超声波辅助提取苦苣总黄酮的工艺研究

目的 研究超声波法提取苦苣中总黄酮的最佳提取工艺.方法 以苦苣中总黄酮的含量为评价指标,通过单因素试验研究提取温度、提取时间、乙醇浓度、料液比、超声功率对苦苣中总黄酮提取率的影响.在单因素基础上进行正交实验设计,筛选出最佳提取工艺.结果 影响苦苣中总黄酮提取率的因素主次顺序为:料液比＞提取时间＞提取温度＞乙醇浓度,最佳提取工艺为:溶剂60％乙醇,料液比1∶20(g/mL),超声提取时间50 main,超声提取温度55℃,此条件下苦苣中总黄酮提取率达0.770％.结论 苦苣中总黄酮含量较高,优化的提取工艺简便、稳定、合理、可行,可为苦苣总黄酮的工业化提取提供参考.     

苣荬菜水煎液对糖尿病大鼠的降血糖作用及其机制

目的观察苣荬菜水煎液对链脲佐菌素致糖尿病大鼠模型的降血糖作用及其机制。方法采用一次性腹腔注射链脲佐菌素的方法制作大鼠糖尿病模型,将大鼠分为空白组,模型组,二甲双胍组(0.47 g·kg^-1),苣荬菜水煎液高、中、低剂量组(3.34,1.67,0.83 g·kg^-1),实验中监测血糖,并检测各组大鼠血清中超氧化物歧化酶(superoxide dismutase,SOD)活力,丙二醛(malondialdehyde,MDA)、谷光甘肽(glutathione,GSH)、一氧化氮(nitric oxide,NO)、总胆固醇(total cholesterol,TC)、低密度脂蛋白(low density lipoprotein,LDL)、高密度脂蛋白(high density lipoprotein,HDL)、甘油三酯(triglyceride,TG)、糖基化血清蛋白(glycosylated serum protein,GSP)、胰岛素(insulin,INS)、胰岛素抗体(insulin antibody,IAA)水平和一氧化氮合酶(nitricoxidesynthase,NOS)活力,并采用HE染色法观察大鼠胰腺和肾脏组织病理变化。结果与空白组相比,模型组大鼠血糖值及血清NOS活力,MDA、NO、TC、LDL、TG、GSP、IAA水平显著升高(P<0.01),SOD活力,GSH、HDL、INS水平显著降低(P<0.01);与模型组相比,二甲双胍组和苣荬菜水煎液组各剂量均可不同程度降低血糖水平,二甲双胍组与苣荬菜水煎液高剂量组可显著升高SOD活力,GSH、HDL、INS水平(P<0.01),显著降低NOS活力,MDA、NO、TC、LDL、TG、GSP、IAA水平(P<0.01或P<0.05),改善胰腺、肾脏的病理变化。结论苣荬菜水煎液具有较好的降血糖效果,其作用机制与促进胰岛β细胞释放胰岛素有关,并可修复胰岛细胞组织、保护肾脏。     

Simultaneous occurrence of immediate and delayed allergy as a cause of contact dermatitis

Four patients with occupational contact dermatitis to Lactuca sativa had cross-sensitivity to Cichorium endivia. One of the patients also had contact urticaria to Lactuca and Cichorium, and another reacted positively to scratch tests with these plants as a sign of immediate allergy. In two cases such immediate allergy was considered the cause of a vesicular, intense itching eruption within a few minutes of contact with fresh leaves of Lactuca on previously eczematous skin. The severe chronic dermatitis of the hands of these patients is ascribed to combined delayed and immediate allergy.     

Influence of cultivation sites on sterol,nitrate, total phenolic contents and antioxidant activity in endive and stem chicory edible products

Chicories produce a wide range of vegetables with important nutritional value. We determined the variation of sterol, total polyphenol, nitrate contents and antioxidant capacity (SC, TPC, NC, AC) in endive leaves and stem-chicory novel vegetables, cultivated in two Italian regions. Within a given area, the SC was similar in smooth- and curly leafed endives (106.3–176.0?mg/kg FW); sitosterol and stigmasterol were major fractions (45–56 versus 38–43%). The stem SC was independent of landrace (101.5–118.6?mg/kg FW); sitosterol prevailed on stigmasterol and fucosterol (73–76 versus 12–14% versus 8–9%); the latter reached 15.7?mg/kg FW, conferring value as potential antidiabetes food. The planting site affected the AC and TPC of endives (893.1–1571.4 μmTE/100?g FW, 30.8–76.1 GAE100/g FW) and chicory stems (729.8–1152.5 μmTE/100?g FW; 56.2–124.4 GAE100/g FW), while the NC was recurrently below dangerous thresholds. PCA showed that environment was the major cause of variation, though it modestly affected these parameters.     

钾肥和有机肥对油荬菜产量及商品品质的影响

试验结果表明 ,土壤缺钾是该试验的主要养分限制因子之一 ;在NP基础上施钾肥增产 5 5 0 6 % ;有机无机肥料配合施用 ,比单施有机肥增产 4 5 0 1% ,比单施化肥仅增产 3 88% ,并可提高油荬菜的商品质量 ;化肥的利用率为 6 2 11% ,钾肥的利用率为 77 90 %。