Cholesterol-Modified Amino-Pullulan Nanoparticles as a Drug Carrier: Comparative Study of Cholesterol-Modified Carboxyethyl Pullulan and Pullulan Nanoparticles.

To search for nano-drug preparations with high efficiency in tumor treatment, we evaluated the drug-loading capacity and cell-uptake toxicity of three kinds of nanoparticles (NPs). Pullulan was grafted with ethylenediamine and hydrophobic groups to form hydrophobic cholesterol-modified amino-pullulan (CHAP) conjugates. Fourier transform infrared spectroscopy and nuclear magnetic resonance were used to identify the CHAP structure and calculate the degree of substitution of the cholesterol group. We compared three types of NPs with close cholesterol hydrophobic properties: CHAP, cholesterol-modified pullulan (CHP), and cholesterol-modified carboxylethylpullulan (CHCP), with the degree of substitution of cholesterol of 2.92%, 3.11%, and 3.46%, respectively. As compared with the two other NPs, CHAP NPs were larger, 263.9 nm, and had a positive surface charge of 7.22 mV by dynamic light-scattering measurement. CHAP NPs showed low drug-loading capacity, 12.3%, and encapsulation efficiency of 70.8%, which depended on NP hydrophobicity and was affected by surface charge. The drug release amounts of all NPs increased in the acid media, with CHAP NPs showing drug-release sensitivity with acid change. Cytotoxicity of HeLa cells was highest with mitoxantrone-loaded CHAP NPs on MTT assay. CHAP NPs may have potential as a high-efficiency drug carrier for tumor treatment.

Separation of phenolic acids and flavonoids from Trollius chinensis Bunge by high speed counter-current chromatography.

In this work, eleven compounds were successfully separated from Trollius chinensis Bunge by using a two-step high-speed counter-current chromatography (HSCCC) method. NRTL-SAC (nonrandom two-liquid segment activity coefficient) method, a newly developed solvent system selection strategy, was applied to screening the suitable biphasic liquid systems. Hexane/ethyl acetate/ethanol/water (3:7:3:7, v/v) solvent system was used in the first step, while the hexane/ethyl acetate/methanol/water (1:2:1:2, 1:4:1:4, 1:9:1:9, v/v) systems were employed in the second step. The chemical structures of the separated compounds were identified by UV, high resolution ESI-MS and MS/MS data. The separated compounds are 3,4-dihydroxyphenylethanol (1), vanillic acid (2), orientin (3), vitexin (4), veratric acid (5), 2″-O-(3‴, 4‴-dimethoxybenzoyl) orientin (6), 2″-O-feruloylorientin (7), 2″-O-feruloylvitexin (8), 2″-O-(2‴-methylbutyryl) vitexin (9), 2″-O-(2‴-methylbutyryl) isoswertiajaponin (10), 2″-O-(2‴-methylbutyryl) isoswertisin (11). The results demonstrate that HSCCC is a powerful tool for the separation of compounds from extremely complex samples.

Novel on-line column extraction apparatus coupled with binary peak focusing for high-performance liquid chromatography determination of rifampicin in human plasma: a strategy for therapeutic drug monitoring.

In order to develop a method that is completely suitable for the routine therapeutic drug monitoring, a sensitive and fully automated on-line column extraction apparatus in combination with high-performance liquid chromatography allowing binary peak focusing was developed and validated for the determination of rifampicin in human plasma. Rifapentine was used as an internal standard. The analytical cycle started with the injection of 100 µL of the sample pretreated by protein precipitation in a Venusil SCX extraction column. After the elution, the analytes were transferred and concentrated in an Xtimate C18 trap column. Finally, the trapped analytes were separated by an Xtimate C18 analytical column and were analyzed by an ultraviolet detector at 336 nm. With this new strategy, continuous on-line analysis of the compounds was successfully performed. The method showed excellent performance for the analysis of rifampicin in plasma samples, including calibration curve linearity (All r were larger than 0.9996), sensitivity (lowest limit of quantification was 0.12 µg/mL), method accuracy (within 6.6% in terms of relative error), and precision (relative standard deviations of intra- and interday precision were less than 7.8%). These results demonstrated that the simple, reliable, and automatic method based on on-line column extraction and binary peak focusing is a promising approach for therapeutic drug monitoring in complex biomatrix samples.

Hypolipidemic effect of the Chinese polyherbal Huanglian Jiedu decoction in type 2 diabetic rats and its possible mechanism.

Huanglian Jiedu Decoction (HLJDD) is used traditionally in China for the treatment of diabetes mellitus in clinical practice, which has been proved to be effective. In present investigation, the 3D-HPLC fingerprint of HLJDD and the contents of main components (namely berberine, baicalin and geniposide) contained in the extract of HLJDD were assayed with high performance liquid chromatography (HPLC). Type 2 diabetic rats were induced by high fat diet and streptozotocin. Type 2 diabetic rats were treated with HLJDD extract for 30d, while blood glucose and body weight were monitored during the experiment. At the end of experiment, the levels of total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C) were assayed. Intestinal mucosa homogenate was prepared and the activity of pancreatic lipase was analyzed. Moreover, the olive oil loading test (OOLT) was performed and the inhibitory effect of HLJDD extract on the pancreatic lipase in vitro was evaluated. The results showed that, after the treatment of HLJDD extract, the final body weight and the levels of fasting plasma glucose, TC, TG and LDL-C were significantly reduced while the HDL-C level was increased in type 2 diabetic rats. The OOLT showed that HLJDD extract could lower the postprandial plasma TG level of type 2 diabetic rats. The activity of pancreatic lipase in type 2 diabetic rats was decreased after the treatment of HLJDD extract. Moreover, HLJDD extract could inhibit the activity of pancreatic lipase in vitro. In conclusion, the TCM prescription HLJDD possessed potent lipid-modulating effect on type 2 diabetic rats. And HLJDD extract exerted hypolipidemic effects partly via inhibiting the increased activity of intestinal pancreatic lipase in type 2 diabetic rats.

Antihyperglycemic effect of the traditional Chinese scutellaria-coptis herb couple and its main components in streptozotocin-induced diabetic rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Scutellaria-coptis herb couple (SC) is the main herb couple in many traditional Chinese compound formulas used for the treatment of diabetes mellitus, which has been used to treat diabetes mellitus for thousands of years in China. In this study we provide experimental evidence for the clinical use of SC in the treatment of diabetes mellitus. AIM OF THE STUDY: To confirm the anti-diabetic effect of SC extract and its main components, and to explore its mechanism from the effect on intestinal disaccharidases by in vivo and in vitro experiment. MATERIALS AND METHODS: SC extract was prepared and the main components (namely berberine and baicalin) contained in the extract were assayed with high performance liquid chromatography (HPLC). And diabetic model rats were induced by intraperitoneal injection of streptozotocin (STZ). After grouped randomly, diabetic rats were administered SC extract, berberine, baicalin, berberine+baicalin, acarbose and vehicle for 33d, respectively. Body weight, food intake, urine volume, urine sugars, fasting plasma glucose and fasting plasma insulin were monitored to evaluate the antidiabetic effects on diabetic rats. Intestinal mucosa homogenate was prepared and the activities of intestinal disaccharidases were assayed. Moreover, oral sucrose tolerance test (OSTT) was performed and the inhibitory effects of SC extract and its main components (berberine and baicalin) on the maltase and sucrase in vitro was evaluated. RESULTS: After the treatment of SC extract and its main components, the body weight and the fasting plasma insulin level were found to be increased while food intake, urine volume, urine sugars and fasting plasma were decreased. OSTT showed that SC extract and its main components could lower the postprandial plasma glucose level of diabetic rats. Furthermore, SC extract and its main components could inhibit the activities of intestinal disaccharidases in diabetic rats, whereas only SC extract and berberine could inhibit the activity of maltase in vitro. CONCLUSIONS: According to our present findings, scutellaria-coptis herb couple (SC) possessed potent anti-hyperglycemic effect on STZ-induced diabetic rats. And SC extract and its main components exerted anti-hyperglycemic effect partly via inhibiting the increased activities of intestinal disaccharidases and elevating the level of plasma insulin in diabetic rats induced by STZ.

[Isolation and identification of brine shrimp lethal activities from Derris trifoliata].

OBJECTIVE: To study the brine shrimp lethal activities of the roots and stems from Derris trifoliata. METHODS: The biological activity of the athyl acetate extract was tested by the 2nd-instar of Artemia franciscana by the method of Silica gel column chromatography, Sephadex LH-20 column chromatography, Semipreparative HPLC, and their structures were elucidated by spectral analysis. RESULTS: Eleven compounds were isolated from the athyl acetate extract, and LD50 s of 12a-hydroxyrotenone, tephrosin, rotenone and deguelin were 0.365, 0.236, 0.060 and 0.734 microg/mL, respectively. CONCLUSION: The results of bioassay show that 12a-hydroxyrotenone, tephrosin,rotenone and deguelin have strong brine shrimp lethal activity.

Anti-hyperglycemic effects and mechanism of traditional Chinese medicine Huanglian Wan in streptozocin-induced diabetic rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Huanglian Wan (HLW) is a prescription of traditional Chinese medicine (TCM), which has been used to treat diabetes mellitus for thousands of years in China. In this study we provide experimental evidence for the clinical use of HLW in the treatment of diabetes mellitus. MATERIALS AND METHODS: HLW extract was prepared and the main components (namely berberine and catalpol) contained in the extract were assayed with high performance liquid chromatography (HPLC), and diabetic model rats were induced by intraperitoneal injection of streptozotocin (STZ). After grouped randomly, diabetic rats were administered low or high dose of HLW extract, acarbose and vehicle for 33 days, respectively. Body weight, food intake, urine volume, urine sugars, fasting plasma glucose and fasting plasma insulin were monitored to evaluate its antidiabetic effects in diabetic rats. Intestinal mucosa homogenate was prepared and the activities of intestinal disaccharidases were assayed. Moreover, oral sucrose tolerance test (OSTT) was performed and the inhibitory effect of HLW extract on the maltase and sucrase in vitro was evaluated. RESULTS: After the treatment of HLW extract, the body weight and the fasting plasma insulin level were found to be increased while food intake, urine volume, urine sugars and fasting plasma were decreased. OSTT showed that HLW extract could lower the postprandial plasma glucose level of diabetic rats. Furthermore, HLW extract could inhibit the activities of sucrase and maltase in vitro. CONCLUSIONS: According to our present findings, the TCM prescription HLW possessed potent anti-hyperglycemic effect on STZ-induced diabetic rats. And HLW extract exerted anti-hyperglycemic effect partly via inhibiting the increased activities of intestinal disaccharidases and elevating the level of plasma insulin in diabetic rats induced by streptozotocin.

A new prenylated flavanone from Derris trifoliata Lour.

A new flavanone, 4',5,7-trihydroxy-6,8-di-(2-hydroxy-3-methylbut-3-enyl)- flavanone, was isolated from the aerial parts of Derris trifoliate, together with eleven known compounds: rotenone, tephrosin, 12a-hydroxyrotenone, deguelin, 6a,12a-dehydro-rotenone, dehydrodeguelin, 7a-O-methyldeguelol, 7a-O-methylelliptonol, 5,7,3',4'-tetra-hydroxy-6,8-diprenylisoflavone, daidzein and 4'-hydroxy-7-methoxyflavanone. 7a-O-Methylelliptonol was isolated for the first time from the genus Derris. Their structures were characterized on the basis of spectral data. Eight of the isolated compounds were found to be significantly toxic to brine shrimp (LC(50) range 0.06-9.95 µg/mL). The new compound showed weak toxicity (LC(50) = 211.31 µg/mL).

Comparative pharmacokinetics of baicalin in normal and the type 2 diabetic rats after oral administration of the Radix scutellariae extract.

Radix scutellariaewas used alone or in combinationwith othermedicinal herbs in the treatment oftype 2 diabetes mellitus in China. At present, the pharmacokinetics of baicalin in type 2 diabeticrats following oral administration of Radix scutellariae extract was investigated. The resultsshowed that the pharmacokinetics (especially AUC) of baicalin in type 2 diabetic rats after oraladministration of Radix scutellariae extract was remarkably different from that in normal rats.Then the mechanism which resulted in the increased AUC of baicalin in diabetic rats wasinvestigated from system clearance and presystemic metabolism. And it was found that theincreased AUC of baicalin in diabetic rats at least partly resulted from higher production ofbaicalein in the intestinal tract of type 2 diabetic rats.Moreover, the activity of ß-glucuronidase inintestinal mucosa of type 2 diabetic rats was demonstrated to be higher than that in normal rats,which confirmed the results above. In conclusion, the pharmacokinetic behavior of baicalin wassignificantly altered in type 2 diabetic rats after orally administrated Radix scutellariae extract,which may partly result from the increased activity of intestinal ß-glucuronidase under thepathological state of type 2 diabetes mellitus.

Polysaccharide from Gynura divaricata modulates the activities of intestinal disaccharidases in streptozotocin-induced diabetic rats.

During diabetes, structural and functional changes in the alimentary tract are known to take place resulting in an increased absorption of intestinal glucose and alterations in the activities of brush-border disaccharidases. To elucidate the effect of administrating polysaccharide from Gynura divaricata (PGD) on disaccharidase activities, the specific activities of intestinal disaccharidases, namely sucrase, maltase and lactase, were measured in streptozotocin-induced diabetic rats. Normal control and diabetic rats were treated by oral administration with PGD. Specific activities of intestinal disaccharidases were increased significantly during diabetes, and amelioration of the activities of sucrase and maltase during diabetes was clearly visible by the treatment with PGD. However, the increased activity of lactase during diabetes mellitus was remarkably alleviated by the administration of PGD only in the duodenum. Meanwhile, oral sucrose tolerance tests demonstrated that PGD alleviated the hyperglycaemia during diabetes mellitus, resulting from the amelioration in the activities of intestinal disaccharidases. The present investigation suggests that PGD exerted an anti-diabetic effect partly via inhibiting the increased intestinal disaccharidase activities of diabetic rats. This beneficial influence of administration of PGD on intestinal disaccharidases clearly indicates their helpful role in the management of diabetes.