Effects of triterpenic acid from Prunella vulgaris L. on glycemia and pancreas in rat model of streptozotozin diabetes

Background The effects of triterpenic acid from Prunella vulgaris L. （TAP） on diabetes and its mechanism are uncertain. The aim of this study was to investigate the effects of TAP on antihyperglycemic, antioxidant, and pancreas-protective in streptozotozin （STZ）-diabetic rats. Methods The diabetic model was produced by injection of 60 mg/kg STZ. Blood was drawn from the tail vein of rats after 72 hours. Rats with blood glucose 〉16.7 mmol/L were considered diabetic. Diabetic rats were randomly divided into four groups： （1） Diabetes rat （STZ）, （2） Diabetic rats treated with 50 mg/kg of triterpenic acid from Prunella vulgaris L （STZ＋TAP50）, （3） Diabetic rats treated with 100 mg/kg TAP （STZ＋TAP100）, and （4） Diabetic rats treated with 200 mg/kg TAP （STZ＋TAP200）. Normal rats （n=10） acted as the control group （NC）. TAP was administered by the intragastric route once each day for six weeks. Body weight and the concentration of blood glucose （BG） were measured after three and six weeks. Fructosamine （FMN）, malondialdehyde （MDA）, and nitric oxide （NO）, and the activities of nitric oxide synthase （NOS） and superoxide dismutase （SOD） in serum were determined after six weeks using commercially available kits following the manufacturer＇s instructions. Pathologic changes in pancreatic β-cells were also investigated by microscopic examination after hematoxylin-eosin （HE） staining. The level of SOD mRNA in pancreatic β-cells was measured by polymerase chain reaction （PCR）. Results The levels of BG, FMN, NO, and MDA and the activities of NOS in serum in the four diabetes groups were significantly increased compared with the control group （P 〈0.01）. The activity of SOD in serum and the body weight was significantly decreased compared with the control group （P 〈0.01）. After administration of TAP to diabetic rats for six weeks, the body weight and the levels of BG, FMN, MDA, NO and the activity of NOS in serum decreased significantly compared with the STZ group in a dose-dependent manner. The activity of SOD in serum and body weight increased significantly compared with the STZ group in a dose-dependent manner. In addition, diabetic rats showed a significant decrease in SOD mRNA expression in pancreatic β cells. However, these changes were reversed by TAP. Histopathological examination also showed the protective effect of TAP on pancreatic β cells. Conclusions Triterpenic acid from Prunella vulgaris L. has an anti-diabetic effect, by controlling blood glucose and antioxidants, and has a protective effect on the pancreas.

Simultaneous determination of oleanolic acid and ursolic acid by RP-HPLC in the leaves of Eriobotrya japonica Lindl

Oleanolic acid(OA) and ursolic acid(UA) are isomeric triterpenic acids and only one methyl’s position is different between them.OA and UA always exist in the same plant,so it is difficult to separate them when determining contents by RP-HPLC.In this study,a very simple mobile phase for HPLC was developed to simultaneously determine UA and OA,and the factors affecting separation were also discussed.The mobile phase is methanol:water(95:5) with flow rate 0.4 mL/min.The retention time for OA and UA was 20.58 and 21.57 min,respectively,the resolution was 1.61.The average contents of OA and UA of three Loquat leaves sets were 1.4 mg/g and 5.6 mg/g,respectively.Regarding the HPLC,we found that changing mobile phase,adjusting the pH value or adding ion-pairing agent could not affect the separation between UA and OA greatly.While adjustment of the flow rate and column temperature could improve the resolution greatly.

Triterpene Acids from Cynoglossum amabile

Cynoglossum amabile Stapf et Drumm is widely distributed in southern China, which has been used as an anti-inflammatory, antihepatitis, anticystitis agent in Chinese folk medicine. However, only a few phytochemical researches have been performed . Therefore, a systematic chemical investigation of it was carried out. In this work, we further investigated the chemical constituents and ten compounds were obtained, three of which were triterpene acids.

Two New Pentacyclic Triterpenes from Sabia parviflora

Two new pentacyclic triterpene acids, 1a, 3b-dihydroxyl-olean-12-en-28-oic acid and 1a, 2a, 3b-trihydroxyl-olean-12-en-28-oic acid, were isolated from the arial parts of Sabia parviflora.

Thin Layer Chromatography and Chemometric Studies of Selected Potentilla Species

Herbal medicinal products have a long-standing therapeutic record. To ensure the quality of herbal products specific identification tests which allow experts to discriminate related species and/or potential adulterants/substitutes are required. The purpose of the research was to recommend an original and simple method for the separation of closely related five triterpenic acids (ursolic, oleanolic, tormentic, euscaphic, pomolic acid) and its application to chemotaxonomy studies. 17 standard samples of Potentilla species and 3 test samples were chromatographed (with or without prechromatographic derivatization) on silica gel plates using the mobile phase: chloroform-diethyl ether-methanol-formic acid (30:10:1:0.2 v/v/v/v);they were subsequently derivatized, and visualized in UV 366 nm light. After images received pre-treatment (montaging stack, removal of noise, background subtract, horizontal equalization, two types of warping) exploratory analysis of the investigated Potentilla species fingerprints was processed. The method without prechromatographic derivatization was used to create differential fingerprints. Good results were obtained by the application of r-project iterative algorithm for subtract background and our simple algorithm for warping to image processing of TLC chromatograms for the first time.

Total Triterpene Acids,Isolated from Corni Fructus,Ameliorate Progression of Renal Damage in Streptozotocin-Induced Diabetic Rats

Objective： To investigate whether total triterpene acids （TTAs）, isolated from Comus Fructus, attenuates renal function by reducing oxidative stress and down-regulating the expression of transforming growth factor β1 （TGF- β1）. Methods： Diabetes was induced by an injection of streptozotocin （40 mg/kg intravenously）. Thirty rats were randomly divided into three groups： control group, diabetic model group and l-rAs treatment group （50 mg/kg, intragastrically） administrated for 8 weeks from 5th to 12th week. All rats were anaesthetized and then were killed to remove kidneys. The renal function and redox enzyme system parameters were tested. Glomerular morphology was observed by a light microscopy. Immunohistochemistry and Western blot assays were employed to determine the protein levels of TGF- β1. Results： TTAs attenuated the levels of urinary protein, serum creatinine and blood urea nitrogen, although it did not significantly reduce the level of glucose. In addition, TTAs decreased the malondialdehyde while increased superoxide dismutase, catalase and glutathione peroxide activities in diabetic rats. The renal pathological changes in TTAs treatment group were ameliorated. Furthermore, TTAs also ameliorated the expression of TGF- β1. Conclusion： TTAs improved renal function via reducing oxidative stress and down-regulation the expression of TGF- β1 in diabetic rats.

Synthesis and biological evaluation of echinocystic acid derivatives as HCV entry inhibitors

A series of echinocystic acid （EA） 28-COOH derivatives was synthesized, and their anti-HCV entry activity was evaluated by HCVpp and VSVpp entry assay. It was found that some of them showed moderate anti-HCV entry activity, especially compound 12, and these modifications also removed the undesired hemolytic effect.

Tyrosinase Inhibitory Activity of Total Triterpenes and Poricoic Acid A Isolated from Poria cocos

Objective With the improvement of people＇s living standards, people＇s requests for beauty are increasing. Skin whitening and lightening have become the pursuit of many women, and whitening and removing freckles have become the focus of scientific research. At present, widely used whitening agents, such as kojic acid, vitamin C, and its derivatives, have shortcomings such as poor stability and retarded effect. Therefore, safer and more effective whitening products from herbs are urgently needed. To explore the possibility of triterpenes as whitening active substance, the effects of total triterpenes of Poria（TTP） and poricoic acid A（PAA） on mushroom tyrosinase activities and B16 cells were investigated, and their mechanisms on mushroom tyrosinase were also studied. Methods Using arbutin and nicotinamide as reference substances, we determinated the inhibitory effects of TTP and PAA on mushroom tyrosinase and tyrosinase in B16 cells and then studied the inhibitory mechanism on mushroom tyrosinase. Results TTP and PAA exhibited good inhibitory effects on the activities of monophenolase and diphenolase in mushroom tyrosinase, as well as a certain inhibitory effect on tyrosinase in B16 cells. Conclusion TTP and PAA are potential whitening active ingredients.