Study On The Hypoglycemic And Anti-fatigue Components Of The Urtica Angustifolia

Urtica angustifolia is one species of Urtica. It is extremely rich in the northeast, Mongolia, Hebei and so on. Urtica is a kind of traditional medicine edible wild plant in China. It was reported that Urtica angustifolia has the function of blocking the wind dehumidification, promoting blood circulation and stopping pain, relaxing convulsions, antiinflammation, detumescence and anti-fatigue. In northeast of China, the people used Urtica angustifolia to care rheumatoid arthritis, urticaria, diabetes and so on. In Europe, the United States and other developed countries have researched on the nettle, especially the Urtica dioica. In particular, the development of medicine (Rheumatoid arthritis and Benign Prostatic Hyperplasia) had made remarkable achievements. In China, Urtica angustifolia has not been developed and utilized yet. In order to take full advantage of the northeastern region rich plant resources, this article studed on the hypoglycemic and anti-fatigue cmponents of the Urtica angustifolia. First,we conducted study of the chemical composition, and through oral glucose tolerance test in mice further selected hypoglycemic activity components from Urtica angustifolia; Secondly the crude polysaccharides were extracted from the Urtica angustifolia roots,and the crude polysaccharides were fractionated into fractions through the ion-exchange chromatography and Gel chromatography methods. Purity and uniformity were identificated, and using modern method to analysis composition and structure of polysaccharides. Meanwhile, the anti-fatigue activity of the polysaccharides was evaluated in mice. The investigation results are as follows:Studied on the Urtica angustifolia root, stem and leaf chemical composition, the identification results shown that the roots contained flavonoids, sterols, organic acids, glycosides, phenolic compounds and carbohydrates, protein, amino acids, fats and other ingredients; stem contained sugar and glycosides, steroids and terpenes, organic acids and other ingredients; leaf contained pigments, flavonoids, sterols, glycosides, sugars, proteins, amino acids, fats and other ingredients.Through the oral glucose tolerance test in mice, leaf decoration showed significantly hypoglycemic trend among root, stem, and leaf extracts from Urtica angustifolia. For further screening of leaf hypoglycemic active ingredients, four kinds of extractions were obtained from leaves and fed to mice. Through the oral glucose tolerance test in mice, which indicated extractions U3 and U4 had hypoglycemic effect. Also extraction U3 and U4 were flavonoids with 7’-Glc and daucosterol compounds, respectively which was identified by Chemical analysis and structural identification Study on hypoglycemic ingredients from Urtica angustifolia, after feding mice with Urtica angustifolia root polysaccharide, it was found without lowering blood sugar effect, but it shown anti-fatigue activity, therefore, the anti-fatigue activity of Urtica angustifolia roots polysaccharide was studied.The polysaccharides (UA) were extracted from the roots Urtica angustifolia with hot water, precipitated by 80% ethanol and deproteinated using the Sevag method. The polysaccharide mixture, referred to as UA(for Urtica angustifolia Polysaccharides), was obtained in a yield of 1.6%(w/w).The anti-fatigue experiment was studied in mice. It showed that three dose groups of UA were extend the swimming time of mice, improve the mouse athleticism, the high-dosage groups (300mg/kg/d) was perfect (P<0.01). After swimming, the content of serum urea nitrogen in the experimental groups were significantly lower than the control group, UA can extend exercise load capability of mice, it is not easy to occur fatigue. At the same time, glycogen content in mice were tested, the influence of the results shown that UA can maintain the high leve content of hepatic glycogen, it has positive function, thus to delay fatigue to appear. Meanwhile, the composition of of UA has been analysised, UA contained 44.6% total sugar, 12.7% uronic acid and less than 1% protein. Sugar composition analysised by HPLC indicated that UA consisted of Glucose (64.3%), Galacturonic acid (15.9%), Galactose (8.2%) and Arabinose (5.9%).UA was separated on a preparative DEAE-Cellulose column into two fractions first: an unbound fraction(UAN)by water elution and a bound fraction(UAA)by 0.5 M NaCl elution. Then, UAA was separated on a preparative DEAE-Cellulose column into four fractions UAA-1, UAA-2, UAA-3 and UAA-4 corresponding to 0.0, 0.1, 0.2, 0.3 and 0.5 M NaCl elutions, respectively. Finally, the acidic fractions UAA-3 was separated on a preparative DEAE-Cellulose column into two fractions UAA-3-1 and UAA-3-2.Using periodate oxidation, smith degradation, and 13C-NMR to analysis the structure of UAA-3-1 and UAA-3-2. According to the data analysis, UAA-3-1 might constitute type-I Rhamnogalacturonan (RG-I), Gal and Ara have several complex connections. The 13C-NMR result showed that UAA-3-2 might constitute Homogalacturonan (HG) linked toα-(1,4)-GalA.