Abstract
Ligustilide is the most abundant bioactive ingredient in Rhizoma Chuanxiong, a Chinese medicinal herb commonly used for the treatment of cardiovascular ailments. The present study reported, for the first time, the pharmacokinetics of ligustilide, administered in its pure form and in an herbal extract, in rats. After i.v. administration of pure ligustilide, it was distributed extensively (Vd, 3.76 ± 1.23 l/kg) and eliminated rapidly (t1/2, 0.31 ± 0.12 h). The i.v. clearance (CL) of ligustilide after Chuanxiong extract administration was significantly higher than that dosed in its pure form [CL, 20.35 ± 3.05 versus 9.14 ± 1.27 l/h/kg, p < 0.01; area under the curve (AUC), 0.79 ± 0.10 versus 1.81 ± 0.24 mg · h/l, p < 0.01], suggesting significant interaction between ligustilide and components present in the extract. Dose-dependent pharmacokinetics was observed after i.p. administration, and a significantly higher dose-normalized AUC (1.77 ± 0.23 mg · h/l) at 52 mg/kg was obtained than that at 26 mg/kg (0.93 ± 0.07 mg · h/l, p < 0.05). Oral bioavailability of ligustilide was low (2.6%), which was partly because of extensive first-pass metabolism in the liver. Seven metabolites of ligustilide were identified, and three of them were unequivocally characterized as butylidenephthalide, senkyunolide I, and senkyunolide H. These three compounds also occurred naturally in the herb and were reported to be bioactive.
Footnotes
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The research grant supported by ITF fund (UIM/34) from the Innovative Technology Council of The Hong Kong SAR Government is acknowledged.
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Article, publication date, and citation information can be found at http://dmd.aspetjournals.org.
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doi:10.1124/dmd.107.017707.
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ABBREVIATIONS: CM, Chinese medicine; HPLC, high-performance liquid chromatography; MS, mass spectrometry; SD, Sprague-Dawley; LOQ, limit of quantification; AUC0→∝, area under the plasma concentration-time curve from time 0 to time infinity; MRT, mean residence time; GSH, glutathione.
- Received July 20, 2007.
- Accepted November 21, 2007.
- The American Society for Pharmacology and Experimental Therapeutics
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