Fabrication and characterization of a composite monolithic guard column for the analysis of active components contained in medicinal plants using high-performance liquid chromatography.

A composite monolithic column was prepared via polymerization in a 10-mm-long tube, using a porphyrin-based covalent organic framework (COF) as the co-monomer. The fabricated monolith exhibit good permeability, relatively uniform porous structure and high specific surface area, which was used as a guard column prior to an analytical column for the analysis of active components in medicinal plants with HPLC. Ten kinds of medicinal plants were used as the samples, in which sixteen target components were separated and analyzed, as well as the fingerprints of herb and herb couple. Compared to a generally used commercial VAST silica gel-C18 guard column, the homemade guard column shows good permeability with fast mass transfer, short analytical time and strong reusability with more than 100 injections, thus indicating the present monolith is an outstanding guard column prior to the C18 analytical column for the analysis of multiple active components in various medicinal plants.

Relative bioavailability of humate-manganese complex for broilers fed a corn-soya bean meal diet.

The experiment was conducted to investigate the bioavailability of manganese (Mn) from humate-Mn complex relative to Mn sulphate for the starter broilers fed a conventional corn-soya bean meal diet. A total of 560 1-day-old Arbor Acres male broiler chicks were randomly allotted to one of eight replicate cages (10 chicks per cage) for each of seven treatments in a completely randomized design involving a 2 × 3 factorial arrangement of treatments with two Mn sources (humate-Mn and Mn sulphate) and three levels of added Mn (60, 120 or 180 mg Mn/kg) plus a Mn-unsupplemented control diet containing 27.23 mg Mn/kg by analysis. At 14 days of age, the blood, liver, heart and tibia were collected for Mn analyses, and the activity and mRNA abundance of heart manganese superoxide dismutase (MnSOD). The results showed that humate-Mn supplementation decreased feed intake from day 1 to day 14, whereas it did not influence (p > 0.20) body weight at day 14 as compared to Mn sulphate. The Mn source did not influence Mn concentration in the liver, heart and tibia, and the activity and mRNA abundance of heart MnSOD, while humate-Mn decreased plasma Mn as compared to Mn sulphate. The Mn concentration in the plasma and heart, and the activity and mRNA abundance of heart MnSOD increased linearly as dietary Mn concentration increased. Based on slope ratios from multiple linear regressions of Mn concentrations in the plasma and heart, and the activity and mRNA abundance of heart MnSOD on daily intake amount of dietary analysed Mn, the bioavailability of humate-Mn complex relative to Mn sulphate (100%) was 82.8, 90.4, 82.8 and 81.9 respectively. These results indicated that the Mn from humate-Mn complex was just as bioavailable as the Mn from Mn sulphate for the starter broilers (day 1-14).

The anti-obesity and anti-diabetic effects of kaempferol glycosides from unripe soybean leaves in high-fat-diet mice.

The present study investigated the anti-obesity and anti-diabetic effects of kaempferol glycoside (KG) fractions which were composed of four kaempferol glycosides and purified from unripe Jindai-soybean (Edamame) leaves in C57BL/6J mice. High fat-fed mice treated with 0.15% dietary KG for 92 days had reduced body weight, adipose tissue and TG levels compared to the high fat-fed control group. KG-treatment also decreased fasting blood glucose, serum HbA1c (hemoglobin A(1c)) levels and improved insulin resistance. Gene expression analysis of the liver showed that KG decreased peroxisome proliferator-activated receptor (PPAR-γ) and sterol regulatory element-binding protein (SREBP-1c) expression. These results suggest that KG reduced the accumulation of adipose tissue, improving hyperlipidemia as well as diabetes in obese mice by increasing lipid metabolism through the downregulation of PPAR-γ and SREBP-1c. Thus, KG may have an anti-obesity and anti-diabetic potential.

(-)-Epigallocatechin gallate suppresses proliferation of vascular smooth muscle cells induced by high glucose by inhibition of PKC and ERK1/2 signalings.

Proliferation of vascular smooth muscle cells (VSMCs) plays an important role in the development and progression of diabetes-related vascular complications. (-)-Epigallocatechin gallate (EGCG), the major catechin derived from green tea, is able to exert antidiabetes effects in animal models. However, it is not known whether or not EGCG inhibits VSMC proliferation induced by high glucose. This study tested the hypothesis that EGCG might have an inhibitory effect on VSMC proliferation induced by high glucose. VSMC proliferation was determined by [(3)H]-thymidine incorporation and uptake of 3-(4,5-dimethylthiazol-2-yl)-diphenyltetrazolium bromide (MTT). Extracellular signal-regulated kinase (ERK) 1/2 phosphorylation was determined by immunoblotting, and ERK 1/2 activity was detected by measuring the ability to phosphorylate its substrate Elk-1. Glucose increased VSMC proliferation in a concentration-dependent manner, which was reduced in the presence of EGCG. VSMC proliferation mediated by high glucose (30 mM) was involved in protein kinase C (PKC) and ERK1/2 signalings, because its effect was blocked by PKC inhibitor (PKC inhibitor 19-31) and ERK1/2 inhibitor (PD98059). Pretreatment of VSMCs with EGCG significantly inhibited the stimulatory effect of high glucose on PKC and ERK1/2 activation, followed by attenuation of its downstream transcription factor Elk-1 phosphorylation. Taken together, these results suggest that EGCG could suppress VSMC proliferation induced by high glucose by inhibition of PKC and ERK1/2 signalings in VSMCs, which indicates that EGCG might be a possible medicine to reduce vascular complications in diabetes.