Bleomycin hydrochloride is a potent antitumor antibiotic that functions as a DNA synthesis inhibitor and DNA damaging agent.

Bleomycin hydrochloride is chosen as the best-studied micronucleus inducers in human lymphocytes with different mechanisms of genotoxicity. The most frequent Bleomycin-induced DNA lesions are single and double strand breaks and single apuinic/apyrimidinic sites. At the same time Bleomycin is true radiomimetic compound, resembling almost completely the genetic effect of ionizing radiation[1]. The IC50 value of Bleomycin hydrochloride for UT-SCC-19A cell line is 4.0±1.3 nM. UT-SCC-12A and UT-SCC-12B are both more resistant to Bleomycin; IC50 values are 14.2±2.8 nM and 13.0±1.1 nM, respectively[2]. Bleomycin hydrochloride (50, 100 μM; for 24, 48 h) induce pulmonary fibrosis in RLE-6TN cell (50 μM) and A549 cell (100 μM)[4].

Bleomycin hydrochloride treatment (3.5-4.0 mg/kg; intra-tracheal) on day 0, body weights decreases by day 4 then increases by Day 7 through the end of the study[3]. Bleomycin hydrochloride (3.5-4.0 mg/kg; intra-tracheal) produces a statistically significant increase in lung hydroxyproline levels, and also increases right caudal lung lobe mass[3]. Bleomycin hydrochloride (intratracheal instillation; 5.0 mg/kg/day) induces pulmonary fibrosis in eighty 8-week-old male BALB/c mice with weight about 20-30 g. Bleomycin induces the expression levels of α-SMA and collagen I[4]. Bleomycin hydrochloride (intratracheally; 2.5 mg/kg; 1.25 mg/ml, approximately 50 µl per mouse) induces pulmonary fibrosis in male C57BL/6 mice (8 weeks old, average weight approximately 24.5 g)[5].