Efficacy Evaluation and Mechanism Research of Qi-Shen-Yi-Zhi Formula in Improving the Learning and Memory Ability of Aβ1-42 Hippocampus Injection Mice / 世界科学技术-中医药现代化

Objective Evaluation of the effect and mechanism research of Qi-Shen-Yi-Zhi formula on improving learning and memory ability in mice injected with Aβ1-42 in hippocampus.Methods Alzheimer's disease model mice were constructed by injecting β amyloid peptide 1-42 into hippocampus and treated with water extracts of Qi-Shen-Yi-Zhi formula.The cognitive abilities of mice were assessed using Morris water maze and Y maze tests,which measure learning and memory capabilities.HE staining was used to observe the damage and TUNEL method was used to determine apoptosis of hippocampus.Detection of the expression of oxidative factors,inflammatory factors,and related antioxidant proteins and apoptotic proteins in the hippocampal tissue of a mouse model of dementia.Results Both high-dose and low-dose groups of Qi-Shen-Yi-Zhi formula significantly improved cognitive dysfunction in mice injected with Aβ1-42 in hippocampus,and attenuated the damage and apoptosis of the hippocampus.It also inhibited oxidative stress and downregulated the expressions of inflammatory factors IL-6,IL-1β and TNF-a,increased the expression of antioxidant proteins Nrf2 and HO-1,and regulated the expressions of apoptotic proteins Caspase-9,Caspase-3,Bax and Bcl-2.Conclusion Qi-Shen-Yi-Zhi formula improves the learning and memory abilities of mice injected with Aβ1-42 in hippocampus,which might be related to the attenuation of oxidative stress and neuronal inflammation of hippocampus.

Epigallocatechin-3-gallate rescues LPS-impaired adult hippocampal neurogenesis through suppressing the TLR4-NF-kappaB signaling pathway in mice

Adult hippocampal dentate granule neurons are generated from neural stem cells (NSCs) in the mammalian brain, and the fate specification of adult NSCs is precisely controlled by the local niches and environment, such as the subventricular zone (SVZ), dentate gyrus (DG), and Toll-like receptors (TLRs). Epigallocatechin-3-gallate (EGCG) is the main polyphenolic flavonoid in green tea that has neuroprotective activities, but there is no clear understanding of the role of EGCG in adult neurogenesis in the DG after neuroinflammation. Here, we investigate the effect and the mechanism of EGCG on adult neurogenesis impaired by lipopolysaccharides (LPS). LPS-induced neuroinflammation inhibited adult neurogenesis by suppressing the proliferation and differentiation of neural stem cells in the DG, which was indicated by the decreased number of Bromodeoxyuridine (BrdU)-, Doublecortin (DCX)- and Neuronal Nuclei (NeuN)-positive cells. In addition, microglia were recruited with activatingTLR4-NF-kappaB signaling in the adult hippocampus by LPS injection. Treating LPS-injured mice with EGCG restored the proliferation and differentiation of NSCs in the DG, which were decreased by LPS, and EGCG treatment also ameliorated the apoptosis of NSCs. Moreover, pro-inflammatory cytokine production induced by LPS was attenuated by EGCG treatment through modulating the TLR4-NF-kappaB pathway. These results illustrate that EGCG has a beneficial effect on impaired adult neurogenesis caused by LPSinduced neuroinflammation, and it may be applicable as a therapeutic agent against neurodegenerative disorders caused by inflammation.