Efeito do extrato etanólico da entrecasca de Caesalpinia pyramidalis Tul. na cistite hemorrágica em ratos

• Autor(a) principal: Matos, Alexandre Santos
• Data de Publicação: 2013
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFS
• Texto Completo: https://ri.ufs.br/handle/riufs/3866
• topic: Cistite hemorrágica; Caesalpinia pyramidalis; Ciclofosfamida; Hemorrhagic cystitis; Cyclophosphamide; Caesalpinia pyramidalis; CNPQ::CIENCIAS DA SAUDE

Introduction: Hemorrhagic cystitis (HC) is the main side effect of cyclophosphamide (CP) chemotherapy. This condition is characterized by the macro and microhaematuria, dysuria, suprapubic pain and increased urinary frequency. It is believed that acrolein, a CP metabolite, induces the generation of reactive oxygen species in the uroepithelial cell, resulting in peroxynitrite formation, which can cause damage to these cells. Mesna is the choice drug used to prophylactically treat HC, because it prevents the acrolein contact with the uroepithelium. Besides, antioxidant substances are thought to have a protective effect on HC, mainly because of the reduction of peroxynitrite formation through the inhibition of superoxide production. In this way, natural compounds or extracts with antioxidant and anti-inflammatory properties may possess potential to treat HC. Objectives: In the present study the effect of the ethanol extract of the inner bark of Caesalpinia pyramidalis (EECp) was investigated in the HC model in rats. Methods: In order to induce HC, animals received an i.p. injection of CP (200 mg/kg). A control group received only saline (0.9%) by the same route. One hour before this injection, animals were pre-treated with vehicle (Tween 80, 5%, p.o.) or EECP (100-400 mg/kg, p.o.). Mesna was used as a control and was administrated 5 min before and 4 and 8 h after the CP injection. In this manner, there were used 6 experimental groups: (i) Vehicle+Saline; (ii) Vehicle+CP; (iii) EECp (100 mg/kg)+CP; (iv) EECp (200 mg/kg)+CP; (v) EECp (400 mg/kg)+CP; (vi) Mesna+CP. After 24 h of CP or saline injection, animals were euthanized and the inflammatory/oxidative parameters were measured: (i) myeloperoxidase (MPO) activity in the urinary bladder and lung tissues; (ii) malondialdehyde (MDA) concentration in the urinary bladder and lung tissues; (iii) edema index in bladder; (iv) serum concentrations of nitrite and nitrate; (v) total and differential leukocyte counts in the peripheral blood; (vi) histological analyses of the urinary bladder. Results: The injection of CP increased the MPO activity in the urinary bladder (P<0.001) and significantly altered all the histological parameters evaluated, when compared with the saline+vehicle group. Besides, it augmented the bladder weight (P<0.01), when compared with the saline+vehicle group, without changing the MDA concentrations. Systemically, we observed higher serum concentration of nitrite and nitrate and lung MPO activity, as wells as a decrease in the total leukocyte and mononuclear counts, with a slight increase in the polymorphonuclear counts (P<0.05), when compared with saline+vehicle group. Pre-treatment with EECp reduced the leukocyte influx to the urinary bladder, evidenced by the reduction of the MPO activity (P<0.001 for 100 and 400 mg/kg and P<0.05 for 200 mg/kg) and the histological score (P<0.05 for 100 mg/kg), accompanied by the diminution of the total histological score (P<0.05 for 100 mg/kg) and the basal concentration of MDA (P<0.05 for 100 and 400 mg/kg), when compared with the vehicle+CP group. It was also observed an attenuation of the lung injury caused by CP administration, by the reduction of the MPO activity (P<0.05 for 200 and 400 mg/kg) and basal MDA concentration (P<0.05 for 200 and 400 mg/kg), when compared with the vehicle+CP group. The pretreatment with EECp also reduced the serum concentration of the nitrate and nitrite (P<0.05 for 100 mg/kg and P<0.01 for 400 mg/kg), in addition to the polymorphonuclear cell counts (P<0.05 for all doses used), without any significant alteration in the total leukocyte and mononuclear counts. Conclusions: These results suggested that EECp possesses moderate anti-inflammatory and antioxidant effects on the HC and attenuates the CP-induced lung injury, being of interest for future studies involving therapeutical strategies to treat the effects associated with the chemotherapy with CP.