Antioxidant and anti-melanogenic activities of ultrasonic extract from Stichopus japonicus

Objective:To investigate the antioxidant and anti-melanogenesis activities of an ultrasonic extract of red sea cucumber,Stichopus japonicus,collected from Jeju Island.Methods:Antioxidant activity experiments were assessed by an electron spin resonance system and a cellular model of immortalized human keratinocytes(HaCaT)to determine its radical scavenging activity and protective effects against 2,2’-azobis(2-amidinopropane)dihydrochloride(AAPH)-induced oxidative stress.Antimelanogenic activity of the ultrasonic extract of red sea cucumber was also examined using the melanoma cell model B16F10 and mushroom tyrosinase.Following the induction byα-melanocytestimulating hormone,the effects of the ultrasonic extract of red sea cucumber on intracellular tyrosinase activity,melanin content and the melanogenic protein expression of microphthalmia-associated transcription factor,tyrosinase,and tyrosinase-related proteins(TRP-1,and TRP-2)were examined.Results:The ultrasonic extract of red sea cucumber significantly scavenged 2,2-diphenyl-1-picrylhydrazyl and alkyl radicals[IC50:(0.924±0.035)and(0.327±0.006)mg/mL,respectively],as well as showed a protective effect against oxidative stress and attenuated generation of intracellular reactive oxygen species on AAPHinduced HaCaT cells,with no cytotoxicity(12.5-400μg/mL).The ultrasonic extract of red sea cucumber also exhibited a tyrosinase inhibitory effect[IC50:(2.750±0.006)mg/mL].Onα-melanocytestimulating hormone-stimulated B16F10 melanoma cells,the ultrasonic extract of red sea cucumber(25-200μg/mL)significantly inhibited not only melanin synthesis and tyrosinase activity,but also protein expressions of microphthalmia-associated transcriptional factor,tyrosinase,TRP-1,and TRP-2.Conclusions:The ultrasonic extract of red sea cucumber shows antioxidant and anti-melanogenic potential and may be a natural candidate for anti-aging as well as a whitening agent in the cosmeceuticals industry.

Anti-senescence and anti-wrinkle activities of 3-bromo-4,5-dihydroxybenzaldehyde from Polysiphonia morrowii Harvey in human dermal fibroblasts

Objective:To investigate the anti-senescence effect of 3-bromo-4,5-dihydroxybenzaldehyde(BDB)from Polysiphonia morrowii Harvey in human dermal fibroblasts(HDF).Methods:HDF were subjected to treatment of BDB and then treated with hydrogen peroxide(H2O2)to induce premature senescence.Senescence-associatedβ-galactosidase(SA-β-gal)activity in HDF was determined using the SA-β-gal staining method.Intracellular reactive oxygen species(ROS)production was measured using the 2’,7’-dichlorodihydrofluorescein diacetate assay.Western blotting assay was performed to assess the level of antioxidant enzyme glutathione peroxidase 1(GPX1).In addition,intracellular collagen and collagenase contents were analyzed using the respective ELISA kits.Elastase activity in HDF supernatants was measured from p-nitroaniline release and normalized using total protein content.Results:Treatment of HDF with H2O2 increased the activity of SA-β-gal,but BDB pre-treatment resulted in the reduction of SA-β-gal activity.Moreover,BDB significantly reduced H2O2-induced intracellular ROS production.BDB also markedly increased the level of GPX1,which was inhibited by 400μM of H2O2.Furthermore,in in vitro study,BDB significantly increased intracellular collagen content and decreased matrix metalloproteinase-1 and elastase activities in HDF.Conclusions:Our results demonstrate that BDB shows antisenescence and anti-wrinkle activities in vitro.