Preliminary Study On Bioactivity Of Sea Cucumber Oligo-peptides

Sea cucumber is famous tonic,containing a variety of bioactive ingredients,which includes sea cucumber saponin,polysaccharide and collagen,etc.Sea cucumber peptides are extracted from sea cucumber,which have many biological functions such as anti-oxidant,enhancing immunity,lowering blood pressure,anti-bacterial,anti-tumor,anti-fatigue and hypoglycemic.These activities have been mainly focused on poly-peptides,however few have been studied about the oligo-peptides,which molecular weight is<1000 Da.This paper mainly studied the related bioactivities of sea cucumber oligo-peptides.(1)To investigate the effect of sea cucumber oligo-peptides on the anti-aging of silkworm,the same batch of silkworm larvae were randomly divided into four groups(control,low-concentration,medium-concentration and high-concentration groups).Larvae were cultured into cocoon,decocoon,moth and until death using mulberry coated by different concentrations of oligo-peptide.Results showed that the oligo-peptides elongated larval growth stage,leading to the significant difference of larval weight.However,larval cocoon and adult decocoon were not affected.Larval average and longest lifetime was significantly elongated under different concentration groups and the highest elongation rate reached 10.79%.The average and longest lifetime of adults was significantly elongated in high-concentration group,and medium and high-concentration groups,respectively.The above indicates that sea cucumber oligo-peptides do not affect the growth rhythm of silkworm,whereas have the anti-aging effect.Moreover,only relatively higher concentrations can pass the anti-aging effect from the larvae on to adults.(2)To investigate the aphrodisiac effect of sea cucumber oligo-peptides on Kidney Yang Deficiency mice induced by hydrocortisone,the negative control group,blank control group,positive control group and experimental group(sea cucumber oligo-peptides group and sea cucumber powder group)were set up.The immune organs index,genital organs index and sperm concentration of mice were measured.Results showed that oligo-peptide group had the significant effect on immunity enhancement,genital organs and sperm concentration of Kidney Yang Deficiency mice.Sea cucumber powder group also had positive effects,however less than that of oligo-peptide group.(3)To investigate the effects of oligo-peptides on alloxan-induced diabetic mice,the diabetic mice were induced by alloxan,and administered by oral gavage at different dose for 6 weeks.The contents of fasting blood glucose(Glu)and the body weights on 0,2,4,6 weeks were detected for each group.The organ weight,MDA contents and SOD activity in serum were measured.Results showed that the Glu in different groups were obviously decreased and weight loss was also relieved(p<0.01).The high-dose-group could increase the organ index significantly.The high-dose-group both could decrease MDA contents(p<0.05)and increase SOD activity in serum(p<0.01).This indicates that oligo-peptides can decrease Glu of alloxan-induced diabetic mice and enhance immunity and anti-oxidative activity.(4)To investigate the anti-fatigue effects of oligo-peptides,the mice were administered by oral gavage at different dose for 30 days.The time of mice loaded swimming,BUN contents and hepatic glycogen contents were measured to study the anti-fatigue effects.The results showed that the loaded-swimming time of oligo-peptides group was longer than other groups significantly comparing with the negative group.The contents of blood urea nitrogen(BUN)were degraded strongly and the contents of hepatic glycogen of the mice were increased(p<0.05).The anti-fatigue effect of sea cucumber oligo-peptides was stronger than Glycine max oligo-peptides and sea cucumber powder obviously(p<0.05).This indicates that oligo-peptides have significant anti-fatigue effects.