番茄红素在大鼠电离辐射后氧化应激反应中减轻晶状体损伤的作用

Lycopene attenuates lens injury via inhibiting oxidative stress in rats after ionizing radiation

目的研究番茄红素(LYC)对大鼠2 Gy X线全身照射后氧化应激状态的调节以及对晶状体损伤的保护作用。方法30只雄性SD大鼠随机分成正常对照组、电离辐射(IR)组、LYC低剂量组(5 mg·kg^(-1))、LYC中剂量组(10 mg·kg^(-1))、LYC高剂量组(15 mg·kg^(-1)),每组各6只。辐照后连续灌胃24 d,提取血清检测丙二醛(MDA)、超氧化物歧化酶(SOD)、总抗氧化能力(T-AOC)水平,取眼球行HE染色和TUNEL检测。结果辐照后,IR组大鼠血清SOD、T-AOC水平均低于正常对照组,MDA水平高于正常对照组(均为P<0.05)。LYC低剂量组大鼠血清SOD、T-AOC水平均较IR组升高,MDA水平较IR组降低,但差异均无统计学意义(均为P>0.05);LYC中、高剂量组大鼠血清SOD、T-AOC水平均高于IR组,MDA水平均低于IR组(均为P<0.05)。与正常对照组相比,LYC低剂量组大鼠血清SOD、T-AOC水平均下降,血清MDA水平均上升(均为P<0.05)。HE染色结果显示,辐照后24 d,IR组大鼠晶状体结构受损。LYC低、中、高剂量组能够减轻IR引起的晶状体结构损伤,其中以LYC高剂量组改善最明显。TUNEL检测结果显示,与正常对照组相比,IR组大鼠晶状体上皮细胞(LECs)凋亡明显增加(P<0.05);与IR组相比,LYC治疗能够减少大鼠LECs的凋亡,其中以LYC中、高剂量组效果明显(均为P<0.05);LYC低剂量组大鼠LECs的凋亡比IR组低,但差异无统计学意义(P>0.05);与LYC低剂量组相比,LYC中、高剂量组抑制大鼠LECs凋亡作用更强(均为P<0.05);其中,LYC高剂量组比LYC中剂量组抑制效果更佳(P<0.05)。结论LYC能够抑制IR引起的大鼠氧化应激反应,减轻辐射对晶状体的损伤。LYC有潜力被开发为预防、延缓放射性白内障发生的药物。

Objective To study the effect of lycopene(LYC)on regulating oxidative status and its protective effect against lens injury after whole body radiation of rats with a single X-ray dose of 2 Gy.Methods Thirty male SD rats were randomly divided into 5 groups,with 6 rats in each group,including control group,ionizing radiation(IR)group,LYC low dose(5 mg·kg^(-1))group,LYC medium dose(10 mg·kg^(-1))group,LYC high dose(15 mg·kg^(-1))group.LYC was administrated by oral gavage for 24 consecutive days after radiation.At the end of the experiment,the serum levels of malondialdehyde(MDA),superoxide dismutase(SOD),and total antioxidant capacity(T-AOC)were measured,and the eyeballs were taken for HE and TUNEL assays.Results After radiation,the serum levels of SOD and T-AOC were significantly higher than those of the control group,and the serum levels of MDA were significantly lower than those of the control group(all P<0.05).Although low-dose LYC increased SOD and T-AOC levels and decreased MDA levels compared with IR group,however,the differences were not statistically significant(all P>0.05).Compared with IR group,SOD and T-AOC levels in the LYC medium and high dose group increased but MDA levels decreased(all P<0.05).Compared with the control group,the serum SOD and T-AOC levels of rats in the LYC low dose group decreased,and the serum MDA levels increased(all P<0.05).HE showed that,24 days after radiation,the lens structure was injured.After low-,medium-,and high-dose LYC treatment,the structure improved,of which the outcome was the most significant in high dose group.TUNEL assay showed the cell apoptosis of lens epithelial cells(LECs)increased after radiation compared with control group(P<0.05),and LYC treatment decreased cell apoptosis,of which the outcomes were significant in the LYC medium and high dose groups(both P<0.05);LECs apoptosis decreased in LYC low dose group compared with IR group,but the difference was not statistically significant(P>0.05).Compared with LYC low dose group,LYC medium and high dose groups had a stronger effect in inhibiting cell apoptosis(both P<0.05),and LYC high dose group had a lower apoptosis rate than LYC medium dose group(P<0.05).Conclusion LYC treatment can alleviate IR-induced lens injury by inhibiting oxidative stress.LYC could be a potent therapeutic agent to prevent and slow the progression of IR-induced cataract.