Pharmacokinetic analysis and tissue distribution of Vam3 in the rat by a validated LC-MS/MS method

Vam3 is a potential pharmacologically active ingredient isolated from Vitis amurensis Rupr. A rapid, simple and sensitive method to determine Vam3 levels in rat plasma and tissue was developed based on LC-MS/MS. Vam3 and an internal standard (IS) were chromatographed on a C18 short column with acetonitrile-0.1% formic acid in water by gradient elution. MS detection was performed by electrospray ionization in negative ion multiple reaction-monitoring modes. This method monitored the transitions m/z 451.0→345.0 and m/z 301.0→164.0 for Vam3 and IS, respectively. The calibration curve was linear over a concentration range of 1.64-1000 ng/mL. The inter-day and intra-day variabilities in precision was less than 12.8%, while the inter-day and intra-day accuracies ranged from -10.60% to 9.08% in plasma and tissue homogenates. This method was applied to investigate the pharmacokinetics and tissue distribution of Vam3 in rats. The results indicated that Vam3 had poor absorption into systemic circulation and extensive tissue distribution after oral administration, and the absolute bioavailability was low (0.79%). Vam3 had a relatively long terminal elimination half-life in lung, and the highest concentration was found in small intestinal tissue. The developed method and the pharmacokinetic data can provide a basis for further studies on the bioactivity of Vam3.

Influence of dihydroxy-stilbene compound Vam3 on ATP-induced inflammatory response in macrophages and the underlying mechanisms / 中国药理学通报

Aim To investigate the effects of Vam3 on ATP-induced inflammatory response in macrophages and the underlying mechanisms. Methods LPS primed mouse peritoneal macrophages were stimulated with ATP,and IL-1βlevel in supernatants was meas-ured by ELISA.Activity of caspase 1 was measured u-sing caspase 1 activity assay kit.Reactive oxygen spe-cies (ROS )level was detected with fluorescent probe DCFH-DA.MTT assay was used to detect cell prolifer-ation,and intracellular Ca2+concentration was meas-ured using laser scanning confocal microscope.Results Extracellular ATP led to increase in IL-1βrelease, caspase 1 activity and ROS production.It also led to rapid increase in intracellular Ca2+concentration and induced cell death.These effects were inhibited by Vam3 .Conclusion Vam3 inhibits ATP-induced in-flammatory response in macrophages,which may sug-gest the blocking effect of Vam3 on caspase 1 ~IL-1βinflammatory signaling pathway in macrophages.