SIRT1 and Alzheimer disease: Moreover, hitherto known allosteric activators of sirtuins, such as resveratrol (SIRT1 activator), honokiol (SIRT3 activator), or SRT1720 may require chemical modifications to improve their crossing through blood-brain barrier, while sirtuin activity boosters in the form of close NAD+ precursors require introducing to the pharmaceutical retail market to provide their broad availability for people who would like to use them within the frames of AD prevention.