Pharmacokinetics of sulfur?containing compounds in aged garlic extract: S?Allylcysteine, S?1?propenylcysteine, S?methylcysteine, S?allylmercaptocysteine and others (Review).

Aged garlic extract (AGE) is produced by aging raw garlic (Allium sativum L.) in an alcoholic solution for >10 months. AGE is rich in sulfur-containing amino acids, such as S-allylcysteine (SAC), S-1-propenylcysteine (S1PC), S-methylcysteine (SMC) and S-allylmercaptocysteine (SAMC). These sulfur-containing amino acids exert various beneficial pharmacological effects and have different pharmacokinetic properties. For instance, SAC, S1PC and SMC are well absorbed in rats with high bioavailability (88.0-95.8%), whereas SAMC is not detected in the plasma after oral administration. Orally administered SAC and S1PC are excreted in urine in their N-acetylated forms and ~50% of SMC is excreted as inorganic sulfur compounds, whereas SAMC immediately reacts with blood and is metabolized into volatile sulfur compounds. The present review summarizes and discusses the pharmacokinetic profiles (absorption, distribution, metabolism and excretion) of sulfur-containing compounds present in AGE and other garlic-derived substances, such as allicin.