Development and validation of an LC-MS/MS method for determination of compound K in human plasma and clinical application.

A rapid, sensitive and selective analytical method was developed and validated for the determination of compound K, a major intestinal bacterial metabolite of ginsenosides in human plasma. Liquid-liquid extraction was used for sample preparation and analysis, followed by liquid chromatography tandem spectrometric analysis and an electrospray-ionization interface. Compound K was analyzed on a Phenomenex Luna C18 column (100×2.00 mm, 3 µm) with the mobile phase run isocratically with 10 mM ammonium acetate-methanol-acetonitrile (5:47.5:47.5, v/v/v) at a flow rate of 0.5 mL/min. The method was validated for accuracy (relative error <12.63%), precision (coefficient of variation <9.14%), linearity, and recovery. The assay was linear over the entire range of calibration standards i.e., a concentration range of 1 ng/mL to 1,000 ng/ mL (r (2) >0.9968). The recoveries of compound K after liquid-liquid extraction at 1, 2, 400, and 800 ng/mL were 106.00±0.08%, 103.50±0.19%, 111.45±5.21%, and 89.62±34.46% for intra-day and 85.40±0.08%, 94.50±0.09%, 112.50±5.21%, and 95.87±34.46% for inter-day, respectively. The lower limit of quantification of the analytical method of compound K was 1 ng/ mL in human plasma. The developed method was successfully applied to a pharmacokinetic study of compound K after oral administration in ten of healthy human subjects.

Effects of Ficus carica paste on constipation induced by a high-protein feed and movement restriction in beagles.

Constipation is one of the most common functional digestive complaints worldwide. We investigated the laxative effects of figs (Ficus carica L) in a beagle model of constipation induced by high protein diet and movement restriction. The experiments were consecutively conducted over 9 weeks divided into 3 periods of 3 weeks each. All 15 beagles were subjected to a non-treatment (control) period, a constipation induction period, and a fig paste treatment period. We administered fig paste (12 g/kg daily, by gavage) for 3 weeks following a 3-week period of constipation induction in dogs. Segmental colonic transit time (CTT) was measured by counting radiopaque markers (Kolomark) using a radiograph performed every 6 h after feeding Kolomark capsules, until capsules were no longer observed. Fig paste significantly increased fecal quantity in constipated dogs, and segmental CTT was also reduced following fig paste administration. There were no significant differences in feed intake, water intake, body weight, or blood test results, between the constipation and fig paste administration periods. Our results demonstrate that fig is an effective treatment for constipation in beagles. Specifically, stool weight increased and segmental CTT decreased. Fig pastes may be useful as a complementary medicine in humans suffering from chronic constipation.