Figure 3.

Dose–response effect of flavonols on anti-IgE-mediated tryptase (n=6–16) and histamine release (n=6–31) from hCBMCs. hCBMCs were pretreated with quercetin, kaempferol, myricetin and morin each at 0.01, 0.1, 1, 10 and 100 μM for 15 min and then incubated with anti-IgE (10 μg ml⁻¹) for 30 min in Tyrode's buffer at 37°C in a shaking water bath. Control cells were treated with equal volume of Tyrode's buffer only. Tryptase and histamine levels were measured in the supernatant fluid by fluoroenzyme immunoassay using the Unicap Tryptase assay kit and Luminescence Spectrometer, respectively. The mean net anti-IgE-mediated tryptase and histamine release were significantly higher than the control release. These flavonols significantly inhibited tryptase release (a), as well as histamine release (b) at higher concentrations. Values are expressed as the percent inhibition of the anti-human-IgE-mediated tryptase or histamine release. Each value represents the mean±s.e.m. ^*Significant difference (P<0.05) compared to samples treated with anti-IgE alone.