| Oyster(Crassostrea hongkongensis), which is a large output shellfish in coastal area in China, constitutes a rich nutritional components. Recently, improving learning and memory function of Oyster was found. The bioactive of improving learning and memory is a new finding and its beneficial effects and mechanisms need further study to clarify. The goal of this study is to investigate its bioactive components of improving learning and memory and its mechanisms. In this study, Scopolamine was used to induce learning and memory impairment; Morris water maze was used to assess learning and memory ability; biochemistry index, which include anti-oxidant; cholinergic and glutamatergic; TNOS activity were examined to clarify its mechanisms.The main results are as follows:(1)In this chapter, 5 oyster samples contained different nutritional components were prepared and then its enhancing learning and memory ability were studied. The results showed that the dose of 2 mg/kg of Scopolamine, which prolonged the escape latency and reduced the percentage of time/total path length in target quadrant, induced learning and memory impairment; all the 5 oyster samples improved learning and memory in different degrees, in which sample 1, 2, 3 exhibited the most beneficial samples; all the 5 oyster samples attenuated oxidant stress and cholinergic damage induced by Scopolamine in different degrees.(2)Nutritional components, including protein, amino acids, peptides, fatty acids and inorganic elements, in 5 different oyster samples were examined to clarify its functional components. It concluded that all the 5 samples constituted a high content of crude protein, amino acids and a high concentration of peptides(<5kDa); In addition, 5—10kDa peptides were richer in sample 3, 4, 5; All 5 samples constitued many kinds of fatty acid in which sample 1, 2, 3 has 17, 17, 18 kinds of fatty acids, respectively; components of inorganic elements in 5 samples were complex, in which content of both K and Na were increased largely in sample 3, 4, 5, respectively; while content of both Ca and Mg were decreased largely in sample 3, 4, 5, respectively. In conclusion, rich concentration of protein, amino acids(include taurine), peptides(<5kDa) and fatty acids are the nutritional components for improving learning and memory of 5 oyster samples.(3)Oyster enzymatic extracts(OEE1 and OEE2) and crude taurine extracts(TE) were prepared and its effects on learning and memory were investigated. The results showed that small peptides(<1kDa) were richer in OEE1; the content of taurine in TE was 17.48mg/g; OEE1, OEE2 and two doses of TE enhanced the learning and memory ability in which OEE1 exhiboted the strongest effect; OEE1, OEE2 and two doses of TE increased the total antioxidant capacity and decreased content of protein carbonyl, inhibited AchE activity, increased TNOS activity and reduced content of glutamate in hippocampus tissue.In conclusion, oyster can improve learning and memory ability and the main components of this function are proteins, amino acids, peptides, and fatty acids; small peptides(<1kDa) and water solubility components including taurine in oyster are beneficial for enhancing learning and memory; the effects of improving learning and memory of oyster has a close relationship with its anti-oxidant, restoring cholinergic and glutamatergic damage, increasing TNOS activity. |
