Theobjectiveofthisstudywastoinvestigatetheeffectofgelatin(SG)isolatedfromsalmonskinanditshydrolysate(SGH)onphotoagingskin,andthemechanismresponsibleforanti-photoaging.TheaveragemolecularweightsofSGandSGHwere65kDaand873Da,respectively.TheaminoacidcompositionsofSGandSGHweresimilar.Bothofthemwereabundantinhydrophobicaminoacids.Twenty-fivepeptideswereidentifiedfromSGH.SGandSGHcouldimproveUVirradiation-inducedpathologicalchangesofmacroscopicaltissuetextureandskinmorphology.Hydroxyprolinecontentisanindicatorofmatrixcollagencontent,SGandSGHcouldinhibitthedecreaseofhydroxyprolinecontentinphotoagingskininadosedependentmanner.Inaddition,SGandSGHcouldalleviateUVirradiation-inducedoxidativedamagestoskinbyincreasingtheactivitiesoftotalsuperoxidedismutase(T-SOD),glutathioneperoxidase(GSH-Px)andcatalase(CAT),increasingthecontentofglutathione(GSH)anddecreasingthecontentofmalonaldehyde(MDA).Moreover,SGandSGHcouldenhanceimmuneregulationsystembyincreasingthethymusindex.Thus,theanti-photoagingmechanismsofSGandSGHwerebyinhibitingthedepletionofantioxidantdefensecomponents,involvinginthesynthesisofcollagenandenhancingthefunctionofimmunesystem.Besides,SGHshowedabetterresultinprotectingskinfromphotoagingthanSG.
