Yu Cai

Publications of Yu Cai

• Triterpenes from the fungus Poria cocos and their inhibitory activity on nitric oxide production in mouse macrophages via blockade of activating protein-1 pathway.

  Authors: Tian-Ge Cai, Yu Cai

  Chemistry & biodiversity. 11/2011; 8(11):2135-43.

  Two new triterpenes, 29-hydroxydehydrotumulosic acid (1) and 29-hydroxydehydropachymic acid (2), together with six known compounds, dehydropachymic acid (3), dehydrotumulosic acid (4),Two new triterpenes, 29-hydroxydehydrotumulosic acid (1) and 29-hydroxydehydropachymic acid (2), together with six known compounds, dehydropachymic acid (3), dehydrotumulosic acid (4), 29-hydroxypolyporenic acid C (5), polyporenic acid C (6), tumulosic acid (7), and pachymic acid (8), were isolated from the dried sclerotia of Poria cocos. In the in vitro bioassays, these isolated compounds reduced, in a dose-dependent manner, nitric oxide (NO) production from lipopolysaccharide (LPS)-induced RAW 264.7 cells, with compounds 5 and 6, the IC(50) values of which were 16.8±2.7 and 18.2±3.3 μM, respectively, exhibiting the greatest inhibition activity. Further Western blot analysis conducted on cells pre-treated with compounds 5 and 6, and luciferase assays on activator protein 1-dependent gene expression revealed that the inhibited NO release was attributed to the reduced expression of iNOs (=inducible NO synthase) enzymes, which might be regulated via the blockade of activator protein-1 signaling pathway.

• cis-Ampelopsin E, a stilbene isolated from the seeds of Paeonia suffruticosa, inhibits lipopolysaccharide-stimulated nitric oxide production in RAW 264.7 macrophages via blockade of nuclear factor-kappa B signaling pathway.

  Authors: Tiange Cai, Yu Cai

  Biological & pharmaceutical bulletin. 01/2011; 34(9):1501-7.

  Stilbenes are a class of compounds that has been reported to inhibit a variety of pathological processes during inflammatory reactions. In this study, cis-ampelopsin E, a stilbene isolated from theStilbenes are a class of compounds that has been reported to inhibit a variety of pathological processes during inflammatory reactions. In this study, cis-ampelopsin E, a stilbene isolated from the seeds of Paeonia suffruticosa, was shown to dose-dependently reduce the nitric oxide (NO) production from lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. The reduction in the nitric oxide release occurred in parallel with the comparable inhibition of inducible nitric oxide synthase (iNOS) enzyme expression, which was achieved by cis-ampelopsin E's suppressive effect on nuclear factor-kappa B (NF-κB) signaling activation. By inhibiting LPS-induced inhibitor kinase (IKKα/β) phosphorylation, cis-ampelopsin E significantly decreased LPS-induced IκBα phosphorylation, prevented IκBα degradation, and subsequently reduced the translocating of transcription factor p65 into the nucleus. As a result, the LPS-induced upregulation of NF-κB transcriptional activity was efficiently inhibited. Moreover, it is revealed that cis-ampelopsin E inhibited LPS-induced cyclooxygenase-2 (Cox-2) expression, cPLA2 activation and prostaglandin E2 (PGE2) production. These results, taken together, suggested that cis-ampelopsin E might exert potential anti-inflammatory effects via blockage of the NF-κB signaling pathway.

• Two new aristolochic acid derivatives from the roots of Aristolochia fangchi and their cytotoxicities.

  Authors: Yu Cai, Tian-Ge Cai

  Chemical & pharmaceutical bulletin. 08/2010; 58(8):1093-5.

  Phytochemical investigation of 90% ethanol extracts of the roots of Aristolochia fangchi yielded two new aristolochic acid derivatives named Aristolochic Acid F and Aristolochic Acid G, together withPhytochemical investigation of 90% ethanol extracts of the roots of Aristolochia fangchi yielded two new aristolochic acid derivatives named Aristolochic Acid F and Aristolochic Acid G, together with three known compounds. Their structures were elucidated by spectral analysis. The cytotoxicity of the isolated compounds was also determined.