The Quality Evaluation Of Hippophae Rhamnosides L. Leaves And Its Function Research Of Antilipidemic And Antifatigue

Sea buckthorn leaf, with rich active ingredients and high nutritional value, belongs to the genus Hippophae, the family of Elaeagnaceae.There are 7 species and 11 subspecies of the genus Hippophae throughout the world, which distribute widely in Northern China, northwest and southwest of China with 7 species and 7 subspecies. Fruits are recorded as the medicinal parts in 2010 Chinese Pharmacopoeia, and flavonoids is the main active components.Studies haveshown that flavonoids in Sea buckthorn leaves were higher than that in fruits and the resources are more abundant. Therefore, Sea buckthorn leaveswere selected as research materialsin this topic, the qualities of which from different origins were evaluated and the activities of reducing blood fat and relieving fatigue were studied.The main results are as follows:1. HPLC fingerprint was first established to evaluate the qualities of Sea buckthorn leaves collected from different origins. Chemometrics methods(similarity evaluation, cluster analysis, principal component analysis) were applied to statistic analysis the 16 characteristic peakareasin fingerprints andrutin, isoquercetin, narcissoside, isorhamnetin-3-O-glucoside, quercetin, kaempferol, isorhamnetin were quantitative analyzed by HPLC.UHPLC-QTOF-MS/MS was utilized to identify the compounds in Sea buckthorn leaves. Results have shown that sea buckthorn leaves varied significantly different regions and these 21 batches of sea buckthorn leaves were divided into three groups by cluster analysis. Among them, the sea buckthorn leaves in southwest region(Sichuan, Yunnan, Tibet, southern of Qinghai) showed lower contents of flavonoids, which may effected by southwest monsoon. The Sea buckthorn leaves collected in the month of 5-6 from Qinghai and Gansu showed higher contents of flavonoids and classified into the same cluster. The results of principal component analysis(PCA) were similar to the results of cluster analysis, and 12 compounds were identified as flavonoids by UHPLC-QTOF-MS/MS.2. Single factor and orthogonal experiment were adopted to optimizedthe extraction process of Sea buckthorn leaf flavnoids(isorhamnetinas index component), and the factors of ethanol concentration, extraction temperature, extraction time and solid-liquid ratio were selected. Results showed that ethanol concentration influenced most, followed by extraction time, extraction temperature and solid-liquid ratio. The optimum extraction processare as follows: 70% ethanol reflux extraction twice at 80℃(120 min at the first time; 90 min at the second time), and material liquid ratios were 1:10 and 1:8, respectively.3. The healthcare functions of reducing blood fat and relieving fatigue of sea buckthorn leaves were studied in this topic. Diet-induced hyperlipidemia models in rats were established and sea buckthorn leaves ethanol extracts were given by intragastric administration for 30 days. Results showed that the rise of serum TG, TC, LDL caused by high-fat diet were obviously inhibited and HDL level increased to some extent, which demonstrated that sea buckthorn leaf extraction has the ability to improve disorders of the blood lipid level in hyperlipidemia rats and control theweight gain of rats to some extent.The activity of relieving sports fatigue of sea buckthorn leaves was reported for the first time and the low, medium and high dose groups of water extraction of which significantly extend mice loading swimming time. Among them, high dose group of sea buckthorn leaves water extraction could significantly improve liver glycogen stores and reduce the areas under blood lactic acid curves, which showed strong activity of relieving fatigue. These studies provide reliable theoretical basis for the development and utilization of sea buckthorn leaves health food.4. In addition, content variations of four kinds of flavonoid glycosides in Hippophae rhamnoides L. leaves before and after fermentation were determined by RP-HPLC. The contents of Rutin decreased while the contents of isoquercitrin increased, which may due to the loss a rhamnose from Rutin.The research above provides a reliable source and quality assurance for development and utilization of sea buckthorn leaves. The total flavnoids and isorhamnetin of ten batches of sea buckthorn leaves were determinated andthe quality standard with total flavonoids and isorhamnetin contents were established with no less than 0.4% and 0.12%, respectively.The standard of isorhamnetin in leaves was slightly higher than that in the fruits recorded in Pharmacopoeia.