Legume seeds are proven to contain high levels of PI, such as for instance those from the Kunitz and BowmanBirk type people. Kunitz type inhibitors are proteins of buy Bicalutamide, with low cysteine content and an individual reactive site, whereas the BowmanBirk type inhibitors have Mrs 810 kDa, with large cysteine content and two reactive sites. Several serine PI have been proven to act on platelet aggregation, body coagulation, fibrinolysis and inflammation. Because of this, place Kunitz inhibitors are as tools in the research of these biochemical processes useful. As a type of cancer chemopreventive agents pi is currently well established. Soybean Bowman Birk trypsin inhibitor. The absolute most studied, is an efficient anti tumoral representative since it prevents and suppresses malignant transformation in vitro and carcinogenesis in vivo in a wide variety of methods. This inhibitor is under clinical Plastid trials and studies on human populations are now being assessed. Some other plant or synthetic PI have been shown to be involved in development arrest, cytotoxicity, and metastasis suppression or invasiveness inhibition of transformed cells. Lately, we described the isolation of a inhibitor from the seeds of Peltophorum dubium Taub. P. dubium is really a tree from the Leguminosae family which grows in Argentina, Brazil, Uruguay and Paraguay. Its fruits, leaves and roots are utilized in popular medicine and methanolic extracts showed antimicrobial activity. Nevertheless, no protein had been characterized. We separated Clindamycin clinical trial PDTI by affinity chromatography on a trypsin agarose order, it was active against bovine trypsin and chymotrypsin, and its amino terminal sequence was much like that of professional Kunitz sort soybean trypsin inhibitor. We demonstrated that both PDTI and SBTI showed a like exercise detected by hemagglutination of rabbit erythrocytes, which was inhibited by sialic acid containing compounds. We also showed evidence that PDTI and SBTI caused apoptosis of Nb2 rat lymphoma cells and had no effect on normal mouse splenocytes or lymphocytes, while they caused apoptosis on concanavalin A stimulated mouse lymphocytes. While SBTI may be the archetypical Kunitz form trypsin inhibitor and has been extensively examined, these properties had remained undetected. More over, PDTI was also proved to be effective against trypsinlike proteases taken from different lepidopteran larvae. Taking this into consideration, it had been particularly interesting to gauge PDTI and SBTI effect on human lymphocytes. Here, we describe for the very first time that both trypsin inhibitors encourage human Jurkat leukemia cell apoptosis, demonstrated by a decrease of cell viability followed by DNA fragmentation and no cell cycle profile change.