[Determination of berberine in biological specimen by high performance TLC and fluoro-densitometric method]

In this paper, a simple and specific high performance TLC and fluoro-densitometric method for separating and determining berberine in biological specimen was developed. Two hundred microliters of plasma or tissue homogenate mixed with 20 microliters of sodium lauryl sulfate (18%) and quinidine (300 ng, as internal standard) were extracted with 1 ml of chloroform. The developing solvent consisted of ethyl acetate-methyl acetate-methanol-water (5.4:4.6:1.2:1.0). The determination was carried out with a Shimadzu TLC-Scanner CS-910. Berberine spots were measured using an excitation wavelength of 350 nm and an emission wavelength of 550 nm, while using 350 nm and 450 nm for quinidine spots as the excitation and emission wavelength respectively. The average recoveries were 100.3% from plasma and 103.8% from tissue homogenate. The berberine levels in plasma and in tissues were compared in normal mice after oral administration of berberine (100 mg/kg) or the powder of Coptis chinensis (2 g/kg) containing the same amount of berberine. Simultaneously, the hypoglycemic effect of berberine and that of the powder of Coptis chinensis were measured in these mice. Results indicate that the concentrations of berberine in plasma and tissues given the powder of Coptis chinensis orally were higher than those given berberine and that the hypoglycemic effect of the powder was also stronger than that of berberine. Evidently, the changes of the blood glucose level and the level of berberine in plasma showed an opposite relationship.