OBJECTIVETo evaluate effect of amygdalin on expression of four biomarkers in the animal model of pulmonary fibrosis induced by bleomycin.

METHODSRats were given one dose (5 mg/kg) of bleomycin in bleomycin-treated groups, amygdalin-treated groups and saline in controls by intratracheal instillation exposed surgically. The amygdalin-treated groups rats were treated with intraperitoneal injection of amygdalin (15 mg x kg(-1) x day(-1)). The rats were sacrificed 7, 14 and 28 days after bleomycin administration. Polarized light microscopy and Image-Pro Plus detected I and III collagen expressed in Paraffin-embedded lung sections stained with Sirius red. Surface-enhanced laser desorption-ionization time-of-flight mass spectrometry (SELDI-TOF MS) with weak cationic proteinchip (CM10) detected differentially expressed proteins in the pooled serum samples of all groups.

RESULTSConsistent fibrotic responses were found in all bleomycin and amygdalin-tread groups. On the 7th, 14th and 28th day after bleomycin or saline instillation, four differentially expressed proteins were detected in the pooled serum of all groups rats, consisting of 4 proteins with mass/charge ratio of 3530.7, 7043.5, 8332.6 and 9068.0, respectively. Compared with control groups, protein peaks intensity ratio with mass/charge ratio of 3530.7 on 7, 28 d and 7043.5, 8332.6 and 9068.0 on 7, 14 and 28 d was > 2 in bleomycin-treated groups. Compared with amygdalin-treated groups, protein peaks intensity with mass/charge ratio of 3530.7 at 7, 14, 28 d had no change almost, but protein peaks intensity ratio with mass/charge ratio of 7043.5 at 7 d, 8332.6 on 28 d and 9068.0 on 14 d was > 2 in bleomycin-tread groups. All the four protein peaks intensity had no change almost at other point.

CONCLUSIONAmygdalin may reduce the bleomycin-induced increase of differentially expressed protein peak intensities in rat serum.