Abstract

The aims of this work are to investigate the in vitro stability of quercetin, a focused compound in food components and a candidate drug, and to supply the essential information for the experimental researches of quercetin. The stability of quercetin in Dulbecco’s modified Eagle’s medium (DMEM) and H₂O at the cell culture pH range of 6 of 8 at continued time points, as well as 6 frequently used supplements in DMEM was investigated. The assay of high-performance liquid chromatography (HPLC) was used for quercetin determination. Considering the stable conditions of quercetin, the transport behavior of quercetin in Neuro-2a (N2a) cells was investigated at the dosages of 58.8 and 7.83 μg/ml at 37°C for different time points. It is shown that quercetin remained stable in DMEM at pH of 6 with or without 10 mM/L HEPES, 5% D (+)-glucose, 110 mg/L sodium pyruvate, antibiotics (50 IU/ml penicillin and 0.05 mg/ml streptomycin), or 10% fetal bovine serum (FBS), but was decreasing at pH of 7 or 8 with or without 3.7 g/L NaHCO₃. Quercetin transported through N2a cells in 10 min in both dosages of 58.8 and 7.83 μg/ml. Our data demonstrate that the culture conditions of quercetin in vitroshould be considered to acquire the convictive results in the experiments.

Key words: Quercetin, stability, high performance liquid chromatography (HPLC), in vitro, transportation.