PTP1B inhibitory and anti-inflammatory effects of secondary metabolites isolated from the marine-derived fungus Penicillium sp. JF-55.

ABSTRACT: Protein tyrosine phosphatase 1B (PTP1B) plays a major role in the negative regulation of insulin signaling, and is thus considered as an attractive therapeutic target for the treatment of diabetes. Bioassay-guided investigation of the methylethylketone extract of marine-derived fungus Penicillium sp. JF-55 cultures afforded a new PTP1B inhibitory styrylpyrone-type metabolite named penstyrylpyrone (1), and two known metabolites, anhydrofulvic acid (2) and citromycetin (3). Compounds 1 and 2 inhibited PTP1B activity in a dose-dependent manner, and kinetic analyses of PTP1B inhibition suggested that these compounds inhibited PTP1B activity in a competitive manner. In an effort to gain more biological potential of the isolated compounds, the anti-inflammatory effects of compounds 1-3 were also evaluated. Among the tested compounds, only compound 1 inhibited the production of NO and PGE2, due to the inhibition of the expression of iNOS and COX-2. Penstyrylpyrone (1) also reduced TNF-? and IL-1? production, and these anti-inflammatory effects were shown to be correlated with the suppression of the phosphorylation and degradation of I?B-?, NF-?B nuclear translocation, and NF-?B DNA binding activity. In addition, using inhibitor tin protoporphyrin (SnPP), an inhibitor of HO-1, it was verified that the inhibitory effects of penstyrylpyrone (1) on the pro-inflammatory mediators and NF-?B DNA binding activity were associated with the HO-1 expression. Therefore, these results suggest that penstyrylpyrone (1) suppresses PTP1B activity, as well as the production of pro-inflammatory mediators via NF-?B pathway, through expression of anti-inflammatory HO-1.

SUBMITTER: Lee DS 

PROVIDER: S-EPMC3705412 | biostudies-literature | 2013 Apr

REPOSITORIES: biostudies-literature