Bestatin hydrochloride (Ubenimex hydrochloride) is an inhibitor of aminopeptidase N (APN)/CD13 and aminopeptidase B.

Bestatin，亦称为Ubenimex (INN)，是一种具有竞争性的蛋白酶抑制剂。它能抑制aminopeptidase B、leukotriene A4 hydrolase和aminopeptidase N。目前正在研究其用于治疗急性髓细胞性白血病的可能性。Bestatin可低毒性地用于培养细胞、完整动物及人类。它已成为探究某些哺乳动物外肽酶在调节免疫系统、肿瘤生长及其侵入周围组织、以及细胞蛋白质降解方面生理作用的有用工具。

Bestatin是一种活性抗血管生成剂，通过抑制APN/CD13活性，可能在体内抑制肿瘤血管生成，在体外抑制内皮细胞的管状形成。通过口服Bestatin（100-200 mg/kg/天），显著抑制了小鼠背部气囊试验中由黑色素瘤细胞引起的血管生成。

Cells are harvested, washed, and lysed in NP-40 lysis buffer (50 mM Tris-HCl [pH 7.5], 150 mM NaCl, 0.5% NP-40). Total cell protein is quantified using the Bradford assay and 1-mg/mL protein aliquots are made. Ten microliters of total cell protein is mixed with 290 μL of substrate solution (0.1 mg/mL dithiothreitol [DTT], 0.1 mg/mL albumin, and 1 mM alanine-β-naphthylamide). Fluorometric measurements (340 nm excitation, 400 nm emission) are made after 15 and 30 min. The slope of the line between the 15- and 30-min measurements is used to represent aminopeptidase activity. Total cell protein is preincubated with bestatin, amastatin, puromycin, EDTA, and/or ZnCl2 for 20 min before the fluorometric aminopeptidase assay.

Growing cells (1×106 to 2×106 cells/mL) are diluted to 1.0×103 cells/mL and transferred (3 mL) into a well in a 12-well multiwell plate (2.5-cm diameter/well). Cells are treated with 0, 10, 50, 100, 300, or 600 μM Bestatin and allowed to grow at 21°C shaking at 180 rpm for 48 h. A hemocytometer is used to measure cell density after 0, 24, and 48 h.