ABSTRACT
A rapid liquid chromatography_tandem mass spectrometric ( LC_MS/MS) method was developed for the determination of aflatoxin B1(AFB1), Deoxynivalenol (DON), Zearalenone (ZEA) in artificial porcine gastrointestinal digested juices, as pigs reacted most sensitively to these mycotoxins. The formula feed was digested by artificial gastric and intestinal juices respectively, then the mycotoxins and adsorbent were added in ratio. After incubation and centrifugation, the supernatant was diluted 10_folds by injection solution and analyzed by LC_MS/MS. The 3 analytes were separated on a reversed phase C18 column using a gradient elution program of aqueous solution containing 0 . 2 mmol/L ammonium acetate and 0 . 1% formic acid methanol. Qualitative analysis was performed using multiple_reaction monitoring ( MRM ) , and quantitative analysis was by internal standard method. Under optimum conditions, the limit of quantitation ( LOQ ) of AFB1 , DON, ZEA was 1, 50, 40 and 0. 3, 50, 20 μg/L in artificial gastric and intestinal digested juices respectively, and the relative standard deviations (RSDs) were below 5. 0%. Then, the thermal stability was studied by incubating the analytes at 39 ℃±0. 5 ℃ for 1, 2, 5 and 10 h, and the results showed 3 analytes were stable under the conditions. Furthermore, the method was applied to evaluate the binding efficacy of 8 mineral benders and 5 organic adsorbents. The adsorbents demonstrated binding efficacy of 85. 1%-96. 5%, 8 . 1%-14 . 7%, 13 . 7%-30 . 0% and 7 . 4%-16 . 6%, 6 . 7%-16 . 2%, 18 . 6%-39 . 0% in gastric digested juice, and 76. 2%-93. 0%, 12. 3%-31. 3%, 0%-23. 2% and 8. 6%-13. 4%, 3. 8%-23. 5%, 24. 9%-34. 8% in intestinal digested juice for these 3 mycotoxins, respectively, with 2 kinds of adsorbents.
ABSTRACT
<p><b>OBJECTIVE</b>To study the preventive effects of Lycium barbarum polysaccharide (LBP) on the development of alcoholic fatty liver (AFL) in rats and its possible mechanisms.</p><p><b>METHODS</b>One hundred twenty-five Wistar rats were randomly divided into 4 groups: a blank control group, with distilled water intragastric infusion (GI); an alcohol group, with alcohol GI; a 5% LBP plus alcohol GI group; and a 10% LBP plus alcohol GI group. Liver pathologic changes were studied together with the activity of serum ALT, AST, GGT, the activity of liver SOD, GSH-PX and the content of liver MDA, GSH, H2O2; CYP2E1 gene and protein expressions were also detected.</p><p><b>RESULTS</b>At the end of ten weeks, the activity of serum AST [(132.3+/-25.7) U/L, (127.5+/-29.1)U/L] and GGT [(1.9+/-0.5)U/L, (1.8+/-0.7)U/L] of the two LBP groups were all significantly lower than those of the alcohol group [serum AST (245.7+/-32.1) and GGT (4.4+/-0.6)]. At the end of ten weeks, the content of liver MDA [(5.1+/-0.3) nmol/mg, (5.1+/-0.4) nmol/mg] and H2O2 [(135.4+/-23.5) mmol/g, (132.6+/-31.8) mmol/g] of the two LBP groups were significantly lower than those of the alcohol group [MDA (14.5+/-3.2) nmol/mgprot) and H2O2 (328.5+/-45.6)]. The activity of SOD [(206.7+/-13.2)U/L, (203.2+/-18.8)U/L], GSH-PX [(13.5+/-1.4)U/mg/min, (13.6+/-1.5)U/mg/min] and the content of GSH [(65.1+/-11.0)mg/g, (66.6+/-11.1) mg/g] of the two LBP groups were all significantly higher than those of the alcohol group [SOD (116.5+/-13.6)U/mg/min, GSH-PX (7.2+/-1.6)U/mg/min and the content of GSH (30.5+/-10.7)mg/g] (P less than 0.01). At the end of five weeks, levels of CYP2E1 gene and protein expression of the two LBP groups were 0.39+/-0.04, 0.40+/-0.06 and 3.49+/-0.36, 3.29+/-0.30 respectively. At the end of ten weeks, levels of CYP2E1 gene and protein expression of the two LBP groups were 0.41+/-0.05, 0.42+/-0.08 and 3.58+/-0.30, 3.36+/-0.37 respectively. They were all significantly lower than those of the alcohol group [the gene expression (5 week: 0.74+/-0.05, 10 week: 1.02+/-0.08) and the protein expression (5 week: 5.63+/-0.44, 10 week: 7.90+/-0.26)]. There were no typical alcoholic fatty liver pathologic changes observed in the two LBP groups.</p><p><b>CONCLUSION</b>LBP can effectively prevent AFL. This may be due to its effects in inhibiting the hepatocyte CYP2E1 expression and prevention of lipid peroxidation.</p>