Efeito da levedura Pichia pastoris sobre parâmetros imunológicos e de estresse oxidativo em camundongos Swiss submetidos à quimioterapia com ciclofosfamida

Abstract

Actually the potential of probiotics to modulate the host immune system and to reduce oxidative stress is being observed in several studies. Antineoplastic cyclophosphamide (CF) has the effect of compromising the immune system's cell function, inducing increased markers of oxidative stress, and causing renal and hepatic damage. Pichia pastoris yeast is currently used as a recombinant protein expression system for the production of the most different types of heterologous proteins. However, some studies have shown that this yeast possesses probiotic properties. The present study aimed to evaluate the safety of the use of the P. pastoris yeast, as well as its effect on immunological, histopathological and oxidative stress parameters in an immunosuppressive model. Twenty male Swiss mice were divided into four groups: control, CF control (250 mg.kg-1), P. p control(109 CFU.mL-1) and CF + P. p. Leukogram, histopathological analysis, animal weighing and TBARS assay were performed. It was observed that CF reduced the levels of leukocytes, neutrophils and lymphocytes, and P. pastoris was able to increase the number of leukocytes and neutrophils of immunosuppressed animals. In addition, P. pastoris was also safe in immunosuppressed animals, not causing deaths. Histopathological analyzes demonstrated that CF caused renal and hepatics lesions and P. pastoris was able to reduce the hepatics lesions caused by chemotherapy. When oxidative stress was evaluated, it was observed that P. pastoris reduced the levels of TBA reactive species in the kidney and brain of animals treated with CF, and in the liver and brain of healthy animals. Therefore, P. pastoris yeast demonstrates a protective effect to CF damage.