Neutrophil effector functions triggered by Fc-gamma and/or complement receptors are dependent on B-ring hydroxylation pattern and physicochemical properties of flavonols

Moreira, Mirian R.; Kanashiro, Alexandre; Kabeya, Luciana M.; Polizello, Ana Cristina Morseli; Azzolini, Ana Elisa Caleiro Seixas; Curti, Carlos; Oliveira, Carlos Alberto de; Amaral, Antônia Tavares do; Lucisano-Valim, Yara Maria

doi:10.1016/j.lfs.2007.05.016

Cited by 30 publications

(28 citation statements)

References 45 publications

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“…All the isolated flavonoids showed antioxidant activity because they have one to three hydroxyl groups in the B-ring of their structure (Urzúa et al 2001). It has also been proven that a higher number of hydroxyl groups exhibited stronger antioxidant activity but lack of them reduced the ability to scavenge free radicals (Moreira et al 2007). The DPPH scavenging activity of galangin was in agreement with the other reported results of an earlier study (Laskar et al 2010).…”

Section: Discussionmentioning

confidence: 98%

Flavonoids from Heliotropium subulatum exudate and their evaluation for antioxidant, antineoplastic and cytotoxic activities II

2016

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The flavonoids are the largest group of phenolic compounds isolated from a wide range of higher plants. These compounds work as antimicrobials, anti-insect agents and protect plants from other types of biotic and abiotic stresses. Various researchers have suggested that flavonoids possessed antioxidant, antineoplastic and cytotoxic activities. The main objective of this study was to test dichloromethane fraction of resinous exudate of Heliotropium subulatum for their antioxidant, antineoplastic and cytotoxic activities, as well as to search new antioxidant and antineoplastic agents for pharmaceutical formulations. Five flavonoids were isolated from resinous exudate of this plant species and screened for their in vitro and in vivo antioxidant models (DPPH radical scavenging, reducing power, superoxide anion scavenging, metal chelating scavenging systems, catalase and lipid peroxidation), antineoplastic (Sarcoma 180), and cytotoxic (Chinese hamster V79 cells) activities. Tricetin demonstrated maximum antioxidant activity against both in vitro and in vivo experimental systems while galangin exhibited maximum inhibition (78.35%) at a dose of 10 lg/kg/day against Sarcoma 180. Similarly, it was found that galangin also showed highest activity (21.1 ± 0.15%) at a concentration of 70 lg/ml to Chinese hamster V79 cells. The observed results suggest that tricetin has a potential to scavenge free radicals in both in vitro and in vivo models while the galangin could be considered as antitumor and cytotoxic agent.

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Section: Discussionmentioning

confidence: 98%

Flavonoids from Heliotropium subulatum exudate and their evaluation for antioxidant, antineoplastic and cytotoxic activities II

2016

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“…In addition, quercetin exerts antimicrobial, antihypertensive, neuroprotective, and chemoprotective effects (16). The immunomodulatory activity of quercetin has been investigated in NK cells (17), macrophages (18), mast cells (19), neutrophils (20), B cells (21), and T cells (22). Although a number of studies have reported the activity of flavonoids in the modulation of DC activation (23)(24)(25)(26)(27), the effect of quercetin on DCs remains unknown.…”

mentioning

confidence: 99%

Immunosuppressive Effect of Quercetin on Dendritic Cell Activation and Function

Huang

Cheng

et al. 2010

The Journal of Immunology

173

120

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“…[1][2][3] However, increased neutrophil recruitment and activation are involved in the pathogenesis of a number of autoimmune and inflammatory human diseases, such as systemic lupus erythematosus, rheumatoid arthritis, Graves' disease, Crohn's disease, Behçet's disease, and chronic obstructive pulmonary disease. 1,2,4,5 Our research group has investigated the antioxidant and immunomodulatory activities of plant extracts [6][7][8] and isolated secondary metabolites like coumarins, [9][10][11] flavonoids, 7,[12][13][14] and sesquiterpene lactones. 15 We aim to discover prototypes of compounds that can modulate the effector functions of neutrophils and supplement the endogenous antioxidant defense system.…”

Section: Introductionmentioning

confidence: 99%

4-Methylcoumarin Derivatives Inhibit Human Neutrophil Oxidative Metabolism and Elastase Activity

Kabeya

Fuzissaki

Andrade

et al. 2013

Journal of Medicinal Food

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Increased neutrophil activation significantly contributes to the tissue damage in inflammatory illnesses; this phenomenon has motivated the search for new compounds to modulate their effector functions. Coumarins are natural products that are widely consumed in the human diet. We have evaluated the antioxidant and immunomodulator potential of five 4-methylcoumarin derivatives. We found that the 4-methylcoumarin derivatives inhibited the generation of reactive oxygen species by human neutrophils triggered by serum-opsonized zymosan or phorbol-12-myristate-13-acetate; this inhibition occurred in a concentration-dependent manner, as revealed by lucigenin-and luminol-enhanced chemiluminescence assays. Cytotoxicity did not mediate this inhibitory effect. The 7,8-dihydroxy-4-methylcoumarin suppressed the neutrophil oxidative metabolism more effectively than the 6,7-and 5,7-dihydroxy-4-methylcoumarins, but the 5,7-and 7,8-diacetoxy-4-methylcoumarins were less effective than their hydroxylated counterparts. An analysis of the biochemical pathways suggested that the 6,7-and 7,8-dihydroxy-4-methylcoumarins inhibit the protein kinase C-mediated signaling pathway, but 5,7-dihydroxy-4-methylcoumarin, as well as 5,7-and 7,8-diacetoxy-4-methylcoumarins do not significantly interfere in this pathway of the activation of the human neutrophil oxidative metabolism. The 4-methylcoumarin derivatives bearing the catechol group suppressed the elastase and myeloperoxidase activity and reduced the 1,1-diphenyl-2-picrylhydrazyl free radical the most strongly. Interestingly, the 5,7-dihydroxy-4-methylcoumarin scavenged hypochlorous acid more effectively than the o-dihydroxy-substituted 4-methylcoumarin derivatives, and the diacetoxylated 4-methylcoumarin derivatives scavenged hypochlorous acid as effectively as the 7,8-dihydroxy-4-methylcoumarin. The significant influence of small structural modifications in the inhibitory potential of 4-methylcoumarin derivatives on the effector functions of neutrophil makes them interesting candidates to develop new drugs for the treatment of inflammatory diseases mediated by increased neutrophil activation.KEY WORDS: antioxidant chemiluminescence elastase hypochlorous acid immunomodulation 4-methylcoumarin myeloperoxidase neutrophil protein kinase C

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Neutrophil effector functions triggered by Fc-gamma and/or complement receptors are dependent on B-ring hydroxylation pattern and physicochemical properties of flavonols

Cited by 30 publications

References 45 publications

Flavonoids from Heliotropium subulatum exudate and their evaluation for antioxidant, antineoplastic and cytotoxic activities II

Flavonoids from Heliotropium subulatum exudate and their evaluation for antioxidant, antineoplastic and cytotoxic activities II

Immunosuppressive Effect of Quercetin on Dendritic Cell Activation and Function

4-Methylcoumarin Derivatives Inhibit Human Neutrophil Oxidative Metabolism and Elastase Activity

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