Life Extension Of Caenorhabditis Elegans Caused By Epimedium Flavoniods Treatment

[Background]China has been an aging society.Researches on aging mechanism and intervention are essential to improve the People's life and reduce medical cost. Traditional Chinese Medicine(TCM) has systemic theories and plentiful clinical practice on delaying aging."Kidney deficiency causes aging" is a dominant theory. According to previous clinical and laboratory studies,we have found that Epimedium Flavoniods(EF) is the major functional reconstituent in Epimedium Herb and Kidney-tonifying prescription on delaying aging.In order to evaluate the anti-aging effect of EF,we selected C.elegans as our experimental model.C.elegans is the premier aging research organism for its short lifespan and unlimited molecular and genetic analysis.Through delicate design,we choose life span analysis,fecundity test and stress resistance on C.elegans.[Objective]To evaluate the anti-aging effect of EF on C.elegans and explore its initial mechanism[Methods]1.Dosage-effect test:synchronized L4s were treated as 0mg/L control,EF 25mg/L,EF 50mg/L and EF 100mg/L groups,tested by lifespan assay to determine the effective dosages of EF.2.Life span analysis assay:synchronized L4s were treated as normal group(N), CR group(CR) and EF group(EF),tested by life span assay to evaluate the life-extension effect of EF.A simple kinetic analysis was used to analyze the aging-dependent phase of the survival curve of N and EF.3.Fecundity test:EF treated and control animals' fecundity were tested to see whether EF harmed the worms' reproduction.4.Stress resistance:EF treated and control animals were treated by acute heat and oxidative stress to confirm the life span assay and explore the initial mechanism.[Results]1.Dosage-effect test:control(m=20.48±5.52,M=30.8±1.1,n=50),EF 25mg/L (m =23.73±4.75,M=32±2,n=52),EF 50 mg/L(m =29.04±6.39,M=41.67±2.9,n=56), EF 100mg/L(m =22.55±4.49,M=30.7±1,n=58).Compared to 0mg/L control,all the EF groups extended mean lifespan(m) significantly(P＜0.05),especially the 50mg/L (P＜0.01),but only the EF 50mg/L group extends the maximum lifespan(M,P＜0.01).2.Life span analysis:control(m =20.48±5.52,M=30.8±1.1,n=50),CR(m=26. 52±5.08,M=36±2,n=50),EF(m=29.04±6.39,M=41.67±2.9,n=56).Compared to control,EF and CR extended the mean and maximum lifespan significantly(P＜0.01). Meanwhile compared to CR,EF had a significant statistical difference on mean lifespan and maximum lifespan(P＜0.01).Kinetic analysis revealed that EF significantly delayed the onset of the dying phase and reduced the age-dependent mortality once the dying phase had begun.3.Fecundity:the total progenies in control:211.9±38.73(n=10);EF group:198. 8±42.5(n=13,P＞0.05).Both groups achieved the peak fecundity in day2 and day3. The progenies at peak days:control:69.9±39.4(day2),49.7±40.7(day3);EF group: 59.8±50.2(day2),88.5±46.8(day3).EF did not harm total fecundity of C elegans. Instead,EF enforceed peak fecundity(P＜0.01).4.Stress resistance:mean survival time in acute heat stress resistance:control (6.71±1.3,n=19),EF group(8.93±1.6,n=21,P＜0.01);mean survival time in acute oxidative resistance:control(6.97±1.26,n=20),EF group(8.945±2.0,n=20,P＜0.01). EF lifted the stress resistance ability of C.elegans significantly.Notes:mean lifespan(m),maximum lifespan(M),number of animals(n).[Conclusions]1.EF extends lifespan of C.elegans in a dosage-dependent manner.It might be superior to CR.2.EF did not harm the fecundity of C.elegans.Instead,it enforced peak fecundity of C.elegans.3.EF lifted the stress resistance ability of C.elegans,which might be a mechanism for EF's anti-aging effect.