根皮素对秀丽隐杆线虫寿命的影响

Effect of Phloretin on Lifespan of Caenorhabditis elegans

目的:研究根皮素对秀丽隐杆线虫延长寿命作用及其作用机制。方法:给予秀丽隐杆线虫一定质量浓度的根皮素(25、50、75μg/mL),分析根皮素对线虫寿命、运动能力、吞咽能力、抵抗应激能力、活性氧和脂褐素水平的调控作用,通过测定正常及突变体线虫的抗氧化酶活力、相关基因表达水平,对根皮素延长寿命的潜在机理进行了初步探讨。结果:根皮素能够显著延长线虫的寿命并抑制衰老相关的运动能力下降,增强抵抗应激能力(双氧水、紫外和高温),提高抗氧化酶活力(超氧化物歧化酶和过氧化氢酶)和自由基清除能力,减少脂褐素堆积和丙二醛的生成。采用根皮素喂养线虫后,daf-2和age-1 mRNA表达水平显著下降(P<0.05,P<0.01),daf-16和sir-2.1 mRNA表达水平显著升高(P<0.05,P<0.01)。突变体线虫经根皮素处理后,daf-2(e1370)、daf-16(mu86)和sir-2.1(ok434)突变体线虫寿命无显著延长;eat-2(ad1116)突变体线虫寿命显著延长(P<0.05);且促进了DAF-16的核定位,并激活了其下游靶基因sod-3、ctl-1和hsp-16.2 mRNA的表达。结论:根皮素可以通过胰岛素信号通路和SIR-2.1信号通路,促进DAF-16的核定位,提高机体应激抵抗能力和抗氧化能力,延长线虫寿命。

Objective:The purpose of this study was to investigate the anti-aging effect of phloretin on Caenorhabditis elegans and the underlying mechanism.Methods:The effect of treatment with different concentrations of phloretin(25,50 and 75μg/mL)on the survival rate,motility,pharynx pumping ability,lipofuscin and reactive oxygen species(ROS)levels,and stress resistance(hydrogen peroxide,high temperature,and ultraviolet)of C.elegans was analysed.The mechanism of action of phloretin in prolonging the lifespan of C.elegans was explored by measuring antioxidant enzyme activities and related gene expression levels as well as using mutant C.elegans.Results:Phloretin could significantly promote the longevity of C.elegans,inhibit the decline of its motility,related to senescence,increase stress resistance,enhance free radical scavenging capacity and antioxidant enzyme activities(superoxide dismutase(SOD)and catalase(CAT)),and reduce the accumulation of lipofuscin and the content of malonaldehyde(MDA).Phloretin significantly down-regulated the mRNA expression levels of daf-2 and age-1(P<0.05,P<0.01),but up-regulated the mRNA expression levels of daf-16 and sir-2.1(P<0.05,P<0.01).Phloretin failed to prolong the lifespan of the mutants daf-2(e1370),daf-16(mu86),and sir-2.1(ok434),but significantly prolonged the lifespan of the mutant eat-2(ad1116)(P<0.05).In addition,phloretin promoted the nuclear localization of DAF-16,and activated the mRNA expression of its downstream target genes sod-3,ctl-1 and hsp-16.2.Conclusion:Phloretin can promote the nuclear localization of DAF-16 through the insulin signaling pathway and the SIR-2.1 signaling pathway,and improve stress resistance and antioxidant capacity,thus prolonging the lifespan of C.elegans.