Proteomic detection of changes in protein expression induced by cordycepin in human hepatocellular carcinoma BEL-7402 cells

The nucleoside analogue cordycepin (3'-deoxyodenosine, 3'-dA), one of the components of cordyceps militaris, has been shown to inhibit the growth of various tumor cells. However, the probable mechanism is still obscure. In this study, the inhibition of cell growth and changes in protein expression induced by cordycepin were investigated in BEL-7402 cells. Using the MTT assay and flow cytometry, we found that cordycepin inhibits cell viability and induces apoptosis in BEL 7402 cells. Additionally. the proteins were separated using two-dimensional polyacrylamide gel electrophoresis, and eight proteins were found to be significantly, affected by cordycepin compared to untreated control; among them, two were downregulated and six were upregulated. Of the eight proteins, six were identified with peptide mass fingerprinting using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) after in-gel trypsin digestion. These proteins are involved in various aspects of cellular metabolism. It is suggested that the effect of cordycepin on the growth of tumor cells is significantly related to the metabolism-associated protein expression induced by cordycepin. Copyright 2008 Prous Science, S.A.U. or its licensors. All rights reserved.

In vitro activities of small peptides from snake venom against clinical isolates of drug-resistant Mycobacterium tuberculosis

The recent re-emergence of tuberculosis, especially the multidrug-resistant cases, has highlighted the importance of screening effective novel drugs against Mycobacterium tuberculosis. In this study, the in vitro activities of small peptides isolated from snake venom were investigated against multidrug-resistant M. tuberculosis. Minimum inhibitory concentrations (MICs) were determined by the Bactec TB-460 radiometric method. A small peptide with the amino acid sequence ECYRKSDIVTCEPWQKFCYREVTFFPNHPVYLSGCASECTETNSKWCCTTDKCNRARGG (designated as vgf-1) from Naja atra (isolated from Yunnan province of China) venom had in vitro activity against clinically isolated multidrug-resistant strains of M. tuberculosis. The MIC was 8.5 mg/l. The antimycobacterial domain of this 60aa peptide is under investigation. (C) 2003 Elsevier Science B.V. and the International Society of Chemotherapy. All rights reserved.