PT - JOURNAL ARTICLE AU - Hirotaka Amano AU - Daichi Kazamori AU - Kenji Itoh AU - Yukihiro Kodera TI - Metabolism, Excretion, and Pharmacokinetics of S-Allyl-<span class="sc">l</span>-Cysteine in Rats and Dogs AID - 10.1124/dmd.115.063230 DP - 2015 May 01 TA - Drug Metabolism and Disposition PG - 749--755 VI - 43 IP - 5 4099 - http://dmd.aspetjournals.org/content/43/5/749.short 4100 - http://dmd.aspetjournals.org/content/43/5/749.full SO - Drug Metab Dispos2015 May 01; 43 AB - The metabolism, excretion, and pharmacokinetics of S-allyl-l-cysteine (SAC), an active key component of garlic supplements, were examined in rats and dogs. A single dose of SAC was administered orally or i.v. to rats (5 mg/kg) and dogs (2 mg/kg). SAC was well absorbed (bioavailability &gt;90%) and its four metabolites—N-acetyl-S-allyl-l-cysteine (NAc-SAC), N-acetyl-S-allyl-l-cysteine sulfoxide (NAc-SACS), S-allyl-l-cysteine sulfoxide (SACS), and l-γ-glutamyl-S-allyl-l-cysteine—were identified in the plasma and/or urine. Renal clearance values (&lt;0.01 l/h/kg) of SAC indicated its extensive renal reabsorption, which contributed to the long elimination half-life of SAC, especially in dogs (12 hours). The metabolism of SAC to NAc-SAC, principal metabolite of SAC, was studied in vitro and in vivo. Liver and kidney S9 fractions of rats and dogs catalyzed both N-acetylation of SAC and deacetylation of NAc-SAC. After i.v. administration of NAc-SAC, SAC appeared in the plasma and its concentration declined in parallel with that of NAc-SAC. These results suggest that the rate and extent of the formation of NAc-SAC are determined by the N-acetylation and deacetylation activities of liver and kidney. Also, NAc-SACS was detected in the plasma after i.v. administration of either NAc-SAC or SACS, suggesting that NAc-SACS could be formed via both N-acetylation of SACS and S-oxidation of NAc-SAC. In conclusion, this study demonstrated that the pharmacokinetics of SAC in rats and dogs is characterized by its high oral bioavailability, N-acetylation and S-oxidation metabolism, and extensive renal reabsorption, indicating the critical roles of liver and kidney in the elimination of SAC.