| Summary: | 博士 === 國立臺灣大學 === 食品科技研究所 === 97 === Sesame exhibits many beneficial physiological effects, which are mostly related to its lignan compounds, such as sesamol, sesaminol glucosides and sesaminol. Sesamol (benzo[1,3]dioxol-5-ol, MW 138) has been generally regarded as the main antioxidative component in sesame oil. Sesaminol glucosides have no antioxidative properties in vitro, but they have been reported to be converted to phenolic compounds after oral administration to rat and showed antioxidative activity in vivo. This investigation intends to study the bioavailability of sesamol, sesaminol glucosides and sesaminol in Sprague Dawley rats. Sesamol, sesaminol glucosides and sesaminol were introduced to rats via gastric gavage (p.o.) or intravenous injection and the various pharmacokinetic parameters were determined. Biological fluid was intravenously sampled following a dose of sesamol, sesaminol glucosides and sesaminol via gastric gavage or by intravenous injection. The pharmacokinetic data of sesamol, sesaminol glucosides and sesaminol were calculated by non-compartmental model. Our results showed that the oral bioavailability of sesamol, sesaminol triglucoside and sesaminol were 35.5 ± 8.5, 0.31 ± 0.04 and 21.1 ± 3.47%, respectively. We have also investigated the distribution of sesamol (100 mg/kg p.o.) in SD rats, the concentration changes of sesamol were determined in various tissues and plasma within 24 h period after oral administration to SD rats. In addition, sesamol was found to be able to penetrate the blood-brain barrier and go through hepatobiliary excretion. Sesamol metabolites (glucuronide) was widely distributed in SD rat tissues, with the highest concentrations in liver and kidneys and the lowest in brain. The bioavailabilities of sesaminol triglucoside and sesaminol were studied in Sprague Dawley rats. In order to investigate the distribution of sesaminol triglucoside and sesaminol (500 mg/kg, 220 mg/kg p.o.) in SD rats, the concentration changes of sesaminol triglucoside and its metabolites were determined in tissues and plasma within 24 h period after tube-feeding to SD rats. Results showed that sesaminol triglucoside may be deglycosylated to from sesaminol first by intestinal microflora and then incorporated via lymphatic absorption into the cardiovascular system, transported to other tissues (lung, liver, and kidneys). Metabolites of sesaminol triglucoside and sesaminol (sesaminol sulfate/glucuronide) were found in many tissues of rat, they were present in higher concentrations in heart, liver and kidneys while the lowest in brain. The eliminations of the metabolites of sesaminol triglucoside and sesaminol (sesaminol sulfate/glucuronide) were fast. From LC/MS/MS analysis of rat excreta, sesaminol triglucoside and sesaminol can be converted to mammalian lignan (enterolactone) in vivo by rat intestinal microflora.
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