered by acacetin (0.3‐3 μM) in a concentration‐dependent manner via activating Sirt1/pAMPK signals and enhancing antioxidation (Nrf2/HO‐1 and SOD1/SOD2) and anti‐apoptosis. These protective effects were abolished in cells with silencing Sirt1. The results demonstrate for the first time that doxorubicin cardiotoxicity is antagonized by acacetin via Sirt1‐mediated activation of AMPK/Nrf2 signal molecules, indicating that acacetin may be a drug candidate used clinically for protecting against doxorubicin cardiomyopathy.

Acacetin, a flavone with diverse therapeutic potential in cancer, inflammation, infections and other metabolic disorders

BackgroundAcacetin is a di-hydroxy and mono-methoxy flavone present in various plants, including black locust, Damiana, Silver birch. Literature information revealed that acacetin exhibits an array of pharmacological potential including chemopreventive and cytotoxic properties in cancer cell lines, prevents ischemia/reperfusion/myocardial infarction-induced cardiac injury, lipopolysaccharide (LPS), 1-methyl-4-phenyl pyridinium ion (MPP+) and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine hydrochloride (MPTP)-induced neuroinflammation, LPS and sepsis-induced lung injury, rheumatoid and collagen-induced arthritis, inhibit the microbial growth, obesity, viral-mediated infections as well as hepatic protection. PurposeThis review highlights the therapeutic potential of acacetin, with updated and comprehensive information on the biological sources, chemistry, and pharmacological properties along with the possible mechanism of action, safety aspects, and future research opportunities. Study designThe information was retrieved from various search engines, including Pubmed, SciFinder, Science direct, Inxight:drugs, Google scholar, and Meta cyc. ResultThe first section of this review focuses on the detailed biological source of acacetin, chromatographic techniques used for isolation, chemical characteristics, the method for the synthesis of acacetin, and the available natural and synthetic derivatives. Subsequently, the pharmacological activities, including anti-cancer, anti-inflammatory, anti-viral, anti-microbial, anti-obesity, have been discussed. The pharmacokinetics data and toxicity profile of acacetin are also discussed. ConclusionAcacetin is a potent molecule reported for its strong anti-inflammatory and anti-cancer activity, however further scientific evidence is essential to validate its potency in disease models associated with inflammation and cancer. There is limited information available for toxicity profiling of acacetin; therefore, further studies would aid in establishing this natural flavone as a potent candidate for research studies at clinical setup.

A Natural Flavone Tricin from Grains Can Alleviate Tumor Growth and Lung Metastasis in Colorectal Tumor Mice.

Tricin, a flavone isolated from rice bran, has been shown to be chemopreventive in a colorectal cancer (CRC) mouse model. This study aimed to illustrate the inhibitory activities of tricin in colon cancer cells and in a metastatic CRC mouse model. BALB/c mice injected with mouse Colon26-Luc cells into the rectum wall were treated with tricin (37.5 mg/kg) daily for 18 days. Orthotopic colon tumor growth and metastasis to lungs were assessed by in vivo bioluminescence imaging. Results showed that tricin suppressed Colon-Luc cells motility and downregulated phosphorylated Akt, Erk1/2 and NF-κB expressions of human colon cancer HT-29 cells. While tricin treatment suppressed tumor growth and lung metastasis as well as altered the populations of myeloid-derived suppressor cells and regulatory T cells in spleens. In summary, the tumor microenvironment modulatory and anti-metastatic effects of tricin in colon cancer mouse model were shown for the first time, suggesting the potential development of tricin-containing food supplements for CRC patients.

Naringenin downregulates inflammation-mediated nitric oxide overproduction and potentiates endogenous antioxidant status during hyperglycemia.

Nitric oxide is a key regulating factor for physiological functions, when elevated during inflammatory conditions, NO, can lower endogenous antioxidants level. Naringenin, a bioflavonoid has shown to possess anti-inflammatory action. However, its role in NO-mediated responses has not been elucidated till date. This study was designed to investigate antioxidant potential of naringenin against inflammation-mediated nitric oxide overproduction and antioxidant status with an improved glycemic profile in diabetic rats. From total rats, Group 1 received normal saline, while remaining received single intraperitoneal injection of alloxan and were then equally divided into group 2, 3, and 4, which latter received no-treatment, metformin (50mgkg-1day-1) and naringenin (50mgkg-1day-1), respectively, for 1month. Results showed that naringenin significantly downregulated levels of glucose (p<.05), lipid profile, inflammatory biomarkers, and nitric oxide (p<.01) in alloxan-induced diabetic rats. It also improved SOD level as compared to that of metformin treatment. This work delivers that naringenin exerts antioxidant effect by downregulating inflammation-mediated nitric oxide overproduction. PRACTICAL APPLICATIONS: Naringenin is a well-recognized member of bioflavonoids and is commonly present in citrus fruits like oranges, grapes, and berries. The foremost property of naringenin is its antioxidant potential, which aids in decreasing the burden of oxidative stress by declining the generation of free radicals. The overproduction of these oxygen or nitrogen reactive species are considered as underlying cause of undesired biological activities like or nitrite-mediated inflammation and altered metabolic parameters. Hence, this study was designed to investigate the antioxidant potential of naringenin as natural flavone to downregulate the inflammation-mediated nitric oxide overproduction and improve glycemic profile. The therapeutic perspective of naringenin from current study against nitric oxide overproduction and to eradicate inflammation via controlling of levels of pro-inflammatory mediators suggests that naringenin holds the forthcoming vision as a supportive constituent alone or in combination with some other conventional medicinal agents against conditions like metabolic disorders.

LC-MS/MS Determination of Apigenin in Rat Plasma and Application to Pharmacokinetic Study.

Apigenin, a natural plant flavone, has been shown to possess a variety of biological properties. In this report, a highly selective and sensitive LC-MS/MS method was developed and validated for the determination of apigenin in rat plasma. Analysts were separated on the HSS T3 column (1.8 μm 2.1×100 mm) using acetonitrile and 0.1% formic acid in 2mM ammonium acetate buffer at a supply rate of 0.200 mL/min as eluent in gradient model. Plasma samples were treated by protein precipitation using acetonitrile for the recovery ranging from 86.5% to 90.1% for apigenin. The calibration curves followed linearity in the concentration range of 0.50-500ng/mL. The inter-day and intra-day precisions at different QC levels within 13.1% and the accuracies ranged from -10.6% to 8.6%. The assay has been successfully applied to the pharmacokinetic study of apigenin in rats.

A Natural Dietary Flavone Myricetin as an α-Hemolysin Inhibitor for Controlling Staphylococcus aureus Infection.

Staphylococcus aureus, an important agent for lethal bacterial infections, can cause a broad spectrum of diseases in various host species. The emergence of multidrug-resistant and highly virulent strains has raised increasing concerns about the novel therapeutic strategies or agents available for treating S. aureus infection. The critical role of Hla, an essential virulence determinant, in the pathogenicity of S. aureus renders this toxin an attractive target for effective therapeutic applications. Here, we have identified myricetin as an effective inhibitor of Hla that simultaneously inhibits Hla production and neutralizes Hla activity without affecting bacterial growth. Myricetin treatment reduced the oligomerization of Hla and Hla-mediated biofilm formation. The addition of myricetin to the coinfection system of host cells and S. aureus significantly decreased cell injury and downregulated the inflammatory response in cells. Furthermore, S. aureus-infected mice that received myricetin showed alleviated tissue damage in the lung. Our results indicated that myricetin inhibits S. aureus virulence by targeting Hla and downregulates the inflammatory response in host cells. Overall, in addition to traditional antibiotics with antibacterial activity, myricetin may represent a potential candidate, and strategy for S. aureus infection.

Synthesis, Biological Evaluation and Molecular Modeling Studies of Novel C (7) Modified Analogues of Chrysin

Background:: Most of the currently available pharmaceutical drugs are either natural products or analogues of natural products. Flavonoids are plant based natural polyphenolic compounds which exhibit a wide range of biological activities. Chrysin, a natural flavone, exhibits several biological activities like antiallergic, anti-inflammatory and anticancer. Many efforts were made to enhance the biological activity of chrysin. In continuation of our work on synthetic modifications of chrysin, amino-alcohol containing heterocyclic moiety is linked to chrysin at C (7) position to enhance its biological activity. Methods:: A series of new C (7) modified analogues of chrysin (3a-k) have been designed and synthesized in two steps. Chrysin, on reacting with epichlorohydrin in the presence of K2CO3 in DMF gave epoxide (2) which was made to react with cyclic secondary amines in the presence of LiBr to form the designed products (3a-k). All the synthesized compounds (3a-k) were well characterized by 1H NMR, 13C NMR and mass spectral data. The synthesized analogues (3a-k) were screened for their in vitro biological activities against a panel of bacterial and fungal strains. Molecular docking studies were also performed on these compounds with E. coli FabH (1HNJ) and S. cerevisiae (5EQB) enzymes, to support the observed biological activities. Results:: A series of new 2-hydroxy 3-amino chrysin derivatives (3a-k) were synthesized in two steps, starting with chrysin and their structures were characterized by spectral analysis. In vitro biological activities of these analogues against a panel of bacterial and fungal strains indicated that some of the derivatives manifested significant activities compared to standard drugs. Molecular docking and binding energy values were also correlated with experimental antimicrobial screening results. Lipinski’s “rule of five” is also obeyed by these analogues (3a-k) and exhibit drug-likeness. Conclusion:: In the present study, a series of new C (7) modified chrysin analogues (3a-k) were synthesized and tested for their in vitro antimicrobial activities. These biological studies indicated that some of the derivatives exhibited moderate to good antimicrobial activities compared to standard drugs. Molecular docking studies performed on these compounds correlated with the experimental antimicrobial activities. The results obtained in the study will be useful in establishing new drug entities to control the pathogenic epidemics.

Enhancing Effect of Vitexin on Osteogenic Activity of Murine Pre-Osteoblastic Mc3t3-E1 Cells

Vitexin (5,7,4-trihydroxyflavone-8-glucoside), a natural flavone present in a variety of plants, is well known for its rich pharmacological properties. However, its osteogenic activity remains unclear to date. The purpose of this study was to explore the effects of vitexin on osteogenic activity in murine pre-osteoblastic MC3T3-E1 cells using the MTT assay for cell proliferation, alkaline phosphatase (ALP) activity assay for cell differentiation, and Von Kossa staining for cell mineralization. Quantitative real-time PCR was used for the detection of osteocalcin (OCN) mRNA expression in cells. Furthermore, effects of vitexin on the differentiation and matrix mineralization of dexamethasone (DEX)- suppressed cells was also investigated. The results showed vitexin could significantly enhance cell proliferation in a low concentration range of 10-10-10-6 μg mL-1. ALP activity was significantly increased after the cells were treated with vitexin at 10-8 and 10-6 μg mL-1. The expression levels of the osteogenic OCN gene in cells treated with vitexin at 10-6, 10- 8, and 10-10 μg mL-1 were improved by 3.1-fold, 5.8-fold, and 4.2-fold over the control, respectively. Additionally, vitexin (10-8 μg mL-1) significantly alleviated the inhibitory effect of osteoblast differentiation and mineralization induced by DEX. Collectively, our findings suggest vitexin could enhance cell proliferation and osteogenic differentiation of MC3T3-E1 cells, as well as rescue the inhibitory effect of cell differentiation and matrix mineralization induced by DEX. Therefore, vitexin may be useful as a promising therapeutic agent for bone disease and plays an important role in the prevention of glucocorticoid-induced osteoporosis.

Jaceosidin: A Natural Flavone with Versatile Pharmacological and Biological Activities.

Nature always remains an inexhaustible source of treasures for mankind. It remains a mystery for every challenge until the completion of the challenge. While we talk about the complicated health issues, nature offers us a great variety of chemical scaffolds and their various moieties packed in the form of natural products e.g., plants, microorganisms (fungi, algae, protozoa), and terrestrial vertebrates and invertebrates. This review article is an update about jaceosidin, a bioactive flavone, from genus Artemisia. This potentially active compound exhibits a variety of pharmacological activities including anti-inflammatory, anti-oxidant, anti-bacterial, antiallergic and anti-cancer activities. The bioactivities and the therapeutic action of jaceosidin, especially the modulation of different cell signaling pathways (ERK1/2, NF-κB, PI3K/Akt and ATM-Chk1/2) which become deregulated in various pathological disorders, have been focused here. The reported data suggest that the bioavailability of this anti-cancer compound should be enhanced by utilizing various chemical, biological and computational techniques. Moreover, it is recommended that researchers and scientists should work on exploring the mode of action of this particular flavone to precede it further as a potent anti-cancer compound.

Apigenin Inhibits Histamine-Induced Cervical Cancer Tumor Growth by Regulating Estrogen Receptor Expression.

Apigenin is a natural flavone with anti-inflammatory and antioxidant properties and antitumor abilities against several types of cancers. Previous studies have found that the antitumor effects of apigenin may be due to its similar chemical structure to 17β-estradiol (E2), a main kind of estrogen in women. However, the precise mechanism underlying the antitumor effects of apigenin in cervical cancer remains unknown. On the other hand, there is increasing evidence that describes a histamine role in cancer cell proliferation. In this study, we examined whether apigenin can attenuate the effects of histamine on tumors by regulating the expression level of estrogen receptors (ERs) to inhibit cervical cancer growth. Our in vitro data indicates that apigenin inhibited cell proliferation in a dose-dependent manner in human cervical cancer cells (HeLa), while histamine shows the opposite effects. After that, the xenograft model was established to explore the antitumor effects of apigenin in vivo, the results show that apigenin inhibited cervical tumor growth by reversing the abnormal ER signal in tumor tissue which was caused by histamine. We also demonstrate that apigenin inhibited cell proliferation via suppressing the PI3K/Akt/mTOR signaling pathway. Collectively, our results suggest that apigenin may inhibit tumor growth through the ER-mediated PI3K/Akt/mTOR pathway and that it can also attenuate the effects of histamine on tumors.

Apigenin attenuates Aluminum phosphide-induced cytotoxicity via reducing mitochondrial/Lysosomal damages and oxidative stress in rat Cardiomyocytes

Apigenin, is a natural compound that found in high amounts in vegetables and fruits. This natural flavone has shown strong cardioprotective effects in animal and clinical studies. Due to cardioprotective effects of apigenin in previous studies, we hypothesized that apigenin protects isolated cardiomyocytes from aluminum phosphide(AlP)-induced toxicity as the most common disturbances after exposure with this agent. By using of biochemical and flowcytometry techniques; cell viability, reactive oxygen species (ROS) generation, mitochondria membrane potential (MMP), lysosomal membrane integrity, malondialdehyde (MDA) and oxidized/reduced glutathione (GSH/GSSG) content were measured in rat heart isolated cardiomyocytes. Our results showed that the administration of apigenin (5–100 μM) efficiently decreased (P < .05) cytotoxicity, oxidative, lysosomal and mitochondrial damages induced by AlP (20 μg/ml) in isolated cardiomyocytes. Taken together, apigenin protected the cardiomyocytes against AlP toxicity via the protection of mitochondria and lysosome mediated by its antioxidant properties.

Chrysin-Anchored Silver and Gold Nanoparticle-Reduced Graphene Oxide Composites for Breast Cancer Therapy

Natural polyphenol assisted fabrication of nanohybrids with improved stability and bioactivity have gained considerable interest in material science. In this study, the anticancer flavone chrysin (5,7-dihydroxyflavone ChR) was employed to fabricate silver (AgNPs) and gold nanoparticles (AuNPs) hybridized reduced graphene oxide (rGO) nanocomposites (ChR@Ag-rGONCs and ChR@Au-rGONCs) with long-term stabilities. Prepared nanocomposites (NCs) were characterized using high-throughput analyses. The hydroxyl (O–H) and carbonyl (C═O) functional groups of ChR actively contribute to the reduction of GO/metal ions (Ag+ and Au3+) and uniform decoration of Ag and AuNPs on the rGO active sites. The presence of noble metal NPs on the rGO surface improved its thermal stability and performances in diverse physiological conditions. Moreover, the surface passivation of the fabricated NCs with natural anticancer flavone ChR improved its biocompatibility. Due to the synergistic impact of the plasmonic metal–rGO hybrids, the fabricated NCs exhibited an increased cytotoxic effect over that of free-ChR against two different breast carcinoma (MDA-MD-468 and MDA-MD-231) cell lines. The prepared NCs showed comparatively less toxicity against the normal mouse fibroblast (L929) cells, demonstrating the high safety of biofunctionalized NCs in anticancer therapy. We demonstrated that the generation of reactive oxygen species released by the metal ions coexisting on the rGO induce apoptosis. Hence, this work offers a natural and viable scaling-up procedure to synthesize noble metal NPs decorated hybrid rGO composites for useful antibreast cancer applications.

Novel synthesised chrysin derivatives offer noteworthy insight into the structural scaffolds required for improved anti-proliferative activity

In the present investigations, a novel series of chrysin derivatives were prepared using Mannich base approach and screened for in vitro antiproliferative activity against human cancer cells. Among the derivatives, 4e exhibited 10 fold improved anti-proliferative efficiency than the free chrysin. The correlation of chemical structural core–biological efficiency indicated that free hydroxyl groups and the substituents in the B-ring were involved in the improved anti-proliferative efficiencies. The removal of oxygen atom in the ring C by the utilization of different aliphatic/aromatic/heterocyclic molecules to arrive different structural motifs could lead to chrysin derivatives with desirable structural features were also increased lipophilic character and stability in medium. The prepared compounds exhibited strong antiproliferative efficacies may be mimics the natural flavone derivatives. The utmost promising structural lead molecules in particular the chrysin derivatives 4e, 4f and 4 g, will be screened for their anti-proliferative activities against a broader range of cancer cell lines (obtained from cancer Institute) and may be potent molecule for anticancer agents. The synthesized chrysin derivatives have obeyed Lipinski’s “rule of five” and have drug-likeness.

Flavones and flavonols may have clinical potential as CK2 inhibitors in cancer therapy

The serine-threonine kinase CK2, which targets over 300 cellular proteins, is overexpressed in all cancers, presumably reflecting its ability to promote proliferation, spread, and survival through a wide range of complementary mechanisms. Via an activating phosphorylation of Cdc373, a co-chaperone which partners with Hsp90, CK2 prolongs the half-life of protein kinases that promote proliferation and survival in many cancers, including Akt, Src, EGFR, Raf-1, and several cyclin-dependent kinases. CK2 works in other ways to boost the activity of signaling pathways that promote cancer aggressiveness and chemoresistance, including those driven by Akt, NF-kappaB, hypoxia-inducible factor-1, beta-catenin, TGF-beta, STAT3, hedgehog, Notch1, and the androgen receptor; it promotes the epidermal-mesenchymal transition and aids efficiency of DNA repair. Several potent and relatively specific inhibitors of CK2 are now being evaluated as potential cancer drugs; CX-4945 has shown impressive activity in cell culture studies and xenograft models, and is now entering clinical trials. Moreover, it has long been recognized that the natural flavone apigenin can inhibit CK2, with a Ki near 1 µM; more recent work indicates that a range of flavones and flavonols, characterized by a planar structure and hydroxylations at the 7 and 4′ positions – including apigenin, luteolin kaempferol, fisetin, quercetin, and myricetin - can inhibit CK2 with Ki s in the sub-micromolar range. This finding is particularly intriguing in light of the numerous studies demonstrating that each of these agents can inhibit the growth of cancer cells lines in vitro and of human xenografts in nude mice. These studies attribute the cancer-retardant efficacy of flavones/flavonols to impacts on a bewildering array of cellular targets, including those whose activities are boosted by CK2; it is reasonable to suspect that, at least in physiologically achievable concentrations, these agents may be achieving these effects primarily via CK2 inhibition. Inefficient absorption and rapid conjugation limit the bioefficacy of orally administered flavonoids; however, the increased extracellular beta-glucuronidase of many tumors may give tumors privileged access to glucuronidated flavonoids, and nanopartical technology can improve the bioavailability of these agents. Enzymatically modified isoquercitrin has particular promise as a delivery vehicle for quercetin. Hence, it may be worthwhile to explore the clinical potential of flavones/flavonols as CK2 inhibitors for cancer therapy.

Chrysin Induced Cell Apoptosis and Inhibited Invasion Through Regulation of TET1 Expression in Gastric Cancer Cells.

ObjectiveTen-eleven translocation (TET) enzymes that oxidize a 5-methylcytosine (5mC) to yield 5-hydroxymethylcytosine (5hmC) have been responsible for fine-tuning methylation patterns and exhibit role in epigenetic modifications. Chrysin, a natural flavone frequently present in honey, has been recognized to exhibit anti-tumor properties. In this study, we investigated the effects of Chrysin in the expression pattern of TET proteins in gastric cancer (GC) cells.Materials and MethodsUsing qRT-PCR and Western blot analysis, we analyzed the expression of TET1 in GC cells in vitro following treatment with Chrysin. Immunofluorescence staining detected the expression levels of 5mC and 5hmC. Flow cytometry, wound healing, and Matrigel invasion assays were performed to determine cell proliferation, cell cycle, apoptosis, and migration and invasion of GC cells following treatment with Chrysin, si-TET1, and TET1-KO. Furthermore, a xenograft model was developed to analyze the expression pattern of TET1 on tumor development in vivo.ResultsqRT-PCR and Western blot assays indicated that treatment with Chrysin significantly promoted the expression of TET1 in GC cells. Immunofluorescence study further confirmed that TET1 and 5hmC levels were significantly enhanced following treatment with Chrysin in MKN45 cells. Moreover, our results suggested that Chrysin could noticeably induce cell apoptosis and inhibit cell migration and invasion. Further, knockdown and overexpression of TET1 were conducted to investigate whether TET1 expression affected cell apoptosis, and cell migration and invasion in MKN45 cells. The results indicated that overexpression of TET1 markedly promoted cell apoptosis and inhibited cell migration and invasion. Furthermore, the TET1 gene knocked out was generated using the CRISPR/Cas9 system. Our data suggested that TET1 expression was associated with GC tumor growth in vivo.ConclusionThis study indicated that Chrysin exerted anti-tumor effects through the regulation of TET1 expression in GC and presented TET1 as a novel promising therapeutic target for GC therapy.

In vitro antivirulence activity of baicalin against Clostridioides difficile.

Introduction. Clostridioides difficile is an enteric pathogen that causes a serious toxin-mediated colitis in humans. Bacterial exotoxins and sporulation are critical virulence components that contribute to pathogenesis, and disease transmission and relapse, respectively. Therefore, reducing toxin production and sporulation could significantly minimize C. difficile pathogenicity and disease outcome in affected individuals.Aim. This study investigated the efficacy of a natural flavone glycoside, baicalin, in reducing toxin synthesis, sporulation and spore germination in C. difficile in vitro.Methodology. Hypervirulent C. difficile isolates BAA 1870 or 1803 were cultured in brain heart infusion broth with or without the subinhibitory concentration (SIC) of baicalin, and incubated at 37 °C for 24 h under strictly anaerobic conditions. The supernatant was harvested after 24 h for determining C. difficile toxin production by ELISA. In addition, a similar experiment was performed wherein samples were harvested for assessing total viable counts, and heat-resistant spore counts at 72 h of incubation. Furthermore, C. difficile spore germination and spore outgrowth kinetics, with or without baicalin treatment, was measured in a plate reader by recording optical density at 600 nm. Finally, the effect of baicalin on C. difficile toxin, sporulation and virulence-associated genes was investigated using real-time quantitative PCR.Results. The SIC of baicalin significantly reduced toxin synthesis, sporulation and spore outgrowth when compared to control. In addition, C. difficile genes critical for pathogenesis were significantly down-regulated in the presence of baicalin.Conclusion. Our results suggest that baicalin could potentially be used to control C. difficile, and warrant future studies in vivo.

Natural Flavones and their Preliminary Structure–Antifouling Activity Relationship

Natural Flavones and their Preliminary Structure–Antifouling Activity Relationship

Flavones from the Flowers of Tridax Procumbens and their Antioxidant Activity

A new flavone, 6-methoxy-7,8-dihydroxyflavone (1), and a new natural flavone, 7-methoxy-6,8- dihydroxyflavone (2), together with two known flavones wogonin (3) and oroxylin A (4), were isolated from Tridax procumbens. The structures of the compounds were established on the basis of 1D and 2D NMR data and HR-ESI-MS data interpretation, as well as by comparison with known analogs in the literature. All the compounds were evaluated for their antioxidant capabilities in vitro using 1,1′-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assays. Compound 1 (EC50 = 21.75 μg/mL) exhibited the most potent antioxidant activity.

Synthesis of Some Substituted Analogues of Natural Flavones and Chalcones

Synthesis of Some Substituted Analogues of Natural Flavones and Chalcones

Role of Diosmin in protection against the oxidative stress induced damage by gamma-radiation in Wistar albino rats

The benchmark of this study is to evaluate the radio protective efficiency of diosmin, a natural citrus flavone of hesperidin derivative on radiation-induced damage in wistar albino rats. Rats orally administered two diosmin doses (100 and 200 mg/kg body wt.) for a month (every other day) prior to exposure to high gamma radiation single dose (8Gy) or cumulative dose (10Gy). To evaluate the radio protective efficiency of diosmin various biochemical estimations, histopathological alterations as well as comet assay and caspase-3 activity for assessment of apoptosis were performed. Results indicated that radiation-induced decline in the levels of antioxidant parameters (SOD and GSH), increased lipid peroxidation, DNA damage and apoptosis were improved by pre-administration of diosmin. Diosmin dose (200 mg/kg body wt.) restored the antioxidant status to near normal and reduced lipid peroxidation, DNA and tissue damage. These results were confirmed by histopathological examinations, which showed that pre-administration of diosmin protected the liver and kidney of albino rats against gamma-irradiation induced damage. Hence, it has been illustrated that diosmin might be an effective radio protector against radiation-induced damage in rats. Moreover, diosmin alone pretreated group did not show any biochemical alterations or DNA damage indicating the protective nature of the drug.