ABSTRACT
Silymarin is the standardized extract from Silybum marianum which consists mainly of flavonoids and polyphenols. It is highly regarded for its hepatoprotective ability. Silybin B is a flavonolignan and one of the active components of silymarin. The content of silybin B in various parts of S. marianum was analyzed by HPLC-UV. Results show that the extract of seeds contain the highest amount of silybin B (7.434 mg/g DW). The petioles of S. marianum showed a low content of silybin B. This study revealed that seeds of S. marianum contain high amount of silybin B and could be a good source of the compound.
Subject(s)
Flavonoids , Silybum marianum , Polyphenols , SilymarinABSTRACT
Objective To investigate the bioavailability and pharmacokinetics of silybin A and silybin B in rats,respectively.Methods Following iv and ig administration of silybin to 20 Wistar rats,the plasma samples were collected at different time points up to 12 h.Sample pretreatment was involved in one-step protein precipitation with acetonitrile.Silybin A and silybin B were simultaneously determined by LC-MS/MS.Results After ig dosing silybin 28,56,and 112 mg/kg to rats,the t1/2β values were 5.48,5.08,and 5.73 h for silybin A,and 4.56,4.12,and 5.53 h for silybin B; The Cmax were 674.3,1349.4,and 2042.5 ng/mL for silybin A,and 671.0,1365.4,and 2066.2 ng/mL for silybin B; The Tmax were 0.20,0.23,and 0.20 h for silybin A,and 0.20,0.23,and 0.20 h for silybin B; The AUC were 454.4,845.9,and 1219.5 h·ng/mL for silybin A,and 432.0,817.1,and 1153.6 h·ng/mL for silybin B.The absolute bioavailabilities of silybin A and silybin B were 2.86％ and 1.93％,respectively.Conclusion Silybin A and silybin B have very low bioavailability after ig administration,and there is no significant difference in the pharmacokinetic parameters between silybin A and silybin B,which indicates that the two diastereoisomers have similar pharmacokinetic behavior in rats.