ABSTRACT
To study the effects of Nelumbinis Receptaculum (the seedpod of Nelumbo nucifera) extract (NRE) on insulin resistance (IR) in type 2 diabetic rats. The experimental type 2 diabetic rats were established by high-fat diet for 4 weeks and injected with low dose of streptozotocin (STZ, 30 mg/kg). After intervention by ig administration of NRE in low, medium, and high dose groups (100, 300, and 500 mg/kg) for 5 weeks, the effects of NRE on the levels of fasting blood glucose (FBG), fasting insulin (FINS), total cholesterol (TC), triglycerides (TG), high density lipoproteins cholesterol (HDL-C), low density lipoproteins cholesterol (LDL-C), the activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and hexokinase (HK), the levels of liver glycogen, muscle glycogen, liver malondialdehyde (MDA), reduced glutathione (GSH), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT), plasma leptin, and TNF-α were observed. The insulin sensitivity index (ISI) and IR were calculated accordingly. NRE could decrease the levels of FBG, increase ISI, reduce the levels of IR, plasma leptin, and TNF-α (P < 0.05 or P < 0.01) in type 2 diabetic rats. The dyslipidemia (TC, TG, HDL-C, and LDL-C) and hepatic metabolism (TC, TG, ALT, and AST) could be improved by NRE (P < 0.05 or P < 0.01). NRE could increase the GSH level and antioxidant enzymes activities, and decrease MDA level. In addition, NRE could increase the glycogens content and HK activity. NRE could improve the IR in the experimental type 2 diabetic rats. It might be related to its effects on improving dyslipidemia, hepatic metabolism, and antioxidant capacity of hepatic tissue, as well as reducing leptin and TNF-α levels.
ABSTRACT
Objective: To study the contents of proanthocyanidins in Nelumbinis Receptaculum (NR) obtained from the different regions and harvest times, so as to determine the appropriate harvest times and proper planting regions of NR as well as provide the support for the reasonable use of NR. Methods: Twelve regions and six different harvest periods in Zhejiang were collected and the contents of proanthocyanidins were determined by UV spectrophotometry. Results: Maturity had great influence on the contents of proanthocyanidins, The mature had much more proanthocyanidins than the young. Different drying methods had influence on the contents of proanthocyanidins, among which oven drying method has the least influence, followed by drying in the shade, then suning method has the most influence. There was a certain difference in the contents of proanthocyanidins in NR from the different regions and harvest times with a characteristic interval fluctuations. Conclusion: Mature NR should be collected consistent with lotus seeds, the NR should be dried in dryer or in shade, avoid exposing to the sun. The contents of proanthocyanidins in NR from different regions and picking times change in the variation range of 6% to 8%. Wide origin places have been demonstrated suitable to providing the raw materials for industrial production and NR collection is appropriate from the middle of July to September.
ABSTRACT
OBJECTIVE:To study the purification technology of total flavonoids from Nelumbinis receptaculum by macropo-rous resin. METHODS:Using adsorption rate and desorption rate of total flavonoids from Nelumbinis receptaculum as index,the type of macroporous resin was selected by static adsorption-desorption tests;With adsorption rate of total flavonoids as index,sin-gle factor test was used to investigate the effects of the concentration of total flavonoids,adsorption time,adsorption speed, drug-loading amount,water amount,volume fraction and amount of eluant and other factors on the purification technology. The op-timal technology was validated. RESULTS:Among 10 kinds of resin,HPD-400 macroporous resin was found to have the best ad-sorption and desorption effects. The optimal purification conditions was as follows as the concentration of total flavonoids 7.00 mg/ml, adsorption time of 3 h,flow rate for sampling of 3 column volume (BV)/h,drug-loading amount of 8 BV,water amount of 6 BV,50% ethanol elution amount of 4 BV. In validation test,mass fraction of total flavonoids from purified Nelumbinis receptacu-lum were 63.88%,62.50% and 63.44%(RSD=1.11%,n=3). CONCLUSIONS:HPD-400 macroporous resin could purify total flavonoids from purified Nelumbinis receptaculum,and established purification technology is stable and practical.