Study On The Method Of Qulity Assessment Of Fenugreek And The Pharmacokinetics Of Trigonelline

Trigonella foenum-graecum L.(fenugreek) is one of the commonly used traditionly Chinese medicines included by the Pharmacopoeia of the People's Republic of China. Its seeds are known for their carminative,tonic and antidiabetic effect. A curative dose of fenugreek also produces antiulcer action. Trigonelline is the main component. It has antineoplastic activity, hypoglycaemic effect and so on. A HPLC method was established to determinate the contents of trigonelline in 24 Trigonella foenum-graecum samples. And the pharmacokinetics was studied in animals. 1. Studies on the assessment of Trigonella foenum-graecumA HPLC method was established to determinate the content of trigonelline in 18 Trigonella foenum-graecum samples. NH2P column was used, mobile phase consisted of acetonitrile-water (75 :25, VIV} and detection was performed at UV 265 nm. Hierarchical cluster analysis was applied to evaluate and classify the quality of the drug in view of trigonelline. The result showed that the standard curve was linear in the range of 3.68-73.60 g ml-1.The correlation coefficient was 0.9999. The average recovery rate and RSD were 97.4 %and 1.83 % (n=7) respectively. The contents of trigonelline in Trigonella foenum-graecum L. from different habitats were quite different. The method was proved to be simple, precise, sensitive and reproductive. It can be helpful for the quality assessment of the medicinal material. The improved method wassuitable for the seperation of trigonelline from instant Que Chao coffee.2. Studies on the pharmacokinetics of trigonelline in animalsTwo sensitive and specific HPLC methods were developed for determination of trigonelline in rabbit and rat plasma , and the pharmacokinetics were studied in rabbits and rats.After ig of fenugreek extract and iv of trigonelline in rabbits, the biological samples could be well purified after precipitation with methanol and acetonitrile. Asahipak NH2P-50 column was used, the mobile phase consisted of acetonitrile-water (90 : 10, V/V)at a flow-rate of 1.2 mL min-1, and detection wavelength was set at UV 265 nm. The column temperature is 30 . The result is that the calibration curve was linear in the range from0.98 g mL-1 to 31.28 g mL-1,with r =0.9986, the detection limit of this method was 50 ng mL-1.After ig of fenugreek extract in rat, the plasma samples were deproteinized with methanol (containing theophylline as internal standard) and the supernatant was dried under N2 stream. The residue was resolved with water and injected into HPLC. The mobile phase consisted of acetonitrile-water (83 : 17, F/F) . The result is the calibration curve was linear in the range from 0.47 g mL-1 to 37.84 g mL-1,with r =0.9987.The methods were both simple, accurate, sensitive and good enough to be used in pharmacokinetic study of trigonelline. The concentration-time curves of trigonelline in rabbits after ig and iv administration were shown to fit one-compartment and two-compartment open model, respectively. Meanwhile, The data in rats fit a one-compartment open model.Trigonelline had a middle velocity absorption and fast velocity elimination. The pharmacokinetic parameters showed species simularities and differences.