ABSTRACT
In order to clarify the influence of acute hypobaric hypoxia on the bile acids of the rat small intestine, we used ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) to identify bile acids in the contents of the small intestine from untreated and acute hypobaric hypoxia-treated rats. Thirty-nine bile acids were detected; PCA and OPLS-DA analysis revealed marked differences in the composition of bile acids between the untreated and the acute hypobaric hypoxia groups. Bile acids were screened with VIP > 1, |log2FC| ≥ 1, P < 0.05, and a total of 7 bile acids with significant differences in content between the two groups were obtained, including 5 conjugated bile acids, 2 unconjugated bile acids; in addition, the content of conjugated bile acids has risen in the treated group. This study demonstrated the influence of high-altitude hypoxic environment on bile acid composition and metabolism in rats. All the animal experiments in this study were approved by the 940th Hospital Ethics Committee (approval No: 2020KYLL012).
ABSTRACT
In this study, the change of intestinal microflora in rat fecal samples after amoxicillin administration was observed. In vitro incubation experiments combined with LC-MS/MS assay were used to test the role of intestinal flora in the metabolism of nifedipine. The effect of changes of intestinal flora was determined after amoxicillin administration on the metabolism of nifedipine. We found that the number and types of intestinal flora decreased after taking amoxicillin. After incubation for 12 h, the results showed that the remaining amounts of nifedipine in the N1 group (nifedipine) and N2 group (amoxicillin + nifedipine) were 0.057 6 and 0.064 8 μmol·L-1, respectively, while the remaining amounts of nifedipine after 24 h of incubation were 0.039 6 and 0.050 4 μmol·L-1, respectively. These results show that the intestinal flora is involved in the metabolism of nifedipine. After administration of amoxicillin, the metabolism of nifedipine was slowed down, the AUC0-t was increased by 39.10%, tmax was advanced by 0.45 h, and the CL was reduced 34.71%. The data suggest that the combination may enhance the therapeutic effect of nifedipine. Therefore, drug-drug interactions mediated by gut microbiota cannot be ignored when combined with antibiotics and nifedipine, one of the important factors affecting drug efficacy.
ABSTRACT
The drug transporter play a key role in the absorption of drugs. Investigation of the changes of drug transporters in response to hypoxia will provide insight into the mechanism of drug absorption. In this study we investigated the mRNA and protein expression of the transporter P-gp after acute hypoxia, and evaluated the effects of P-gp changes on absorption of levofloxacin in the intestine. The relative expression of mRNA and protein were reduced by 50.80% and 71.30% (PP<0.05). These results suggest that hypoxia may decrease the expression of P-gp in the intestine to reduce the excretion of levofloxacin and increase the absorption.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the effects of cis-combretastatin-A1 phosphate (cis-CA1P) on tumor cell proliferation, and its effects on the blood vessel formations.</p><p><b>METHODS</b>MTT and IC50 values were used to assess the inhibitory effects of cis-CA1P on tumor cell proliferation. Chicken embryo chorioallantoic membrane and thoracic aorta annulations isolated from rats were used to investigate the effects of cis-CAIP on the blood vessel formation.</p><p><b>RESULTS</b>Cis-CA1P concentration-dependently inhibited the proliferations of several cancer cell lines, including human gastric carcinoma cell line MGC-803, human leukemic monocyte lymphoma cell line U937, human melanoma cell line A375, human colon cancer cell line HCT116, human breast carcinoma cell line MDA-MB-231, and human leukemia cell line K562. Cis-CAIP significantly decreased the formation of blood vessels in chicken embryo chorioallantoic membrane and in thoracic aorta annulations.</p><p><b>CONCLUSION</b>Cis-CA1P inhibits cancer cell proliferation and prevents blood vessel formation.</p>