The Effects of Matcha and Decaffeinated Matcha on Learning, Memory and Proteomics of Hippocampus in Senescence-Accelerated (SAMP8) Mice

Although the benefits of the consumption of green tea and its components, including catechins and theanine, regarding aging, memory impairment and age-related cognitive decline have been investigated in senescence-accelerated prone mice (SAMP8), studies that simultaneously measured the kinds of proteins that vary in their expression due to the administration of green tea and its extracts were not found. In this study, the effect of dietary and decaffeinated matcha on protein expression in the hippocampus of SAMP 8 was examined comprehensively, mainly using proteomics. Although improvements in memory and the hair appearance of the back coat were limited upon administering the samples, the following regulations were observed in some of the proteins involved in neuron degeneration, Parkinson’s and Alzheimer’s diseases, synapse transmission and nerve cell plasticity, antioxidation, glutamate transport and metabolism, GABA (γ-amino butyric acid) formation and transport and excitatory amino acid transporters: proteins downregulated upon sample intake (p < 0.05): brain acid-soluble protein 1, microtubule-associated protein tau, synapsin-2, sodium- and chloride-dependent GABA transporter; proteins that tended to decrease upon sample intake (0.05 < p < 0.10): Parkinson’s disease (autosomal recessive and early-onset) 7 and synapsin-1; proteins upregulated upon sample intake (p > 0.95): glutathione S-transferase Mu 1, tubulin alpha-1A chain, dynamin-2, calcium/calmodulin-dependent protein kinase type II subunit gamma and tyrosine 3-monooxygenase/tyrosine 5-monooxygenase activation protein epsilon polypeptide; proteins that tended to increase upon sample intake (0.95 > p > 0.90): glutathione S-transferase Mu7 and soluble carrier family 1 (glial high-affinity glutamate transporter); proteins that tended to decrease: sodium- and chloride-dependent GABA transporter 3. These results indicate that matcha and decaffeinated matcha could reduce aging and cognitive impairment by regulating the expression of these proteins. Furthermore, these proteins could be used as markers for the evaluation of food and its available components for reducing aging and cognitive impairment.

Effect of High-Oleic Peanut Intake on Aging and Its Hippocampal Markers in Senescence-Accelerated Mice (SAMP8)

In many previous studies, the preventive effects of peanut against aging and cognitive impairment have often been unclear, so to clarify the effects we first investigated effective markers for evaluating its effects in the hippocampus of senescence-accelerated mouse prone/8 (SAMP8) mice, mainly using proteomics. The effects of dietary high-oleic peanuts on the hair appearance of SAMP8, the expression of effective markers in the hippocampus, and the TBARS and amino acid contents of the hippocampus were examined. Hippocampus solute carrier family 1 (glial high-affinity glutamate transporter), calcium/calmodulin-dependent protein kinase type II, and sodium- and chloride-dependent GABA transporter, which all are considered to be closely related to glutamic acid concentration were decreased by feeding of the samples, and the GABA/glutamic acid ratio in the hippocampus was increased by feeding with the samples. The formation of glial fibrillary acidic protein and synapsin-2, which showed higher levels in the SAMP8 than in SAMR1, and the protein expression of tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein and dihydropteridine reductase, which are considered to be related to the formation of adrenergic neuron transmitters, were reduced by the feeding of peanuts and their germ-rich fraction. Ferulic acid, as an ester and minor component in peanuts, could be partly connected to the effect of peanuts. These results indicate that high-oleic peanuts and their germ-rich fraction can protect against aging and cognitive impairment by regulating protein expression, which could be measured by the proteomics of the above hippocampus proteins of SAMP8 and the hippocampal GABA/glutamic acid ratio.