Study On The Effect Of Hawthorn Fruit Extract On Drosophila Melanogaster And Caenorhabditis Elegans Ginc Regulation

Hawthorn(Crataegus,pinnatifida)classes rosaceae dicotyledonous plants,rich in procyanidins,flavonoids and other active ingredients which can effectively remove free radicals and reduce oxidative damage,had significant antioxidant activity.In this thesis,Drosophila melanogaster and Caenorhabditis elegans were chosen as experimental model organisms,and hawthorn fruit extract(HFE)in vivo antioxidant activity were studied in order to evaluate the antioxidant capacity and aging regulation of HFE.The preliminary study of the molecular mechanism of its action and HFE antioxidant mechanisms were also been explored,which would provide some guidance for the application of related products.In this thesis,high performance liquid chromatography was the major mean to make the qualitative and quantitative analysis of active ingredient within HFE come true.The drosophila and nematodes were fed with different dose {Drosophila melanogaster 0,0.5,1.5,4.5mg/ml;Caenorhabditis elegans 0,25,50,100?g/ml)of HFE.The two model organisms were tested the impacts of HFE on the lifespan,the acute stress tolerance,the antioxidant enzyme activity in vivo,the changes in lipid peroxidation product malondialdehyde(MDA)and antioxidant-related genes mRNA expression levels.This research results indicated that HFE can significantly prolong the lifespan of drosophila and nematode in survival experiments or challenge tests.Compared with the drosophila without HFE,the maximum lifespan and mean lifespan of male and female drosophila with the dose of 1.5,4.5 mg/ml HFE were significantly prolonged(P<0.05),while the same as the activity and lifespan of drosophila in challenge test of paraquat and hydrogen peroxide.It also had a good protective effect on oxidative damage of high fat of drosophila.Enzyme activity assay showed that,1.5,4.5mg/ml group male and female drosophila superoxide dismutase(SOD),catalase(CAT)and other related antioxidant enzyme activity were significantly increased(P<0.05),and MDA content decreased significantly,the content of MDA in male flies were decreased by 48.3%and 54.5%(P<0.01).RT-PCR results showed that the mlRNA expressions of antioxidant-related genes including SOD,CAT and Nrf2 in vivo were significantly increased and Mth decreased effectively.In C.elegans experiments,after feeding with different dose of HFE,C.elegans exhibited a higher lifespan than the normal group,while also the challenge tests of heat stress experiment,UV radiation stress experiment,hydrogen peroxide oxidative stress experiment,juglone oxidative stress experiment and paraquat oxidative stress were carried out.The body length and reproductive ability of nematode feeding with 50,100?g/ml HFE were decreased significantly(P<0.05),which were appropriate for longevity.After feeding with HFE,the lipofuscin autofluorescence level in vivo of C.elegans significantly decreased and it was dose-dependent effect to the concentration of HFE.DCFDA probe results showed that the total reactive oxygen species(ROS)in vivo of HFE group C.elegans significantly reduced,the same as oxidative damage.The SOD activity in vivo of nametode with 50,100?g/ml HFE increased significantly(P<0.05),and the antioxidant-related genes mRNA expression levels were also affected in different degree.This study showed that HFE can significantly affect the mRNA expression levels of endogenous antioxidant genes in model organisms,enhance the activities of antioxidant enzymes and improve antioxidant capacity and the ability of model organism to scaveng free radicals in vivo,effectively delaying aging.