Study On The Effect Of Glycyrrhetinic Acid On Plasma Concentrations And Tissue Distributions Of Three Flavonoids By HPLC Methods

Through summarizing and analysing the compound cormpatibility law of traditional Chinese medicine (TCM), pharmacokinetics interaction between active ingredients from TCM were found having been reported in many papers. It indicated that there existed a great influence between Chinese medicines (or some ingredients in them) on their plasma concentration and tissue distribution. Licorice is most commonly used in TCM, as the saying goes nine tenths of TCM have licorice. However, researches on the licorice compatibility from the point of view of the effecte of licorice on plasma concentrations and tissue distributions of ingredients originated from TCMs have not been reported.In this task, as the most commonly used TCM licorice being selected and HPLC method being used, the compatibility mechanism of licorice was clarified by studying the effects of glycyrrhetinic acid on plasma concentrations and tissue distributions of flavonoids such as kaempferol, hesperetin and quercetin. The research mainly includes the following sections.1. To establish a method of HPLC for determination kaempferol content in rat plasma and tissue coupled with glycyrrhetinic acid. Drawing the blood from eyeball of rat after oral administration and separate the plasma. Plasma sample with hydrochloric acid hydrolyzed in water, use acetonitrile as extractant, ultrasonic assisted extraction, HPLC with UV-vis detection was used to determination of kaempferol in plasma. The mobile phase was a mixing methanol and0.4%phosphoric acid in a ratio of55:45(v/v) at a flow rate of1.0mL/min, the column was thermostatically controlled at32℃, and the detection was set at a wavelength of370nm. Adding saline to the tissue, homogenate. Using acetonitrile precipitate protein, and the supernatant were evaporated under a stream of nitrogen to dryness. The residue was dissolved in methanol, supernatant was injected into the HPLC system for analysis. The mobile phase was a mixing methanol and0.4%phosphoric acid in a ratio of45:55(v/v) at a flow rate of1.0mL/min, the column was thermostatically controlled at32℃, and the detection was set at a wavelength of370nm. The study found that in high concentration group, glycyrrhetinic acid could greatly increased the concentration of kaempferol in plasma of the absorption phase, and it performance of a enhanced synergy. Tissue distribution of kaempferol was Cliver＞Ckidney＞Clung＞Cheart after oral administration of kaempferol, and coupled with glycyrrhetinic acid did not changed the tissue distribution characteristic of kaempferol.2. To establish a method of HPLC for determination hesperetin content in rat plasma and tissue coupled with glycyrrhetinic acid. Drawing the blood from eyeball of rat after oral administration and separate the plasma. Plasma sample with hydrochloric acid hydrolyzed in water, use acetonitrile as extractant, ultrasonic assisted extraction, HPLC with UV-vis detection was used to determination of kaempferol in plasma. The mobile phase was a mixing methanol and0.4%phosphoric acid in a ratio of52:48(v/v) at a flow rate of1.0mL/min, the column was thermostatically controlled at25℃, and the detection was set at a wavelength of370nm. Adding saline to the tissue, homogenate. Using acetonitrile precipitate protein, and the supernatant were evaporated under a stream of nitrogen to dryness. The residue was dissolved in methanol, supernatant was injected into the HPLC system for analysis. The mobile phase was a mixing methanol and0.4%phosphoric acid in a ratio of55:45(v/v) at a flow rate of1.0mL/min, the column was thermostatically controlled at32℃, and the detection was set at a wavelength of370nm. The study found that, glycyrrhetinic acid could significantly increase the concentration of hesperetin in plasma of the elimination phase. Tissue distribution of hesperetin was Cliver＞Ckidney＞Clung after oral administration of hesperetin, and coupled with glycyrrhetinic acid did not changed the tissue distribution characteristic of hesperetin.3. To establish a method of HPLC for determination quercetin content in rat plasma and tissue coupled with glycyrrhetinic acid. Drawing the blood from eyeball of rat after oral administration and separate the plasma. Plasma sample with hydrochloric acid hydrolyzed in water, use acetonitrile as extractant, ultrasonic assisted extraction, high-performance liquid chromatography (HPLC) with UV-vis detection was used to determination of kaempferol in plasma. The mobile phase was a mixing methanol and0.4%phosphoric acid in a ratio of50:50(v/v) at a flow rate of1.0mL/min, the column was thermostatically controlled at30℃, and the detection was set at a wavelength of370nm. Adding saline to the tissue, homogenate. Using acetonitrile precipitate protein, and the supernatant were evaporated under a stream of nitrogen to dryness. The residue was dissolved in methanol, supernatant was injected into the HPLC system for analysis. The mobile phase was a mixing methanol and0.4%phosphoric acid in a ratio of52:48(v/v) at a flow rate of1.0mL/min, the column was thermostatically controlled at32℃, and the detection was set at a wavelength of370nm. The study found that, the concentration of quercetin in plasma tend to balance at distribution phase, and the presence of glycyrrhetinic acid could delayed the absorption of quercetin in liver.