Analysis of cantharidin-induced kidney injury and the protective mechanism of resveratrol in mice determined by liquid chromatography/mass spectrometry-based metabonomics.

Cantharidin (CTD) is the main active component in the traditional Chinese medicine Mylabris and an effective anti-tumor agent. However, it is relatively toxic and exhibits nephrotoxicity, which limits its clinical use. However, its toxic mechanism is not clear. The toxic effects of CTD exposure on the kidney and the protective effect of resveratrol (RES) were studied in a mouse model, by determination of serum biochemical and renal antioxidant indicators, histopathological and ultrastructural observation, and metabonomics. After CTD exposure, serum uric acid, creatinine, and tissue oxidative stress indicators increased, and the renal glomerular and tubular epithelial cells showed clear pathological damage. Ultrastructure observation revealed marked mitochondrial swelling, endoplasmic reticulum dilation, and the presence of autophagy lysosomes in glomerular epithelial cells. RES ameliorated the renal injury induced by CTD. Metabonomics analysis indicated that CTD can induce apoptosis and oxidative damage in kidney cells, mainly by disrupting sphingolipid and glutathione metabolism, increasing sphingosine and sphingomyelin levels, and decreasing glutathione levels. RES counteracts these effects by regulating renal cell proliferation, the inflammatory response, oxidative stress, and apoptosis, by improving the levels of phosphatidylcholine (PC), LysoPC, and lysophosphatidyl glycerol in the glycerophospholipid metabolism pathway, thereby reducing CTD-induced nephrotoxicity. The mechanisms of CTD-induced renal injury and the protective effect of RES were revealed by metabonomics, providing a basis for evaluating clinical treatment regimens to reduce CTD-induced nephrotoxicity.

Chemical components characterization and in vivo metabolites profiling of Lingbao Huxin Dan by gas chromatography-mass spectrometry and ultra-high-performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry.

Lingbao Huxin Dan (LBHX) is an effective prescription for treating various cardiovascular diseases. However, its systematic chemical composition analysis and important marker components remain unclear, which hinders the development of standards or guidelines for quality evaluation. Herein, a high-resolution and efficient method was established to comprehensively investigate the chemical ingredients and metabolites of LBHX by using gas chromatography-tandem mass spectrometry and ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. AutoDock Vina was applied to conduct visual screening for identifying potential active compounds targeting two important sick sinus syndrome-associated proteins. As a result, 53 volatile compounds, as well as 191 non-volatile chemical components, including bufadienolides, diterpenoids, bile acids, phenolic acids, and triterpenoid saponins, were unambiguously characterized or tentatively identified. Fifty prototypes and 62 metabolites were identified in the plasma of rats, whilst metabolism reactions included phase I reactions (hydrolysis, oxidation, and hydroxylation) and phase II reactions (glucuronidation and methylation). Eleven compounds with good binding affinity have been observed by docking with key proteins. It is the first systematic study on the pharmacodynamic material basis of LBHX and the result consolidates the foundation for further study regarding the mechanism in treating cardiovascular diseases.

A novel nanobody and mimotope based immunoassay for rapid analysis of aflatoxin B1.

Mimotopes could replace mycotoxins and their conjugates to develop immunoassay methods. The mimotopes obtained by phage display technology were mainly using monoclonal antibodies or polyclonal antibodies as targets. However, the mimotope of recombinant antibody has not been selected and applied to immunoassay for mycotoxin. The purpose of this study was to prove that an immunoassay for mycotoxin could be developed based on both recombinant antibody and its mimotope. Using aflatoxin B1 (AFB1) as a model system, mimotopes of an aflatoxin nanobody Nb28 were screened by phage display. A rapid magnetic beads-based directed competitive ELISA (MB-dcELISA) was developed utilizing Nb28 and its mimotope ME17. The 50% inhibitory concentration and the detection limit of the MB-dcELISA were 0.75 and 0.13 ng/mL, respectively, with a linear range of 0.24-2.21 ng/mL. Further validation study indicated good recovery (84.2-116.2%) with low coefficient of variable (2.2%-15.9%) in spiked corn, rice, peanut, feedstuff, corn germ oil and peanut oil samples. The developed immunoassay based on nanobody and mimotope provides a new strategy for the monitoring of AFB1 and other toxic small molecular weight compounds.