Suppressive Effect of Quercetin on Nitric Oxide Production from Nasal Epithelial Cells In Vitro

Figure 2

Influence of quercetin on NO production from HNEpCs after IL-4 stimulation in vitro. HNEpCs at 1 x 10⁵ cells/ml are cultured with 10.0 ng/ml of IL-4 for 48 hours in the presence and absence of various concentrations of quercetin. The NO levels in the culture supernatants are measured using the Griess method, and the results are expressed as the mean μM ± SE of the triplicate cultures. The experiments are performed twice with similar results. Med. alone: medium alone; IL-4: interleukin-4; NO: nitric oxide; HNEpCs: human nasal epithelial cells.