Lycopene-Loaded Microemulsion Regulates Neurogenesis in Rats with Aß-Induced Alzheimer's Disease Rats Based on the Wnt/ß-catenin Pathway.

Objective: To investigate the effects of lycopene-loaded microemulsion (LME) on the cognitive function and neurogenesis in the dentate gyrus (DG) of the hippocampus and subventricular (SVZ) region of rats with amyloid ß- (Aß-) induced Alzheimer's disease (AD) and its mechanism based on the Wnt/ß-catenin pathway. Methods: Healthy Wistar rats were divided into four groups: the blank control (CON), AD control, traditional lycopene (LOO), and LME groups. The CON and AD groups were fed with normal saline, while the LOO group was fed with traditional lycopene, and the LME group was fed with lycopene-loaded microemulsion. Behavioral tests were performed after three weeks of gastric administration. Immunofluorescence-labeled cells were used to observe the differentiation and maturation of new nerve cells in the DG of the hippocampus and SVZ region. qRT-PCR and Western blotting detected the expression of neurogenesis genes and Wnt/ß-catenin pathway-related proteins, respectively. Results: On the Morris water maze test, LME rats had significantly shortened movement trajectory on the searching platform, reduced escape latency time, and increased residence time on the original platform quadrant. In addition, more LME rats crossed the platform when it was removed. Thus, LME can improve the spatial learning and memory of Aß-induced AD rats. On qRT-PCR, LME significantly increased Reelin, Nestin, and Pax6 gene expressions, which regulate neurogenesis. Immunofluorescence showed that LME could significantly increase BrdU+, Dcx+, BrdU+/Neun+, BrdU+/Dcx+ cells in the DG and SVZ regions, thus promoting neurogenesis. LME also reduced the number of Iba1+ and Iba1+/BrdU+ cells, thus reducing the neuroinflammatory response. On Western blot, LME upregulated the Wnt/ß-catenin pathway by upregulating Wnt3a, ß-catenin, Disheveled (Dvl), and p-GSK3ß and downregulating p-ß-catenin and GSK3ß. Conclusion: LME attenuates cognitive impairment in Aß-induced AD rats by promoting neurogenesis in the hippocampus and SVZ region through upregulating the Wnt/ß-catenin pathway.

[Pollution Characteristics and Health Risk Assessment of Atmospheric VOCs in Chengdu].

Volatile organic compounds (VOCs) were measured in atmospheric samples collected from urban and roadside atmospheric environments in Chengdu in September 2012. The composition, chemical reactivity, and concentration level and its variation characteristics of VOCs were studied, and the health risk of aromatic compounds was assessed. Results showed that the mean mass concentrations of total VOCs (TVOCs) were (108.57±52.43) µg·m-3 and (132.61±49.31) µg·m-3 for the urban and roadside atmospheric environments, respectively. The highest mass concentrations were observed for alkanes, followed by aromatics, alkenes, and alkynes. Aromatics and alkenes contributed more to ozone formation potential (OFP) of the urban and roadside atmospheric environments, and m/p-xylene, toluene, ethene, o-xylene, and propene were the key reactive species. The values of hazard quotient and hazard index were less than 1 for benzene, toluene, ethylbenzene, and o-xylene (BTEX), showing that they had no appreciable risk of non-cancer health effects on the exposed population. However, the value of cancer risk was above the safety threshold for benzene, showing that it was a potential cancer risk to the exposed population.