The protective effect and mechanism of icarisideⅡ in a rat model of radiation cystitis / 中华泌尿外科杂志

ABSTRACT

Objective:To investigate the protective effect and mechanism of Icaritin Ⅱ (ICAⅡ) on bladder in radiation cystitis model.Methods:A total of 18 10-week-old male SD rats were selected from July 2021 to March 2022 and divided into control group, model group and treatment group by random number table method, with 6 cases in each group. Model group and treatment group were given a single dose of 20 Gy X-ray irradiation in the pelvic area. 24 h after irradiation, the treatment group was given ICAⅡ 4.5 mg/(kg·d) gavage, while the control group and model group were given the same volume of solvent (10% anhydrous ethanol, 20% isopropyl alcohol, 30% polyethylene glycol and 40% deionized water) gavage for 4 consecutive weeks. Drug eluting for 1 week. The bladder volume and leakage point pressure of the three groups of rats were measured by multi-conducting physiological apparatus, and the bladder function was evaluated. HE staining, Masson staining, ELISA, TUNEL staining and western blotting were performed on the bladder samples of the three groups of rats. The pathological changes (thickness of bladder mucosa, ratio of smooth muscle to collagen fiber), oxidative stress level (superoxide dismutase SOD, malondialdehyde), apoptosis rate, protein levels of inflammatory factors (IL-6, NF-kB) and anti-oxidative stress signaling pathway factors (Nrf2, HO-1) of the three groups of rats were compared.Results:After 4 weeks of modeling, in the model group, the bladder volume [(1.01±0.12)ml vs. (1.58±0.21)ml, P=0.001], the bladder leakage point pressure [(38.79±4.12) cmH 2O (1 cmH2O=0.098 kPa)vs.(60.59±3.81) cmH 2O, P=0.001], the ratio of smooth muscle of bladder wall to collagen fiber [1.78±0.17 vs.3.15±0.57, P=0.001], SOD[(6.31±0.73) U/mg vs.(14.67±1.04) U/mg, P=0.001] were lower than the control group, and the differences were statistically significant. In the model group, the thickness of bladder mucosa [(47.33±1.78)μm vs.(20.83±2.33)μm, =, P=0.001], malondialdehyde [(1.01±0.13) nmol/mg vs.(0.49±0.03) nmol/mg, P=0.001], IL-6 (0.87±0.11 vs. 0.33±0.10, P=0.001), NF-kB (0.71±0.14 vs. 0.29±0.07, P=0.001), apoptosis rate [(11.60±3.04)% vs. (3.91±1.40)%, P=0.007] was higher than the control group, and the differences were statistically significant. In the treatment group, the bladder volume [(1.27±0.13)ml, P=0.030], bladder leakage point pressure [(47.83±2.50)cmH 2O, P=0.004], smooth muscle to collagen fiber ratio (2.78±0.68, P=0.015), SOD[(10.48±0.85) U/mg, Compared with model group, bladder mucosa thickness [(31.94±3.20)μm, P=0.001], malondialdehyde [(0.64±0.09) nmol/mg, P=0.001], IL-6 (0.69±0.11, P=0.035), NF-kB (0.45±0.06, P=0.002) and apoptosis rate [(6.05±0.60)%, P=0.030] were lower than those in model group. The protein expression level of Nrf2 in model group (0.73±0.08 vs. 0.58±0.11, P=0.023) was higher than that in control group, but there was no significant difference in the protein expression level of downstream antioxidant factor HO-1 (0.50±0.14 vs. 0.35±0.06, P=0.060). Nrf2 protein expression level (0.88±0.03, P=0.027) and HO-1 expression level (0.68±0.07, P=0.026) in treatment group were higher than those in model group. Conclusion:ICAⅡ can reduce radiation cystitis injury, and its mechanism may be related to anti-oxidative stress and reducing inflammation.