Comparative Study On Biodistribution Of Ephedrine In Traditional And Ultra-micro Powder Of Ephedra

Objective:The dried stem of the Ephedra sinica Stapf,Ephedraintermedia Schrenk et C.A.Mey or Ephedra equisetina Bge. has been used extensively in traditional Chinese medicine(TCM)to treat chill cold,bronchitis and bronchial asthma diseases. Ephedrine is the main active component of Ephedra. But Ephedrine is harmful to the body sometimes. The laboratory has early studies showed that the distribution of Ephedrine in Ephedra ultra-micro powder significantly prolonged the T1/2a than that of traditional powder in the body. Clewing that the distribution of Ephedrine in ultra-micro powder was changed.This thesis is to comparatively study on the distribution of Ephedrine in Ephedra traditional powder and ultra-micro powder in mice, and discuss different particle sizes of the Ephedra powders'efficacy and side effects whether changed. To provide experimental and theoretical basis for Ephedra ultra-micro powder widely used in clinical. ultra-micro powder in 10g·kg-1 dose separately, then kill mices at 0.5,1,2,4,8 hours, isolate the lung,heart,liver,kidney and brain, homogenate, preparate sample solution, HPLC-UV determinate the concentrations of Ephedrine in each tissue. Chromatographic conditions Ephedrine was separated on a C18 column (Kromasil 4.6mm×250mm, 5μm) with a gradient elution system which composed of acetonitrile and 0.1% phosphate (13:87), UV detection was used at 207 nm, velocity is 1ml/min,Column temperature 30℃,incoming sample amount 10μl. The experimental data measured by SPSS software for processing. Compare the differences of Ephedrine distribution in mice tissues.Results:The concentration of Ephedrine was determined by HPLC method in this experiment. Retention time is stable(6.0min).The calibration curves were linear in all tested matrices (r>0.9991) with the concentration range of 0.4～12.8μg·ml-1. The intra-day and inter-day precision were all less than 4%, and the extract recovery was in the range from 81% to 97% for Ephedrine in all tested tissues.The method was successfully used to quantify the contents of Ephedrine in mice tissues, the results were as follows:Ⅰ. Comparative study on the distribution of Ephedrine in Ephedra traditional powder and ultra-micro powder in mice lungs. From 0.5 to 8 hours, The concentration of Ephedrine in Ephedra traditional were 1.0176,2.2480,2.6321,1.9178,1.2745μg/ml, and the concentration of Ephedrine in Ephedra ultra-micro powder were 1.2245,2.4245,3.3098,2.4391,1.3545μg/ml. The concentration of ultra-micro powder group is obviously higher than traditional powder group. So the ultra-micro powder can increase the concentration of Ephedrine in mice lung.Ⅱ. Comparative study on the distribution of Ephedrine in Ephedra traditional powder and ultra-micro powder in mice heart. The distribution of Ephedrine in ultra-micro powder and traditional powder reached the maximun in the 2 hour when the concentration without too much differences. It is to say ultra-micro powder will not add to the side effects of Ephedra in mice heart, but can prolong the time of drug interaction.Ⅲ. Comparative study on the distribution of Ephedrine in Ephedra traditional and ultra-micro powder in mice brain,liver and kidney. The Ephedrine distribution of ultra-micro powder group is also higher than traditional powder group. Brain and liver reached maximum in 2h. In kidney, traditional powder reached maximum in 1h, but ultra-micro powder reached maximum in 0.5h. It means that the absorption,elimination and distribution of the Ephedrine in ultra-micro powder were all faster than ordinary powder in kidney. So, it can reduce the accumulation of Ephedrine in the body.Conclusion:Ephedra ultra-micro powder can improve the distribution of Ephedrine in the body, and can increase the concentration of drug efficacy. This research provide important reference and theoretical basis for Ephedra ultra-micro powder in clinical application and scientific basis for further development and research of Ephedra.