[Chemical constituents and their α-glucosidase inhibitory activities of seeds of Moringa oleifera].

The chemical constituents of the seeds of Moringa oleifera were isolated and purified by using Sephadex LH-20, Toyo-pearl HW-40F, silica gel, ODS, and MCI column chromatography. The structures of compounds were identified by high-resolution mass spectrometry, ~1H-NMR, ~(13)C-NMR, HMQC, HMBC, and ~1H-~1H COSY, as well as physicochemical properties of compounds and literature data. Twelve compounds were isolated from 30% ethanol fraction of the seeds of M. oleifera and identified as ethyl-4-O-α-L-rhamnosyl-α-L-rhamnoside(1), ethyl-3-O-α-L-rhamnosyl-α-L-rhamnoside(2),(4-hydroxybenzyl)ethyl carbamate(3),(4-aminophenyl)acetic acid(4), ethyl-α-L-rhamnoside(5), methyl-α-L-rhamnoside(6), moringapyranosyl(7), 2-[4-(α-L-rhamnosyl)phenyl]methyl acetate(8), niaziridin(9), 5-hydroxymethyl furfural(10), 4-hydroxybenzeneacetamide(11), and 4-hydroxybenzoic acid(12). Among them, compounds 1 and 2 are two new compounds, compound 3 is a new natural product, and compounds 4-5 were yielded from Moringa plant for the first time. All compounds were evaluated for α-glucosidase inhibitory activity in vitro. Compound 10 showed excellent inhibitory activity with IC_(50) of 210 µg·mL~(-1).

Relative bradycardia presented as a clinical feature of Brucella melitensis infection: A case report.

Brucellosis, caused by Brucella species, is an infectious disease transmitted through contact with infected animals or their secretions. The clinical disease is characterized by fever and headache. Relative bradycardia is an inappropriate response of heart rate to body temperature, in which the heart rate does not increase proportionally despite a high fever. In this report, we document one case of Brucella melitensis infection demonstrating relative bradycardia. To our knowledge, this is the first report of relative bradycardia in a patient with brucellosis.

Long noncoding RNA MALAT1 promotes high glucose-induced inflammation and apoptosis of vascular endothelial cells by regulating miR-361-3p/SOCS3 axis.

Vascular complications are the important pathophysiologic manifestations of patients with diabetes mellitus (DM) and many long non-coding RNAs (LncRNAs) are involved in this process. In this study, we aimed to investigate the relationships among LncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), microRNA-361-3p (miR-361-3p), and suppressor of cytokine signaling 3 (SOCS3) in high glucose (HG)-induced human umbilical vein endothelial cell (HUVEC) injury and its underlying mechanism. We found that HG treatment significantly promotes MALAT1 and SOCS3 expressions, but inhibits miR-361-3p expression in HUVECs. Furthermore, through bioinformatics analysis and dual luciferase assay, we found that MALAT1 directly sponges miR-361-3p to counteract its suppression on SOCS3 expression. Moreover, knockdown of MALAT1 evidently inhibits HG-induced inflammatory factors, including tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß) and IL-6 expressions in HUVECs (and HUVEC apoptosis) by regulating the miR-361-3p/SOCS3 axis. In conclusion, our results indicate that knockdown of MALAT1 inhibits HG-induced vascular endothelial injury through regulating miR-361-3p/SOCS3 axis, suggesting that inhibition of MALAT1 as a potential target for endothelial injury therapy for DM.

Screening and separation of α-amylase inhibitors from Solanum nigrum with amylase-functionalized magnetic graphene oxide combined with high-speed counter-current chromatography.

A screening method using α-amylase-functionalized magnetic graphene oxide combined with high-speed counter-current chromatography was proposed and utilized to screen and separate α-amylase inhibitors from extract of Solanum nigrum. The α-amylase-functionalized magnetic graphene oxide was characterized and found to demonstrate satisfactory structure, magnetic response (24.5 emu/g), and reusability (retained 90% of initial activity after five cycles). The conditions for the screening with α-amylase functionalized magnetic graphene oxide were optimized and set at pH 7.0 and 25°C. As a result, two potent flavonoid compounds, apigenin-7-O-glucuronide (1) and astragalin (2), were separated and collected through high-speed counter-current chromatography and subjected to high-performance liquid chromatography analysis with purity higher than 90% (according to HPLC data), which were identified as α-amylase inhibitors. These results suggested that utilization of α-amylase functionalized magnetic graphene oxide in the rapid screening and isolation bioactive compounds from complex natural products is a feasible and environmentally friendly method.

Rapid Screening and Identification of BSA Bound Ligands from Radix astragali Using BSA Immobilized Magnetic Nanoparticles Coupled with HPLC-MS.

Radix astragali is widely used either as a single herb or as a collection of herbs in a complex prescription in China. In this study, bovine serum albumin functionalized magnetic nanoparticles (BSA-MN) coupled with high performance liquid chromatography-mass spectrometry (HPLC-MS) were used to screen and identify bound ligands from the n-butanol part of a Radix astragali extract. The prepared BSA-MN showed sufficient magnetic response for the separation with an ordinary magnet and satisfied reusability. Fundamental parameters affecting the preparation of BSA-MN and the screening efficiency were studied and optimized. Under the optimum conditions, four bound ligands were screened out from the n-butanol part of a Radix astragali extract and identified as genistin (1), calycosin-7-O-ß-d-glucoside (2), ononin (3) and formononetin (4). This effective method could be widely applied for rapid screening and identification of active compounds from complex mixtures without the need for preparative isolation.

Isolation of α-Amylase Inhibitors from Kadsura longipedunculata Using a High-Speed Counter-Current Chromatography Target Guided by Centrifugal Ultrafiltration with LC-MS.

In this study, a high-speed counter-current chromatography (HSCCC) separation method target guided by centrifugal ultrafiltration with high-performance liquid chromatography-mass spectrometry (CU-LC-MS) was proposed. This method was used to analyze α-amylase inhibitors from Kadsura longipedunculata extract. According to previous screening with CU-LC-MS, two screened potential α-amylase inhibitors was successfully isolated from Kadsura longipedunculata extract using HSCCC under the optimized experimental conditions. The isolated two target compounds (with purities of 92.3% and 94.6%) were, respectively, identified as quercetin-3-O-rhamnoside (1) and protocatechuic acid (2) based on the MS, UV, and ¹H-NMR spectrometry data. To verify the inhibition of screened compounds, the inhibitory activities of quercetin-3-O-rhamnoside (1) and protocatechuic acid (2) on α-amylase were tested, and it demonstrated that the experimental IC50 values of quercetin-3-O-rhamnoside (1) and protocatechuic acid (2) were 28.8 and 12.5 µmol/L. These results proved that the hyphenated technique using CU-LC-MS and HSCCC was a rapid, competent, and reproductive method to screen and separate potential active compounds, like enzyme inhibitors from the extract of herbal medicines.

Analysis of α-amylase inhibitor from corni fructus by coupling magnetic cross-linked enzyme aggregates of α-amylase with HPLC-MS.

As a carrier-free immobilization strategy, magnetic cross-linked enzyme aggregates (MCLEAs) showed improved enzyme activity, stability and magnetic response. In this study, MCLEAs of α-amylase (MCLEAs-amylase) was prepared under optimized conditions and characterized with scanning electron microscope and vibrating sample magnetometer. The prepared MCLEAs-amylase showed an amorphous structure and the saturation magnetization was 33.5emu/g, which was sufficient for magnetic separation. Then MCLEAs-amylase coupled with high performance liquid chromatography-mass spectrometry (HPLC-MS) was utilized to screen and identify α-amylase inhibitors from ethyl acetate extract of corni fructus. The experiment conditions were optimized. At the optimum conditions (incubation time: 10min, pH: 7.0 and temperature: 20°C), querciturone was successfully screened and identified with weak non-specific binding. The screening result was verified by inhibition assays and the IC50 value of querciturone was 22.5µg/mL. This method provided a rapid way to screen active compounds from natural products.

[Doxorubicin preconditioning instead of ischemic preconditioning in providing ischemic tolerance for rats abdomen island flaps].

OBJECTIVE: To investigate the effects and mechanism of doxorubicin preconditioning in providing ischemic tolerance for rats abdomen island flaps. METHODS: Twenty-four healthy adult Sprague Dawley rats, 12 males and 12 females, were randomly divided into 3 groups (n = 8): control group (group A), ischemic preconditioning group (group B), and doxorubicin preconditioning group (group C). After the abdomen island flap (6 cm x 3 cm in size) based on the superficial inferior epigastric neurovascular bundle was prepared, group A had no further treatment; group B was given a 10-minute ischemia followed by a 10-minute reperfusion for 4 times; and group C was given pretreatment with doxorubicin (1 mg/kg) by injection of the inferior epigastric vein. After 24 hours, the inferior epigastric vessels were blocked by vascular clamp for 4 hours, followed by reperfusion 2 hours to prepare ischemia/reperfusion (I/R) injury model. The rat survival was observed after operation; at 0, 8, 12, 24, and 30 hours after I/R injury, the malonyldiadehyde (MDA) and superoxide dismutase (SOD) levels were measured. At 7 days after I/R injury, the survival rate of flap were calculated and the flaps were harvested for histological observation. RESULTS: During experiment, 5 rats died (1 rat in groups A and B respectively, 3 rats in group C) and were added. The survival rates of the flap in group A (10.10% +/- 0.43%) was lower than those in group B (91.63% +/- 1.76%) and in group C (92.75% +/- 1.48%) at 7 days after I/R injury, showing significant differences (P < 0.05), and there was no significant difference between groups B and C (t = 0.29, P = 0.77). Significant difference was found in MDA level and SOD level between group A and groups B, C after 8 hours (P < 0.05), and there was no significant difference between groups B and C (P > 0.05). Histological observation showed that inflammatory cells infiltration was more obvious and hyperplasia of fibers was weaker in group A than in groups B and C. CONCLUSION: Doxorubicin preconditioning can provide ischemic tolerance for rats abdomen island flaps and protect flaps from the I/R injury. The possible mechanism may be related to that doxorubicin can induce endogenous protections.

[Study the effect of antisense MMP-2 by transfection of ad-aMMP-2 on vascular endothelial cells from human proferating hemangiomas in vitro].

OBJECTIVE: To investigate the effect of antisense MMP-2 by transfecting the Ad-aMMP-2 on the vascular endothelial cells (VEC) derived from human proferating hemangiomas in vitro. METHODS: Three groups. Group M199, Group Ad-GFP and Group Ad-aMMP-2 were tested in this study with the 100 multiplicity of infection (MOI). Reverse transcription PCR (RT-PCR), Western Blotting and Gelatin Zymography analyses were applied to evaluate the level of endogenous MMP-2 expression. RESULTS: The decreased expression level of endogenous MMP-2 mRNA and protein excretion of MMP-2 and Gelatin Zymography analyses of liveness of Group Ad-aMMP-2 were observed by comparison with Group M199 and Group Ad-GFP (P<0.05). CONCLUSION: Ad-aMMP-2 could inhibit the secretion of MMP-2 from VEC in vitro.