The Study In Antioxidant Of COST Particles And Its Mechanism Of Action

Aging usually is refers to the irreversible and physiological phenomenon tending to death in the normal condition after the mature that along with the age increasing, the hypofunction, internal environment stability and stress ability of body will begin naturally to drop, structure, component degeneration, step by step toward death, the phenomenon of irreversible. Free radical theory has demonstrated thatthe senescence of cells is the result of the accumulation of harmful substances in the reaction process. The toxins produceing in the chemical reaction, that damage cells with the result of the individual aging. Free radicals are closely related to the initiation and progression of many diseases, a lot of literature reviews have reported about that the biochemical properties of reactive oxygen species(ROS) and oxidative stress were closely associated with a variety of degenerative diseases, such as alzheimer’s, atherosclerosis, and Parkinson’s. Therefore, it is of great significance in developing anti-oxidation, anti-aging medicine or health products with high-quality and less adverse reaction. A recent study found that natural antioxidants from a variety of biological resources could effectively scavenge free radicals within biological body that reduce biological molecules suffering from damge of them.Chitosan(CTS) is the second largest biological polysaccharide on earth after cellulose, and it is only edible animal fiber containing free amino alkaline cation in the nature. In recent years, people paid more attention to the antioxidant function of CTS, a large number of experimental results in vivo and in vitro showed that chitosan and its derivatives has more significant role in scavenging free radicals and improving antioxidant enzyme activity. Chitooligosaccharide(COS) is one degradation product of CTS, which is composed of 2-10 monomer, since it has easy to be absorbed by human body, transformation and utilization, etc, so the COS are more better in playing biological function than CTS. Many studies have found that the activity of COS will enhance along with decrease of the molecules weight. Based on this background, this issue will select one type of COS with average molecular weight less than or equal to 1000 Da(COST, Wm≤1000 Da) for anti-oxidation, anti-aging related research.It was found in the experiment of antioxidant in vitro:(1) The different concentrations of COST have shown the strong ability of removing DPPH free radicals, the improvment of scavenging activity with the increase of the concentration;(2) Different concentrations of COST could significantly remove ·OH, the ability to remove·OH were increased with the increase of concentration;(3) When the concentration of COST was less than 0.5 mg/m L, the ability to remove superoxide free radical was weak, once the concentration was more than 0.5 mg/m L, the scavenging activity was raised with the increase of the concentration;(4) It showed that COST had significant reducing power, and there are obvious linear trend between with concentration and reducing power, which also indicated COST possessed certain antioxidant activity.(5) The ability of chelating Fe2+ was found in different concentrations of COS, and it was enhanced with the decreases of concentration.We have researched the anti-aging efficacy of the COST in D-galactose induced aging model mice. The experimental results showed that the aging model mice induced by injection of D-galactose appeared obvious signs of aging, and showed increase of MDA as one of oxide free radical product and drop of SOD activity, which proved that the method of building was success and it was suitable for the anti-aging research of COST. The weight gain rate could be decreased obviously in the D-galactose handling juvenile animals aging model, anti-aging medicine usually eased the decline of weight gain rate, COST could effectively prevent weight loss of aging mice. In addition, COST could enhance the vitality of SOD, reduce the MDA level, increase the GSH product, but the ability to remove protein carbonylation product ability was weak in the serum. It was found in the heart, liver and kidney that COST also reduced the MDA level effectively, increased SOD activity and T-AOC. It was interesting in the liver that in addition to the above anti-aging index, COST was also conducive to be a significant increase in CAT and GSH-px activity, while in other organs it was not obvious.Combined with previous research content of our team, COST protected liver in certain extent, and mainly played anti-aging effect through protecting liver, molecular mechanism of anti-aging remains to be further research. Therefore,We have adopted the FQRT- PCR and Western blotting method to detect SIRT1, Fox Os, PGC1-alpha, SOD2, GPX1, CAT m RNA and protein expression in the liver of mice, which preliminary studied whether COST promoted hepatic SIRT1 expression, then raised Fox Os or PGC1-alpha through acetylation, aimed to improve SOD2, GPX1, CAT antioxidant enzyme activity, which contritubed to anti-aging effect. Our experimental results showed that COST could improve SIRT1 expression in the liver, then raised the expression of Fox O4 with result of the increased expression of SOD2, GPX1, CAT. These data were in accord with a number of researches that it played a role in protecting cell function and resisting oxidative stress through the activation of SIRT1, relied mainly on acetylation of the downstream targets Fox Os to raise SOD2, GPX1, CAT activity.