D-galactose Induced Aging Mice Research Articles

Free radical mediated grafting of chitosan with caffeic and ferulic acids: Structures and antioxidant activity

In this study, two water soluble chitosan derivatives were synthesized by grafting caffeic acid (CA) and ferulic acid (FA) onto chitosan via a free radical mediated method. The structural characterization, antioxidant activity in vitro and in vivo of chitosan derivatives were determined. Results showed that the UV–vis absorption peaks of chitosan derivatives shifted toward longer wavelengths. FT-IR spectroscopy exhibited the typical phenolic characteristics within 1450–1600cm−1. 1H NMR spectroscopy showed new peaks of phenyl protons at 6.2–7.6ppm. 13C NMR spectroscopy showed additional peaks between 110 and 150ppm assigned to the CC of phenolic groups. These results all confirmed the successful grafting of CA and FA onto chitosan backbones. The chitosan derivatives had decreased thermal stability and crystallinity as compared to chitosan. In vitro assays showed that the antioxidant activity decreased in the order of CA-g-chitosan>FA-g-chitosan>chitosan. Moreover, administration of the chitosan derivatives could significantly increase antioxidant enzymes activities and decrease malondialdehyde levels in both serums and livers of d-galactose induced aging mice. Our results indicated the potential of CA-g-chitosan and FA-g-chitosan in the development of novel antioxidant agents.

Mussel oligopeptides ameliorate cognition deficit and attenuate brain senescence in d-galactose-induced aging mice

Dietary supplementation exerts beneficial effects in reducing incidence of chronic neurodegenerative diseases. The purpose of this study was to examine protective effects of mussel (Mytilus edulis) oligopeptides supplementation on brain function in D-galactose induced aging mice. Sixty female 8-month-old mice were randomly divided into five groups: vehicle control, D-galactose, and D-galactose combined with 200, 500, 1000 mg/kg mussel oligopeptides. The results showed that mussel oligopeptides could improve cognitive learning and memory ability and protect the hippocampal neurons. In addition, GSH, SOD and GSH-pX activities were increased and MDA level was significantly decreased in mice fed with mussel oligopeptides. It was also found that mussel oligopeptides supplementation prevented D-galactose-induced elevations of iNOS activity and NO production and lactate acid levels in brain. Moreover, PI3K and Akt genes were up-regulated by mussel oligopeptides supplementation. These findings suggest that mussel oligopeptides are able to enhance exercise capacity and protect against oxidative damage caused by D-galactose in aging model mice through regulating oxidation metabolism and PI3K/Akt/NOS signal pathway. Therefore, mussel oligopeptides are good materials for future development of healthcare products to combat age-related brain dysfunction and to improve healthy life span.

Protective effect of tetrahydroxystilbene glucoside against d-galactose induced aging process in mice

Tetrahydroxystilbene glucoside (TSG) is a strong antioxidant and free radical scavenger derived from Polygonum multiflorum Thunb. The present study aims to evaluate the protective effect of TSG against d-galactose induced aging process in mice and its possible mechanisms of action. Our study revealed that administration of TSG improved the memory ability and regulated the body weight of mice. TSG also reduced the levels of ROS, NO and IGF-1 and increased the levels of SOD, Ca2+ and Klotho protein in the serum. Furthermore, TSG up-regulated the expression of Klotho protein in cerebrum, heart, kidney, testis and epididymis tissues of d-galactose induced aging mice. These results suggested that TSG had a promising anti-aging effect by regulating Klotho gene.

Effects of Alpinia oxyphylla fructus on learning-memory and expression of related signal proteins in hippo campus of brain aging mice

Objective To investigate the effects and mechanisms of Alpinia oxyphylla fructus (AOF) on learning and memory in D-galactose induced brain aging mice. Methods The brain aging model was induced by s. c D-galactose. Learning-memory ability was tested by passive avoidance test and Morris water maze test, and the expression of synapsin ( Syn), mitogen-activated protein kinase (MAPK) and protein kinase ( PKC ) in hippocampus were examined by Western blot. Results ① Passive avoidance test:the latency in brain aging group( ( 119.80 ±101.80)s) significantly decreased,and the number of errors (4.4 ± 1.3 ) significantly increased compared with the control group( latency: (279.30 ± 31.64) s; number of errors: ( 1. 8 ±0.9), P＜0. 01 ) ). The latency in low dose, middle dose and high dose AOF group( ( 170.25 ± 68.31 ) s, (226.31 ± 73.25 ) s, (263.20 ± 70.55 ) s) significantly increased, and the number of errors in middle dose and high dose AOF group ( ( 2.8 ± 1.2 ), ( 2.3 ±0. 9 ) ) significantly decreased compared with brain aging group (P ＜ 0. 05, P ＜ 0. 0 1 ). ② Morris water maze test:the escape latency in brain aging group was significantly longer, and the time spent in the original quadrant that previously contained the platform was significantly shorter compared with the control group (P＜0. 01 ). The escape latency in 3 AOF groups was significantly shorter (P＜ 0. 05 ), and the time spent in the original quadrant that previously contained the platform in middle and high dose AOF groups was significantly longer compared with brain aging group (P＜0. 05, P＜0. 01 ). ③ Western blot test:the expression of Syn,MAPK and PKC in hippocampus of brain aging group was significantly weakened than that of the control group. In contrast, the expression of Syn,MAPK, PKC were significantly enhanced in all AOF groups. Conclusion AOF could significantly improve the ability of learning and memory in brain aging mice. Its effects might be related to the increase of the expression of Syn, MAPK and PKC in hippocampus. Key words: Alpinia oxyphylla fructus; Brain aging; Synapsin; Mitngen-activated protein kinase; Protein kinase