RESUMO
In this study we report the enzymatic synthesis of N-α-[Carbobenzyloxy]-Tyr-Gln-Gln (Z-YQQ), a new anticoagulant tripeptide. It was obtained using phytoproteases from the stems and petioles of Asclepias curassavica L. as catalyst in an aqueous-organic biphasic system formed by 50% (v/v) ethyl acetate and 0.1 M Tris-HCl buffer pH 8. The resulting peptide was compared with the analogous peptide Tyr-Gln-Gln (YQQ) produced by solid-phase chemical synthesis. The in vitro anticoagulant activity of the aforementioned peptides was determined using Wiener Lab Test (Wiener, Argentina). The toxicological activity of the peptides was also determined. The enzymatically synthesized Z-YQQ peptide acted on the extrinsic pathway of the coagulation cascade, delaying the conversion time of prothrombin to thrombin and fibrinogen to fibrin by 136 and 50%, respectively, with respect to the controls. The chemically synthesized YQQ peptide acted specifically on the intrinsic pathway of the coagulation cascade, affecting factors VIII, IX, XI, and XII from such cascade, and increasing the coagulation time by 105% with respect to the control. The results suggest that two new anticoagulant peptides (Z-YQQ and YQQ) can be useful for safe pharmaceutical applications. Nevertheless, some aspects related to peptide production should be optimized. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 2018 © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 34:1093-1101, 2018.
Assuntos
Anticoagulantes/síntese química , Peptídeos/síntese química , Anticoagulantes/química , Anticoagulantes/farmacologia , Coagulação Sanguínea/efeitos dos fármacos , Catálise , Humanos , Peptídeos/química , Peptídeos/farmacologia , Preparações FarmacêuticasRESUMO
OBJECTIVE: Nonvalvular atrial fibrillation (NVAF) is a risk factor for ischemic stroke and systemic embolism. New oral anticoagulants are currently available. The objective of this study was to assess the incremental cost-utility ratio (ICUR) for apixaban vs. acenocoumarol in patients treated in Chile's public health system. STUDY DESIGN AND SETTING: We assessed cost-utility from the payer perspective with a lifetime Markov model. Epidemiologic characteristics, costs, and utilities were obtained from a Chilean cohort; data were completed with information from international literature. RESULTS: Incremental costs when using apixaban vs. acenocoumarol over a lifetime are CH$2,108,600 with an incremental effectiveness of 0.173 years of life gained (YLG) and 0.182 quality-adjusted life-year (QALY). The ICUR of apixaban vs. acenocoumarol was CH$12,188,439 per YLG and CH$11,585,714 per QALY. One to 3 times gross domestic product (GDP) per capita threshold is acceptable based on World Health Organization (WHO) norms. Chilean GDP per capita was CH$7,797,021 in 2013. The sensitivity analysis shows that these results are sensitive to the ischemic stroke risk with apixaban, and the intracranial hemorrhage risk due to the use of acenocoumarol. CONCLUSION: The use of apixaban in patients with NVAF in moderate-to-high risk of stroke is cost-effective, considering the payment threshold suggested by WHO.