ABSTRACT
ObjectiveTo observe the effect of the combination of total saponin of Astragali Radix-total alkaloids of Nelumbinis Folium on reversal cholesterol transport （RCT） in hyperlipidemia rats， and to discuss its mechanism. MethodSixty SD rats were randomly divided into control group， high-fat diet group， total saponin of Astragali Radix-total alkaloids of Nelumbinis Folium low （17 mg·kg-1+40 mg·kg-1）， middle （34 mg·kg-1+80 mg·kg-1）， high dose （68 mg·kg-1+160 mg·kg-1） groups and simvastatin （2.1 mg·kg-1） group， with 10 mice in each group. The Hyperlipidemia model was duplicated by feeding rats with a high-fat diet for 6 weeks. From the 3rd week， except for the control group and the high-fat diet group given distilled water， other groups were given corresponding drugs intragastric treatment for 4 weeks. The changes in blood lipid and liver function of rats were detected by an automatic biochemical analyzer. Hematoxylin-eosin （HE） and oil red O staining were used to observe the pathological morphological changes and steatosis of rat liver tissue. The contents of total cholesterol （TC） and total bile acid （TBA） in rat liver tissue and feces were determined by a semi-automatic biochemical analyzer. The mRNA and protein expression levels of peroxisome proliferators-activated receptors γ （PPARγ）， liver X receptors α （LXRα）， ATP-binding cassette transporter G1 （ABCG1） and cholesterol 7α-hydroxylase （CYP7A1） in rat liver tissue were detected by Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） and Western blot. ResultCompared with the control group， the contents or activities of TC， triglyceride （TG）， low-density lipoprotein cholesterol （LDL-C）， TBA， aspartate aminotransferase （AST）， alanine aminotransferase （ALT） in serum were significantly increased （P<0.01）， and the contents of high-density lipoprotein cholesterol （HDL-C） in the high-fat diet group were significantly decreased （P<0.01）. The hepatocyte was clearly swollen like ballooning degeneration， with a lot of fat vacuoles and red fat droplets. The contents of TC and TBA in liver tissue and feces were significantly increased （P<0.01）， and the mRNA and protein expression levels of PPARγ， LXRα， ABCG1， and CYP7A1 in liver tissue were significantly decreased （P<0.01）. Compared with the high-fat diet group， the contents or activities of TC， TG， LDL-C， TBA， AST， and ALT in the serum of rats in administered groups were significantly decreased （P<0.01）， while the content of HDL-C was significantly increased （P<0.01）. Hepatocyte swelling was significantly reduced， and the ballooning degeneration， fat vacuoles， and red lipid droplets in liver tissue were significantly decreased. The contents of TC and TBA in liver tissue were significantly decreased （P<0.05， P<0.01）， and the contents of TC and TBA in feces were significantly increased （P<0.05， P<0.01）. The mRNA and protein expression levels of PPARγ， LXRα， ABCG1， and CYP7A1 in liver tissue were significantly increased （P<0.05， P<0.01）. ConclusionTotal saponin of Astragali Radix-total alkaloids of Nelumbinis Folium has a positive effect on the prevention and treatment of hyperlipidemia rats， and its mechanism may be related to the activation of PPARγ/LXRα/ABCG1 signaling pathway and regulation of RCT.
ABSTRACT
Objective@#To investigate the antimicrobial resistance and molecular epidemiology of foodborne Yersinia (Y.) enterocolitica in Pudong New District of Shanghai.@*Methods@#Four kinds of raw food samples were collected in retail circulation sites in Pudong from 2012 to 2016. Cold enrichment method was used to isolate Y. enterocolitica and further detection of biotype, serotype, virulent genes, antimicrobial susceptibility of the isolates and pulsed field gel electrophoresis (PFGE) were conducted.@*Results@#A total of 3 900 raw food samples were collected during this period, including poultry product (n=590), livestock product (n=1 074), aquatic product (n=1 488), vegetable (n=748), in which 111 (2.8%) were contaminated by Y. enterocolitica. The detection rates of Y. enterocolitica in poultry product samples (5.3%, 31/590) and livestock product samples (4.5%, 48/1 074) were higher than those in aquatic product samples (1.6%, 24/1 488) and vegetable samples (1.1%, 8/748). The predominant biotype was 1A (95.5%) and predominant serotype was O∶8 (42.3%). All the strains lacked ail, ystA, yadA and virF genes, which encoded pathogenic Y. enterocolitica. Seventy six (68.5%) strains harbored ystB gene, in which 35 (31.5%) belonged to 1A/O∶8/ystB pattern. Most strains were resistant to ampicillin (74.8%) and amoxicillin/clavulanic acid (70.3%), and non-sensitive rate to Cefoxitin was over 50.0%. No third generation cephalosporin or fluoroquinolone resistant strains were detected, but 38.7% (43/111) strains were multidrug resistant (MDR). Serotype O∶8 and O∶5 strains had 44 and 18 PFGE patterns, respectively.@*Conclusions@#The main foodborne exposure sources of Y. enterocolitica in raw food were poultry and livestock products in Pudong New District. 1A/O∶8/ystB was the predominant pattern with potential pathogenicity despite lacks of typical pathogenic virulent genes. The antimicrobial resistant rates of Y. enterocolitica were at a low level, but MDR strains still existed. Molecular types of the isolates showed highly genetic diversity.