Alfa-bisabolol atenua a cistite hemorrágica induzida por ifosfamida em camundongos

Abstract

Hemorrhagic cystitis (HC) is an inflammatory pathology of the bladder induced by the accumulation of acrolein in the bladder, which is generated from the biotransformation of oxazaphosphorines, such as ifosfamide and cyclophosphamide. It is characterized by the presence of hematuria, dysuria, increased urinary frequency and urgency, and pelvic pain. It is estimated that 18-40% of patients treated with ifosfamide have hemorrhagic cystitis. Alpha-bisabolol (ABIS) is a terpene of the sesquiterpene class derived from chamomile (Matricaria recutita), one of the main plant species source of ABIS. Among the therapeutic effects presented by ABIS, the anti-inflammatory action can be highlighted. Evaluate the pharmacological activity of ABIS and study its anti-inflammatory effects on ifosfamide-induced hemorrhagic cystitis (IFO). Cystitis was induced in male Swiss mice, aged 6 to 8 weeks, weighing between 20-24g, with a single dose of ifosfamide (IFO). The animals were divided into 5 groups (n=6/group): control (SF 0.9%, 10 ml/kg, i.p.), IFO (400 mg/kg, i.p.) and ABIS group in three doses (5, 10 and 50 mg/kg, p.o.), being administered one hour before the IFO. After 12 hours of IFO injection, the animals were euthanized with high anesthetic doses. Then, the bladders were removed and weighed to evaluate the bladder wet weight (UVW), the macroscopic analysis, the histopathological analysis according to Gray's criteria and the bladder permeability, mRNA expression of Il-1β, Il-33 and Cox-2 by qPCR and F4/80 by immunofluorescence. For statistical analysis, the ANOVA/Bonferroni or Kruskal Wallis/Dunn tests were used with statistical significance of p<0.05 (approval opinion by CEUA-UFC nº 68310110222). IFO increased PUV (20.45 ± 1.84 mg ) compared to the negative control (saline: 8.29 ± 0.49 mg). ABIS treatment reduced PUV at the three aforementioned doses (5 mg/kg: 16.9 ± 0.75; 10 mg/kg: 16.24 ± 1.20; 50 mg/kg: 13.96 ± 1.58 mg) , however, in the histopathological analysis, the dose of 50 mg/kg showed significant protection. ABIS (50mg/kg) significantly attenuated (p<0.05) histopathological damage scores 1[1-3], macroscopic edema (E) and hemorrhage (H) scores (E: 1 [1-2 ]; H: 1[1-2]); reduced vascular permeability quantified by the Evans blue method (8.67 ± 1.85 µg/ml,) when compared to the IFO group (Histopathology: 2 [2-3]; E: 2.5 (1-3) ;H: 2.5(1-3); permeability: 13.37 ±2.01 µg/ml). Additionally, IFO injection increased the expression of Il1beta (SAL: 1.05 ± 0.17 vs. IFO: 396.9 ± 126), Il33 (SAL: 1.15 ± 0.29 vs. IFO: 15.84 ± 3 .35) and Cox2 (SALT: 1.32 ± 0.43 vs. IFO: 39.09 ± 12.21) (p< 0.05). However, ABIS treatment decreased the gene expression of only Il-1β (88.44 ± 34.54) and Il-33 (9.04 ± 1.87, p<0.05), without interfering with Cox2 expression (40.27 ± 14.04) when compared with the IFO group. Similarly, the ABIS-treated group reduced the amount of bladder-infiltrating macrophages, as detected by immunofluorescence measurement for F4/80 when compared to the IFO group. Treatment with alpha-bisabolol attenuated hemorrhagic cystitis by decreasing edematogenic events and the inflammatory response induced by ifosfamide.