An overview on immunoregulatory and anti-inflammatory properties of chrysin and flavonoids substances

Evaluation of Methanol-Dichloromethane Extract of Stemonocoleus micranthus Harms (Fabaceae) Stem Bark for Anti-Inflammatory and Immunomodulatory Activities

BACKGROUND

The stem bark decoction of Stemonocoleus micranthus Harms (Fabaceae) is most widely used traditionally as a remedy for various diseases such as malaria and boil. In this study, the anti-inflammatory and immunomodulatory activities of the methanol-dichloromethane extract (MDE) from the stem bark of the plant in rodents were evaluated.

METHODS

The carrageenan-induced rat paw oedema, cotton pellet-induced granuloma in rat, and xylene-induced ear oedema in mice were used to study the anti-inflammatory activity of methanol-dichloromethane extract of Stemonocoleus micranthus (MDESm) (100, 200, and 400 mg/kg). The effects of MDESm (100, 200, and 400 mg/kg) on cyclophosphamide-induced immunosuppression, neutrophil adhesion, carbon clearance, and haematological and biochemical parameters were carried out to study its immunomodulatory activity in mice.

RESULT

MDESm (100 mg/kg, p.o.) significantly (p < 0.05) inhibited carrageenan-induced oedema by 57.1% at 5th h posttreatment compared with control. At 100 mg/kg, p.o., MDESm significantly (p < 0.05) reduced cotton pellet-induced granuloma by 39.28% and nonsignificantly reduced xylene-induced ear oedema by 34.1%. Treatment with MDESm (100 and 400 mg/kg) nonsignificantly abolished the neutropenia caused by cyclophosphamide with a percentage neutrophil reduction of 0 and -14.86%, respectively, while MDESm (200 mg/kg) and levamisole (50 mg/kg) had a nonsignificant reduction in neutrophil count (10.16 and 31.40%), respectively, all compared to the distilled water-treated group with a neutrophil count of -9.82%. MDESm at doses of 100 and 200 mg/kg increased phagocytic index by 0.0447 ± 0.00762 and 0.0466 ± 0.00703, respectively, although not significantly when compared to the control group with a value of 0.0226 ± 0.02117. There was a decrease in WBC and lymphocyte counts in MDESm- (200 mg/kg) treated group, suggesting immunosuppressive potential at this dose. MDESm caused a dose-dependent decrease in ALT and core liver enzymes, suggesting a hepatoprotective effect. The acute toxicity test revealed that MDESm is safe in mice with an oral lethal dose (LD50) of >5 g/kg.

CONCLUSION

The methanol-dichloromethane extract of Stemonocoleus micranthus Harms possesses mild anti-inflammatory and immunomodulatory activities which may be more pronounced upon fractionation and purification. Therefore, more investigations are needed to explore these activities further.

In silico and in vitro approaches to evaluate the bioactivity of Cassia auriculata L extracts

The present study is an attempt to evaluate the in vitro anti-inflammatory and in silico anticancer potentials of the plant Cassia auriculata (CA). The aerial parts of CA were subjected to solvent extraction, and the extracts were fractionised by gas chromatography and mass spectrometry analysis for its phytochemical content. The antiinflammatory activity of the extracts were confirmed by the IC50 value of 125.02 µg/ml for red blood cell membrane stabilisation and 195.7 µg/ml for inhibition of protein denaturation activity. The interaction of bioactive compounds of CA ethanol extract with target protein was predicted through molecular docking studies, serine/threonine-protein kinase B (AKT1), responsible for development and progression of lung cancer using AutoDock tools. Extensive studies have been carried out on a range of kinase inhibitors targeting Akt, but obtaining promising results is a challenge yet due to its toxicity and resistance issues. Yohimbine, undecanoic acid 10-methyl-ethyl ester and chrysin significantly bind to the target protein with least binding energy. Hence, the present paper establishes the anti-inflammatory and anticancer capacities of CA ethanol extract as an alternative to the existing therapeutic approach to inflammation and cancer through a systematic in vitro and in silico approaches supplementing the findings.

Ellagic Acid Activated PPAR Signaling Pathway to Protect Ileums Against Castor Oil-Induced Diarrhea in Mice: Application of Transcriptome Analysis in Drug Screening

Background

Acute diarrhea is still a common and serious disease. The causes of acute diarrhea are very complicated. Therefore, we need to find a medicine to control diarrhea symptoms, save time for diagnosis of pathogens, and prevent drug abuse. Ellagic acid (EA), a natural polyphenol drug, has anti-diarrhea effects. However, the action mechanisms of EA for non-specific diarrhea have not been characterized.

Materials and Methods

To study the mechanisms of EA, mice were divided into four groups. Group C were intraperitoneally injected with 0.1 ml physiological saline and orally given 0.2 ml physiological saline, and then after experiment began 0.5 h, orally administered 0.3 ml physiological saline. Group D were intraperitoneally injected with 0.1 ml physiological saline and orally given 0.2 ml castor oil, and then after experiment began 0.5 h, orally administered 0.3 ml physiological saline. Group E were intraperitoneally injected with 0.1 ml physiological saline and orally given 0.2 ml castor oil, and then after experiment began 0.5 h, orally administered 0.3 ml EA (10 mg/ml). Group V were intraperitoneally injected with 0.1ml GW9662 (1m g/ml) and orally given 0.2 ml castor oil, and then after experiment began 0.5 h, orally administered 0.3 ml EA (10 mg/ml). Transcriptome were performed on ileum tissues of mice in group D and E. Histological examination and qRT-PCR were performed on ileum tissues of mice in group C, D, E, and V.

Results

We found that a total of 273 differentially expressed genes (DEGs) were obtained, including 160 up-regulated DEGs and 113 down-regulated DEGs. The DEGs were enriched in 458 Gene Ontology (GO) terms and 15 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, respectively. The peroxisome proliferator activated receptor (PPAR) signaling pathway was the most significantly enriched in KEGG pathways. We used the PPAR-specific antagonist GW9662 to validate the anti-diarrhea and anti-inflammatory effect of EA in group V compared with group E. Conclusively, EA protected ileums against castor oil-induced inflammation and diarrhea by activating the PPAR signaling pathway and a method was used to study the mechanism of EA.

Rhein attenuates lipopolysaccharide-primed inflammation through NF-κB inhibition in RAW264.7 cells: targeting the PPAR-γ signal pathway

Inflammation is a common inducer of numerous severe diseases such as sepsis. The NF-κB signaling pathway plays a key role in the inflammatory process. Its activation promotes the release of pro-inflammatory mediators like inducible nitric oxide synthase and tumor necrosis factor alpha. Peroxisome proliferator-activated receptor gamma (PPAR-γ) inactivates nuclear factor kappa B (NF-κB) and subsequently attenuates inflammation. Rhein, an agent isolated from rhubarb, has been known to have anti-inflammatory effects. However, its influence on PPAR-γ remains largely unknown. In this study, an inflammation model was constructed by stimulating RAW264.7 cells with lipopolysaccharide. Rhein was used as a therapeutic agent, while rosiglitazone (PPAR-γ activator) and GW9662 (PPAR-γ inhibitor) were used as disrupters for in depth studies. The results demonstrated that rhein inhibits NF-κB activation and inflammatory factor release. However, GW9662 significantly reduced this effect, indicating that PPAR-γ is a critical mediator in the rhein-mediated anti-inflammatory process. Additionally, positive modulation of PPAR-γ expression and activity by rosiglitazone correspondingly influenced the effects of rhein on inflammatory factors and NF-κB expression. We also found that rhein could enhance PPAR-γ, NF-κB, and histone deacetylase 3 (HDAC3) binding. These results indicate that rhein exerts its anti-inflammation function by regulating the PPAR-γ-NF-κB-HDAC3 axis.

Identification and characterization of human interferon alpha inhibitors through a WISH cell line-based reporter gene assay

Interferons (IFNs) are important glycoproteins which can stimulate or inhibit up to three hundred different genes encoding proteins involved in antiviral defense mechanisms, inflammation, adaptive immunity, angiogenesis and among other processes. Nevertheless, different genetic alterations may lead to interferon alpha (IFN-α) overproduction in human autoimmune diseases like systemic lupus erythematosus. As a consequence, IFN-α is a central molecule whose activity must be regulated to block their harmful effect on those disorders where the endogenous cytokine production constitutes the etiology of the illnesses. In this work, we evaluate the biological activity of eighty-eight compounds, from our own chemo-library, to find potential IFN-α inhibitors by using a reporter gene assay (RGA) WISH-Mx2/EGFP. We identified some compounds able to modulate negatively the IFN-α activity. The most active IFN-α inhibitors were further studied achieving promising results. In addition, some combinations of the most active compounds were analyzed accomplishing a stronger effect to decrease the IFN-α activity than each compound alone. Furthermore, the complete inhibition of the cytokine activity was reached with some combinations of compounds.

Flavonoids as Natural Anti-Inflammatory Agents Targeting Nuclear Factor-Kappa B (NFκB) Signaling in Cardiovascular Diseases: A Mini Review

Cardiovascular diseases (CVDs) such as angina, hypertension, myocardial ischemia, and heart failure are the leading causes of morbidity and mortality worldwide. One of the major transcription factors widely associated with CVDs is nuclear factor-kappa B (NFκB). NFκB activation initiates the canonical and non-conical pathways that promotes activation of transcription factors leading to inflammation, such as leukocyte adhesion molecules, cytokines, and chemokines. Flavonoids are bioactive polyphenolic compounds found abundantly in various fruits, vegetables, beverages (tea, coffee), nuts, and cereal products with cardiovascular protective properties. Flavonoids can be classified into six subgroups based on their chemical structures: flavanones, flavones, flavonols, flavan-3-ols, isoflavones, and anthocyanidins. As NFκB inhibitors, these flavonoids may modulate the expression of pro-inflammatory genes leading to the attenuation of the inflammatory responses underlying various cardiovascular pathology. This review presents an update on the anti-inflammatory actions of flavonoids via inhibition of NFκB mechanism supporting the therapeutic potential of these natural compounds in various CVDs.

Fluorine-Containing Chrysin Derivatives

Chrysin, a flavonoid, has played a great role in the fields of anticancer, antibacterial, and antiviral drug discovery. A large number of chrysin derivatives have been synthesized recently. The fluorine atom represents an important substituent group for a great number of natural products and pharmaceuticals. Taking into account the importance of both chrysin and the fluorine atom in medicinal chemistry, the synthesis of fluorine-containing chrysin derivatives has gained great interest. Chemically, the synthetic methods for these new chrysin derivatives have also been developed rapidly. In recent years, research on their synthesis has been focused on speeding up the reaction process by changing the catalyst. Biologically, the purpose of introducing fluorine into chrysin was to improve its lipophilicity, but today it is mainly focused on the enhancement and improvement of either its anticancer or antimicrobial activities by incorporating the special properties of fluorine atoms. In this review, synthetic methods for the introduction of fluorine atoms into chrysin are summarized, and their anticancer, antibacterial, antiviral, and hypoglycemic effects are discussed.

Inclusion complexes between chrysin and amino-appended β-cyclodextrins (ACDs): Binding behavior, water solubility, in vitro antioxidant activity and cytotoxicity

Solid inclusion complexes between chrysin and four amino-appended β-cyclodextrins (ACDs) were prepared by suspension method and characterized in solid and solution states by kinds of analytical methods. The scanning electron microscopy (SEM) showed distinct micro-morphologies of them. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) analysis revealed their unique thermal properties, such as decomposition temperatures and endothermic points. Powder X-ray diffractometry (XRD) analysis disclosed their unique crystal patterns. Their nuclear magnetic resonance (NMR) analyses provided the variations of chemical shifts before and after the formation of inclusion complexes. Their binding stability constants (Ks) were 574, 842, 704, and 474 L·mol^-1, respectively, as determined by spectral titration. A 1:1 inclusion mode with self-assembly of their amino side chains inside the ACD cavity was proposed based on Job plot and 2D-ROESY experiments. Water solubility of chrysin was promoted up to 4411.98 μg·mL^-1 after formation of inclusion complexes with ACDs, better than that of β-CD and its derivatives, i.e., HP- and SBE-β-CD. In vitro antioxidant activity of chrysin was also improved after inclusion complexation by the DPPH scavenging assay. Furthermore, in vitro cytotoxicity of solid inclusion complexes towards three human cancer cell lines, A549, HT-29 and HCT116 were enhanced significantly.

Chrysin: Pharmacological and therapeutic properties

Chrysin is a promising phytochemical that is categorized under the class of flavonoids based on its chemical structure. Naturally, it is widely present in propolis, honey, passion fruit, and even in mushrooms and other plant sources, whereas its synthetic counterparts are also being employed for pharmacological purposes. It has widely been employed in treatment of various degenerative disorders and provides cytotoxic and anti-inflammatory functions. Its antioxidant and disease preventing abilities are attributed to its structural diversity arising in ring-A and absence of oxygenation in B and C ring. In this review, the scientific studies are being reported emphasizing benefits and its allied health claims on chrysin in numerous metabolic malfunctions.

Polyphenols of Chinese skullcap roots: from chemical profiles to anticancer effects

Great efforts have been made to identify the principle bioactive constituents of Chinese herbs and to unravel the molecular mechanisms behind their anticancer effects. Scutellaria baicalensis (Huangqin or Chinese skullcap) is a widely consumed herbal medicine and has been historically used in anticancer therapy in China and other countries. Chinese skullcap generates many active chemicals in the root and is abundant in polyphenols, which act as its anti-cancer ingredients. It contains around 53 polyphenols in total: 50 flavonoids and 3 stilbenes. The polyphenols have similar chemical structures since they are derived from similar biochemical synthetic pathways. According to the literature, as the active chemicals of the skullcap root, 18 polyphenols exhibit evident anticancer activities. They can be developed not only as novel candidates and precursors in anticancer drug screening, but also as important tools and agents in cancer pharmacology. We comprehensively elaborated the anticancer pharmacological properties of crude polyphenolic extracts and 12 other single compounds excluding the six well-known polyphenols, i.e., baicalein, baicalin, wogonin, wogonoside, chrysin and verbascoside. In this review, we also discussed the possible mechanisms of the anticancer effect of several skullcap polyphenols. Overall, this paper provides a unique path to understand the anticancer properties of Chinese skullcap as well as guidance to find novel anticancer drugs from a natural polyphenolic reservoir.

Potential of Juniperus communis L as a nutraceutical in human and veterinary medicine

Plants have been used for thousands of years as medicine for treating variety of diseases and medical complaints by most of the civilizations. Juniperus communis L. is an evergreen aromatic shrub with high therapeutic potential for the treatment of diseases in human and animals. The plant is rich in aromatic oils, invert sugars, resins, catechin, organic acid, terpenic acids, leucoanthocyanidin, alkaloids, flavonoids, tannins, gums, lignins, wax, etc. Juniper berries or extract of the plant has traditionally been used as diuretic, anti-arthritis, anti-diabetes, antiseptic as well as for the treatment of gastrointestinal and autoimmune disorders. The essential oil and extracts of juniper have been experimentally documented to have antioxidant, antibacterial, antiviral and antifungal activities. Recent studies have also found anti-inflammatory, cytotoxic, hypoglycemic and hypolipidemic effects of berries in experimental models. Further, the essential oil incorporation retarded lipid peroxidation in preserved meat due to its high antioxidant effect which not only improved meat product quality but also improved shelf life of the product. Thus natural antioxidant such as juniper can be used in place synthetic antioxidant for the preservation and improving self-life of meat products. New well designed clinical trials in human and animals using well-characterized J. communis extract or oil need to be conducted so that additional information is generated which can support the use of this natural product as a nutraceutical.

Therapeutic effects of chrysin in a rat model of traumatic brain injury: A behavioral, biochemical, and histological study

AIMS

Oxidative stress and apoptosis have major roles in the progression of traumatic brain injury (TBI)-associated motor and cognitive deficits. The present study was aimed to elucidate the putative effects of chrysin, a natural flavonoid compound, against TBI-induced motor and cognitive dysfunctions and possible involved mechanisms.

MAIN METHODS

Chrysin (25, 50 or 100 mg/kg) was orally administered to rats starting immediately following TBI induction by Marmarou's weight-drop technique and continuously for 3 or 14 days. Neurological functions, motor coordination, learning and memory performances, histological changes, cell apoptosis, expression of pro- and anti-apoptotic proteins, and oxidative status were assayed at scheduled time points after experimental TBI.

KEY FINDINGS

The results indicated that treatment with chrysin improved learning and memory disabilities in passive avoidance task, and ameliorated motor coordination impairment in rotarod test after TBI. These beneficial effects were accompanied by increased the concentrations of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione (GSH), decreased malondialdehyde (MDA) content, prevented neuronal loss, diminished apoptotic index, elevated the expression of anti-apoptotic Bcl-2 protein, and reduced the expression of pro-apoptotic Bax protein in the cerebral cortex and hippocampus tissues.

SIGNIFICANCE

Our findings suggest that both anti-oxidative and anti-apoptotic properties of chrysin (especially in the dose of 100 mg/kg) are possible mechanisms that improve cognitive/motor deficits and prevent neuronal cell death after TBI.

Influence of Flavonoids on the Cytotoxic Activity of Mononuclear Blood Cells in Model Tests

BACKGROUND:

The spread of phytocomplex application and justification of its selective effects on tumour cells (mainly due to the presence of flavonoids) require research of its cytotoxic and immunomodulatory activity.

AIM:

The goal wa`s to study the direct cytotoxic effect of the phytocomplex and its modulating effect on the cytotoxic activity of the donor’s mononuclear blood cells in in vitro experiments.

METHODS:

The phytocomplex was a dry extract from marsh cinquefoil, creeping alfalfa and common hop; its main active ingredients were flavonoids. Transplantable monolayer cultures of lung adenocarcinoma, colorectal cancer, erythroblastic leukaemia, and fibroblasts were used as target cells. The cytotoxic activity was assessed using a cytotoxic test based on the selective ability to live cells to reduce MTT (3-[4, 5-dimethyltriazol-2-yl]-2, 5 diphenyltetrazolium bromide) to formazan in mitochondria. Quantitative determination of formazan was performed using spectrophotometry.

RESULTS:

A direct cytotoxic effect of the phytocomplex in concentrations of at least 2.5 mg/ml on tumour cells has been established. Its modulating effect on the cytotoxic activity of mononuclear blood cells at a concentration of 0.05 mg/ml was shown. The phytocomplex in doses of 0.25 and 0.5 mg/ml increased the killer activity of the mononuclear cells in a diseased person’s blood, but did not affect these blood cells in a healthy donor. Incubation of lymphocytes with a phytocomplex for 24 hours increased the cytotoxic activity of mononuclear cells by 20-25%.

CONCLUSION:

The direct cytotoxic effect of the phytocomplex and its modulating effect on the cytotoxic activity of mononuclear blood cells in model experiments in vitro have been established.

Non-controlled, open-label clinical trial to assess the effectiveness of a dietetic food on pruritus and dermatologic scoring in atopic dogs

BACKGROUND

Canine atopic dermatitis (AD) is a common skin disease. The goal of this study was to evaluate food designed to improve skin barrier function and lower inflammation to reduce pruritus and clinical severity in client-owned atopic dogs. The food contained an antioxidant blend to reduce oxidative stress, plant polyphenols to stabilize mast cells, and polyunsaturated fatty acids to improve skin health and reduce inflammation.

RESULTS

Seventeen dogs were included in the analysis. Initially 48 adult atopic dogs were enrolled and exclusively fed a dermatologic food for 8 weeks in a non-controlled, open-label study. Thirty-one dogs were excluded for the following reasons: oral and topical medication changes (n = 17), missing data (n = 4), fatty acid supplementation (n = 3), food refusal (n = 3), dropped out (n = 3), and owner concerns (n = 1). Using a scale from 0 (normal) - 4 (severe), veterinarians evaluated the presence and severity of clinical signs of atopy at weeks 0, 4, and 8. Pet owners also rated their pet's clinical signs of atopy on a scale from 0 (not present) - 10 (present continuously) at weeks 0, 4, and 8. Compared with initial baseline scores (median 19, range 3-69), the total veterinarian scores were significantly lower at weeks 4 (median 11, range 1-15) and 8 (median 7, range 3-46) (p < 0.05). Similarly, owner assessments showed significant improvements in the least squares mean (LSM) from baseline to 4 weeks (itching, redness, licking, and scratching) continuing to 8 weeks (itching, redness, and scratching) (p < 0.05).

CONCLUSIONS

In this open, non-controlled study evaluating a dermatologic diet in seventeen client-owned dogs, owner and veterinarian assessments showed statistically significant reductions in clinical scores designed to measure severity of atopic dermatitis. While these results show promise for the management of canine atopic dermatitis, controlled clinical trials are also needed to affirm our findings.

Cardiovascular Effects of Flavonoids

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Cardiovascular Disease (CVD) is the major cause of death worldwide, especially in Western society. Flavonoids are a large group of polyphenolic compounds widely distributed in plants, present in a considerable amount in fruit and vegetable. Several epidemiological studies found an inverse association between flavonoids intake and mortality by CVD. The antioxidant effect of flavonoids was considered the main mechanism of action of flavonoids and other polyphenols. In recent years, the role of modulation of signaling pathways by direct interaction of flavonoids with multiple protein targets, namely kinases, has been increasingly recognized and involved in their cardiovascular protective effect. There are strong evidence, in in vitro and animal experimental models, that some flavonoids induce vasodilator effects, improve endothelial dysfunction and insulin resistance, exert platelet antiaggregant and atheroprotective effects, and reduce blood pressure. Despite interacting with multiple targets, flavonoids are surprisingly safe. This article reviews the recent evidence about cardiovascular effects that support a beneficial role of flavonoids on CVD and the potential molecular targets involved.

Chrysin Suppresses Vascular Endothelial Inflammation via Inhibiting the NF-κB Signaling Pathway

The vascular endothelium is a continuous layer of flat polygonal cells that are in direct contact with the blood and participate in responses to inflammation. Chrysin is a flavonoid compound extracted from plants of the genus Asteraceae with a wide range of pharmacological activities and physiological activities. Here, we studied the effects of chrysin on the regulation of the proadhesion and pro-inflammatory phenotypes of the endothelium both in vitro and in vivo. Our results revealed that chrysin strongly inhibited Tohoku Hospital Pediatrics-1 (THP-1) cell adhesion to primary human umbilical vein endothelial cells and concentration-dependently attenuated interleukin 1β-induced increases in intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), and E-selectin messenger RNA levels and ICAM-1 and VCAM-1 protein levels. Previous studies reported that nuclear factor κB (NF-κB) is important in the inflammatory response in endothelial cells, particularly in regulating adhesion molecules, and our data shed light on the mechanisms whereby chrysin suppressed endothelial inflammation via the NF-κB signaling pathway. In addition, our in vivo findings demonstrated the effects of chrysin in the permeability and inflammatory responses of the endothelium to inflammatory injury. Taken together, we conclude that chrysin inhibits endothelial inflammation both in vitro and in vivo, which could be mainly due to its inhibition of NF-κB signaling activation. In conclusion, chrysin may serve as a promising therapeutic candidate for inflammatory vascular diseases.

Functional mechanism of tracheal relaxation, antiasthmatic, and toxicological studies of 6-hydroxyflavone

Previously, we described tracheal rat rings relaxation by several flavonoids, being 6-hydroxyflavone (6-HOF) the most active derivative of the series. Thus, its mechanism of action was determined in an ex vivo tracheal rat ring bioassay. The anti-asthmatic effect was assayed in in vivo OVAlbumin (OVA)-sensitized guinea pigs. Finally, the toxicological profile of 6-HOF was studied based on Organization of Economic Cooperation and Development guidelines with modifications. 6-HOF-induced relaxation appears to be related with receptor-operated calcium channel and voltage-operated calcium channel blockade as the main mechanism of action, and also through the production of relaxant second messengers NO and cGMP. Molecular docking supports that 6-HOF acts as calcium channel blocker and by activation of nitric oxide synthase. In addition, the in vivo anti-asthmatic experiments demonstrate the dose-dependent significant anti-allergic effect of 6-HOF induced by OVA, with best activity at 50 /kg. Finally, toxicological studies determined a LD50 > 2,000 mg/kg and, after 28 day of treatment with 6-HOF (50 mg/kg) by intragastric route, mice did not exhibit evidence of any significant toxicity. In conclusion, experiments showed that 6-HOF exerts significant relaxant activity through calcium channel blockade, and possibly, by NO/cGMP-system stimulation on rat trachea, which interferes with the contraction mechanism of smooth muscle cells in the airways. In addition, the flavonoid shows potential anti-asthmatic properties in an anti-allergic pathway. Furthermore, because the pharmacological and safety evidence, we propose this flavonoid as lead for the development of a novel therapeutic agent for the treatment of asthma and related respiratory diseases.

Mechanistic approach of the inhibitory effect of chrysin on inflammatory and apoptotic events implicated in radiation-induced premature ovarian failure: Emphasis on TGF-β/MAPKs signaling pathway

Radiotherapy is one of the most relevant treatment modalities for various types of malignancies. However, it causes premature ovarian failure (POF) and subsequent infertility in women of reproductive age; hence urging the development of effective radioprotective agents. Chrysin, a natural flavone, possesses several pharmacological activities owing to its antioxidant, anti-inflammatory and anti-apoptotic properties. Therefore, the aim of this study was to investigate the efficacy of chrysin in limiting γ-radiation-mediated POF and to elucidate the underlying molecular mechanisms. Immature female Sprague-Dawley rats were subjected to a single dose of γ-radiation (3.2 Gy) and/or treated with chrysin (50 mg/kg) once daily for two weeks before and three days post-irradiation. Chrysin prevented the radiation-induced ovarian dysfunction by restoring estradiol levels, preserving the normal ovarian histoarchitecture and combating the follicular loss. Eelectron microscopic analysis showed that the disruption of ultrastructure components due to radiation exposure was hampered by chrysin administration. Mechanistically, chrsyin was able to reduce the levels of the inflammatory markers NF-κB, TNF-α, iNOS and COX-2 in radiation-induced ovarian damage. Chrysin also exhibited potent anti-apoptotic effects against radiation-induced cell death by downregulating the expression of cytochrome c and caspase 3. Radiation obviously induced upregulation of TGF-β protein with subsequent phospholyration and hence activation of downstream mitogen-activated protein kinases (MAPKs); p38 and JNK. Notably, administration of chrysin successfully counteracted these effects. These findings revealed that chrysin may be beneficial in ameliorating radiation-induced POF, predominantly via downregulating TGF-β/MAPK signaling pathways leading subsequently to hindering inflammatory and apoptotic signal transduction pathways implicated in POF.

Study of the Potential Radiomitigator Effect of Quercetin on Human Lymphocytes

Several substances of synthetic and natural origin have been studied to determine their ability to protect the body from damage caused by ionizing radiation. Among these substances, quercetin has been shown to be a naturally occurring molecule with high radioprotective and radiomitigator potential due to its antioxidant properties. The objective of this work was to ascertain the potential radiomitigator effect of quercetin on chromosome aberration yield in lymphocytes of in vitro-irradiated human peripheral blood. At first, the DPPH (2,2-diphenyl-1-picryl-hydrazyl) radical capture test was performed to determine the antioxidant activity of quercetin and to select the concentrations to be tested. The blood was irradiated at doses of 2.5, 3.5, and 4.5 Gy and lymphocytes were cultured with quercetin at preselected concentrations of 37.5 and 75 μM. Then, the slides were prepared for scoring unstable chromosome aberrations (dicentrics, rings, and fragments). The results showed that the lymphocytes irradiated and later exposed to quercetin presented a lower frequency of chromosomal alterations compared to the control sample which was irradiated and not exposed to quercetin. The results suggest a potential radiomitigator effect of the flavonoid quercetin on human lymphocytes exposed, in vitro, to ionizing radiation. This effect may be related to decrease in the release of cytokines (INF-γ, PGE2, IL-1β, IL6, IL-8) involved in the proinflammatory processes as well as downregulation of NF-kB and reduction of expression TGF-β.

Oxidative damage in glutaric aciduria type I patients and the protective effects of l-carnitine treatment

The deficiency of the enzyme glutaryl-CoA dehydrogenase, known as glutaric acidemia type I (GA-I), leads to the accumulation of glutaric acid (GA) and glutarilcarnitine (C5DC) in the tissues and body fluids, unleashing important neurotoxic effects. l-carnitine (l-car) is recommended for the treatment of GA-I, aiming to induce the excretion of toxic metabolites. l-car has also demonstrated an important role as antioxidant and anti-inflammatory in some neurometabolic diseases. This study evaluated GA-I patients at diagnosis moment and treated the oxidative damage to lipids, proteins, and the inflammatory profile, as well as in vivo and in vitro DNA damage, reactive nitrogen species (RNS), and antioxidant capacity, verifying if the actual treatment with l-car (100 mg kg^-1  day^-1 ) is able to protect the organism against these processes. Significant increases of GA and C5DC were observed in GA-I patients. A deficiency of carnitine in patients before the supplementation was found. GA-I patients presented significantly increased levels of isoprostanes, di-tyrosine, urinary oxidized guanine species, and the RNS, as well as a reduced antioxidant capacity. The l-car supplementation induced beneficial effects reducing these biomarkers levels and increasing the antioxidant capacity. GA, in three different concentrations, significantly induced DNA damage in vitro, and the l-car was able to prevent this damage. Significant increases of pro-inflammatory cytokines IL-6, IL-8, GM-CSF, and TNF-α were shown in patients. Thus, the beneficial effects of l-car presented in the treatment of GA-I are due not only by increasing the excretion of accumulated toxic metabolites, but also by preventing oxidative damage.

The flavonoid kurarinone inhibits clinical progression of EAE through inhibiting Th1 and Th17 cell differentiation and proliferation

INTRODUCTION

The flavonoid kurarinone suppresses CD4+ T-cell-mediated chronic inflammatory dermatitis. However, kurarinone's effects upon autoimmune central nervous system (CNS) disease remain unknown. We investigated the potential therapeutic effects and molecular mechanism(s) of kurarinone in an experimental autoimmune encephalomyelitis (EAE) murine model of multiple sclerosis (MS).

MATERIALS AND METHODS

Myelin oligodendrocyte glycoprotein (MOG_35-55) peptide-induced EAE was constructed in wild-type mice. Effects of kurarinone (100 mg/kg/day) upon clinical scores were assessed based on physical traits and signs. Spinal cord sections were extracted to assess inflammation, demyelination, and mRNA expression of key pro-inflammatory cytokines and chemokines. CNS-infiltrating mononuclear cells (MNCs) and splenocytes were harvested; flow cytometry was then applied to determine CD4+ and CD8+ T-cell percentages as well as Th1/Th2/Th17 subset percentages. Purified naïve CD4+ T-cells underwent in vitro T-cell polarization and proliferation to assess kurarinone's effects.

RESULTS

Prophylactic and treatment regimens of kurarinone significantly improved clinical scores in the MOG_35-55 peptide-induced EAE model (P < 0.05). Kurarinone significantly lowered CNS inflammation and demyelination (61% and 83% decreases, respectively; P < 0.05), significantly decreased MNC infiltration into CNS tissue (42% decrease; P < 0.05), and significantly inhibited levels of several pro-inflammatory cytokines and chemokines (P < 0.05). Kurarinone significantly lowered CD4+ and CD8+ CNS T-cell counts (51% and 80% decreases, respectively; P < 0.05) and significantly reduced CNS Th1 and Th17 cell percentages (24% and 44% decreases, respectively; P < 0.05). Kurarinone significantly inhibited in vitro Th1, Th2, and Th17 cell differentiation and proliferation (P < 0.05).

CONCLUSIONS

Kurarinone significantly inhibits the clinical progression of EAE through the inhibition of Th1 and Th17 cell differentiation and proliferation. Kurarinone may show promise as an immunomodulatory therapeutic agent in treating MS.

Chrysin Inhibits Advanced Glycation End Products-Induced Kidney Fibrosis in Renal Mesangial Cells and Diabetic Kidneys

Advanced glycation end products (AGEs) play a causative role in the development of diabetic nephropathy via induction of matrix protein deposition in kidneys. This study investigated inhibitory effects of chrysin, present in bee propolis and herbs, on glomerulosclerosis in db/db mice and AGEs-exposed renal mesangial cells. The in vivo study explored the demoting effects of 10 mg/kg chrysin on glomerular fibrosis in a type 2 diabetic model. Oral supplementation of chrysin inhibited the collagen fiber accumulation and &alpha;-smooth muscle actin (&alpha;-SMA) induction in periodic acid schiff-positive renal tissues of db/db mice. Moreover, treating db/db mice with chrysin diminished the level of AGEs increased in diabetic glomeruli. The in vitro study employed human mesangial cells exposed to 100 &mu;g/mL AGE-BSA for 72 h in the presence of 1⁻20 &mu;M chrysin. Glucose increased mesangial AGE production via induction of receptor for AGEs. Chrysin suppressed the induction of collagens, &alpha;-SMA, fibroblast-specific protein-1 and matrix metalloproteinases enhanced by AGE-bovine serum albumin. Furthermore, chrysin blunted transforming growth factor-&beta;1 induction and Smad 2/3 activation in AGEs-exposed mesangial cells. These results demonstrate that chrysin attenuated accumulation of myofibroblast-like cells and matrix proteins in AGEs-laden diabetic glomeruli. Therefore, chrysin may be a potential renoprotective agent targeting glucose-mediated AGEs-associated glomerulosclerosis and fibrosis.

Regulatory Roles of Flavonoids on Inflammasome Activation during Inflammatory Responses

Inflammation is an innate immune response to noxious stimuli to protect the body from pathogens. Inflammatory responses consist of two main steps: priming and triggering. In priming, inflammatory cells increase expressions of inflammatory molecules, while in triggering, inflammasomes are activated, resulting in cell death and pro-inflammatory cytokine secretion. Inflammasomes are protein complexes comprising intracellular pattern recognition receptors (PRRs) (e.g., nucleotide-binding oligomerization domain-like receptors (NLRs), absent in melanoma 2 (AIM2), and caspases-4/5/11) and pro-caspase-1 with or without a bipartite adaptor molecule ASC. Inflammasome activation induces pyroptosis, inflammatory cell death, and stimulates caspase-1-mediated secretion of interleukin (IL)-1b and IL-18. Flavonoids are secondary metabolites found in various plants and are considered as critical ingredients promoting health and ameliorating various disease symptoms. Anti-inflammatory activity of flavonoids and underlying mechanisms have been widely studied. This review introduces current knowledge on different types of inflammasomes and their activation during inflammatory responses and discusses recent studies regarding anti-inflammatory roles of flavonoids as suppressors of inflammasomes in inflammatory conditions. Understanding the regulatory effects of flavonoids on inflammasome activation will increase our knowledge of flavonoid-mediated anti-inflammatory activity and provide new insights into the development of flavonoid preparations to prevent and treat human inflammatory diseases.

Chrysin Attenuates Cell Viability of Human Colorectal Cancer Cells through Autophagy Induction Unlike 5-Fluorouracil/Oxaliplatin

Chemotherapeutic 5-fluorouracil (5-FU) combined with oxaliplatin is often used as the standard treatment for colorectal cancer (CRC). The disturbing side effects and drug resistance commonly observed in chemotherapy motivate us to develop alternative optimal therapeutic options for CRC treatment. Chrysin, a natural and biologically active flavonoid abundant in propolis, is reported to have antitumor effects on a few CRCs. However, whether and how chrysin achieves similar effectiveness to the 5-FU combination is not clear. In this study, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), western blotting, fluorescence microscopy, and reactive oxygen species (ROS) production were assayed. We found that chrysin exhibited similar inhibition of cell viability as the 5-FU combination in a panel of human CRC cells. Furthermore, the results showed that chrysin significantly increased the levels of LC3-II, an autophagy-related marker, in CRC cells, which was not observed with the 5-FU combination. More importantly, blockage of autophagy induction restored chrysin-attenuated CRC cell viability. Further mechanistic analysis revealed that chrysin, not the 5-FU combination, induced ROS generation, and in turn, inhibited the phosphorylation of protein kinase B (Akt) and mammalian target of rapamycin (mTOR). Collectively, these results imply that chrysin may be a potential replacement for the 5-FU and oxaliplatin combination to achieve antitumor activity through autophagy for CRC treatment in the future.

Phytochemicals That Influence Gut Microbiota as Prophylactics and for the Treatment of Obesity and Inflammatory Diseases

Gut microbiota (GM) plays several crucial roles in host physiology and influences several relevant functions. In more than one respect, it can be said that you “feed your microbiota and are fed by it.” GM diversity is affected by diet and influences metabolic and immune functions of the host's physiology. Consequently, an imbalance of GM, or dysbiosis, may be the cause or at least may lead to the progression of various pathologies such as infectious diseases, gastrointestinal cancers, inflammatory bowel disease, and even obesity and diabetes. Therefore, GM is an appropriate target for nutritional interventions to improve health. For this reason, phytochemicals that can influence GM have recently been studied as adjuvants for the treatment of obesity and inflammatory diseases. Phytochemicals include prebiotics and probiotics, as well as several chemical compounds such as polyphenols and derivatives, carotenoids, and thiosulfates. The largest group of these comprises polyphenols, which can be subclassified into four main groups: flavonoids (including eight subgroups), phenolic acids (such as curcumin), stilbenoids (such as resveratrol), and lignans. Consequently, in this review, we will present, organize, and discuss the most recent evidence indicating a relationship between the effects of different phytochemicals on GM that affect obesity and/or inflammation, focusing on the effect of approximately 40 different phytochemical compounds that have been chemically identified and that constitute some natural reservoir, such as potential prophylactics, as candidates for the treatment of obesity and inflammatory diseases.

Synthetic 3',4'-Dihydroxyflavone Exerts Anti-Neuroinflammatory Effects in BV2 Microglia and a Mouse Model

Neuroinflammation is an immune response within the central nervous system against various proinflammatory stimuli. Abnormal activation of this response contributes to neurodegenerative diseases such as Parkinson disease, Alzheimer’s disease, and Huntington disease. Therefore, pharmacologic modulation of abnormal neuroinflammation is thought to be a promising approach to amelioration of neurodegenerative diseases. In this study, we evaluated the synthetic flavone derivative 3′,4′-dihydroxyflavone, investigating its anti-neuroinflammatory activity in BV2 microglial cells and in a mouse model. In BV2 microglial cells, 3′,4′-dihydroxyflavone successfully inhibited production of chemokines such as nitric oxide and prostaglandin E₂ and proinflammatory cytokines such as tumor necrosis factor alpha, interleukin 1 beta, and interleukin 6 in BV2 microglia. It also inhibited phosphorylation of mitogen-activated protein kinase (MAPK) and nuclear factor (NF)-κB activation. This indicates that the anti-inflammatory activities of 3′,4′-dihydroxyflavone might be related to suppression of the proinflammatory MAPK and NF-κB signaling pathways. Similar anti-neuroinflammatory activities of the compound were observed in the mouse model. These findings suggest that 3′,4′-dihydroxyflavone is a potential drug candidate for the treatment of microglia-related neuroinflammatory diseases.

Chrysophanol demonstrates anti-inflammatory properties in LPS-primed RAW 264.7 macrophages through activating PPAR-γ

Sepsis is a life-threatening disease. Inflammation is a major concomitant symptom of sepsis Chrysophanol, an anthraquinone derivative isolated from the rhizomes of rheumpalmatum, has been reported to have a protective effect against lipopolysaccharide(LPS)-induced inflammation. However, the underlying molecular mechanisms are not well understood. The aim of this study was to explore the effect and mechanism of chrysophanol on lipopolysaccharide (LPS)-induced anti-inflammatory effect of RAW264.7 cells and its involved potential mechanism. The mRNA and protein expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1β and inducible nitric oxide synthase (iNOS), nuclear factor kappa B (NF-κB) and PPAR-γ were measured by qRT-PCR and western blotting, the production of TNF-α, IL-1β was evaluated by ELISA. Then, the phosphorylation of NF-κB p65 was also detected by western blotting. And NF-κB p65 promoter activity was analyzed by the Dual-Luciferase reporter assay system as well. Meanwhile, PPAR-γ inhibitor GW9662 was performed to knockdown PPAR-γ expression in cells. Our data revealed that LPS induced the up-regulation of TNF-α, IL-1β, iNOS and NF-κB p65, the down-regulation of PPAR-γ were substantially suppressed by chrysophanol in RAW264.7 cells. Furthermore, our data also figured out that these effects of chrysophanol were largely abrogated by PPAR-γ inhibitor GW9662. Taken together, our results indicated that LPS-induced inflammation was potently compromised by chrysophanol very likely through the PPAR-γ-dependent inactivation of NF-κB in RAW264.7 cells.

Genoprotective, antioxidant, antifungal and anti-inflammatory evaluation of hydroalcoholic extract of wild-growing Juniperus communis L. (Cupressaceae) native to Romanian southern sub-Carpathian hills

BACKGROUND

Juniperus communis L. represents a multi-purpose crop used in the pharmaceutical, food, and cosmetic industry. Several studies present the possible medicinal properties of different Juniperus taxa native to specific geographical area. The present study aims to evaluate the genoprotective, antioxidant, antifungal and anti-inflammatory potential of hydroalcoholic extract of wild-growing Juniperus communis L. (Cupressaceae) native to Romanian southern sub-Carpathian hills.

METHODS

The prepared hydroethanolic extract of Juniperus communis L. was characterized by GC-MS, HPLC, UV-Vis spectrometry and phytochemical assays. The antioxidant potential was evaluated using the DPPH assay, the antifungal effect was studied on Aspergillus niger ATCC 15475 and Penicillium hirsutum ATCC 52323, while the genoprotective effect was evaluated using the Allium cepa assay. The anti-inflammatory effect was evaluated in two inflammation experimental models (dextran and kaolin) by plethysmometry. Male Wistar rats were treated by gavage with distilled water (negative control), the microemulsion (positive control), diclofenac sodium aqueous solution (reference) and microemulsions containing juniper extract (experimental group). The initial paw volume and the paw volumes at 1, 2, 3, 4, 5 and 24 h were measured.

RESULTS

Total terpenoids, phenolics and flavonoids were estimated to be 13.44 ± 0.14 mg linalool equivalent, 19.23 ± 1.32 mg gallic acid equivalent, and 5109.6 ± 21.47 mg rutin equivalent per 100 g of extract, respectively. GC-MS characterization of the juniper extract identified 57 volatile compounds in the sample, while the HPLC analysis revealed the presence of the selected compounds (α-pinene, chlorogenic acid, rutin, apigenin, quercitin). The antioxidant potential of the crude extract was found to be 81.63 ± 0.38% (measured by the DPPH method). The results of the antifungal activity assay (for Aspergillus niger and Penicillium hirsutum) were 21.6 mm, respectively 17.2 mm as inhibition zone. Test results demonstrated the genoprotective potential of J. communis undiluted extract, inhibiting the mitodepressive effect of ethanol. The anti-inflammatory action of the juniper extract, administered as microemulsion in acute-dextran model was increased when compared to kaolin subacute inflammation induced model.

CONCLUSION

The hydroalcoholic extract obtained from wild-growing Juniperus communis native to Romanian southern sub-Carpathian hills has genoprotective, antioxidant, antifungal and anti-inflammatory properties.

Mitodepressive, antioxidant, antifungal and anti-inflammatory effects of wild-growing Romanian native Arctium lappa L. (Asteraceae) and Veronica persica Poiret (Plantaginaceae)

The present study aims to evaluate the potential uses of hydroalcoholic extracts obtained from Romanian native wild-growing plants. The hydroalcoholic extracts were obtained from the burdock roots and respectively the aerial parts of birdeye speedwell. The extracts were characterised by HPLC (quantifying 13 compounds in the V. persica extract, 6 compounds in the A. lappa extract and confirming the presence of arctiin and arctigenin in the burdock extract). The antioxidant potential of the crude extracts was evaluated using two methods: the DPPH assay (79.91% for speedwell extract, 76.23% for burdock extract) and the phosphomolybdate method (296.5 mg/g ascorbic acid equivalents for burdock, 324.4 mg/g for speedwell). The crude extracts were found to be active against both fungal lines used (Aspergillus niger and Penicillium hirsutum), inhibition zones - 17.1 mm and 13.1 mm against P. hirsutum, respectively ca. 22 mm for both extracts against A. niger. The cytogenetic effects (assessed using the Allium cepa assay) revealed a series of chromosomal aberrations and nuclear aberrations induced in the meristematic root cells. The anti-inflammatory effect, estimated in two inflammation experimental models, showed a significant effect, especially for the speedwell extract. The results recommend the evaluated extracts as promising sources of biologically-active compounds.

Cardiovascular dysfunction in sepsis at the dawn of emerging mediators

Subcellular dysfunction and impaired metabolism derived from the complex interaction of cytokines and mediators with cellular involvement are on the basis of the cardiovascular response to sepsis. The lethal consequences of an infection are intimately related to its ability to spread to other organ sites and the immune system of the host. About one century ago, William Osler (1849-1919), a Canadian physician, remarkably defined the sequelae of the host response in sepsis: "except on few occasions, the patient appears to die from the body's response to infection rather than from it." Cardiac dysfunction has received considerable attention to explain the heart failure in patients progressing from infection to sepsis, but our understanding of the processes remains limited. In fact, most concepts are linked to a mechanical concept of the sarcomeric structure, and physiological data seems to be often disconnected. Cytokines, prostanoids, and nitric oxide release are high direct impact factors, but coronary circulation and cardiomyocyte physiology also play a prominent role in modulating the effects of monocyte adhesion and infiltration. Damage-associated molecular patterns (DAMPs) and pathogen-associated molecular patterns (PAMPs) are involved in the host response. The identification of microRNAs, as well as the cyclic activation of the inflammatory cascade, has further added complexity to the scene. In this review, we delineate the current concepts of cellular dysfunction of the cardiomyocyte in the setting of sepsis and consider potential therapeutic strategies.

Chemical characterization and cytotoxic activity evaluation of Lebanese propolis

Chemical composition, anti-proliferative and proapoptotic activity as well as the effect of various fractions of Lebanese propolis on the cell cycle distribution were evaluated on Jurkat leukemic T-cells, glioblastoma U251 cells, and breast adenocarcinoma MDA-MB-231 cells using cytotoxic assays, flow cytometry as well as western blot analysis. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis revealed that ferulic acid, chrysin, pinocembrin, galangin are major constituents of the ethanolic crude extract of the Lebanese propolis, while the hexane fraction mostly contains chrysin, pinocembrin, galangin but at similar levels. Furthermore chemical analysis was performed using gas chromatography-mass spectrometry (GC-MS) to identify major compounds in the hexane fraction. Reduction of cell viability was observed in Jurkat cells exposed to the ethanolic crude extract and the hexane fraction, while viability of U251 and MDA-MB-231 cells was only affected upon exposure to the hexane fraction; the other fractions (aqueous phase, methylene chloride, and ethyl acetate) were without effect. Maximum toxic effect was obtained when Jurkat cells were cultivated with 90μg/ml of both the crude extract and hexane faction. Toxicity started early after 24h of incubation and remained till 72h. Interestingly, the decrease in cell viability was accompanied by a significant increase in p53 protein expression levels and PARP cleavage. Cell cycle distribution showed an increase in the SubG0 fraction in Jurkat, U251 and MDA-MB-231 cells after 24h incubation with the hexane fraction. This increase in SubG0 was further investigated in Jurkat cells by annexinV/PI and showed an increase in the percentage of cells in early and late apoptosis as well as necrosis. In conclusion, Lebanese propolis exhibited significant cytotoxicity and anti-proliferative activity promising enough that warrant further investigations on the molecular targets and mechanisms of action of Lebanese propolis.