Cloning and gene functional analysis study of dynamin-related protein GeDRP1E gene in Gastrodia elata / 药学学报

The gene GeDRP1E encoding dynamin-related protein 1E in Gastrodia elata was cloned by specific primers which were designed based on the transcriptome data of G. elata. Bioinformatics analysis on GeDRP1E gene was carried out by using ExPASy, ClustalW, MEGA, etc. Positive transgenic Arabidopsis plant and potato minituber were obtained with the genetic transformation system of Arabidopsis and potato. The plant height and seed setting rate of transgenic Arabidopsis, and agronomic characters, such as size, weight and starch content of potato minituber of transgenic potato were tested and analyzed. And GeDRP1E gene function was preliminarily investigated. The results showed that the open reading frame of GeDRP1E gene was 1 899 bp in length and 632 amino acids residues were encoded, with a relative molecular weight of 69.90 kDa and a molecular formula of C3079H4973N883O933S19. It was predicted that the theoretical isoelectric point was 7.27, the instability coefficient was 43.34, and the average hydrophilicity index was -0.259, which was indicative of an unstable hydrophilic protein. GeDRP1E has no transmembrane structure and signal peptide, and was localized in the cytoplasm. The phylogenetic tree showed that GeDRP1E was highly homologous with DRP1E proteins of other plant species, among which GeDRP1E had the highest homology with DcDRP1E (XP_020689662.1) in Dendrobium candidum, reaching 90.05%. GeDRP1E plant expression vector pCambia1300-35Spro-GeDRP1E was constructed by double digests, and Arabidopsis complementary mutant and potato overexpression strain of GeDRP1E gene were obtained by Agrobacterium-mediated gene transformation. Compared with the Arabidopsis AtDRP1E mutant, the height and seed setting rate of the GeDRP1E complementation mutant were rescued. The minituber of GeDRP1E overexpression potato had larger size, heavier weight and higher starch content, comparing to wild-type potato. It was preliminarily induced that GeDRP1E was involved in mitochondrial morphology regulation, which related to the growth and development of Arabidopsis plants and potato miniature. The research results laid a foundation for further elucidating the molecular mechanisms underlying the growth and development of G. elata tuber development.

Screening of an Armillaria gallica strain for Gastrodia elata cultivation / 中国中药杂志

This study aims to screen a strain from Armillaria for the cultivation of Gastrodia elata. Specifically, Armillaria strains were isolated from different producing areas of G. elata and identified. Based on the growth characteristics of the strains and the experiment on the cultivation of G. elata, an optimal A. gallica strain was screened out. The specific process is as follows. The fungus-gro-wing materials of G. elata were collected from four producing areas and the Armillaria strains were isolated(G,Y,S,H). The strains were then identified based on morphological observation and phylogeny analysis and the commonly used strains were determined. The sucrase genotypes of the strains were identified according to our previous research findings, and the growth characteristics of the strains, such as growth rate, diameter, dry weight, and polysaccharide content of the rhizomorphs, were measured. According to the biological characteristics and sucrase genotypes, two strains were selected for the cultivation of G. elata. The tuber yield and the content of gastrodin and p-hydroxybenzyl alcohol in the tuber of G. elata were measured to select the optimal strain. The results showed that the four strains were all A. gallica. The rhizomorphs of strains G and H of the same sucrase genotype had larger/higher length, growth rate, diameter, branch number, dry weight, and polysaccharide content than those of strains S and Y of the same sucrase genotype. The tuber yield and the total content of gastrodin and p-hydroxybenzyl alcohol in tuber of G. elata cultivated with strain H were 6.528 kg·m~(-2) and 0.566%, respectively, which were 4.58 and 1.30 folds those of G. elata cultivated with strain S. Strains H and S were screened out from four strains of A. gallica based on the growth characteristics and sucrase genotype. According to the tuber yield and content of total gastrodin and p-hydroxybenzyl alcohol in the tuber of G. elata, strain H was identified as the optimal one. The findings in this study are expected to lay a basis for cultivating G. elata with high yield and quality of tubers.

Application of strigolactone analogs in storage of Gastrodia elata / 中国中药杂志

This study explored the preservation effect of strigolactone analogs on Gastrodia elata tubers and screened out the suitable preservation measures of G. elata to provide a safer and more effective method for its storage and preservation. Fresh G. elata tubers were treated with 7FGR24, 2,4-D isooctyl ester, and maleic hydrazide, respectively. The growth of flower buds, the activities of CAT, and MDA, and the content of gastrodin and p-hydroxybenzyl alcohol were measured to compare the effects of different compounds on the storage and preservation of G. elata. The effects of different storage temperatures on the preservation of 7FGR24 were compared and analyzed. The gibberellin signal transduction receptor gene GeGID1 was cloned, and the effect of 7FGR24 on the expression level of GeGID1 was analyzed by quantitative polymerase chain reaction(qPCR). The toxicity of the G. elata preservative 7FGR24 was analyzed by intragastric administration in mice to evaluate its safety. The results showed that compared with 2,4-D isooctyl ester and maleic hydrazide, 7FGR24 treatment had a significant inhibitory effect on the growth of G. elata flower buds, and the CAT enzyme activity of G. elata was the highest, indicating that its preservation effect was stronger. Different storage temperatures had different effects on the preservation of G. elata, and the preservation effect was the strongest at 5 ℃. The open reading frame(ORF) of GeGID1 gene was 936 bp in length, and its expression level was significantly down-regulated after 7FGR24 treatment, indicating that 7FGR24 may inhibit the growth of flower buds by inhibiting the gibberellin signal of G. elata, thereby exerting a fresh-keeping effect. Feeding preservative 7FGR24 had no significant effect on the behavior and physiology of mice, indicating that it had no obvious toxicity. This study explored the application of the strigolactone analog 7FGR24 in the storage and preservation of G. elata and preliminarily established a method for the storage and preservation of G. elata, laying a foundation for the molecular mechanism of 7FGR24 in the storage and preservation of G. elata.

Cloning and gene function of dicarboxylate-tricarboxylate carrier protein in Gastrodia elata / 中国中药杂志

The gene GeDTC encoding the dicarboxylate-tricarboxylate carrier protein in Gastrodia elata was cloned by specific primers which were designed based on the transcriptome data of G. elata. Bioinformatics analysis on GeDTC gene was carried out by using ExPASY, ClustalW, MEGA, etc. Positive transgenic plants and potato minituber were obtained by virtue of the potato genetic transformation system. Agronomic characters, such as size, weight, organic acid content, and starch content, of potato minituber were tested and analyzed and GeDTC gene function was preliminarily investigated. The results showed that the open reading frame of GeDTC gene was 981 bp in length and 326 amino acid residues were encoded, with a relative molecular weight of 35.01 kDa. It was predicted that the theoretical isoelectric point of GeDTC protein was 9.83, the instability coefficient was 27.88, and the average index of hydrophilicity was 0.104, which was indicative of a stable hydrophilic protein. GeDTC protein had a transmembrane structure and no signal peptide and was located in the inner membrane of mitochondria. The phylogenetic tree showed that GeDTC was highly homologous with DTC proteins of other plant species, among which GeDTC had the highest homology with DcDTC(XP＿020675804.1) in Dendrobium candidum, reaching 85.89%. GeDTC overexpression vector pCambia1300-35Spro-GeDTC was constructed by double digests, and transgenic potato plants were obtained by Agrobacterium-mediated gene transformation. Compared with the wild-type plants, transgenic potato minituber harvested by transplanting had smaller size, lighter weight, lower organic acid content, and no significant difference in starch content. It is preliminarily induced that GeDTC is the efflux channel of tricarboxylate and related to the tuber development, which lays a foundation for further elucidating the molecular mechanism of G. elata tuber development.

Challenges and Perspectives in Target Identification and Mechanism Illustration for Chinese Medicine / 中国结合医学杂志

Chinese medicine (CM) is an important resource for human life understanding and discovery of drugs. However, due to the unclear pharmacological mechanism caused by unclear target, research and international promotion of many active components have made little progress in the past decades of years. CM is mainly composed of multi-ingredients with multi-targets. The identification of targets of multiple active components and the weight analysis of multiple targets in a specific pathological environment, that is, the determination of the most important target is the main obstacle to the mechanism clarification and thus hinders its internationalization. In this review, the main approach to target identification and network pharmacology were summarized. And BIBm (Bayesian inference modeling), a powerful method for drug target identification and key pathway determination was introduced. We aim to provide a new scientific basis and ideas for the development and international promotion of new drugs based on CM.

The Role of Mast Cells on Tumor Occurrence and Development / 中国生物化学与分子生物学报

Mast cells are one of the major immune cells in the human body and best known for their role in allergy and anaphylaxis. The main structural characteristic of mast cells is that they contain a large number of basophilic granules, and the basophilic granules are rich in a variety of bioactive substances including histamine, vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), matrix metalloproteinase (MMP), tryptase, chymase and a diverse number of inflammatory mediators. Histamine is involved in the proliferation, migration and invasion of some kinds of cancer cells, and VEGF, FGF, MMP, tryptase and chymotryptase play a significant role in different stages of tumor angiogenesis. The release of various inflammatory mediators from mast cells can lead to inflammatory response at the site of tumor formation, and it is well known that chronic inflammation is a primary risk factor for cancer development and progression. Some studies have shown that a significantly increased number of mast cells can be detected in different tumor tissues. The active substances released by mastcells can stimulate tumor growth, tumor angiogenesis and promote tumor metastasis. Furthermore, the tumor microenvironment also plays an important role in regulating the recruitment of mast cells to tumor tissues and the maturation and activation of mast cells. In this article, we will review the latest progress in the effects of mast cells on tumor growth, tumor angiogenesis, and tumor microenvironment on mast cellactivation.

Research progress of famesyltransferase and its inhibitors in cancer therapy / 中国药理学通报

Famesyltransferase, a membrane-associated protein, catalyzes the addition of the 15-carbon fragment of famesyl diphosphate to the cysteine SH group of the CAAX motif containing protein substrates to regulate the function of target proteins through famesylation. As one of the most important target proteins of FTase, oncogenic forms of Ras mutants have been reportedly involved in more than 30% human cancers, and are known to play critical roles in cancer development and progression. Despite decades of research, Ras inhibitors are so elusive that no therapeutic agents directly targeting Ras mutants have been clinically approved, the primary reason for which is the lack of druggable pockets on the surface of Ras. Therefore, FTase, the main regulator of Ras protein, has gradually become a research hotspot, and many FTase inhibitors have been developed, synthesized and used for the treatment of malignant tumors. In the present review, we briefly describe the regulation of Ras functions by FTase and the role of FTase in cancers, and mainly explore the research progress of FTase inhibitors as a promising strategy for cancer therapy.

A Soybean Straw Cultivation Medium for Armillaria gallica and Optimal Composition / 中国实验方剂学杂志

Objective:To explore the feasibility of replacing wood （or wood chips） with crop residues for culturing <italic>Armillaria gallica</italic> targeting the problems of forest resource destruction and increased cultivation cost caused by the extensive use of wood in <italic>Gastrodia elata</italic> cultivation， so as to reduce the cultivation cost of <italic>G. elata</italic>， promote the effective use of crop residues， and protect forest resources. Method:The growth situation of <italic>A. gallica</italic> in different media was observed， followed by the measurement of its growth rate using streaking method and the determination of total polysaccharide content of <italic>A. gallica</italic> by phenol-concentrated sulfuric acid colorimetric method. In order to further optimize the soybean straw cultivation medium， we carried out a four-factor three-level L₉（3⁴） orthogonal assay on the ratio of main ingredients， sucrose content， inorganic salt content， and water content. Result:The comparison of growing states of <italic>A. gallica</italic> cultured in different media revealed that <italic>A. gallica</italic> in soybean straw medium began to grow since the fourth day of inoculation， and the mycelium grew well， with the growth rate being 0.352 cm·d^-1， which was 1.48 times that in birch wood medium. The total polysaccharide content of <italic>A. gallica</italic> cultured in soybean straw medium was the highest， which was 39.260 mg·g^-1， much higher than 17.028 mg·g^-1 of that cultured in birch wood medium. This demonstrated the obvious advantage of soybean straw medium， whose main ingredients were soybean straw and wheat bran at the ratio of 8：2， with the sucrose and inorganic salt content accounting for 1% and 0.5% of the main ingredients， respectively. When the water content reached 50%， the growth rate of <italic>A. gallica</italic> was maintained at 0.392 cm·d^-1. Conclusion:This study has provided a basis for utilizing soybean straw instead of wood （or wood chips） as cultivation medium for <italic>A. gallica</italic>， thus better reducing the waste of forest resources and protecting the natural environment in the cultivation of <italic>G. elata</italic>.

Resina draconis inhibits the endoplasmic-reticulum-induced apoptosis of myocardial cells via regulating miR-423-3p/ERK signaling pathway in a tree shrew myocardial ischemia– reperfusion model

Ischemia-reperfusion (IR) is one of the significant medical problems in China. Triphenyltetrazolium chloride (TTC) stainingis used to detect the status of the infarct size, and real-time PCR and western blotting are used to detect expressions ofgenes. TUNEL assay has been used to detect apoptosis. Using a tree shrew myocardial IR model, we found that in thereperfusion period, resina draconis (RD) treatment reduced the infarct size by TTC staining, and significantly enhanced thesuperoxide dismutase expression and down-regulated the malondialdehyde concentration in a dose-dependent manner. Inhearts showing IR, Bax was increased and Bcl-2 was reduced, and RD treatment inhibited the IR-induced Bax expressionand up-regulated the IR suppressed level of Bcl-2. TUNEL assay showed that IR induced the apoptosis of myocardial cells,and RD treatment suppressed the IR-induced apoptosis. CHOP and GRP78 were also upregulated in IR hearts, and RDtreatment could significantly attenuate the CHOP and GRP78 levels compared with IR group. We further found that IRdecreased the miR-423-3p expression and upregulated its target gene ERK both in mRNA and protein levels, and RDtreatment upregulated miR-423-3p expression and downregulated ERK expression compared with the IR group. Importantly, miR-423-3p mimics inhibited IR increased ERK, CHOP and GRP78 expressions, and enhanced IR decreased Bcl-2expression, and inhibited the IR-induced apoptosis of myocardial cells. The findings of this study suggest that RD treatmentinhibited the endoplasmic reticulum induced apoptosis of myocardial cells via regulating miR-423-3p/ERK signalingpathway in a tree shrew myocardial IR model.

Identification of four Armillaria strains and their effects on quality and yield of Gastrodia elata f. glauca / 中国中药杂志

In order to improve the quality and yield of Gastrodia elata f. glauca,determine the suitable Armillaria strains for the accompanying experiment in Xiaocaoba,Yiliang,four Armillaria strains were selected. They were used for G. elata cultivation,and the gene sequence,r DNA-ITS,β-tubulin and EF1-α of four Armillaria strains,were compared and analyzed. The yield was mesured in November which was based on previous laboratory research. The tubers were washed and steamed,then dried and powdered. The content of gastrodin and p-hydroxybenzyl alcohol was determined by UPLC,the polysaccharide was determined by phenol-concentrated sulfuric acid method. The results showed that the strains M1,M2,M3 and M4 were Armillaria gallica group but there were differences in the yield and active ingredient content when they were cultivated with the same G. elata. The yield of G. elata( Jian Ma) was the lowest when cultivated with Armillaria strain M3,but it was not the same when used M1,0. 981 kg·m-2,the highest yield in the four stains.The content of gastrodin was 0. 581%,the total content of gastrodin and p-hydroxybenzyl alcohol was 0. 595%,when accompanied with M1 strains. It was higher than other strains. The content of G. elata polysaccharide was 2. 132%,which was similar to the content of M3 strain,higher than that of M2 and M4 strain. Selecting phylogenesis of Armillaria strians,the content of active ingredient,and the yield as indicators,it was concluded concerned that the M1 strain was the best of four strains. The results will provide a theoretical basis and guidance for higher yield and quality in cultivation of G. elata in Yiliang.

Establishment of an ex vivo myocardial ischemia-reperfusion model in tree shrews / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish an ex vivo model of myocardial ischemia reperfusion in tree shrews.</p><p><b>METHODS</b>The Langendorff ex vivo heart perfusion system was used to establish the myocardial ischemia reperfusion model in tree shrews with different irrigation and reperfusion time settings. Alanine aminotransferase (ALT), aspartate transaminase (AST) and lactic dehydrogenase (LDH) levels were measured by enzyme-labeled immunosorbent assay, creatine kinase MB (CK-MB) was detected using immunosuppression method, and malondialdehyde was measured with thiobarbital staining method; the infarct size was measured using 2, 3, 5-triphenyltrazoliumchloride (TTC) method.</p><p><b>RESULTS</b>Ischemia for 30 min and reperfusion for 30 and 60 min caused more significant increase in CK-MB and LDH levels in the perfusion fluid and also in the levels of ALT, CK-MB and AST in the myocardial tissue compared with other experimental settings (P<0.05), but these parameters were comparable between the former two settings (P>0.05). The mean heart rate in 30-min ischemia with 60-min reperfusion group was obviously lower than that in continuous reperfusion group, 15-min ischemia with 30-min reperfusion group and 30-min ischemia with 30-min reperfusion group (P<0.05), and the heart rate was similar between the latter 3 groups (P>0.05). ECG analysis showed that the mean heart rate in 30-min ischemia with 30-min reperfusion group was closer to the physiological heart rate of tree shrews.</p><p><b>CONCLUSION</b>We successfully established an ex vivo myocardial ischemia reperfusion model using tree shrews, and ischemia for 30 min followed by reperfusion for 30 min is the optimal experimental setting.</p>

Research progress on pathophysiological function of SOS1 protein / 生理学报

Son of sevenless homolog 1 (SOS1) protein is a ubiquitously expressed adapter. As a key protein in intracellular signaling, SOS1 plays an important role in many signal transduction pathways, such as Ras and Rac signaling pathways. The abnormal expression or mutation of SOS1 is closely related to clinical diseases. In this article, we review research progress on SOS1 functions and its roles in physiology and pathophysiology.

Structure and function of the adapter protein Gab and its role in the development of tumor, inflammation and cardiovascular diseases / 生理学报

Gab proteins, Grb2 (growth factor receptor binding protein 2)-associated binder, are important scaffolding adapter proteins required by many signaling pathways. In mammals, the Gab proteins mainly consist of Gab1, Gab2 and Gab3, and are involved in the amplification and integration of signal transduction evoked by a variety of extracellular stimuli, including various growth factors and cytokines. They are known to play key roles in many biological processes through the two classical signal pathways, SHP2/RAS/ERK and PI3K/AKT. In this review, we provide an overview of the structure and function of the scaffolding adapter, Gab, with a special focus on its role in tumor, inflammation and cardiovascular diseases.

Study of melatonin on the protective effect of hydrogen peroxide - induced oxidative damage in human lens epithelial cells / 国际眼科杂志(Guoji Yanke Zazhi)

?AlM: To investigate theprotective effect of melatonin against hydrogen peroxide ( H2 O2 )-induced oxidative damage to human lens epithelial cells. ?METHODS: Sub-culture human lens epithelial cells preprocessed with different concentrations of melatonin for 12h and then 100 μmol/L H2 O2 for 24h. The impact of melatonin on H2 O2-induced lens epithelial cell viability was detected by MTT assay, rate of apoptosis was detected by flow cytometry instrument and activity of apoptosis-related factors, Caspase-3 and Caspase-9, were detected by colorimetric method. ?RESULTS: MTT assay showed that melatonin had no effect on the activity of lens epithelial cells, and the drug can inhibit the decrease of H2 O2-induced cell activity, as well as flow cytometry showed that melatonin can inhibit H2 O2-induced apoptosis. ln addition, melatonin can also reduce H2 O2-induced Caspase-3 and Caspase-9 activity in lens epithelial cells, and their activity decreased with effect of melatonin along with extending time. ?CONCLUSlON: Melatonin can obviously inhibit H2 O2 -induced apoptosis of human lens epithelial cells, which provide reliable experimental basis for drug on treatment of cataract.

Side Population Cells in Human Gallbladder Cancer Cell Line GBC-SD Regulated by TGF-β-induced Epithelial-mesenchymal Transition / 华中科技大学学报（医学）（英德文版）

Mounting evidence has shown that side population (SP) cells are enriched for cancer stem cells (CSCs) responsible for cancer malignancy.In this study,SP technology was used to isolate a small subpopulation of SP cells in human gallbladder cancer cell line GBC-SD,and SP cells which had superior potential for proliferation in vitro and tumorigenesis in vivo were identified.Importantly,the abundance of GBC-SD SP cells was increased by a transforming growth factor-β (TGF-β)-induced epithelial-mesenchymal transition (EMT),and this effect was accompanied with a strong up-regulation of ABCG2 mRNA expression,and a decreased sensitivity to mitoxantrone.SP cells were restored upon the removal of TGF-β and the reversion of the cells to an epithelial phenotype,and smad3-specific siRNA reduced SP abundance in response to TGF-β.In conclusion,TGF-β-induced EMT by smad-dependent signaling pathway promotes cancer development and anti-cancer drug resistant phenotype by augmenting the abundance of GBC-SD SP cells,and a better understanding of mechanisms involved in TGF-β-induced EMT may provide a novel strategy for preventing cancer progression.

The application of DNA molecular markers in conservation of the rare and endangered medicinal plants / 中国中药杂志

In this paper, the advance in DNA molecular markers techniques in recent years was reviewed. The application of DNA markers in conservation of the rare and endangered medicinal plants was explicated, of which included identification of germ-plasm resource, determination of the habitats unite which should be protected in situ, sampling strategies of ex-situ conservation, evaluation of the conservation effects of the rare and endangered medicinal plants, as well as elucidation of their endangered mechanism etc. The information could help drawing up conservation strategies and conservation measures for references.

Establishment and application of the model of islet impaired by NO free radical released from streptozotocin / 生物工程学报

For diabetes mellitus, little research has been done on the tissue-based or cell-based drug screening model, which has advantages over traditional animal diabetic model in high specificity, high screening volume, low cost and simple manipulation. Considering that the maintenance of complete islet tissue structure is the prerequisite for islet cells to perform their functions normally, an in vitro islet-based drug screening model for diabetes mellitus was established and evaluated. Pancreatic islets were isolated from 3 weeks old mice of either sex by collagenase digestion and density gradient centrifugation as prescribed by Ramanadham S. The volume of 0.1% (W/V) collagenase IV, 0.1% (W/V) Hyaluroridase and 0.1% (W/V) DNase I were 4 times, 2 times and 1 times that of the islets to be digested. And a 2 hours' cold digestion at 4 degrees C was followed by a 10 minutes' warm digestion at 37 degrees C. Under the optimized digestion condition, the islet recovery could be increased by 10%. The isolated islets could survive 6 weeks in vitro and show stable insulin secretion in the first 10 days after inoculation. The obtained islets were cultured in RPMI-1640 medium at 37 degrees C with 5% CO2. Then a diabetic model was established by selecting streptozotocin (STZ) as the evocator and nitric oxide (NO) as the responding index. After 1 day's inoculation, islets culture was treated with STZ, whose concentration ranged from 0 to 5.0 mmol/L. NO was measured by a colorimetric assay at 540nm based on the Griess reaction for 10 min with 0.1 mL Griess reagent and 0.1 mL culture supernatants. Insulin secretion was assayed by RIA methods. Due to the islets-related inoculation variations, NO release and insulin content were both expressed as a percentage of the value recorded in basal experiment which was in the only presence of Krebs culture medium. It was testified that the amount of NO released from islet itself remained steady at 30-35 mmol/L regardless of the changes of STZ concentration from 0 to 5.0 mmol/L. However the NO content in the supernatants of islets culture had close relationship with STZ concentration. This indicated that in this STZ-induced islet diabetic model, NO mainly comes from STZ when it dissolves in water. On the other hand, when STZ changed from 0 to 5.0 mmol/L, the dose-dependent relationship between NO content and insulin secretion showed that the increase of NO came along with the decrease of insulin secretion, which is an important symbol of islet function. As a kind of oxidative free radical, NO is capable of impair islet cells. Thus, NO is a reliable responding index of the model. The optimal STZ concentration in the model is finally determined to be 5.0 mmol/L, under which condition the NO content and insulin secretion is 10.81 times and 0.43 times that in the medium before STZ is added. So if anything is effective in lowering the NO content in the culture, it could protect islets cells from the oxidative attacks of NO. Finally, as an application of the model, the scavenging effect of KOSCr on NO was studied. In a series of KOSCr with different chromium content, all had shown better NO scavenging effects than KOS itself, which could give us an enlightenment of the influence of chromium ion on oligosaccharide. And 1 g/mL KOSCr with 3.519% chromium content can significantly inhibit the NO formation. This has lain a theoretic basis for the research of KOSCr bioactivity and quality control. These results suggested that the STZ-induced diabetic islet model which is impaired by NO free radical can be used effectively, fast and conveniently when screening potential diabetes drugs.