Anti-aging effects of oligomeric proanthocyanidins isolated from persimmon fruits

Abstract

Senescence-accelerated mouse prone/8 (SAMP8), a murine model of accelerated senescence, shows age-related deficits in learning and memory. The oral administration of oligomers improved spatial and object recognition impairment in SAMP8. The expression of phosphorylated neurofilament-H was significantly elevated in the hippocampal CA1. This indicates that oligomers induce an increase in the density of axons. To investigate the protective mechanisms of oligomers against brain dysfunction with aging, we carried out a receptor tyrosine kinase phosphorylation antibody array, and clarified that the administration of oligomers led to an increase in the phosphorylation of vascular endothelial growth factor receptor (VEGFR)-2, suggesting the neuroprotective role of oligomers. The phosphorylation of VEGFR-2 was more markedly increased in the hypothalamus and choroid plexus than in other brain regions of SAMP8. Memory in oligomer-treated mice was impaired by SU1498, a VEGFR-2-specific antagonist. Elucidating the relationship between memory impairment with aging and VEGFR-2 signaling may provide new suggestions for protection against memory deficit in the aging brain. In addition, we revealed that the administration of oligomers extended the life span of SAMP8. Oligomers elevated SIRT1 expression, which is recognized as an essential factor for life span extension in the brain. However, the administration of oligomers did not induce stereotypical behaviors such as rearing, jumping, or hanging from the lid of a cage, while food restriction increased these frequencies without a significant change in motor function. The present study suggests the promising role of oligomers as an anti-aging agent to extend life span.

Moderate-dose Regular Lifelong Alcohol Intake Changes the Intestinal Flora, Protects against Aging, and Keeps Spatial Memory in the Senescence-accelerated Mouse Prone 8 (SAMP8) Model

“…Similarly, Yokozawa et al reported that SAMP8 model presented a deficit in object recognition and spatial recognition at 41-42 weeks of age (71). In these reports, the mice were younger than in our study when the memory deficit was detected.…”

Fabrication of Tamarindus indica seeds extract loaded-cream for photo-aged skin: Visioscan® studies

“…Antioxidants tender protection to cell membranes as they neutralize free radicals and noxious oxygen molecules and prevent oxidative stress to the tissues of the body. They supply elasticity to the skin by actively countering free radical attacks [ 10 – 12 ].…”

SIRT1 Regulates Cognitive Performance and Ability of Learning and Memory in Diabetic and Nondiabetic Models

“…Several studies have demonstrated that SIRT1 modulates neuronal viability [ 36 , 37 ], neuronal differentiation [ 38 – 41 ], neuronal protection [ 42 – 44 ], and synaptic plasticity [ 21 , 45 – 47 ], all of which are key factors largely linked to cognitive improvement. It is well established that insulin exerts its actions in a series of biological processes through binding to insulin receptors [ 108 ], as well as plays an essential role in IR and T2DM.…”

“…In addition, SIRT1 was downregulated in diverse models of cognitive impairment in vivo and in vitro , such as in juvenile C57BL/6J mice with dysmetabolism induced by high-caloric diet [ 45 ] and neurotoxic primary hippocampal neurons caused by toxins [ 44 ]. A study by Yokozawa et al on antiaging effects of oligomeric proanthocyanidins found that SIRT1 was increased both in the cellular senescence model [ 46 ] and SAMP8 mouse model [ 47 ]. On the other hand, some researchers believed that SIRT1 has no effect on cognitive improvement and has a counterproductive effect.…”