Salvianolic acid A attenuates steroid resistant nephrotic syndrome through suPAR/uPAR-αvβ3 signaling Inhibition

ETHNOPHARMACOLOGICAL RELEVANCE

Salvianolic acid A (SAA) is extracted from traditional Chinese medicine Salvia miltiorrhiza and is the main water-soluble and the biologically active ingredient. SAA possesses a variety of pharmacological activities and has an excellent protective effect on kidney disease, especially steroid resistant nephrotic syndrome (SRNS), and has advantages in improving the efficacy of glucocorticoids, but its mechanism needs to be further explored.

PURPOSE

The study was designed to explore the effect of suPAR and uPAR in SRNS patients and evaluate the potential effect of SAA in improving podocyte steroid resistance and explore its mechanism.

METHODS AND MATERIALS

The ELISA kits were used to detect the levels of suPAR in the blood and urine of subjects. The levels of uPAR, GRα, and GRβ expression in renal tissues of SRNS patients was detected by immunohistochemistry and analyzed using the Pearson method. In vitro studies, steroid resistance model was induced by the TNF-α and IFN-γ. The protein and mRNA expression of Nephrin, GR, GRα and GRβ were analyzed using western blot and qRT-PCR. The activity of GR-DNA binding was detected by using TransAM™ GR kits. Adriamycin further induced steroid resistance podocyte. Flow cytometry was used to detect the effect of SAA on podocyte apoptosis. ELISA assay was used to detect the suPAR expression in the podocyte supernatant. Western blot and qRT-PCR were used to detect the protein and mRNA expression of uPAR and Nephrin in podocytes.

RESULTS

The serum and urine levels of suPAR were conspicuously higher in SRNS patients than healthy volunteers and SSNS patients, and the expression of uPAR in renal tissue of SRNS patients is negatively correlated with GRα, but positively correlated with GRβ. The combination of TNF-α and IFN-γ could conspicuously increase the GRβ expression and reduce GRα/GRβ, and induce steroid resistance in podocytes. Moreover, we found that SAA could reduce the apoptosis of podocytes and suppress the expression of suPAR/uPAR, and increase the expression of Nephrin.

CONCLUSION

The level of suPAR and uPAR expression may have important value in predicting glucocorticoids resistance in patients with idiopathic nephrotic syndrome (INS). The combination of TNF-α and IFN-γ induce podocytes can establish steroid resistance model in vitro. SAA could improve glucocorticoids resistance of podocyte which can be attributed in part to regulate the suPAR/uPAR-αvβ3 signaling pathway.

The attenuation of HIV-1 Tat-induced neurotoxicity by Salvianic acid A and Danshen granule

The neurotoxicity of HIV-1 Tat protein contributes significantly to the pathogenesis of HAND, and hence the attractive therapeutic strategies focusing on Tat-induced neurotoxicity are warranted. Salvia miltiorrhiza have been known to antioxidant property and neuroprotective effects. The Danshen granule is the pharmaceutical dosage forms of Salvia miltiorrhiza and Salvianic acid A is an essential chemical constituent of Salvia miltiorrhiza. However, the protective effects of Salvianic acid A and Danshen granule on Tat-induced neurotoxicity remain unknown. Here, we found that Salvianic acid A and Danshen granule remarkable inhibited Tat-induced cell death, blocked LDH release and rescued dendritic spine loss. Furthermore, Salvianic acid A and Danshen granule significantly ameliorates Tat-induced intracellular ROS and MDA production, attenuates cell apoptosis. In addition, Salvianic acid A and Danshen granule pretreatment obviously increases antioxidant enzymatic activity of CAT, SOD and GSH-Px and inhibits apoptotic pathways. In conclusion, this study demonstrated that Salvianic acid A and Danshen granule provides substantial neuroprotection against Tat-induced neurotoxicity, which may be new therapeutic agent in Tat induced HAND or neurodegenerative diseases.

Salvianolic acids from antithrombotic Traditional Chinese Medicine Danshen are antagonists of human P2Y1 and P2Y12 receptors

Many hemorheologic Traditional Chinese Medicines (TCMs) that are widely-used clinically lack molecular mechanisms of action. We hypothesized that some of the active components of hemorheologic TCMs may function through targeting prothrombotic P2Y1 and/or P2Y12 receptors. The interactions between 253 antithrombotic compounds from TCM and these two G protein-coupled P2Y receptors were evaluated using virtual screening. Eleven highly ranked hits were further tested in radioligand binding and functional assays. Among these compounds, salvianolic acid A and C antagonized the activity of both P2Y1 and P2Y12 receptors in the low µM range, while salvianolic acid B antagonized the P2Y12 receptor. These three salvianolic acids are the major active components of the broadly-used hemorheologic TCM Danshen (Salvia militorrhiza), the antithrombotic molecular mechanisms of which were largely unknown. Thus, the combination of virtual screening and experimental validation identified potential mechanisms of action of multicomponent drugs that are already employed clinically.

Longterm storage of post-packaged bread by controlling spoilage pathogens using Lactobacillus fermentum C14 isolated from homemade curd

One potent lactic acid bacterial strain C14 with strong antifungal activity was isolated from homemade curd. Based on morphological as well as biochemical characters and 16S rDNA sequence homology the strain was identified as Lactobacillus fermentum. It displayed a wide antimicrobial spectrum against both Gram-positive and Gram-negative pathogenic bacteria, and also against number of food spoilage, plant and human pathogenic fungi. The cell free supernatant (CFS) of the strain C14 was also effective against the fungi tested. Inhibition of radial growth of Penicillium digitatum, Trichophyton rubrum and Mucor sp. was noticed in the presence of CFS of C14 even at low concentration (1%). More than 94.3 ± 1.6% and 91.5 ± 2.2% inhibition of conidial germination of P. digitatum and Mucor sp. were noticed in the presence of 10-fold-concentrated CFS of C14. Massive deformation of the fungal mycelia was observed by SEM studies, and losses of cellular proteins and DNA are also evident upon its treatment with C14. HPLC analysis revealed the presence of phenyl lactic acid, lactic acid along with some unidentified compounds in the antifungal extract. Challenge experiment showed immense potential of the strain C14 in preventing the spoilage of bread samples caused by Mucor sp. and Bacillus subtilis. The bread samples remained fresh upto 25 days even after inoculation with Mucor sp. (3.7 × 104 spores /ml) and B. subtilis (4.6 × 104 CFU /ml). Along with the antifungal properties, the isolated lactic acid bacterial strain also showed very good antioxidant activities. Unchanged level of liver enzymes serum glutamic pyruvic transaminase and serum glutamic oxaloacetic transaminase in albino mice upon feeding with C14 also suggested non-toxic nature of the bacterial isolate.

Efficient magnesium lactate production with in situ product removal by crystallization

In this paper, attempts were made to develop an in situ product removal process for magnesium lactate production based on crystallization. The crystallization was conducted at 42°C without seed crystal addition. The product concentration, productivity and yield of fermentation coupled with in situ product removal (ISPR) reached 143 g L(-1), 2.41 g L(-1)h(-1) and 94.3%. In four cycles of crystallization, the average reuse rate of fermentation medium and removal rate of product reached 64.0% and 77.7%. At the same time, ISPR fermentation saved 40% water, 41% inorganic salts and 43% yeast extract (YE) as compared to fed-batch fermentation. The process introduces an effective way to reduce the amount of waste water and the raw material cost in magnesium lactate fermentation.

Efficient calcium lactate production by fermentation coupled with crystallization-based in situ product removal

Lactic acid is a platform chemical with various industrial applications, and its derivative, calcium lactate, is an important food additive. Fermentation coupled with in situ product removal (ISPR) can provide more outputs with high productivity. The method used in this study was based on calcium lactate crystallization. Three cycles of crystallization were performed during the fermentation course using a Bacillus coagulans strain H-1. As compared to fed-batch fermentation, this method showed 1.7 times higher average productivity considering seed culture, with 74.4% more L-lactic acid produced in the fermentation with ISPR. Thus, fermentation coupled with crystallization-based ISPR may be a biotechnological alternative that provides an efficient system for production of calcium lactate or lactic acid.

Salvianolic acid A protects against vascular endothelial dysfunction in high-fat diet fed and streptozotocin-induced diabetic rats

Salvianolic acid A (SalA) is one of the main active ingredients of Salvia miltiorrhizae. The objective of this study was to evaluate the effect of SalA on the diabetic vascular endothelial dysfunction (VED). The rats were given a high-fat and high-sucrose diet for 1 month followed by intraperitoneal injection of streptozotocin (30 mg/kg). The diabetic rats were treated with SalA (1 mg/kg, 90% purity) orally for 10 weeks after modeling, and were given a high-fat diet. Contractile and relaxant responses of aorta rings as well as the serum indications were measured. Our results indicated that SalA treatment decreased the level of serum Von Willebrand factor and ameliorated acetylcholine-induced relaxation and KCl-induced contraction in aorta rings of the diabetic rats. SalA treatment also reduced the serum malondialdehyde, the content of aortic advanced glycation end products (AGEs), and the nitric oxide synthase (NOS) activity as well as the expression of endothelial NOS protein in the rat aorta. Exposure of EA.hy926 cells to AGEs decreased the cell viability and changed the cell morphology, whereas SalA had protective effect on AGEs-induced cellular vitality. Our data suggested that SalA could protect against vascular VED in diabetes, which might attribute to its suppressive effect on oxidative stress and AGEs-induced endothelial dysfunction.

[Research progress of salvianolic acid A]

Salvianolic acid A is a water-soluble component from Danshen, which is frequently used in traditional Chinese medicine. High performance liquid chromatography was often used to analyze content of salvianolic acid A. The yield of salvianolic acid A increased by the technological improvement of extraction and separation. Salvianolic acid A possessed multiple pharmacological activities, including antioxidants, myocardial ischemic protection, antithrombatic, neuroprotection, anti fibrosis, prevention of diabetes and complications. Recently, preliminary pharmacokinetics characteristics of salvianolic acid A were clarified. Based on the research literature and study work from author's laboratory, this review will focus on recent developments concerning the chemistry, pharmacology and pharmacokinetic of salvianolic acid A, and prospect further research.

[Intestinal absorption properties of three components in salvianolic acid extract and the effect of borneol on their absorption in rats]

This study aimed to investigate the effects of concentration, intestinal section and borneol on the intestinal absorption of salvianolic acids. The experiment not only studied the intestinal absorption properties of three concentrations of rosmarinic acid, salvianolic acid B and salvianolic acid A at duodenum, jejunum and ileum, but also of salvianolic acids compatible with borneol at different concentrations using single-pass intestinal perfusion model in rat with phenol red as the marker. The results showed that salvianolic acids was stable under weak-acid condition and affected by metabolism enzyme; The Peff and Ka significantly different among three concentrations of rosmarinic acid and salvianolic acid B, whose intestinal absorption were saturated in high concentration, suggesting that the transport mechanisms of rosmarinic acid and salvianolic acid B were similar to active transport or facilitated diffusion; However, there was inconspicuousness in the Peff and Ka of salvianolic acid A at different concentrations, whose absorption was not saturated in high concentration, indicating that the transport mechanisms of salvianolic acid A was passive diffusion; The Peff and Ka in the ileum obviously higher than those in the duodenum and jejunum, namely the ileum was the best absorption section; When concentration of borneol increased, the enhancing effect of intestinal absorption of salvianolic acids increased, but significantly decreased when borneol increased to some degree. The enhancing effect of medium borneol concentration was the optimum. This implied that borneol can enhance the intestinal absorption of salvianolic acids, and the capacity of enhancing effect was influenced by the concentration of borneol.

Isolation of salvianolic acid A, a minor phenolic carboxylic acid of Salvia miltiorrhiza

Salvianolic acid A (Sal A), a caffeic acid derivative present in Salvia miltiorrhiza (Danshen), has shown significant biological activities, some of which are more potent than those of salvianolic acid (Sal B), the most abundant and bioactive compound in Danshen. However, its low content in the raw material makes it difficult to be used in the clinic. In this study, a novel procedure was developed to isolate Sal A from Salvia miltiorrhiza. Using this procedure, Sal A could be enriched to 1.7% in the raw material by hydrolyzing Sal B. The solution was further purified by macroporous resin and ODS column chromatography. The yield of Sal A was 0.5% with a purity of 98.0%. The procedure is efficient and convenient and is considered suitable for the separation of Sal A from Danshen.

Isolation and purification of salvianolic acid A and salvianolic acid B from Salvia miltiorrhiza by high-speed counter-current chromatography and comparison of their antioxidant activity

Water-soluble salvianolic acid A (Sal A) and salvianolic acid B (Sal B) were successfully isolated and purified from the crude extract of Salvia miltiorrhiza by high-speed counter-current chromatography (HSCCC). The solvent system was n-hexane-ethyl acetate-methanol-water (3:6:6:10, v/v/v/v). 4.27 mg of Sal A and 32.09 mg of Sal B were obtained from 260 mg of the crude sample. The purities of Sal A and Sal B were 96.67% and 97.43%, respectively. Their structures were identified by (1)H NMR and (13)C NMR. Antioxidant activities of Sal A and Sal B were also evaluated and compared by the methods of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay and 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS(+)) radical cation decolourisation assay. Both Sal A and Sal B showed high radical scavenging activities with their EC(50) values being 1.43+/-0.09 and 1.81+/-0.01 microg/ml in DPPH radical method. The ABTS results showed that Sal A and Sal B exhibited high total antioxidant activities, their EC(50) values were 1.35+/-0.00 and 1.43+/-0.01 microg/ml, respectively.

Substituting citrate for lactate in peritoneal dialysis fluid improves ultrafiltration in rats

BACKGROUND

Exposure to peritoneal dialysis (PD) fluid induces an inflammatory response in the peritoneal cavity. Blockers of complement and coagulation have improved ultrafiltration in animal models of PD. Citrate is a clinically established anticoagulant that also blocks complement activation.

OBJECTIVE

The aim of the present study was to evaluate the effects on ultrafiltration of a gradual substitution of citrate for lactate in an experimental model of PD.

METHODS

Fractions (0, 5, 10, and 15 mmol/L) of the 40 mmol/L lactate buffer of filter-sterilized 2.5% glucose PD fluid were replaced by citrate. The modified fluids were compared in a rat model of single PD fluid exposure through an indwelling catheter. The initial kinetics of citrate and ionized calcium were evaluated in separate, single, short time dwell experiments.

RESULTS

Replacing 10 and 15 mmol/L of the lactate buffer by sodium citrate significantly increased osmotic ultrafiltration (by 24.7%+/-7.7% at 10 mmol/L), net ultrafiltration, and glucose retention at 4 hours of dwell time in the rat model. Osmotic ultrafiltration was significantly correlated to citrate concentration and glucose concentration. Citrate was rapidly eliminated from the peritoneal cavity, concentrations falling to less than half in 1 hour and concentrations of calcium ions concomitantly normalized.

CONCLUSIONS

Substituting citrate for lactate induced a dose-dependent increase in ultrafiltration. Mechanisms probably involve the relation between diffusion and ultrafiltration, leading to increased glucose retention. The increase in ultrafiltration was quantitatively important at a citrate concentration (10 mmol/L) that is compatible with clinical applications of citrate.

Three new derivatives of anti-HIV-1 polyphenols isolated from Salvia yunnanensis

During the study of anti-HIV-1 active components of the aqueous extracts of the roots of Salvia yunnanensis, three new derivatives of polyphenols, namely: methyl salvianolate A (2), ethyl salvianolate A (3) and cis-lithospermic acid (5) were isolated along with two known polyphenols, salvianolic acid A (1) and lithospermic acid (4) their structures were elucidated on the basis of NMR and MS spectral analyses. The anti-HIV-1 activities of the 5 polyphenols were tested for the inhibition of P24 antigen in HIV-1 infected MT-4 cell cultures and HIV-1 replicative enzymes in vitro.

[Absorption and isolation of macroporous resin for five salvianolic acids from Salviae mitiorrhizae]

OBJECTIVE

To study the adsorption of the macroporous resin for the five salvianolic acids (danshen su, rosmarinic acid, protocate chualdehyde, salvianolic acid B, salvianolic acid A, extracted from Salviae mitiorrhizae.

METHOD

The five salvianolic acids were employed as an index, and the change of them in the static and dynamic absorbent was detected by HPLC, respectively.

RESULT

HP20 resin was a suitable marcoporous resin to purify salvianolic acids. The dynamic adsorption capacity of rosmarinic acid, salvianolic acid B and salvianolic acid A was 30.506 mg x g(-1) (dry resin), 36.996 mg x g(-1), (dry resin), 43.85 mg x g(-1) (dry resin) respectively.

CONCLUSION

It is not suitable that danshensu and protocate chualdehyde are the evaluation indexes for using 8 macroporous resins to purify salvianolic acids.

Chromatographic fingerprinting analysis of Danshen root (Salvia miltiorrhiza Radix et Rhizoma) and its preparations using high performance liquid chromatography with diode array detection and electrospray mass spectrometry (HPLC-DAD-ESI/MS)

Danshen root (Salvia miltiorrhiza Radix et Rhizoma) is a representative Chinese herb containing multiple components contributing to its polyvalent bioactivities. Advanced analysis approaches are needed to obtain a comprehensive picture of the targeting constituents in complete matrix. In this study, a chromatographic fingerprinting method to monitor simultaneously the hydrophilic and lipophilic constituents was developed for the quality evaluation of Danshen root and its preparations. Ten hydrophilic and nine lipophilic components were identified using HPLC-diode array detection-electrospray-MS (HPLC-DAD-ESI/MS) by comparing with the available references and reported data. Using the established method, 13 Danshen root samples collected from different sources, and 21 batches of Danshen preparations including tablets, injections, capsules, and dropping pills produced by different manufacturers were analyzed and their chromatographic fingerprints (CFP) were constructed. The results showed that the products of Danshen roots such as the tablets and capsules contained both the hydrophilic and lipophilic components, while the injections and dropping pills contained mainly the hydrophilic components. Principal components analysis (PCA) was applied for the statistical analysis of the fingerprinting data of crude herb and its preparations. The established CFPs demonstrate the representative chemical profiling of the existing components and can be applied to the authentication and quality assessment of Danshen roots and other Danshen containing formulated preparations.

[Studies on polyphenolic chemical constitutents from root of Salvia yunnansis]

OBJECTIVE

To study the chemical constituents in the root of Salvia yunnansis.

METHOD

Compounds were isolated and purified by Diaion HP20, Sephadex LH - 20, ODS chromatography. Their structures were determined by spectral analysis and chemical evidence.

RESULT

Twelve compounds were isolated and identified from the root of S. yunnansis protocatechaldehyde (1), caffeic acid (2), ferulic acid (3), rosmarinic acid (4), salvianolic acid A (5), salvianolic acid C (6), lithospermicacid (7), lithospermicacid B (8), 9'-methyl lithospermate B (9), 9"'-methyl lithospermate B (10), 9',9'''-dimethyl lithospermate B (11), 9'-ethyl lithospermate B (12).

CONCLUSION

The compounds 1, 2, 3, 5, 6, 9, 10, 11 and 12 were first isolated from S. yunnanensis.

[Separation of water-soluble active components in Salvia miltiorrhiza bge. f. alba using capillary zone electrophoresis]

To establish a high performance capillary zone electrophoretic method for the separation of water-soluble active components, protocatechuic aldehyde (PAH), danshensu (DSS), and protocatechuic acid (PA), in Salvia miltiorrhiza bge. f. alba, many factors that can affect the resolution and the migration time, including the concentration of phosphate-borax buffer, pH value, separation voltage and detection wavelength were investigated. The optimized conditions were as follows: uncoated capillary column, 75 microm x 60.2 cm (effective length of 50 cm); column temperature, 25 degrees C; detection wavelength of the photo-diode-array detector, 210 nm; injection, 3.45 kPa x 4 s; separation voltage, 27.5 kV; running buffer, 5 mmol/L borax (pH 7.5). Under the optimized conditions, good separation of PAH, DSS and PA can be achieved in less than 8 min.

[Studies on chemical constituents of Prunella vulgaris]

OBJECTIVE

To study the chemical constituents of Prunella vulgaris.

METHOD

To separate the constituents of P. vulgaris by using various kinds of chromatography and identify their structures on the basis of spectral analysis.

RESULT

Seven compounds were isolated from the spikes of P. vulgaris. Their structures were established as autantiamide acetate (1), rhein (2), tanshinone I (3), danshensu (4), stigmast-7, 22-dien-3-one (5), 3, 4, alpha-trihydroxy-methyl phenylpropionate (6), butyl rosmarinate (7).

CONCLUSION

Compounds 1-4 were isolated from this genus for the first time.

Antifungal compounds from cultures of dairy propionibacteria type strains

Antifungal compounds from cultures of five type strains of dairy propionibacteria, as well as from the cultivation medium, were studied. Cell-free supernatants and medium were fractionated by C(18) solid phase extraction. The aqueous 95% acetonitrile fractions were analyzed by GC-MS or subjected to reversed-phase HPLC, to identify, quantify or isolate antifungal substances. The resulting HPLC fractions were screened for antifungal activity against the mold Aspergillus fumigatus and the yeast Rhodotorula mucilaginosa. Active fractions were further separated by HPLC and the structures of the compounds were determined by spectroscopic and chromatographic methods. All five strains produced 3-phenyllactic acid, at concentrations ranging from 1.0 microg mL(-1) (Propionibacterium freudenreichii ssp. shermanii) to 15.1 microg mL(-1) (Propionibacterium thoenii), and at L/D -ratios ranging from 2 : 3 (Propionibacterium acidipropionici) to 9 : 1 (Propionibacterium freudenreichii). A number of active compounds found in cultures of propionibacteria were also present in noninoculated growth medium: two antifungal diketopiperazines, cyclo(L-Phe-L-Pro) and cyclo(L-Ile-L-Pro), and seven antifungal linear peptides. Three of the linear peptides corresponded to sequences found in the medium component casein, suggesting their origin from this component, whereas the diketopiperazines were suggested to be formed from medium peptides by heat treatment.

Protective effect of salvianic acid a on acute liver injury induced by carbon tetrachloride in rats

Previous research has shown that salvianic acid A [2-(3,4-dihydroxyphenyl)-2-hydroxy-propanoic acid, SA] extracted from Salvia miltiorrhiza BGE (Danshen) markedly inhibits lipid peroxidation of mitochondrial membrane of hepatic cells in vitro. The present study was conducted to examine protective effect of SA on liver injury induced by carbon tetrachloride (CCl4) and its possible mechanism in vivo. Male Sprague-Dawley rats weighing 180-200 g were used in the experiments. Five mmol/kg CCl4 in olive oil was given to rats i.p. Spectrophotometrical method was used to measure activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in serum, activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) as well as malondialdehyde (MDA) level in hepatic tissue and the rate of superoxide anion (O2*-) generation in hepatic submitochondrial particles. Hepatic histological structure was observed under light microscopy. CCl4 caused significant changes of activities of the enzymes, MDA level, and the rate of O2*- generation and histopathological changes of acute hepatic injury were noted. SA reversed the significant changes induced by CCl4. These results demonstrate that SA produces protective action on acute hepatic injury induced by CCl4 via an antioxidative mechanism.

One-step separation and purification of 3,4-dihydroxyphenyllactic acid, salvianolic acid B and protocatechualdehyde from Salvia miltiorrhiza Bunge by high-speed counter-current chromatography

Three kinds of polyphenols of Salvia miltiorrhiza Bunge, 3,4-dihydroxyphenyllactic acid, salvianolic acid B and protocatechualdehyde, were separated and purified in one step with solvent system n-hexane-ethyl acetate-methanol-acetic acid-water (1:6:1.5:1.5:8) by high-speed counter-current chromatography. Acetic acid was successfully used to increase the partition of high polar target compounds in organic phase to modify partition coefficient value. 3,4-Dihydroxyphenyllactic acid, salvianolic acid B and protocatechualdehyde were purified from 100mg water extracted crude sample of Salvia miltiorrhiza Bunge at purity of 97.6%, 94.2% and 98.2% and at yield of 98.6%, 73.6% and 90.2%. High-speed counter-current chromatography together with organic/aqueous solvent system supplied an efficient method to purify water-soluble compounds directly from crude samples of traditional Chinese medicines.

Relaxant effects of danshen aqueous extract and its constituent danshensu on rat coronary artery are mediated by inhibition of calcium channels

In this study, we have investigated the actions of danshensu, an active, water-extractable component of the medicinal herb danshen (Salvia miltiorrhiza), on rat isolated coronary artery rings precontracted with 1 microM 5-hydroxytryptamine (5-HT) and its action compared to the water-extractable fraction of the herb. Extraction of the water-soluble fraction from danshen (S. miltiorrhiza) provided yield of 17.5% (35 g/200 g). The amount of danshensu determined in the crude danshen herb and in its aqueous fraction was 0.45 mg/g (0.045%) and 3.28 mg/g (0.33%). The danshen aqueous extract was 13 times less potent than danshensu in relaxing 5-HT-precontracted coronary artery rings; IC50 values were 930.3+/-133.5 microg/ml and 71.5+/-11.0 microg/ml. Removal of the endothelium did not significantly affect their vasodilator potencies; IC50 values were 842.1+/-123.8 microg/ml and 84.8+/-8.8 microg/ml. On the other hand, a potassium channel inhibitor tetraethylammonium (TEA, 10 mM) shifted their concentration-response curves by 1.7 and 2.2 folds. The possible involvement of Ca2+ channels was investigated in artery rings incubated with Ca2+-free buffer and primed with 1 microM 5-HT or 60 mM KCl for 5 min prior to addition of CaCl2 to elicit contraction. In 5-HT-primed preparations, the CaCl2-induced vasoconstriction was abolished by 2 mg/ml danshen aqueous extract and 200 microg/ml danshensu, whereas, in KCl-primed preparations, 10 mg/ml danshen aqueous extract and 600 microg/ml danshensu were required to abrogate the vasoconstriction. These findings suggest the vasorelaxant actions of danshen aqueous extract and danshensu were produced by inhibition of Ca2+ influx in the vascular smooth muscle cells. The opening of K+ channels had a minor contribution to the response, but endothelium-dependent mechanisms were not involved.

Rosmarinic acid, a new snake venom phospholipase A2 inhibitor from Cordia verbenacea (Boraginaceae): antiserum action potentiation and molecular interaction

Many plants are used in traditional medicine as active agents against various effects induced by snakebite. The methanolic extract from Cordia verbenacea (Cv) significantly inhibited paw edema induced by Bothrops jararacussu snake venom and by its main basic phospholipase A2 homologs, namely bothropstoxins I and II (BthTXs). The active component was isolated by chromatography on Sephadex LH-20 and by RP-HPLC on a C18 column and identified as rosmarinic acid (Cv-RA). Rosmarinic acid is an ester of caffeic acid and 3,4-dihydroxyphenyllactic acid [2-O-cafeoil-3-(3,4-di-hydroxy-phenyl)-R-lactic acid]. This is the first report of RA in the species C. verbenacea ('baleeira', 'whaler') and of its anti-inflammatory and antimyotoxic properties against snake venoms and isolated toxins. RA inhibited the edema and myotoxic activity induced by the basic PLA2s BthTX-I and BthTX-II. It was, however, less efficient to inhibit the PLA2 activity of BthTX-II and, still less, the PLA2 and edema-inducing activities of the acidic isoform BthA-I-PLA2 from the same venom, showing therefore a higher inhibitory activity upon basic PLA2s. RA also inhibited most of the myotoxic and partially the edema-inducing effects of both basic PLA2s, thus reinforcing the idea of dissociation between the catalytic and pharmacological domains. The pure compound potentiated the ability of the commercial equine polyvalent antivenom in neutralizing lethal and myotoxic effects of the crude venom and of isolated PLA2s in experimental models. CD data presented here suggest that, after binding, no significant conformation changes occur either in the Cv-RA or in the target PLA2. A possible model for the interaction of rosmarinic acid with Lys49-PLA2 BthTX-I is proposed.

[The qualitative analysis and quantitative analysis of purification of salvianolic acids by macroreticular resin]

OBJECTIVE

To purify salvianolic acids by macroreticular resin,then mensurate the contents of salvianolic acids and analyse the chromatogram with HPLC.

METHOD

Make salvianolic acids with macroreticular resin; mensurate the content of Salvianolic acids with UV spestrophotometry: the control compound is protocaechuic aldehyde, and the wavelength is 281 nm. Analysis the chromatogram with HPLC, and compare the chromatogram in different technics: zorbax ODS column (4.6 mm x 250 mm, 5 microm), mobilephase: 1% aceticacid-water and methanol in different proportions, the wavelength is 281 nm.

RESULT

The contents of salvianolic acids is 53.8%; HPLC chromatogram indicate that the method is reasonable to make salvianolic acids.

CONCLUSION

Determination of contents and HPLC chromatogram can control the quality of Salvianolic acids more accurately.

[Advances in study of the pharmacological effects of danshen on hemorheology]

The article reviewed the research on the pharmacological effects of Danshen on hemorheology. We discussed the action mechanism of Danshen and its preparations from the points of hemorheology, blood and vessel endothelium cell. Danshen and its preparations can obviously improve the hemorheological characteristic by various ways.

[Quantitative analysis of Danshensu in Tongmai Oral Solution by HPLC]

OBJECTIVE

To establish a method by RP-HPLC for determination of content of Danshensu (3,4-hydroxybenzyl lacticacid) in Tongmai Oral Solution.

METHODS

The samples were separated on an ODS column Hypersil C18 (10 microm, 4.6 mm x 200 mm) with the mobile phase 0. 5% acetic acid-methanol-dimethyl formamide (99:0.5:0.5). The flow rate was 1.2 ml/min, and the detection wavelength was set at 335nm.

RESULTS

The average recovery of Danshensu was 98.31%, and RSD was 2. 11%.

CONCLUSION

The method is efficient and accurate with a good repeatability and can be used for the quality control of Tongmai Oral Solution.

Protective effects of Danshensu from the aqueous extract of Salvia miltiorrhiza (Danshen) against homocysteine-induced endothelial dysfunction

Homocysteine (Hcy) is a by-product of methionine metabolism. An imbalance of Hcy in the body may lead to hyperhomocysteinemia, a condition with elevated Hcy concentration in blood that may be one of the risk factors responsible for the development of several vascular diseases (thromboembolism, atherosclerosis, stroke, vascular diseases and dementia). Radix Salvia miltiorrhiza (Danshen), a well-known Chinese medicinal herb that can activate and improve blood microcirculation, is noticeable for its beneficial effect in treating cardiovascular diseases. The present study is to demonstrate the protective effect of Danshen extract against the homocysteine-induced adverse effect on human umbilical vein endothelial cell (HUVEC). Homocysteine (5 mM) not only decreased the cell viability but also caused the disruption of capillary-like structure formation in vitro. The protective effect of Danshen aqueous extract and its active compounds on endothelial cell function were demonstrated through an in vitro tube formation assay, which mimics the new blood vessel formation. To identify the active components in the aqueous extract of Danshen, the content was characterized by instrumental analysis using high performance liquid chromatography with diode array detector (DAD) and electrospray tandem mass spectrometry (ESI-MS/MS). Interestingly, Danshen extract and its pure compounds showed different effectiveness in protecting HUVEC against Hcy-induced injury according to the following descending order: Danshen aqueous extract, 3-(3,4-dihydroxy-phenyl)-2-hydroxy-propionic acid (Danshensu), protocatechuic acid, catechin and protocatechualdehyde. We believed that such findings might provide evidence in understanding the beneficial effects of Danshen on the cardiovascular system.

Metabolic studies on the total phenolic acids from the roots ofSalvia miltiorrhiza in rats

Phenolic acids are the main active constituents of Salvia miltiorrhiza Bunge. The metabolism of total phenolic acids from the roots of Salvia miltiorrhiza in rats was investigated. A sample preparation method combining the solid-phase extraction with liquid-liquid extraction was established to separate metabolites from the biological matrix. HPLC-UV and HPLC-MS methods were employed to analyze the metabolites. Five metabolites (M1-M5) were identified by HPLC-MS analysis and comparison with those of the reference standards. The fi ve metabolites were characterized as danshensu (M1), caffeic acid (M2), ferulic acid (M3), isoferulic acid (M4) and methylized ferulic acid (M5), respectively. The possible metabolic pathway of the phenolic acids is proposed.

[Effect of danshensu, protocatechualdehyde and danshen injection on calcium ion concentration in cytoplasm of human erythrocytes]

OBJECTIVE

To study the predominant calcium-antagonist components of Danshen injection.

METHOD

The effects of danshensu, protocatechualdehyde and Danshen injection on calcium concentration in cytoplasm of erythrocytes were examined in vitro by the fluorescent Ca+ -chelator fura-2.

RESULT

Either DS182 or PCAD can decrease in dose-dependent cytosolic free calcium concentration in human erythrocytes. They had additive effect when mixed, which was similar to Danshen injection.

CONCLUSION

DS182 and PCAD may be predominant calcium-antagonist components of Danshen injection.

[Study on adsorption of danshen water-soluble compounds with macroporous resin D301]

OBJECTIVE

To study the adsorption and enrichment of effective compounds of danshensu, and protocatechualdehyde from Danshen water extracts by macroporous resin D301.

METHOD

The change of active compounds was observed by detecting the amount of danshensu and protocatechualdehyde with HPLC.

RESULT AND CONCLUSION

Macroporous resins D301 can be used in the process of adsorbing and purifying active compounds of danshensu and protocatechualdehyde, and increase the amount of active compounds in water extracts.

Preparation and characterization of poly(lactic acid)-poly(ethylene glycol)-poly(lactic acid) (PLA-PEG-PLA) microspheres for controlled release of paclitaxel

Microspheres of a new kind of copolymer, poly(lactic acid)-poly(ethylene glycol)-poly(lactic acid) (PLA-PEG-PLA), are proposed in the present work for clinical administration of an antineoplastic drug paclitaxel with hypothesis that incorporation of a hydrophilic PEG segment within the hydrophobic PLA might facilitate the paclitaxel release. Paclitaxel-loaded PLA-PEG-PLA microspheres of various compositions were prepared by the solvent extraction/evaporation method. Characterization of the microspheres was then followed to examine the particle size and size distribution, the drug encapsulation efficiency, the colloidal stability, the surface chemistry, the surface and internal morphology, the drug physical state and its in vitro release behavior. The effects of polymer types, solvents and drug loading were investigated. It was found that in the microspheres the PEG segment was homogeneously distributed and caused porosity. Significantly faster release from PLA-PEG-PLA microspheres resulted in comparison with the PLGA counterpart. Incorporation of water-soluble solvent acetone in the organic solvent phase further increased the porosity of the PLA-PEG-PLA microspheres and facilitated the drug release. A total of 49.6% sustained release of paclitaxel within 1 month was achieved. Potentially, the presence of PEG on the surface of PLA-PEG-PLA microspheres could improve their biocompatibility. PLA-PEG-PLA microspheres could thus be promising for the clinical administration of highly hydrophobic antineoplastic drugs such as paclitaxel.

[Salvianolic acid A inhibits nucleoside transport and potentiates the antitumor activity of chemotherapeutic drugs]

AIM

To investigate the inhibitory activity of salvianolic acid A (SAA) on nucleoside transport in cancer cells and its antitumor effect.

METHODS

[3H] thymidine and [3H] uridine transport assays were used to determine the inhibitory activity on nucleoside transport in Ehrlich carcinoma cells. The cytotoxicity to cultured cancer cells was examined with clonogenic assay. The antitumor effect in vivo was evaluated with transplantable tumor model in mice.

RESULTS

SAA was shown to inhibit thymidine and uridine transport in Ehrlich carcinoma cells with IC50 values of 18.1 and 17.1 micromol x L(-1), respectively. By clonogenic assay, the IC50 of SAA for KB cells was 44.7 micromol x L(-1). SAA markedly potentiated the cytotoxicity of 5-FU and mitomycin C in KB cells as well as the cytotoxicity of MTX in human hepatoma BEL-7402 cells. For in vivo experiment, sarcoma 180 cells were transplanted sc in mice and tested drugs were administered ip. When administered separately, SAA at 200 mg x kg(-1) and 5-FU at 10 mg x kg(-1) inhibited tumor growth by 41% and 27%, respectively. Combination of the two drugs inhibited tumor growth by 63% (CDI = 0.86).

CONCLUSION

SAA is active in blocking nucleoside transport in cancer cells and potentiates the cytotoxicity of chemotherapeutic drugs. As an agent showing moderate antitumor effect in vivo, SAA might be useful in combination cancer therapy.

Recovery of Ammonium Lactate and Removal of Hardness from Fermentation Broth by Nanofiltration

Nanofiltration (NF) was investigated as an alternative to desalting electrodialysis (ED) and ion exchange for the recovery of ammonium lactate from fermentation broth. Three commercial NF membranes, NF45, NF70, and NTR-729HF, were characterized with 50 mM NaCl, MgSO(4), and glucose solutions. NF45 membrane was selected because it showed the lowest rejection of monovalent ion, the highest rejection of divalent ion, and the highest rejection of nonpolar molecule. Effects of the operating pressure were investigated in a range of 100-400 psig, on the flux, lactate recovery, and glucose and magnesium removal from a real fermentation broth containing about 1.0 M of ammonium lactate. The flux and recovery rate increased linearly with the pressure. However, lactate rejection also increased with the pressure, lowering the recovery yield. More magnesium ions and glucose were rejected as the pressure was increased, and at 400 psig, for example, magnesium ion was almost completely rejected, highlighting the chance of obviating the necessity of ion exchange to remove hardness, by using NF instead of desalting ED. Membrane fouling was not so severe as expected, considering the complex nature and a rather high concentration of the fermentation broth treated.

Lactobacillus plantarum MiLAB 393 produces the antifungal cyclic dipeptides cyclo(L-Phe-L-Pro) and cyclo(L-Phe-trans-4-OH-L-Pro) and 3-phenyllactic acid

We have isolated a Lactobacillus plantarum strain (MiLAB 393) from grass silage that produces broad-spectrum antifungal compounds, active against food- and feed-borne filamentous fungi and yeasts in a dual-culture agar plate assay. Fusarium sporotrichioides and Aspergillus fumigatus were the most sensitive among the molds, and Kluyveromyces marxianus was the most sensitive yeast species. No inhibitory activity could be detected against the mold Penicillium roqueforti or the yeast Zygosaccharomyces bailii. An isolation procedure, employing a microtiter well spore germination bioassay, was devised to isolate active compounds from culture filtrate. Cell-free supernatant was fractionated on a C(18) SPE column, and the 95% aqueous acetonitrile fraction was further separated on a preparative HPLC C(18) column. Fractions active in the bioassay were then fractionated on a porous graphitic carbon column. The structures of the antifungal compounds cyclo(L-Phe-L-Pro), cyclo(L-Phe-trans-4-OH-L-Pro) and 3-phenyllactic acid (L/D isomer ratio, 9:1), were determined by nuclear magnetic resonance spectroscopy, mass spectrometry, and gas chromatography. MIC values against A. fumigatus and P. roqueforti were 20 mg ml(-1) for cyclo(L-Phe-L-Pro) and 7.5 mg ml(-1) for phenyllactic acid. Combinations of the antifungal compounds revealed weak synergistic effects. The production of the antifungal cyclic dipeptides cyclo(L-Phe-L-Pro) and cyclo(L-Phe-trans-4-OH-L-Pro) by lactic acid bacteria is reported here for the first time.

[Studies on lipase-catalyzed synthesis of ethylglucoside lactate in non-aqueous phase]

Ethylglucoside lactate, a novel Alpha-Hydroxy Acids Derivative, was synthesized by transesterification in non-aqueous phase using immobilized lipase as biocatalyst. Based on the studies of the factors effecting initial rate and conversion under atmospheric pressure (solvent, acyl donor, different immobilized lipase, substrate concentration, enzyme concentration and temperature), the results show that solvent-free medium using butyllactate as acyl donor is suitable to the ester synthesis. The reaction conditions have been optimized as the following: the amount of enzyme = 75 g/L, the ethylglucoside concentration = 0.4 mol/L, 70 degrees C, 200 r/min, 50 h, which the conversion was 71%. A 90% conversion and a 60.7 mmol.L-1.h-1 initial rate can be obtained under reduced pressure, which the conditions are enzyme 75 g/L, ethylglucoside 0.35 mol/L, 65 degrees C, 200 r/min and 40 h. The product purified by extraction and SIO2 chromatography was identified by infrared spectroscopy and 1H NMR.

Determination of Danshensu, a major active compound of Radix Salvia miltiorrhiza in dog plasma by HPLC with fluorescence detection

A simple and sensitive high performance liquid chromatography method has been developed for the determination of Danshensu (3, 4-dihydroxyphenyllactic acid) in dog plasma. Plasma samples were extracted with ethyl acetate. Analysis of the extracts was performed on a reversed-phase column with an aqueous phosphate buffer-acetonitrile (93:7, v/v) mobile phase, and 4-hydroxybenzoic acid was used as the internal standard. Fluorescence detection at 285 nm (excitation) and 320 nm (emission) was employed. Standard curves were linear in the range from 0.125 to 11.3 microg/mL (regression coefficient r > 0.993) on three different days. Mean recovery was determined as 96.4% by analysis of plasma standard containing 0.63, 5.65 and 11.3 microg/mL of Danshensu. The inter-day precision (RSD) ranged from 3.4 to 8.6% at concentrations of 0.125, 1.88, 6.28 and 11.3 microg/mL, and the intra-day precision was better than 7.2%. The detection and quantitation limits were 0.063 and 0.125 microg/mL, respectively. This validated assay was applied to the determination of Danshensu concentration in dog plasma after oral administration of Radix Salvia miltiorrhiza extracts.

[Preparation and evaluation of in-situ synthesis zeolite gas-liquid modified columns]

A new kind of NaA zeolite column has been prepared by in-situ synthesis technique. In comparing with traditional coating method, the in-situ NaA zeolite carrier is much more uniform and rigid. Several kinds of zeolite gas-liquid modified columns have been prepared with this in-situ technology, which showed satisfactory features in separation property and thermal stability. The successful utilization of mini-length and wide-bore columns showed good practical prospect of this new kind of zeolite column.

Purification and characterization of novel antifungal compounds from the sourdough Lactobacillus plantarum strain 21B

Sourdough lactic acid bacteria were selected for antifungal activity by a conidial germination assay. The 10-fold-concentrated culture filtrate of Lactobacillus plantarum 21B grown in wheat flour hydrolysate almost completely inhibited Eurotium repens IBT18000, Eurotium rubrum FTDC3228, Penicillium corylophilum IBT6978, Penicillium roqueforti IBT18687, Penicillium expansum IDM/FS2, Endomyces fibuliger IBT605 and IDM3812, Aspergillus niger FTDC3227 and IDM1, Aspergillus flavus FTDC3226, Monilia sitophila IDM/FS5, and Fusarium graminearum IDM623. The nonconcentrated culture filtrate of L. plantarum 21B grown in whole wheat flour hydrolysate had similar inhibitory activity. The activity was fungicidal. Calcium propionate at 3 mg ml(-1) was not effective under the same assay conditions, while sodium benzoate caused inhibition similar to L. plantarum 21B. After extraction with ethyl acetate, preparative silica gel thin-layer chromatography, and chromatographic and spectroscopic analyses, novel antifungal compounds such as phenyllactic and 4-hydroxy-phenyllactic acids were identified in the culture filtrate of L. plantarum 21B. Phenyllactic acid was contained at the highest concentration in the bacterial culture filtrate and had the highest activity. It inhibited all the fungi tested at a concentration of 50 mg ml(-1) except for P. roqueforti IBT18687 and P. corylophilum IBT6978 (inhibitory concentration, 166 mg ml(-1)). L. plantarum 20B, which showed high antimold activity, was also selected. Preliminary studies showed that phenyllactic and 4-hydroxy-phenyllactic acids were also contained in the bacterial culture filtrate of strain 20B. Growth of A. niger FTDC3227 occurred after 2 days in breads started with Saccharomyces cerevisiae 141 alone or with S. cerevisiae and Lactobacillus brevis 1D, an unselected but acidifying lactic acid bacterium, while the onset of fungal growth was delayed for 7 days in bread started with S. cerevisiae and selected L. plantarum 21B.

[Study on mixed stationary phase composed of 2,3,6-tributyl-beta-cyclodextrin and AgNO3 for capillary gas chromatography]

A new mixed gas chromatographic stationary phase composed of 2,3,6-tributyl-beta-cyclodextrin and AgNO3(in polyethylene glycol 400) was synthesized for the first time. It was coated on fused silica capillary column. Excellent selectivity was obtained for the separation of seven enantiomeric pairs and four groups of positional isomers of aromatic compounds. The recognition and separation mechanisms were discussed by measuring enthalpy, entropy, free energy and the difference in enthalpy and entropy of these compounds. Results were compared with those obtained on 2,3,6-tributyl-beta-cyclodextrin stationary phase. The results showed that the mixed stationary phase had positive synergistic effects.

Effect of Salvia miltiorrhiza on aflatoxin B1-induced oxidative stress in cultured rat hepatocytes

Recent findings have suggested that oxidative damage might contribute to the cytotoxicity and carcinogenicity of aflatoxin B1 (AFB1). Salvia miltiorrhiza (Sm), a herbal plant that has been used extensively in traditional Chinese medicine for treating cardiovascular and liver diseases, is believed to have some antioxidative capabilities. In this study, the protective effect of Sm against AFB1-induced cytotoxicity was investigated in cultured primary rat hepatocytes. AFB1-induced cytotoxicity and lipid peroxidation (LPO) were estimated by determination of lactate dehydrogenase (LDH) leakage and thiobarbituric acid reactive substances (TBARS) formation, respectively. Intracellular reactive oxygen species (ROS) formation was measured using a fluorescent probe 2',7'-dichlorofluorescein diacetate (DCFH-DA). In addition, changes of intracellular glutathione (GSH) content were also studied. Results showed that Sm was able to suppress the LDH leakage induced by AFB1 in a dose-dependent manner. A dose-dependent inhibitory effect of Sm on AFB1-induced LPO was also found in hepatocytes treated with Sm. It was further observed that Sm produced an inhibitory effect on ROS formation caused by AFB1. Concomitantly, the GSH content in Sm-treated groups increased substantially compared to those without Sm treatment. These findings suggest that Sm can inhibit the cytotoxicity of AFB1 through decreasing ROS formation, inhibiting LPO and preventing GSH depletion. The major component of the aqueous extract of Sm was identified by using high performance liquid chromatography (HPLC), proton magnetic resonance (1H-NMR) and mass spectrum (MS). Analytical results suggested that D(+)beta3,4-dihydroxyphenol lactic acid (DA) is the main compound of the aqueous extract of Sm.

Purification and characterization of anti-Listeria compounds produced by Geotrichum candidum

Geotrichum candidum can produce and excrete compounds that inhibit Listeria monocytogenes. These were purified by ultrafiltration, centrifugal partition chromatography, thin-layer chromatography, gel filtration, and high-pressure liquid chromatography, and analyzed by liquid chromatography-mass spectrometry, infrared spectrometry, nuclear magnetic resonance spectrometry, and optical rotation. Two inhibitors were identified: D-3-phenyllactic acid and D-3-indollactic acid.

An aminopeptidase N deficiency in dog small intestine

This study has identified a naturally occurring, specific deficiency of a brush border aminopeptidase N (ApN) in the small intestines of five clinically healthy dogs. ApN activity in mucosal homogenates of dog small intestine was reduced significantly in deficient animals (13.4 (1.1) nmol min-1 mg-1 protein, n = 5, P < 0.002) compared to healthy control dogs (95.1 (6.7), n = 22). Alkaline phosphatase, gamma-glutamyl transferase, zinc-resistant alpha-glucosidase, maltase, sucrase and lactase in the ApN deficient dogs exhibited comparable activities to those in the control dogs. Microvillar membranes were analysed by one- and two-dimensional electrophoresis. ApN was represented by a single 145kDa band in all control dogs, identified by immunoblotting and immunoprecipitation. Protein maps from deficient dogs were normal apart from the virtual absence of an ApN spot and there were no apparent abnormalities in the glycosylation of microvillar proteins. The findings suggest that intestinal ApN deficiency in these dogs is a primary lesion involving diminished expression of an otherwise normal enzyme protein.

Further study on the use of uncharged beta-cyclodextrin polymer in capillary electrophoresis: enantiomeric separation of some alpha-hydroxy acids

Uncharged beta-cyclodextrin polymer was used as chiral selector for the enantiomeric separation of some alpha-hydroxy acids by capillary electrophoresis. Complexation and enantiomeric resolution of mandelic acid, m-hydroxy and p-hydroxymandelic acid, 3,4-dihydroxymandelic acid, as well as 2- and 3-phenyllactic acid were studied, changing the concentration of the beta-cyclodextrin polymer added to the background electrolyte at different pH in the range of 4.5-7. Furthermore, the effects of the concentration of the background electrolyte, column temperature, and applied voltage on chiral resolution were also examined. The best enantiomeric separations were obtained using a background electrolyte at pH 6 containing 100 mg/mL of beta-cyclodextrin polymer.

Novel antioxidants from roasted perilla seed

Novel antioxidants, 5-(3,4-dihydroxyphenylmethyl)oxazolidine-2,4-dione (1) and 3-(3,4-dihydroxyphenyl)lactamide (2), have been isolated from roasted perilla seed. Compound 1 was the first example of non-synthetic oxazolidinedione.

Stealth Me.PEG-PLA nanoparticles avoid uptake by the mononuclear phagocytes system

Nanoparticles were prepared from methoxy poly(ethylene glycol)poly(d,l-lactic acid) block copolymers (Me.PEG-PLA) or blends of Me.PEG-PLA and PLA by the precipitation-solvent diffusion method. These nanoparticles, labeled by introducing [14C]PLA in the formulation, were shown to be more slowly captured by cultured THP-1 monocytes than F68-coated PLA nanoparticles, in a PEG chain-length-dependent manner. In vivo, the half-life in plasma of the Me.PEG-PLA nanoparticles that were intravenously administered to rats is increased by a factor 180 compared with the F68-coated PLA nanoparticles. This mononuclear phagocytes system avoidance was explained according to a conformation model in which the PEG density at the surface of the particles is a key parameter.

Tissue lactate in pediatric head trauma: a clinical study using 1H NMR spectroscopy

In order to define the metabolic abnormalities associated with different types of pediatric head injury, proton magnetic resonance spectroscopy was performed on 21 cerebral regions obtained from 17 patients. On the basis of MRI scans, the regions of interest were classified as normal (6 hemispheres), or showing diffuse axonal injury (3 hemispheres), contusion (4 hemispheres), or cerebral infarction (8 hemispheres). In comparison with normal brain there was no significant elevation in tissue lactate in the diffuse axonal injury patients, but a significant increase in the regions of contusion and infarction. It is concluded that treatment strategies using buffering agents are most likely to benefit these two groups of patients.

Quality improvement of spray-dried, protein-loaded D,L-PLA microspheres by appropriate polymer solvent selection

The aim was to study the effect of the type of polymer solvent on characteristics of microspheres produced by spray drying. The water-soluble model protein, bovine serum albumin (BSA) was microencapsulated into biodegradable poly(D,L-lactic acid) using the following 10 different polymer solvents: acetaldehyde dimethyl acetal, acetone, dichloromethane, dioxane, ethyl acetate, ethyl vinyl ether, nitromethane, tetrahydrofuran, 1,1,1-trichloroethane, and 1,1,2-trichloroethylene. These solvents having similar toxicity levels differ greatly in their physico-chemical characteristics such as boiling point, vapour pressure, miscibility and interfacial tension with an aqueous phase, and solubility parameter. The effect of these solvents on microsphere morphology was studied by SEM-micrographs. Regular particle morphology was obtained when dichloromethane, ethyl acetate, or nitromethane was used as the polymer solvent, whereas the trichlorinated solvents, tetrahydrofuran, and dioxane produced a substantial number of coalesced particles. The results are interpreted in terms of boiling point, vapour pressure, and polymer-solvent affinity. Further, BSA-loading and -integrity in the microspheres, and burst release were analysed. The theoretical loading of 2.9% was attained with dichloromethane, ethyl acetate and nitromethane, in agreement with observations of particle morphology. HPLC- and SDS-PAGE analysis of the microencapsulated BSA did not show any protein degradation or dimerization, whereas solid-phase ELISA clearly revealed that the in vitro protein antigenicity was substantially reduced (50%), particularly by water miscible solvents. Dichloromethane and ethyl acetate did not show any detrimental effect on protein antigenicity. Finally, burst release could be related again to particle morphology, with dichloromethane and nitromethane giving a burst release of only 5%. In conclusion, dichloromethane, ethyl acetate and nitromethane proved to be the most suitable solvents for the polymer-protein system studied.

Biocompatibilities of organic solvents with Lactobacillus delbrueckii

In the search for biocompatible extractants for extractive fermentation of lactic acid, the effect of twelve organic solvents on the activity of L. delbrueckii were studied at different concentration levels. On this basis, the compatibilities of twelve solvents with L. delbrueckii were summarized into four classes: completely compatible, compatible at molecular level, partially compatible and non-compatible. The characteristics were described qualitatively for each class in terms of relative values between the solubility of organic solvent in water (Cs) and the toxicity of organic solvent, which is indicated by a newly defined concentration parameter (Cm). The classification was helpful for the selection of extractant in extractive fermentation.

Quantification of glucose cycling and the extent of equilibration of glucose 6-phosphate with fructose 6-phosphate in islets from ob/ob mice

Pancreatic islets from fed and fasted obese hyperglycaemic (ob/ob) mice were incubated with [1-14C]glucose at 5.5 mM and 16.7 mM, [1-14C]mannose at 16.7 mM, and 3H2O. Yields of 14CO2 and 14C-labelled lactate, and amounts of 14C from [1-14C]mannose incorporated into glucose and of 3H bound to C-2 of glucose, were measured. Glucose utilization was determined from yields of 3H2O from [5-3H]glucose. From the results using 14C, 32-43% of the hexoses phosphorylated to hexose 6-phosphate were estimated to have been dephosphorylated, i.e. cycled. Estimates of hexose cycling from 3H incorporation into glucose were similar. Differences in the ratios of 14C yields in CO2 and lactate indicated incomplete isotopic equilibration between glucose 6-phosphate and fructose 6-phosphate, making the estimates of cycling semi-quantitative. In the fasted state, a larger percentage of the hexose utilized went to lactate than in the fed state. Thus conversion of mannose into glucose in islets indicates the occurrence of glucose cycling in islets. Yields of 14C from [1-14C]mannose, compared with from [1-14C]glucose, provide an approach for quantifying the extent of this cycling. These data provide further evidence for extensive glucose cycling occurring in ob/ob islets in both the fed and the fasted state.