Content Determination Of1-DNJ In Mulberry Latex And Its Pharmacokinetic Research

1-deoxynojirimycin (DNJ) is a kind of natural active substances in mulberry, whichbelongs to potent α-glucosidase inhibitors and has the hypoglycemic functions, it attracts thebiggest concern and becomes one of the most potential for development and utilization ofmulberry active substances. This paper mainly explore the factors affecting the content ofDNJ in mulberry latex and its pharmacokinetic and explain the direction for future research aswell. It also looks ahead the main research direction in this field in future and provides basicpharmacology basis for drug design, dosing regimens, drug dosage, side effects and clinicalapplication of mulberry DNJ.This study was consisted of three parts:1. Screening of ratio of solid to liquid of extracting DNJ from mulberry latex and leafpowerThe alcoholic extraction is mainly used in this experiment to extract DNJ in mulberrylatex, in order to confirm the validity of this method, we used RP-HPLC-UV detect thestability, reproducibility and recovery of the sample. The results showed: The relativestandard deviation (RSD)of the sample stability was1.42%, the DNJ in test solution wasstable within16h after deriving. RSD of the sample reproducibility was1.96%, indicatinggood reproducibility of the test method; The average recovery rate was95.3%, RSD was2.54%, It showed the sample preparation could meet the needs of the determination.On thisbasis, we investigated the effect of solid-liquid ratio on the extraction results, it showed that:the ratio of mulberry latex (mL) to ethanol (mL) was1:7, the extraction effects was the best;the ratio of mulberry leaf powder (g) to ethanol (mL) was1:15, the extraction effects was thebest.2. Content determination and analysis of1-DNJ in mulberry latexMulberry latex are collected from leaf axil of mulberry branch, and it contains1-deoxynojirimycin which belongs to alkaloids. Collecting the latex from leaf axil ofmulberry branch which come from different mulberry varieties, growth stages and positions,then a precolumn derivatization reverse phase high performance liquid chromatography andUV detection method is employed to determine DNJ content in latex, and we analyze the DNJcontent stability of latex sample and extracting solution in different holding conditions, and diurnal variation rules of DNJ content in mulberry latex for supplying the development andutilization of mulberry latex with experimental evidence. There are large differences for DNJcontent among different mulberry varieties and ploidy, different growth stage and positions inmulberry latex: All determined varieties get the highest content which the latex are collectedon July and August, and Shin Ichinose belong to the high yield gets up to993μg/mL, whichis apparently higher than its triploid Shansang305and7.7times higher over that indrought-enduring variety Wubaosang(P<0.05). For the determined varietiy Shansang305, itsDNJ content in latex from leaf axil of middle position mulberry branch is relatively high,which gets up to811μg/mL and is very significant difference compared with up and lowbranches(P<0.01).Mulberry latex are stored in normal tempreture,4℃and-20℃for a shortperiod of time(in28days), its DNJ content is relatively stable, however, DNJ in crudeextracting solution are easy to be degraded. The high yield Shin Ichinose and Shansang305present the same diurnal variation rules, and the light intensity also may be one of the factorsinfluencing the synthesis of mulberry DNJ.3.The production and pharmacokinetic of controlled-release granuleThe half-life of DNJ in vivo is relatively short, about2h, therefor,several does of pureDNJ are required to inhibit blood glucose level, the cost is too high. In this experiment,weembedded the pure DNJ in10%gelatin by means of the nature of gelatin cross-linking withtransglutaminase to manufacture controlled-release granules in order to achieve the effect ofdelaying the release of DNJ; at same time, we do the research related to the effects of therelease in vitro and in vivo effects.The results showed the release rate of controlled-releasegranules was slower than the standards and mulberry latex in vivo and in vitro, and DNJ incontrolled-release granules can not be degraded entirely in6-8h. Finally, we verified the effectof lowering blood glucose by experiments in vivo of mice, the results show thecontrolled-release granules group had significant inhibitory effect for high blood glucose afterintragastric administration of sucrose, and the standard group had no significant inhibitioneffect; these results indicate that DNJ in the form of controlled-release granules,by retardingDNJ release from gelatin carrier,provides a prolonged hypoglycaemic effect.