Flavonoids: old and new aspects of a class of natural therapeutic drugs

Isorhamnetin inhibits cell proliferation and induces apoptosis in breast cancer via Akt and mitogen‑activated protein kinase kinase signaling pathways

Breast cancer is the most common cause of female cancer-associated mortality. Although treatment options, including chemotherapy, radiotherapy and surgery have led to a decline in the mortality rates associated with breast cancer, drug resistance remains one of the predominant causes for poor prognosis and high recurrence rates. The present study investigated the potential effects of the natural product, isorhamnetin on breast cancer, and examined the effects of isorhamnetin on the Akt/mammalian target of rapamycin (mTOR) and the mitogen-activated protein kinase (MAPK)/MAPK kinase (MEK) signaling cascades, which are two important signaling pathways for endocrine therapy resistance in breast cancer. The results of the present study indicate that isorhamnetin inhibits cell proliferation and induces cell apoptosis. In addition, isorhamnetin was observed to inhibit the Akt/mTOR and the MEK/extracellular signal-regulated kinase phosphorylation cascades. The inhibition of these two signaling pathways was attenuated by the two Akt and MEK1 inhibitors, but not by the nuclear factor-κB inhibitor. Furthermore, epidermal growth factor inhibited the effects of isorhamnetin via activation of the Akt and MEK signaling pathways. These results indicate that isorhamnetin exhibits antitumor effects in breast cancer, which are mediated by the Akt and MEK signaling pathways.

Role of hesperetin in LDL-receptor expression in hepatoma HepG2 cells

BACKGROUND

High plasma concentration of low-density lipoprotein cholesterol (LDL-c) plays a significant role in the incidence of atherosclerosis and coronary heart diseases. The aim of this study was to investigate the mechanism by which the citrus flavonoid, hesperetin, regulates the LDL receptor (LDLr) gene in the human liver using the human hepatoma cell line, HepG2.

METHODS

Luciferase reporter gene assays were performed (in the absence of lipoprotein) to measure the activity of the LDLr promoter and the promoters of the sterol regulatory element binding protein (SREBP) transcription factors that control the LDLr promoter.

RESULTS

Only SREBP-1 promoter activity was significantly increased 4 h after exposure to 200 μM hesperetin. However, after 24 h incubation with 200 μM hesperetin, the activities of all the promoter-constructs, SREBP-1a, -1c, -2 and LDLr, were significantly increased. The effects of 200 μM hesperetin on elevating LDLr mRNA levels were possibly due to regulation of LDLr gene transcription by SREBP-la and SREBP-2.

CONCLUSIONS

We conclude that 200 μM hesperetin was likely to have stimulated LDLr gene expression in human hepatoma HepG2 cells via increased phosphorylation of PI3K andERK1/2, which increased SREBP-1a and SREBP-2 mRNA levels and enhanced the maturation of the encoded proteins. This may lead to lower plasma LDL cholesterol; therefore, diets supplemented with hesperidin might provide cardio-protective effects and reduce mortality and morbidity from coronary heart diseases.

Neuroinflammatory response to experimental stroke is inhibited by eriodictyol

BACKGROUND

Cerebral ischemia is a common disease and one of the most common causes of death and disability worldwide. The lack of glucose and oxygen in neuronal tissue leads to a series of inflammatory events, culminating in neuronal death. Eriodictyol is a flavonoid isolated from the Chinese herb Dracocephalum rupestre that has been proven to have anti-inflammatory properties.

HYPOTHESIS/PURPOSE

Thus, the present study was designed to explore whether eriodictyol has neuroprotective effects against the neuronal damage, motor and memory deficits induced by permanent middle cerebral artery occlusion (pMCAO) in mice.

STUDY DESIGN

Animals were orally treated with eriodictyol (1, 2 and 4mg/kg) or vehicle (saline) 30min before pMCAO, 2h after, and then once daily for the following five days.

METHODS

The parameters studied were neuronal viability, brain infarcted area; sensorimotor deficits; exploratory activity; working and aversive memory; myeloperoxidase (MPO) activity; TNFα, iNOS and GFAP immunoreactivity.

RESULTS

The treatment with eriodictyol prevented neuronal death, reduced infarct area and improved neurological and memory deficits induced by brain ischemia. The increase of MPO activity and TNF-α, iNOS and GFAP expression were also reduced by eriodictyol treatment.

CONCLUSION

These findings demonstrate that eriodictyol exhibit promising neuroprotection effects against the permanent focal ischemia cerebral injury in the mice experimental model and the underlying mechanisms might be mediated through inhibition of neuroinflammation.

A Citrus bergamia Extract Decreases Adipogenesis and Increases Lipolysis by Modulating PPAR Levels in Mesenchymal Stem Cells from Human Adipose Tissue

The aim of this research was to assess the impact of a well-characterized extract from Citrus bergamia juice on adipogenesis and/or lipolysis using mesenchymal stem cells from human adipose tissue as a cell model. To evaluate the effects on adipogenesis, some cell cultures were treated with adipogenic medium plus 10 or 100 μg/mL of extract. To determine the properties on lipolysis, additional mesenchymal stem cells were cultured with adipogenic medium for 14 days and after this time added with Citrus bergamia for further 14 days. To verify adipogenic differentiation, oil red O staining at 7, 14, 21, and 28 days was performed. Moreover, the expression of peroxisome proliferator-activated receptor gamma (PPAR-γ), adipocytes fatty acid-binding protein (A-FABP), adipose triglyceride lipase (ATGL), hormone-sensitive lipase (HSL), monoglyceride lipase (MGL), 5′-adenosine monophosphate-activated protein kinase (AMPK)α1/2, and pAMPKα1/2 was evaluated by Western blot analysis and the release of glycerol by colorimetric assay. Citrus bergamia extract suppressed the accumulation of intracellular lipids in mesenchymal stem cells during adipogenic differentiation and promoted lipolysis by repressing the expression of adipogenic genes and activating lipolytic genes. Citrus bergamia extract could be a useful natural product for improving adipose mobilization in obesity-related disorders.

Acacetin promotes healthy aging by altering stress response in Caenorhabditis elegans

The progression in lifespan has been associated with elevated intracellular reactive oxygen species (ROS) and oxidative stress level which contributes to development of age related disorders. The discovery of lifespan modulating phytomolecules may promote development of natural therapies against age related afflictions. Acacetin (5,7-dihydroxy-4-methoxyflavone), is a naturally occurring flavonoid known to possess therapeutic properties. To this end, the present study evaluates effect of acacetin (AC) on lifespan, stress and neurotoxicity for the first time by using well-established free living, multicellular Caenorhabditis elegans model system. The 25 μM dose of AC significantly prolonged the mean lifespan of worms by 27.31% in comparison to untreated control and other tested doses of AC. Additionally, AC enhanced stress resistance against oxidative and thermal stress in worms. Furthermore, AC attenuated age related intracellular ROS level, aggregation of age pigment lipofuscin and increased the mean survival in stress hypersensitive mev-1 mutant by 40.5%. AC supplementation also reduced the alpha synuclein aggregation in transgenic worm model of Parkinson's disease. The enhanced stress resistance, lifespan and alleviation of age related pathology can be attributed to increment in stress modulatory enzymes like superoxide dismutase (SOD) and catalase (CAT) level. Altogether the results suggest AC exposure maintains stress level, health span and extends mean lifespan of C. elegans. The longevity promoting and neuromodulatory effects of AC are mediated by up regulation of the stress response genes sod-3 and gst-4. The present finding gives new insights of natural remedies and their future prospects in developing therapeutic interventions for managing age related diseases.

Protective effect of polyphenols in an inflammatory process associated with experimental pulmonary fibrosis in mice

Polyphenols have been described to have a wide range of biological activities, and many reports, published during recent years, have highlighted the beneficial effects of phenolic compounds, illustrating their promising role as therapeutic tools in several acute and chronic disorders. The purpose of study was to evaluate, in an already-assessed model of lung injury caused by bleomycin (BLM) administration, the role of resveratrol and quercetin, as well as to explore the potential beneficial properties of a mango leaf extract, rich in mangiferin, and a grape leaf extract, rich in dihydroquercetin (DHQ), on the same model. Mice were subjected to intra-tracheal administration of BLM, and polyphenols were administered by oral route immediately after BLM instillation and daily for 7 d. Treatment with resveratrol, mangiferin, quercetin and DHQ inhibited oedema formation and body weight loss, as well as ameliorated polymorphonuclear infiltration into the lung tissue and reduced the number of inflammatory cells in bronchoalveolar lavage fluid. Moreover, polyphenols suppressed inducible nitric oxide synthase expression, and prevented oxidative and nitroxidative lung injury, as shown by the reduced nitrotyrosine and poly (ADP-ribose) polymerase levels. The degree of apoptosis, as evaluated by Bid and Bcl-2 balance, was also suppressed after polyphenol treatment. Finally, these natural products down-regulated cyclo-oxygenase-2, extracellular signal-regulated kinase phosphorylated expression and reduced NF-κBp65 translocation. Our findings confirmed the anti-inflammatory effects of resveratrol and quercetin in BLM-induced lung damage, and highlight, for the first time, the protective properties of exogenous administration of mangiferin and DHQ on experimental pulmonary fibrosis.

Antituberculosis Activity of a Naturally Occurring Flavonoid, Isorhamnetin

Isorhamnetin (1) is a naturally occurring flavonoid having anticancer and anti-inflammatory properties. The present study demonstrated that 1 had antimycobacterial effects on Mycobacterium tuberculosis H37Rv, multi-drug- and extensively drug-resistant clinical isolates with minimum inhibitory concentrations of 158 and 316 μM, respectively. Mycobacteria mainly affect the lungs, causing an intense local inflammatory response that is critical to the pathogenesis of tuberculosis. We investigated the effects of 1 on interferon (IFN)-γ-stimulated human lung fibroblast MRC-5 cells. Isorhamnetin suppressed the release of tumor necrosis factor (TNF)-α and interleukin (IL)-12. A nontoxic dose of 1 reduced mRNA expression of TNF-α, IL-1β, IL-6, IL-12, and matrix metalloproteinase-1 in IFN-γ-stimulated cells. Isorhamnetin inhibited IFN-γ-mediated stimulation of extracellular signal-regulated kinase and p38 mitogen-activated protein kinase and showed high-affinity binding to these kinases (binding constants: 4.46 × 10(6) M(-1) and 7.6 × 10(6) M(-1), respectively). The 4'-hydroxy group and the 3'-methoxy group of the B-ring and the 5-hydroxy group of the A-ring of 1 play key roles in these binding interactions. A mouse in vivo study of lipopolysaccharide-induced lung inflammation revealed that a nontoxic dose of 1 reduced the levels of IL-1β, IL-6, IL-12, and INF-γ in lung tissue. These data provide the first evidence that 1 could be developed as a potent antituberculosis drug.

1-[4-(1H-Imidazol-1-yl)Phenyl]-3-Phenylprop-2-En-1-Ones – a Potential Pharmacophore Bearing Anti-Leishmanial Activity

A series of new potentially anti-microbial 1-[4-(1 H-imidazol-1-yl)phenyl]-3-phenylprop-2-en-1-ones was synthesised by condensation of various substituted benzaldehydes with 1-[4-(1 H-imidazol-1-yl)phenyl]ethanone, which was itself prepared by N-arylation of imidazole with p-haloacetophenones, using copper iodide and 1,3-di(pyridin-2-yl)propane-1,3-dione as a catalyst. All the synthesised compounds were subjected to preliminary evaluation for their anti-leishmanial and anti-fungal activities. Some of the synthesised compounds showed significant activities.

Evaluation of In Vitro Cytotoxic and Antioxidant Activity of Datura metel Linn. and Cynodon dactylon Linn. Extracts

Aim:

To evaluate in vitro cytotoxicity and antioxidant activity of Datura metel L. and Cynodon dactylon L. extracts.

Materials and Methods:

The extraction of plants parts (datura seed and fruit pulp) and areal parts of durva was carried out using soxhlet and cold extraction method using solvents namely methanol and distilled water. The total phenolic content (TPC) and total flavonoid content (TFC) was determined by established methods. The in vitro cytotoxicity assay was performed in vero cell line by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay method. In vitro antioxidant activity of the extract was performed by 2, 2-diphenyl-1-picrylhydrazyl radical scavenging method.

Results:

We found that the highest amount of TPC and TFC in methanolic extracts of seed (268.6 μg of gallic acid equivalence/mg of dry plant material) and fruit pulp (8.84 μg of quercetin equivalence/mg dry plant material) of D. metel, respectively prepared by Soxhlet method. The methanolic extract of C. dactylon prepared using soxhlation has shown potent free radical scavenging activity with 50% inhibitory concentration (IC₅₀) value of 100 μg/ml. The IC₅₀ of a methanolic cold extract of datura fruit was found to be 3 mg/ml against vero cell line.

Conclusion:

We observed that plant parts of C. dactylon and D. metel have a high antioxidant activity. Further research is needed to explore the therapeutic potential of these plant extracts.

SUMMARY

In the present study we observed a positive correlation was between the phenolic and flavanoid content of the Datura metel and cynodon doctylon (durva) extracts with the free radical scavenging activities. Both were found to have a high antioxidant activity.

Abbreviations used: BHA: Butylated hydroxyanisole, BHT: Butylated hydroxytoluene, CC50: 50% cell cytotoxic concentration, CNS: Central nervous system, DPPH: 2, 2-diphenyl-1-picrylhydrazyl, IC50: 50% inhibitory concentration, MTT: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), TFC: Total flavonoid content, TPC: Total phenolic content.

Synthesis and screening of ursolic acid-benzylidine derivatives as potential anti-cancer agents

Ursolic acid present abundantly in plant kingdom is a well-known compound with various promising biological activities including, anti-cancer, anti-inflammatory, hepatoprotective, antiallergic and anti-HIV properties. Herein, a library of ursolic acid-benzylidine derivatives have been designed and synthesized using Claisen Schmidt condensation of ursolic acid with various aromatic aldehydes in an attempt to develop potent antitumor agents. The compounds were evaluated against a panel of four human carcinoma cell lines including, A-549 (lung), MCF-7 (breast), HCT-116 (colon), THP-1 (leukemia) and a normal human epithelial cell line (FR-2). The results from MTT assay revealed that all the compounds displayed high level of antitumor activities compared with the triazole analogs (previously reported) and the parent ursolic acid. However, compound 3b, the most active derivative was subjected to mechanistic studies to understand the underlying mechanism. The results revealed that compound 3b induced apoptosis in HCT-116 cell lines, arrest cell cycle in the G1 phase, caused accumulation of cytochrome c in the cytosol and increased the expression levels of caspase-9 and caspase-3 proteins. Therefore, compound 3b induces apoptosis in HCT-116 cells through mitochondrial pathway.

Non-targeted chromatographic analyses of cuticular wax flavonoids from Physalis alkekengi L

Since Chinese lantern (Physalis alkekengi L.) represents a rich source of various bioactive secondary metabolites, there is an urge for its detailed characterization. Non-polar flavonoid aglycones represent one of the few bioactive species found in plant's cuticular waxes. The separation of flavonoids is already extensively covered in the literature, but methods dedicated to separation and identification of methylated flavonoids are rather scarce. In the present study a non-targeted approach for the separation, isolation and identification of methylated flavonoids present in P. alkekengi L. var. franchetii cuticular waxes was established. A rapid and simple separation on HPTLC silica gel was developed for preliminary screening of flavonoids. Fast HPLC-UV-MS(n) and HPLC-UV methods using a C6-Phenyl and a C18 stationary phase were also developed, respectively. In both cases, the right combination of temperature and tetrahydrofuran, as a mobile phase modifier, were shown to be crucial for a baseline separation of all studied compounds. By employing a semi-preparative analog of the C18 column, a simultaneous isolation of pure unknown analytes was achieved. Using these developed methods in combination with NMR, four 3-O-methylated flavonols were detected and identified in P. alkekengi L. var. franchetii cuticular waxes: myricetin 3,7,3'-trimethyl ether, quercetin 3,7-dimethyl ether, myricetin 3,7,3',5'-tetramethyl ether and quercetin 3,7,3'-trimethyl ether. Moreover, the simple and fast isocratic HPLC-UV-MS(n) method (under 8min) should prove useful in quality control of P. alkekengi L. var. franchetii by enabling chromatographic fingerprinting of external methylated flavonols. Finally, a rationale for the mechanism of separation of these metabolites by HPLC is also given, which establishes a foundation for future development of chromatographic methods for methylated flavonols and related compounds.

The Nrf2 Activator Vinylsulfone Reduces High Glucose-Induced Neural Tube Defects by Suppressing Cellular Stress and Apoptosis

The nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway is one of the primary pathways responsible for the cellular defense system against oxidative stress. Oxidative stress-induced apoptosis is a causal event in diabetic embryopathy. Thus, the Nrf2 pathway may play an important role in the induction of diabetic embryopathy. In the present study, we investigated the potentially protective effect of the Nrf2 activator, vinylsulfone, on high glucose-induced cellular stress, apoptosis, and neural tube defects (NTDs). Embryonic day 8.5 (E8.5) whole mouse embryos were cultured in normal (5 mmol/L) or high (16.7 mmol/L) glucose conditions, with or without vinylsulfone. At a concentration of 10 μmol/L, vinylsulfone had an inhibitory effect on high glucose-induced NTD formation, but it was not significant. At a concentration of 20 μmol/L, vinylsulfone significantly reduced high glucose-induced NTDs. In addition, 20 μmol/L vinylsulfone abrogated the high glucose-induced oxidative stress markers lipid hydroperoxide (LPO), 4-hydroxynonenal (4-HNE), and nitrotyrosine-modified proteins. The high glucose-induced endoplasmic reticulum (ER) stress biomarkers were also suppressed by 20 μmol/L vinylsulfone through the inhibition of phosphorylated protein kinase RNA-like ER kinase (PERK), inositol requiring protein 1α (IRE1a), eukaryotic initiation factor 2α (eIF2a), upregulated C/EBP-homologous protein (CHOP), binding immunoglobulin protein (BiP), and x-box binding protein 1 (XBP1) messenger RNA splicing. Furthermore, 20 μmol/L vinylsulfone abolished caspase 3 and caspase 8 cleavage, markers of apoptosis, in embryos cultured under high glucose conditions. The Nrf2 activator, vinylsulfone, is protective against high glucose-induced cellular stress, caspase activation, and subsequent NTD formation. Our data suggest that vinylsulfone supplementation is a potential therapy for diabetes-associated neurodevelopmental defects.

Effect of Hydroalcoholic Leaves Extract of Rhus Coriaria on Pain in Male Rats

BACKGROUND

The drive toward the use of medicinal plants has been increasing in recent years. They have few side effects and a large variety of efficient components.

OBJECTIVES

This study was designed to investigate the analgesic effects of hydroalcoholic Rhus coriaria leaf extract (HRCLE) in a rat model.

MATERIALS AND METHODS

A total of 42 adult male rats were divided into seven groups: a control group (the animals did not receive any drug), three HRCLE groups, (receiving 80, 100, and 300 mg/kg, intraperitoneally [ip]), a morphine group (1 mg/kg, ip) an aspirin group (1 mg/kg, ip), and a group that received 300 mg/kg of HRCLE plus naloxone (1 mg/kg, ip). The analgesic effects of HRCLE were assessed via writhing, tail flick, and formalin tests, and the data obtained were compared with the control group using one-way analysis of variance and Tukey post hoc tests.

RESULTS

HRCLE significantly inhibited the number of contractions induced by acetic acid in the writhing test at all doses, while anti-nociceptive activity was only shown at the 100 mg/kg dose (in the chronic phase) and at the 300 mg/kg dose (in the chronic-acute phase) in the formalin test. Interestingly, the greatest effect was observed at the 300 mg/kg HRCLE dose in the tail flick test. Simultaneous utilization of naloxone and HRCLE inhibited the anti-nociceptive effect of the extract in all tests. It is worth mentioning that aspirin and morphine revealed anti-nociceptive effects in all tests.

CONCLUSIONS

Our findings suggest that the analgesic effect of HRCLE may be mediated via both peripheral and central mechanisms. The presence of flavonoids might be responsible for the anti-nociceptive activity of this plant.

Negative ion electrospray high-resolution tandem mass spectrometry of polyphenols

Representative compounds with a 1,3-dihydroxybenzene substructure belonging to different important polyphenol classes (stilbenes, flavones, isoflavones, flavonols, flavanones, flavanols, phloroglucinols, anthraquinones and bisanthraquinones) were investigated based on detailed high-resolution tandem mass spectrometry measurements with an Orbitrap system under negative ion electrospray conditions. The mass spectral behaviour of these compound classes was compared among each other not only with respect to previously described losses of CO, CH2 CO and C3 O2 but also concerning the loss of CO2 and successive specific fragmentations. Furthermore, some unusual fragmentations such as the loss of a methyl radical during mass spectral decomposition are discussed. The obtained results demonstrate both similarities and differences in their mass spectral fragmentation under MS(n) conditions, allowing a characterization of the corresponding compound type. Copyright © 2015 John Wiley & Sons, Ltd.

Elucidation of Flavonoids from Carissa congesta, Polyalthia longifolia, and Benincasa hispida Plant Extracts by Hyphenated Technique of Liquid Chromatography-mass Spectroscopy

BACKGROUND

Carissa congesta (CC), Polyalthia longifolia (PL), and Benincasa hispida (BH) are economically important plants.

OBJECTIVE

Current research encompasses identification of quercetin and rutin and their analogues by liquid chromatography-mass spectroscopy (LC-MS) from the selected plant species.

MATERIALS AND METHODS

Fresh roots, leaves, and seeds of CC, PL, and BH plants respectively were shade-dried followed by extraction and elucidation of rutin and quercetin by LC-MS.

RESULTS

Structural elucidation of CC, PL, and BH extracts revealed the presence of flavonoids such as quercetin (m/z 301) and rutin (m/z 610) as the parent ions along with presence of close analogues such as quercetin-O-hexoside, Vicenin 2, quercetin-3-O-xyloside/arabinoside, and quercetin-3-O-glucoside were identified as fragments.

CONCLUSIONS

Thus, CC, PL, and BH extracts revealed the presence of flavonoids belonging to the class of flavonols such as rutin and quercetin.

SUMMARY

Quercetin and rutin were identified from CC roots, PL leaves and BH seeds by liquid chromatography-mass spectroscopy.Quercetin was characterized at (m/z 301) and rutin (m/z 610) as the parent ion peaks.Analogues such as quercetin-O-hexoside, Vicenin 2 and quercetin-3-O-glucoside were identified as fragments.

Synthesis and Regioselective Reaction of Some Unsymmetrical Heterocyclic Chalcone Derivatives and Spiro Heterocyclic Compounds as Antibacterial Agents

A number of novel heterocyclic chalcone derivatives can be synthesized by thermal and microwave tools. Treatment of 4-(4-Acetylamino- and/or 4-bromo-phenyl)-4-oxobut-2-enoic acids with hydrogen peroxide in alkaline medium were afforded oxirane derivatives 2. Reaction of the epoxide 2 with 2-amino-5-aryl-1,3,4-thiadiazole derivatives yielded chalcone of imidazo[2,1-b]thiadiazole derivative 4 via two thermal routes. In one pot reaction of 4-bromoacetophenone, diethyloxalate, and 2-amino-5-aryl-1,3,4-thiadiazole derivatives in MW irradiation (W 250 and T 150 °C) under eco-friendly conditions afforded an unsuitable yield of the desired chalcone 4d. The chalcone derivatives 4 were used as a key starting material to synthesize some new spiroheterocyclic compounds via Michael and aza-Michael adducts. The chalcone 4f was similar to the aryl-oxo-vinylamide derivatives for the inhibition of tyrosine kinase and cancer cell growth. The electron-withdrawing substituents, such as halogens, and 2-amino-1,3,4-thiadiazole moeity decreasing the electron density, thereby decreasing the energy of HOMO, and the presence of imidazothiadiazole moiety should improve the antibacterial activity. Thus, the newly synthesized compounds were evaluated for their anti-bacterial activity against (ATCC 25923), (ATCC 10987), (ATCC 274,) and (SM514). The structure of the newly synthesized compounds was confirmed by elemental analysis and spectroscopic data.

Toxicity study about a medicinal plant Casearia sylvestris: A contribution to the Brazilian Unified Health System (SUS)

ETHNOPHARMACOLOGICAL RELEVANCE

Casearia sylvestris S.w (Salicaceae) is catalogued by the Brazilian Unified Health System as a plant of interest for the Brazilian population with the purpose of treating inflammatory disorders, such as pain and gastrointestinal disorders based on the folk use and some literature about efficacy; however, no toxicological studies concerned the safety of extract fluid of this plant have been reported.

AIM OF THE STUDY

The present study was carried out to evaluate the acute and subchronic toxicity of the hydroethanolic extract fluid (FE) obtained from leaves of C. sylvestris in Wistar rats.

MATERIALS AND METHODS

In the acute toxicity test three female Wistar rats were treated with a single dose of FE (2000 mg/kg) administered by oral gavage and observed for 14 days in order to identify signs of toxicity or death. In subchronic toxicity study animals received, by daily gavage three doses 60, 120 and 240 mg/kg of the FE of the plant for 28 and 90 days. The animals were observed daily for clinical signs and mortality. Body weight and food consumption were measured weekly and at the end of treatment were analysed hematological, biochemical and histopathological parameters. Also was analysed the cellularity of bone marrow and spleen. Moreover, phytochemical analysis by HPLC-PDA-ESI(+)/MS and CG/MS/EI was carried out to qualify the constituents of the extract.

RESULTS

The results of acute study indicated that the LD50 is higher than 2000 mg/kg and at 28 and 90 day oral toxicity showed that there were no toxic effects detected in any of the parameters evaluated: body weight and relative organ weight, general behavioral changes, haematological and biochemical parameters and histopathological examination. The analysis by HPLC-PDA-ESI(+)/MS and CG/MS/EI identified the flavonoids rutin, quercetin and luteolin and also chlorogenic on the extract.

CONCLUSION

Based on this study the hydroethanolic fluid extract of C. sylvestris could be safe even when used over a long period for therapeutic uses proposed by the Brazilian Unified Health System.

Apigenin Attenuates Inflammation in Experimentally Induced Acute Pancreatitis-Associated Lung Injury

BACKGROUND

Acute pancreatitis is associated with acute lung injury. The aim of the present study is to evaluate alterations of lungs in an experimental model of acute pancreatitis (AP) following both bilio-pancreatic duct obstruction close to the duodenum. Acute pancreatitis is a common disease with significant mortality. This situation makes the need of finding protective factors for the lung parenchyma, imperative. In the present study there is an effort to clarify the role of apigenin, a substance which is well known for its antioxidant and anti-inflammatory effects, on lung injury, following acute pancreatitis in rats.

MATERIALS AND METHODS

In the present study, 126 male Wistar-type rats 3-4 months old and 220-350 g weight were used. At time 0 we randomly assigned the following groups: Group Sham: Rats were subjected to virtual surgery. Group Control: Rats were subjected to surgery for induction of acute pancreatitis. Group Apigenin: Rats were subjected to surgery for induction of acute pancreatitis and enteral feeding with apigenin. Immunochemistry for TNF-α and IL-6 as well as MPO activity were measured at predetermined time intervals 6, 12, 24, 48, and 72 h, in order to evaluate architectural disturbances of the lung tissue.

RESULTS

From the pathological reports we realized that comparing the control group with the apigenin group, there is an improvement of lung tissue damage following apigenin administration, with statistical significance. Apigenin reduces most histopathological alterations of the pulmonary tissue, reduces MPO and TNF-α activity at 48 hours and, furthermore, reduces IL-6 activity at 72 hours post-administration.

CONCLUSIONS

Oral Apigenin administration in rats, following experimental induced acute pancreatitis, seems to be protective on the lung tissue. Apigenin administration to humans could potentially ameliorate acute lung injuries. However, special caution is required for humans' use, as more detailed studies are needed.

Anti-inflammatory and antipyretic properties of Kang 601 heji, a traditional Chinese oral liquid dosage form

Objective

To evaluate the scientific basis for the use of Kang 601 heji (K-601) as an anti-inflammatory and antipyretic agent using appropriate animal models.

Methods

Carrageenan-induced rat paw and xylene-induced ear oedemas were models used to investigate anti-inflammatory actions of K-601. Lipopolysaccharide-induced pyrexia model was used to evaluate antipyretic activity in Wistar rats. The anti-inflammatory and antipyretic mechanisms were evaluated by detecting prostaglandins E₂, nitric oxide, interleukin-1β and tumour necrosis factor-α levels using appropriate reagents and ELISA kits.

Results

The results revealed that K-601 reduced the level of inflammations in both anti-inflammatory models in a dose-dependent manner. The same was true for the antipyretic model. The possible mechanisms of actions were through the inhibition of prostaglandins E₂, interleukin-1β, tumour necrosis factor-α and nitric oxide.

Conclusions

K-601 has proven anti-inflammatory and antipyretic actions. The findings provide a scientific basis for the use of K-601 as anti-inflammatory and antipyretic agent in traditional Chinese medicinal practice.

Tricin, flavonoid from Njavara reduces inflammatory responses in hPBMCs by modulating the p38MAPK and PI3K/Akt pathways and prevents inflammation associated endothelial dysfunction in HUVECs

Previous studies revealed the potent anti-inflammatory activity of tricin, the active component of Njavara rice bran. Here, we report the involvement of specific signaling pathways in the protective effect of tricin against LPS induced inflammation in hPBMCs and the role of tricin in modulating endothelial dysfunction in LPS induced HUVECs. Pretreatment with tricin (15μM) significantly inhibited the release of TNF-α and was comparable to the specific pathway blockers like ERK inhibitor (PD98059), JNK inhibitor (SP600125) and p38 inhibitor (SB203580), whereas an increased release of TNF-α was observed in PI3K/Akt inhibitor (LY294002) treated cells. Tricin alone and combination treatment of tricin and SB203580 showed more significant inhibition of activation of COX-2 and TNF-α than that of SB203580 alone treated group. Combination treatment of tricin and LY294002 showed increased activation of COX-2 and TNF-α, proved that PI3K activation is essential for the anti-inflammatory effect of tricin. Studies conducted on HUVECs revealed the protective effect of tricin against endothelial dysfunction associated with LPS induced inflammation by inhibiting the activation of proinflammatory mediators like TNF-α, IFN-γ, MCP 1 by modulating NF-κB and MAPK signaling pathways. ELISA and flow cytometric analysis again confirmed the protection of tricin against endothelial damage, especially from the decreased activation of cell adhesion molecules like ICAM-1, VCAM-1 and E-Selectin upon tricin treatment. This work establishes the mechanism behind the potent anti-inflammatory activity of the flavonoid tricin.

Effect of quercetin, genistein and kaempferol on glutathione and glutathione-redox cycle enzymes in 3T3-L1 preadipocytes

CONTEXT AND OBJECTIVE

Many studies have shown that cellular redox potential is largely determined by glutathione (GSH), which accounts for more than 90% of cellular nonprotein thiols. The aim of this study was to delineate the effect of three flavonoids - namely, quercetin, kaempferol and genistein - and exogenous GSH on oxidative damage by the Fenton's pathway through the GSH and GSH-redox cycle enzymes in 3T3-L1 cells.

MATERIALS AND METHODS

3T3-L1 preadipocytes were exposed to each flavonoid and GSH at concentrations of 0, 5, 10, 15, 20 and 25 µM and then GSH levels and activities of glutathione peroxidase (GSH-Px), glutathione reductase (GSH-Rx) and superoxide dismutase (SOD) were measured.

RESULTS

Exogenous GSH did not have significant effect on intracellular GSH although slight decrease was observed at 15-25 µM doses. However, each of the three flavonoids sustained intracellular GSH levels in the cells as compared to the respective controls. Quercetin had the most profound effect, followed by kaempferol and genistein in that order. GSH-Px, GSH-Rx and SOD activities increased for all the doses tested compared to their respective controls. Again, quercetin had the maximum increase in enzyme activities followed by kaempferol and genistein for the enzymes tested.

DISCUSSION AND CONCLUSION

These findings suggest that the flavonoids play an important role in diminishing oxidation-induced biochemical damages. The enhancement of these enzymes may increase the resistance of the organism against oxidative damage by the Fenton's pathway.

Flt3 is a target of coumestrol in protecting against UVB-induced skin photoaging

While skin aging is a naturally occurring process by senescence, exposure to ultraviolet (UV) radiation accelerates wrinkle formation and sagging of skin. UV induces skin aging by degrading collagen via activating matrix metalloproteinases (MMPs). In this study, we show that coumestrol, a metabolite of the soybean isoflavone daidzein, has a preventive effect on skin photoaging in three-dimensional human skin equivalent model. Coumestrol inhibited UVB-induced MMP-1 expression and activity. Whole human kinase profiling assay identified FLT3 kinase as a novel target protein of coumestrol in UVB-induced signaling pathway in skin. Coumestrol suppresses FLT3 kinase activity, and subsequently, Ras/MEK/ERK and Akt/p70 ribosomal S6 kinase pathway. This suppresses AP-1 activity and in turn, diminishes MMP-1 gene transcription. Using X-ray crystallography, the binding of coumestrol to FLT3 was defined and implied ATP-competitive inhibition. Residues Lys644 and Phe830 showed local changes to accommodate coumestrol in the ATP-binding pocket. 4-APIA, a pharmacological inhibitor of FLT3, inhibited MMP-1 expression and induced signal transduction changes similar to coumestrol. Taken together, coumestrol inhibits UVB-induced MMP-1 expression by suppressing FLT3 kinase activity. These findings suggest that coumestrol is a novel dietary compound with potential application in preventing and improving UVB-associated skin aging.

Degradable poly(apigenin) polymer inhibits tumor cell adhesion to vascular endothelial cells

Cancer and the inflammatory system share a complex intertwined relationship. For instance, in response to an injury or stress, vascular endothelial cells will express cell adhesion molecules as a means of recruiting leukocytes. However, circulating tumor cells (CTCs) have been shown to highjack this expression for the adhesion and invasion during the metastatic cascade. As such, the initiation of endothelial cell inflammation, either by surgical procedures (cancer resection) or chemotherapy can inadvertently increase the metastatic potential of CTCs. Yet, systemic delivery of anti-inflammatories, which weaken the entire immune system, may not be preferred in some treatment settings. In this work, we demonstrate that a long-term releasing flavone-based polymer and subsequent nanoparticle delivery system can inhibit tumor cell adhesion, through the suppression of endothelial cell adhesion molecule expression. The degradation of a this anti-inflammatory polymer provides longer term, localized release profile of active therapeutic drug in nanoparticle form as compared with that of the free drug, permitting more targeted anti-metastatic therapies. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1438-1447, 2016.

Crystal structures of (2E)-1-(3-bromo-thio-phen-2-yl)-3-(2-meth-oxy-phen-yl)prop-2-en-1-one and (2E)-1-(3-bromo-thio-phen-2-yl)-3-(3,4-di-meth-oxy-phen-yl)prop-2-en-1-one

In the mol-ecules of the title compounds, (2E)-1-(3-bromo-thio-phen-2-yl)-3-(2-meth-oxy-phen-yl)prop-2-en-1-one, C14H11BrO2S, (I), which crystallizes in the space group P-1 with four independent mol-ecules in the asymmetric unit (Z' = 8), and (2E)-1-(3-bromo-thio-phen-2-yl)-3-(3,4-di-meth-oxy-phen-yl)prop-2-en-1-one, C15H13BrO3S, (II), which crystallizes with Z' = 8 in the space group I2/a, the non-H atoms are nearly coplanar. The mol-ecules of (I) pack with inversion symmetry stacked diagonally along the a-axis direction. Weak C-H⋯Br intra-molecular inter-actions in each of the four mol-ecules in the asymmetric unit are observed. In (II), weak C-H⋯O, bifurcated three-center inter-molecular inter-actions forming dimers along with weak C-H⋯π and π-π stacking inter-actions are observed, linking the mol-ecules into sheets along [001]. A weak C-H⋯Br intra-molecular inter-action is also present. There are no classical hydrogen bonds present in either structure.

Development of fluorinated methoxylated chalcones as selective monoamine oxidase-B inhibitors: Synthesis, biochemistry and molecular docking studies

A series of methoxylated chalcones with fluoro and trifluoromethyl derivatives were synthesized and investigated for their ability to inhibit human monoamine oxidase A and B. The chemical structures of the compounds have been characterized by means of their (1)H NMR, (13)C NMR, Mass spectroscopic datas and elemental analysis. The results demonstrate that these compounds are reversible and selective MAO-B inhibitors with a competitive mode of inhibition. The most potent compound (2E)-1-(4-methoxyphenyl)-3-[4-(trifluoromethyl)phenyl] prop-2-en-1-one showed the best activity and higher selectivity towards hMAO-B with Ki and SI values of 0.22±0.01μM and 0.05 comparable to that standard drug, Selegiline Ki and SI values were found as 0.33±0.03μM and 0.04, respectively. Molecular docking studies were carried out to further explain the in vitro results of the new compounds, and to identify the hypothetical binding mode for the compounds inside the inhibitor binding cavity of hMAO-B.

Antinociceptive effects of Rhus coriaria L. extract in male rats

It is well known that the tendency toward the medicinal plants is increasing in recent years. They have low side-effects and high varieties of efficient components. This study was designed to investigate the analgesic effect of hydro alcoholic leaf extract of Rhus coriaria (HRCLE) in a rat model. For this purpose, 42 adult male rats were divided into 7 groups: control, HRCLE (80, 100 and 300 mg/kg, i.p.), morphine (1 mg/kg, i.p.), aspirin (1 mg/kg, i.p.), and HRCLE 300 mg/kg plus naloxone (1 mg/kg, i.p.). The analgesic effects of HRCLE were assessed with writhing, tail flick and formalin tests. The data were compared with control by one-way ANOVA and Tukey post hoc test. All dose levels of HRCLE inhibited the number of contractions induced by acetic acid in the writhing test signfiicantly. None of the dose levels of HRCE have been showed antinociceptive activity in the formalin test except the dose of 100 mg/kg (at chronic phase) and the dose of 300 mg/kg (at chronic- acute phase). In the tail flick model, the highest effect was at the dose of 300 mg/kg of HRCLE (P < 0.01). Utilization of naloxone plus extract inhibited the antinociceptive effect of HRCLE. In this study, our findings suggest that analgesic effect for the HRCLE may be mediated via both peripheral and central mechanisms. The presence of flavonoids might be responsible for the antinociceptive activity of this plant.

Protective Effect of Piper aduncum Capsule on DMBA-induced Breast Cancer in Rats

The possible protective effect of Piper aduncum capsule on DMBA (dimethylbenz[α]anthracene)-induced breast cancer in rats was assessed by monitoring the tumor and lung metastases incidence and recording hematological and biochemical parameters and frequency of micronuclei. Mammary carcinogenesis was induced in 36 female Holtzman rats by providing a single subcutaneous injection of DMBA. Oral administration of P. aduncum capsule lowered adenocarcinoma and lymph node metastases incidence. Pulmonary metastasis was significantly lowered (P < 0.05). Hematological indicators showed that the triglyceride level was significantly lowered (P < 0.01) and high-density lipoprotein (HDL) level was significantly increased (P < 0.01). Also, P. aduncum capsule significantly lowered the C reactive protein (CRP) level (P < 0.01) and malondialdehyde level (P < 0.05). There was a significant decrease in the frequency of DMBA-induced micronucleated polychromatic erythrocyte (P < 0.01). Considering the antitumorigenic, hypolipidemic, anti-inflammatory, antioxidant, and antigenotoxic properties of P. aduncum capsule, we conclude that it has a protective effect on DMBA-induced breast cancer in rats.

Combined Autodock and comparative molecular field analysis study on predicting 5-lipoxygenase inhibitory activity of flavonoids isolated from Spatholobus suberectus Dunn

5-Lipoxygenase (5-LOX) plays a key role in the pathway of leukotriene biosynthesis. To predict the inhibitory activity of flavonoid inhibitors against 5-LOX from Spatholobus suberectus Dunn, Autodock 4.2 and comparative molecular field analysis (CoMFA) were employed. For the positive inhibitors (n=7), the value of the coefficient of determination (R2) between the binding free energy, calculated using Autodock 4.2, and the experimental pIC50 is 0.838. In the training set (n=21) of inhibitors against 5-LOX, the R2 of non-cross-validated partial least squares analysis between the actual and predicted pIC50 values, using the no-validation with the optimum number of components set to 6, is 0.997 (p=0.000). For the model generated by CoMFA, the contribution of electrostatic and steric factors are 0.522 and 0.478, respectively. Among the flavonoids of S. suberectus, liquiritigenin, catechin, butin, 3',4',7-trihydroxyflavone, plathymenin, and gallocatechin are the more potent inhibitors of 5-LOX based on the calculated binding free energy and the predicted pIC50 value.

In vitro and in vivo antitumoral effects of combinations of polyphenols, or polyphenols and anticancer drugs: perspectives on cancer treatment

Carcinogenesis is a multistep process triggered by genetic alterations that activate different signal transduction pathways and cause the progressive transformation of a normal cell into a cancer cell. Polyphenols, compounds ubiquitously expressed in plants, have anti-inflammatory, antimicrobial, antiviral, anticancer, and immunomodulatory properties, all of which are beneficial to human health. Due to their ability to modulate the activity of multiple targets involved in carcinogenesis through direct interaction or modulation of gene expression, polyphenols can be employed to inhibit the growth of cancer cells. However, the main problem related to the use of polyphenols as anticancer agents is their poor bioavailability, which might hinder the in vivo effects of the single compound. In fact, polyphenols have a poor absorption and biodistribution, but also a fast metabolism and excretion in the human body. The poor bioavailability of a polyphenol will affect the effective dose delivered to cancer cells. One way to counteract this drawback could be combination treatment with different polyphenols or with polyphenols and other anti-cancer drugs, which can lead to more effective antitumor effects than treatment using only one of the compounds. This report reviews current knowledge on the anticancer effects of combinations of polyphenols or polyphenols and anticancer drugs, with a focus on their ability to modulate multiple signaling transduction pathways involved in cancer.

Naturally occurring products in cancer therapy

Natural products have been used for the treatment of various diseases and are becoming an important research area for drug discovery. These products, especially phytochemicals have been extensively studies and have exhibited anti-carcinogenic activities by interfering with the initiation, development and progression of cancer through the modulation of various mechanisms including cellular proliferation, differentiation, apoptosis, angiogenesis, and metastasis. This concept is gaining attention because it is a cost-effective alternative to cancer treatment. In this article, we have discussed some of the naturally occurring products used in cancer treatment.

Biotransformations and biological activities of hop flavonoids

Female hop cones are used extensively in the brewing industry, but there is now increasing interest in possible uses of hops for non-brewing purposes, especially in the pharmaceutical industry. Among pharmaceutically important compounds from hops are flavonoids, having proven anticarcinogenic, antioxidant, antimicrobial, anti-inflammatory and estrogenic effects. In this review we aim to present current knowledge on the biotransformation of flavonoids from hop cones with respect to products, catalysis and conversion. A list of microbial enzymatic reactions associated with gastrointestinal microbiota is presented. A comparative analysis of the biological activities of hop flavonoids and their biotransformation products is described, indicating where further research has potential for applications in the pharmaceutical industry.