Studies On Identification And Quality Of Three Crude Drugs From Elaeagnus

Elaeagni Folium, Elaeagni lanceolatis Folium and Elaeagni henryis Foliumrespectively are the dried leaves of Elaeagnus pungens Thunb., E. lanceolata Warb. and E.henryi Warb., subordinated to Elaeagnaceae. Among them, Elaeagni Folium has significanteffects on relieving cough, preventing asthma, hemostasis and detoxification. The leaf is mainraw material for making Chinese patent drug named “Hai Zhu Chuan Xi Ding Tablet”, whichcures cough and asthma effectively. Modern pharmacological studies indicated that ElaeagniFolium extracts not only possessed obvious effects of preventing asthma, relieving cough andremoving phlegm, but also inhibited proliferation of human cervical cancer cell line Hela andhuman gastric carcinoma cell line SGC-7901in vitro. Similarly, the leaves of E. lanceolataWarb. and E. henryi Warb. from the same genus are used for treating cough, asthma in folk aswell. Three medicinal plants are rich in resources, with broad application and promisingdevelopment prospect.At present, the preliminary macroscopic and microscopic identification, chemicalcomposition and pharmacological effects of Elaeagni Folium have reported. However,researches on microscopical characteristics, chemical constitution of Elaeagni lanceolatisFolium and Elaeagni henryis Folium have only been conducted. In view of lacking systematic,detailed identification and quality analysis methods, macroscopic and microscopiccharacteristics （transverse section and leaf epidermis）, TLC identification, flavonoidsextraction conditions and determination of flavonoids contents by UV and HPLC werestudied, aimed at providing a good foundation for authentification, quality evaluation,establishment and improvement of the quality standards of these crude drugs from the samegenus, so as to ensure the safety and efficiency in clinical medication.The study of macroscopic and microscopic identification showed three medicinalmaterials had some common characteristics whereas each had individual characteristics. Inthe respect of macroscopic characteristics, they had leathery leaves and smooth adaxialsurface, with abaxial one exhibiting scale hairs densely. Nevertheless, morphologicalcharacters somewhat differed between each other. In terms of microscopic identification, thetype of main vein vascular bundles made transition from amphicribral vascular bundle at leafbase to bicollateral vascular bundle, then to collateral vascular bundle at leaf apex, which wasfirstly discovered. In addition, there was a layer of hypodermis under the upper epidermis ofthe leaf from E. lanceolata Warb. and E. henryi Warb.. These results had significant value to identify related medicinal materials from this genus.The TLC identification methods of petroleum ether and chloroform fractions from threekinds of crude drugs alcohol extracts were developed, showing that the TLC of petroleumether fraction had obvious feature, i.e., the TLC of Elaeagni Folium had two moregreenish-yellow spots than that of Elaeagni lanceolatis Folium and Elaeagni henryis Folium（Rf value was about0.43and0.48respectively）, while Elaeagni henryis Folium had one lightblueish-purple sport than that of Elaeagni Folium and Elaeagni lanceolatis Folium （Rf valuewas about0.7）, which could be used to authenticate them. Furthermore, the resultsmanifested that the TLC of Elaeagni lanceolatis Folium and Elaeagni henryis Folium hadhighly similar characteristics, so as to infer that E. lanceolata Warb. and E. henryi Warb. werenear in genetic relationship while far with E. pungens Thunb., according to similarity ofchemical composition.With the yield of total flavonoids in Elaeagni Folium as an index, the L9（34） orthogonaltest was carried out in the optimization of technological parameters.The optimal extractionparameters showed that ethanol concentration was85%, ratio of solvent to raw material40:1and extraction time1.5h. Then according to optimal extraction and determination method,the contents of total flavonoids in three crude medicines were measured. The results showedthat the flavonoids contents in Elaeagni Folium collected at same habitat （Wuhan,HubeiProvince）but different harvest time （May, June, July and October,2010） reached30.0mg·g^-1,27.2mg·g^-1,32.2mg·g^-1and33.2mg·g^-1respectively, representing little difference.However, the amounts of total flavonoids in samples harvested in same collected period butdifferent places （Huangmei and Wuhan, Hubei Province） were20.8mg·g^-1，30.0mg·g^-1respectively, which differed obviously. Moreover, the flavonoids contents in Elaeagnilanceolatis Folium from different harvest time （July,2009; December,2010） and habitats（Badong and Jianshi, Hubei Province） had greater difference, i.e.,13.9mg·g^-1,20.7mg·g^-1.Thesame went for Elaeagni henryis Folium collected in various harvest periods（October,2008;January,2011） but the same habitat （Jianshi, Hubei Province）.And the amounts of totalflavonoids were18.5mg·g^-1,25.6mg·g^-1respectively.The determination method of kaempferol content, one of hydrolysis products fromflavonoids ingredients, was established by HPLC. Then the amount of kaempferol in thesamples was measured. It turned out that the kaempferol content (4.28mg·g^-1,1.87mg·g^-1)varied significantly in samples of Elaeagni Folium from different habitats（Wuhan andHuangmei, Hubei Province） but the same harvest time（May）, while the amount(3.68-4.28mg·g^-1)had little difference in this crude medicine collected in the same habitat （Wuhan, Hubei Province） but different harvest period（May, June, July and October）. Therefore, it canbe suggested that the quality of Elaeagni Folium has little correlation with harvest time whenflavonoids were considered as effective constituent. Hence this crude drug can be harvestedfrom the early summer to autumn.The results above provided significant experimental basis for quality standardsestablishment, quality evaluation and further exploitation and application of these three foliacrude drugs.