No medications prevent or reverse age-related cognitive decline. Physical activity (PA) enhances memory in rodents, but findings are mixed in human studies. As a result, exercise guidelines specific for brain health are absent. Here, we reexamine results from human studies, and suggest the use of more sensitive tasks to evaluate PA effects on age-related changes in the hippocampus, such as relational memory and mnemonic discrimination. We discuss recent advances from rodent and human studies into the underlying mechanisms at both the central and peripheral levels, including neurotrophins and myokines that could contribute to improved memory. Finally, we suggest guidelines for future research to help expedite well-founded PA recommendations for the public.
The effect of enzymatic hydrolysis on phenolic antioxidant extraction was studied in raspberry solid wastes. This by-product possesses high content of crude fiber (60%) and low values of protein, oil and ash. Raspberry fiber composition suggests that biocatalysts with cellulase, hemicellulase and pectinase activities would be useful for carrying out an enzymatically assisted antioxidant extraction. Hydro-alcoholic extraction was done using different commercial enzymes. Total phenol content and antioxidant activity of enzyme-hydrolyzed residue extracts were measured and compared with those obtained without enzyme application.All biocatalysts evaluated increased soluble solids in comparison to the non-enzymatic control. Among them, Grindamyl and Maxoliva offered the best recovery of polyphenols. Enzymatic assisted extraction with an hydro-ethanolic mixture (75:25, v/v) during 18 hrs at 50°C increased phenolic content up to 35% and antioxidant capacity around 50%, 15% and 30% according to 2,2-diphenyl-1-picrylhydrazyl = 2,2-diphenyl-1-(2,4,6-trinitrophenyl) hydrazyl) (DPPH), 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) and ferric reducing antioxidant power (FRAP) methods, respectively. Use of a higher enzyme concentration significantly improved extraction of phenolic antioxidants.
The physicochemical properties of oil from Rosa affinis rubiginosa seeds were analyzed after extraction by (i) organic solvent, (ii) cold pressing, and (iii) cold pressing assisted by enzymatic pretreatment using a mixture of the Novo-Nordisk A/S products Cellubrix (cellulase and hemicellulase activities) and Olivex (pectinase, cellulase, and hemicellulase activities). There were no significant differences in oil quality parameters, such as iodine value, refractive index, saponification value, unsaponifiable matter, and FA profile, when applying any of the three extraction processes. Although significant variations were observed in FFA content (acid value) and PV of the oil obtained by both of the cold-pressing oil extraction processes, these results were lower than the maximum value established from the Codex Alimentarius Commission. All-trans-retinoic acid content improved by 700% in rosehip oil obtained through cold pressing, with and without enzymatic pretreatment, in comparison with organic solvent extraction. This result is quite important for cosmetic oil because all-trans-retinoic acid is the main bioactive component responsible for the regenerative properties of this oil.Paper no. J11343 in JAOCS 83, 771-775 (September 2006).
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