Pharmacokinetics of Protocatechuic Acid in Rats after Intravenous Administration

Protocatechuic acid is a phenolic acid naturally found in many vegetables, fruits and nuts, and is also an effective active ingredient of many traditional Chinese medicines such as Salvia miltiorrhiza, Eucommia ulmoides and hibiscus. Protocatechuic acid is the main metabolite of anthocyanin-glycoside and flavonoids in human body. Protocatechuic acid has many biological activities, such as strong antioxidant and anti-cancer, anti-inflammation and so on. An UPLC-MS/MS method was established to determine the protocatechuic acid in rat plasma, and the pharmacokinetics of protocatechuic acid was studied. Six rats were used for intravenous administration (5 mg/kg), proteins from rat plasma were removed by acetonitrile precipitation. In the concentration range of 10-3000 ng/mL, the protocatechuic acid in the rat plasma was linear (r(2) > 0.995), and the lower limit of quantification was 10 ng/mL. In the rat plasma, the intra-day precision CV was less than 7% and the inter-day precision CV was less than 15%. The accuracy ranged from 91.7% to 106.1%. The average recovery was higher than 79.6%, and the matrix effect was between 80.5% and 88.7%. The UPLC-MS/MS method was successfully applied to the pharmacokinetic study of protocatechuic acid in rats after intravenous (5 mg/kg) administration.