Pharmacokinetics Of Sulfur Compounds In Garlic And Its Relationship With H₂S

Objective:By studying the metabolism and distribution and pharmacokinetics of garlic sulfur compounds,including alliin,allicin,DAS,DADS and DATS in rat plasma,determine their metabolites and whether there generate H2 S and compare the amount of H2 S and further illustrating the biological activityof garlic sulfur compounds in vivo is mediated by H2 S.Methods:The study describes the use of the automated blood-sampling system followed with RP-HPLC-fluorescence by derivatization of OPA for the quantification of alliin in rat plasma and applies to a pharmacokinetic study.Establish an HPLC-methylene blue-based method to measure the H2 S level in rat blood, then added alliin,a serial dilution of allicin,DAS,DADS and DATS individually to rat blood cells and incubated the resulting solutions at 37°C for H2 S measurement.Establish a UPLC-MS/MS method to measure the H2 S level in biological sample.At different time points taken blood and tissues after allicin injected via tail vein to determine the content of H2 S to study the pharmacokinetics and its distribution in tissues.Results:1.The main pharmacokinetics parameters of alliin in rat plasma were as follows,K:0.02min-1,T1/2:34.62 min,Cmax:96.51μg/m L,Tmax:5.00 min,AUC(0-120min):4004.63min·μg/m L,AUC(0-∞):4347.93min·μg/m L,Vd:615.35 m L/kg,CL:12.60 m L/min/kg.2.The HPLC-methylene blue method showed great specificity,and the linearity of H2 S ranged from 0.8 to 80μmol/L.The limit of quantitation was 0.8μmol/L.Ten min after the garlic sulfur-containing compounds were added to rat blood cells,all but alliin yielded H2 S.The efficiency of H2 S production showed the following order:DATS>DADS=allicin>DAS.The UPLC-MS/MS method is more sensitive than the HPLC-methylene blue,which can be detected endogenous H2 S in rat blood and the linearity of H2 S ranged from 0.15 to 9.60μmol/L.The limit of quantitation was 0.15μmol/L.In pre-experiment,the plasma samples detected by mass,while undetectable allicin,DAS,DADS and DATS and other sulfur-containing compounds,but can be detected H2 S after derivatization. Experiment with H2 S as an indicator to study the pharmacokinetics and tissue distribution studies of allicin.The main pharmacokinetics parameters of metabolites H2 S were as fllows,K:0.086min-1,T1/2:8.926 min,Cmax:0.968μmol/L,Tmax:15min,AUC(0-45min):375.617 min·μg/m L,AUC(0-∞):376.233min·μg/m L,Vd:3808.050 m L/kg,CL:320.561 m L/min/kg.Afte r administration,the content of H2 S in plasma and tissues were increased and the Tmax in plasma was 15 min after administration and 20 min after administration, the content of H2 S in tissues also reached the highest value.The content o f H2 S in rat tissues were as follows:kidney > brain > spleen > liver > lung > heart.Comparing to the previous administration after administration,the H2 S increased by 367.35% in kidney. Conclusion:The pharmacokinetic parameters of alliin can be used to study the distribution and metabolism and bioavailability.The in vitro results show that alliin in the blood can not be metabolized to H2 S,while the reaction product allicin and allicin degradation products,including DAS,DADS and DATS can metabolized into H2 S.In vivo experiments confirmed H2 S is the metabolic product of allicin and suggesting that the biological activity of allicin exert by H2 S,garlic sulfur compounds is expected to become a natural sulfur compound H2 S donor.