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Pharmacological actions of nobiletin in the modulation of platelet function.

Vaiyapuri S, Roweth H, Ali MS, Unsworth AJ, Stainer AR, Flora GD, Crescente M, Jones CI, Moraes LA, Gibbins JM - Br. J. Pharmacol. (2015)

Bottom Line: The effect of nobiletin in vivo was assessed by measuring tail bleeding time using C57BL/6 mice.Nobiletin extended bleeding time in mice and reduced the phosphorylation of PKB (Akt) and PLCγ2 within the collagen receptor (glycoprotein VI)-stimulated pathway, in addition to increasing the levels of cGMP and phosphorylation of vasodilator-stimulated phosphoprotein, a protein whose activity is associated with inhibitory cyclic nucleotide signalling.Therefore, nobiletin may represent a potential antithrombotic agent of dietary origins.

View Article: PubMed Central - PubMed

Affiliation: Institute for Cardiovascular and Metabolic Research, School of Biological Sciences, University of Reading, Reading, UK.

No MeSH data available.


Related in: MedlinePlus

Nobiletin modulates platelet inside-out signalling, granule secretion and calcium mobilization. The effect of nobiletin on CRP-XL (1 μg·mL−1)-induced fibrinogen binding (A) and P-selectin exposure (B) in PRP was measured by flow cytometry. The median fluorescence intensity values were converted into percentages for comparison. The level of fibrinogen binding or P-selectin exposure with vehicle controls was taken as 100%. Data represent mean ± SD (n = 5) and the P-values shown were calculated using non-parametric repeated measures anova (Friedman test). Similarly, the effect of nobiletin on dense granule secretion upon stimulation with CRP-XL (1 μg·mL−1) was measured in washed platelets (C and D). The level of ATP obtained with vehicle controls was taken as 100%. Data represent mean ± SD (n = 4) and the P-values shown were calculated using parametric repeated measures anova. Fluo4-NW dye labelled human PRP was stimulated with 1 μg·mL−1 CRP-XL in the presence of 50 or 100 μM nobiletin or vehicle control and the intracellular calcium levels were measured by flow cytometry (E). Traces shown are representative of four separate experiments. The inhibition of intracellular calcium levels was calculated by comparing the levels obtained at 5 min (F) in the presence or absence (taken as 100%) of nobiletin. Data represent mean ± SD (n = 4). The P-values shown in the figure were as calculated by using non-parametric repeated measures anova (Friedman test; ***P < 0.001 and ****P < 0.0001). AU represents arbitrary units.
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fig02: Nobiletin modulates platelet inside-out signalling, granule secretion and calcium mobilization. The effect of nobiletin on CRP-XL (1 μg·mL−1)-induced fibrinogen binding (A) and P-selectin exposure (B) in PRP was measured by flow cytometry. The median fluorescence intensity values were converted into percentages for comparison. The level of fibrinogen binding or P-selectin exposure with vehicle controls was taken as 100%. Data represent mean ± SD (n = 5) and the P-values shown were calculated using non-parametric repeated measures anova (Friedman test). Similarly, the effect of nobiletin on dense granule secretion upon stimulation with CRP-XL (1 μg·mL−1) was measured in washed platelets (C and D). The level of ATP obtained with vehicle controls was taken as 100%. Data represent mean ± SD (n = 4) and the P-values shown were calculated using parametric repeated measures anova. Fluo4-NW dye labelled human PRP was stimulated with 1 μg·mL−1 CRP-XL in the presence of 50 or 100 μM nobiletin or vehicle control and the intracellular calcium levels were measured by flow cytometry (E). Traces shown are representative of four separate experiments. The inhibition of intracellular calcium levels was calculated by comparing the levels obtained at 5 min (F) in the presence or absence (taken as 100%) of nobiletin. Data represent mean ± SD (n = 4). The P-values shown in the figure were as calculated by using non-parametric repeated measures anova (Friedman test; ***P < 0.001 and ****P < 0.0001). AU represents arbitrary units.

Mentions: Platelet inside-out signalling to integrin αIIbβ3 plays an essential role in the modulation of its conformation to increase affinity for plasma fibrinogen and von Willebrand factor (vWF) binding and consequent platelet aggregation (Calderwood, 2004). In order to explore the effects of nobiletin in inside-out signalling that leads to the modulation of integrin αIIbβ3 affinity, fibrinogen binding was measured by flow cytometry in the presence or absence of nobiletin. Consistent with platelet aggregation, CRP-XL (1 μg·mL−1)-induced fibrinogen binding in PRP was inhibited significantly at all concentrations of nobiletin used (6.25, 12.5, 25, 50, 100 and 200 μM; Figure 2A and Supporting Information Fig. S1A).


Pharmacological actions of nobiletin in the modulation of platelet function.

Vaiyapuri S, Roweth H, Ali MS, Unsworth AJ, Stainer AR, Flora GD, Crescente M, Jones CI, Moraes LA, Gibbins JM - Br. J. Pharmacol. (2015)

Nobiletin modulates platelet inside-out signalling, granule secretion and calcium mobilization. The effect of nobiletin on CRP-XL (1 μg·mL−1)-induced fibrinogen binding (A) and P-selectin exposure (B) in PRP was measured by flow cytometry. The median fluorescence intensity values were converted into percentages for comparison. The level of fibrinogen binding or P-selectin exposure with vehicle controls was taken as 100%. Data represent mean ± SD (n = 5) and the P-values shown were calculated using non-parametric repeated measures anova (Friedman test). Similarly, the effect of nobiletin on dense granule secretion upon stimulation with CRP-XL (1 μg·mL−1) was measured in washed platelets (C and D). The level of ATP obtained with vehicle controls was taken as 100%. Data represent mean ± SD (n = 4) and the P-values shown were calculated using parametric repeated measures anova. Fluo4-NW dye labelled human PRP was stimulated with 1 μg·mL−1 CRP-XL in the presence of 50 or 100 μM nobiletin or vehicle control and the intracellular calcium levels were measured by flow cytometry (E). Traces shown are representative of four separate experiments. The inhibition of intracellular calcium levels was calculated by comparing the levels obtained at 5 min (F) in the presence or absence (taken as 100%) of nobiletin. Data represent mean ± SD (n = 4). The P-values shown in the figure were as calculated by using non-parametric repeated measures anova (Friedman test; ***P < 0.001 and ****P < 0.0001). AU represents arbitrary units.
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Related In: Results  -  Collection

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fig02: Nobiletin modulates platelet inside-out signalling, granule secretion and calcium mobilization. The effect of nobiletin on CRP-XL (1 μg·mL−1)-induced fibrinogen binding (A) and P-selectin exposure (B) in PRP was measured by flow cytometry. The median fluorescence intensity values were converted into percentages for comparison. The level of fibrinogen binding or P-selectin exposure with vehicle controls was taken as 100%. Data represent mean ± SD (n = 5) and the P-values shown were calculated using non-parametric repeated measures anova (Friedman test). Similarly, the effect of nobiletin on dense granule secretion upon stimulation with CRP-XL (1 μg·mL−1) was measured in washed platelets (C and D). The level of ATP obtained with vehicle controls was taken as 100%. Data represent mean ± SD (n = 4) and the P-values shown were calculated using parametric repeated measures anova. Fluo4-NW dye labelled human PRP was stimulated with 1 μg·mL−1 CRP-XL in the presence of 50 or 100 μM nobiletin or vehicle control and the intracellular calcium levels were measured by flow cytometry (E). Traces shown are representative of four separate experiments. The inhibition of intracellular calcium levels was calculated by comparing the levels obtained at 5 min (F) in the presence or absence (taken as 100%) of nobiletin. Data represent mean ± SD (n = 4). The P-values shown in the figure were as calculated by using non-parametric repeated measures anova (Friedman test; ***P < 0.001 and ****P < 0.0001). AU represents arbitrary units.
Mentions: Platelet inside-out signalling to integrin αIIbβ3 plays an essential role in the modulation of its conformation to increase affinity for plasma fibrinogen and von Willebrand factor (vWF) binding and consequent platelet aggregation (Calderwood, 2004). In order to explore the effects of nobiletin in inside-out signalling that leads to the modulation of integrin αIIbβ3 affinity, fibrinogen binding was measured by flow cytometry in the presence or absence of nobiletin. Consistent with platelet aggregation, CRP-XL (1 μg·mL−1)-induced fibrinogen binding in PRP was inhibited significantly at all concentrations of nobiletin used (6.25, 12.5, 25, 50, 100 and 200 μM; Figure 2A and Supporting Information Fig. S1A).

Bottom Line: The effect of nobiletin in vivo was assessed by measuring tail bleeding time using C57BL/6 mice.Nobiletin extended bleeding time in mice and reduced the phosphorylation of PKB (Akt) and PLCγ2 within the collagen receptor (glycoprotein VI)-stimulated pathway, in addition to increasing the levels of cGMP and phosphorylation of vasodilator-stimulated phosphoprotein, a protein whose activity is associated with inhibitory cyclic nucleotide signalling.Therefore, nobiletin may represent a potential antithrombotic agent of dietary origins.

View Article: PubMed Central - PubMed

Affiliation: Institute for Cardiovascular and Metabolic Research, School of Biological Sciences, University of Reading, Reading, UK.

No MeSH data available.


Related in: MedlinePlus