Advances and prospects of pharmacological activities of Dendrobium officinale Kimura et Migo polysaccharides / 药学学报

italic>Dendrobium officinale Kimura et Migo (D. officinale) has been used as a valuable traditional Chinese medicine for more than 2 000 years in China. Modern research has confirmed a wide range of pharmacological activities, such as regulating blood sugar, improving gastrointestinal inflammation, and regulating immunity. Polysaccharides are the main active ingredients of D. officinale. With the intensive studies of the pharmacological activities of D. officinale, evidence for the pharmacological effects and potential mechanisms of D. officinale polysaccharides has increased dramatically. In this review, we summarized the latest progress in the pharmacological and mechanical studies of D. officinale polysaccharides, and based on the pharmacological efficacy and oral absorption and utilization characteristics of D. officinale polysaccharides, it is proposed that regulating the gut microbiota may be one of the key mechanisms for D. officinale to exert its beneficial effects. Research on the mechanism of D. officinale polysaccharides puts forward new research directions and prospects.

Pandanus tectorius derived caffeoylquinic acids inhibit lipid accumulation in HepG2 hepatoma cells through regulation of gene expression involved in lipid metabolism / 药学学报

The fruit of Pandanus tectorius (PTF) has a long history of use as a folk medicine to treat hyperlipidemia in Hainan province, South China. Our previous studies have shown that the n-butanol extract of PTF is rich in caffeoylquinic acids and has an adequate therapeutic effect on dyslipidemic animals induced by high-fat diet. In this work, seven caffeoylquinic acids isolated from PTF were screened for the lipid-lowering activity in HepG2 hepatoma cells. Oil-Red O staining, microscopy and intracellular triglyceride (TG) and total cholesterol (TC) quantification showed that 3-O-caffeoylquinic acid (3-CQA), 3, 5-di-O-caffeoylquinic acid (3,5-CQA), and 3,4,5-tri-O-caffeoylquinic acid (3,4,5-CQA) significantly inhibited lipid accumulation induced by oleic acid and decreased intracellular levels of TC and TG in a dose-dependent manner. These three caffeoylquinic acids showed no significant cytotoxicity at concentrations of 1 -50 μmol x L(-1) as determined by MTT assay. Realtime quantitative PCR revealed that 3-CQA and 3, 5-CQA significantly increased the expression of lipid oxidation-related genes PPARα, CPT-1 and ACOX1 while 3-CQA, 3, 5-CQA and 3,4,5-CQA decreased the expression of lipogenic genes SREBP-1c, SREBP-2, HMGR, ACC, FAS. Overall, 3-CQA, 3, 5-CQA and 3, 4, 5-CQA may be the principal hypolipidemic components in PTF which can decrease intracellular lipid accumulation through up-regulating the expression of lipid oxidative genes and down-regulating the expression of lipogenic genes.

Development of a rapid multi-residue assay for detecting β-lactams using penicillin binding protein 2x* / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To develop a rapid multi-residue assay for detecting 16 demanded by the European Union (EU).</p><p><b>METHODS</b>A recombinant penicillin-binding protein (PBP) 2x* from Streptococcus pneumoniae R6 was expressed in vitro and six β-lactams were conjugated to HRP by four methods. A rapid multi-residue assay for β-lactams was established with PBP2x* and HRP-conjugate.</p><p><b>RESULTS</b>PBP2x* was expressed and purified successfully and the ideal HRP-conjugate was identified. The multi-residue assay was developed. After optimization, penicillin G, ampicillin, amoxicillin, cloxacillin, dicloxacillin, oxacillin, nafcillin, cephalexin, ceftiofur, cefalonium, cefquinome, cefazolin, cefoperazone, cephacetrile, and cephapirin can be detected at levels below MRL in milk with simple pretreatment.</p><p><b>CONCLUSION</b>This assay developed can detect all 16 β-lactams demanded by the European Union (EU). The whole procedure takes only 45 min and can detect 42 samples and the standards with duplicate analysis.</p>