Since the hippocampus plays an important role in establishing new memories, Maher, and co-authors Tatsuhiro Akaishi and Kazuho Abe, both at Musashino University in Tokyo, Japan, extended the study and found that fisetin activates the same signaling pathway in rat hippocampal tissues and also induces LTP.
Next, they tested fisetin's effects in a so-called object discrimination test in mice. The mice get to explore two objects for a certain amount of time. The next day, one of the objects is replaced with a novel one. If the mice remember the object from the day before, they spend less time exploring the old one and instead turn their attention to the novel object. Indeed, mice administered a single dose of fisetin could better recall familiar objects. In fact, fisetin worked almost as well as rolipram, a substance known to enhance memory.
Memory loss caused by neurodegenerative disease occurs due to loss of neurons, a situation very different from that of healthy mice. Thus the ultimate goal is to stop neuronal loss. Nevertheless, memory-enhancing drugs can improve Alzheimer's disease symptoms.
The observations that fisetin protects and promotes survival of cultured neurons and boosts memory in healthy mice make it a promising candidate for further studies. Notes Maher, "This is the first time that the function of a defined natural product has been characterized at the molecular level in the central nervous system and also shown to enhance both LTP in vitro and long-term memory in vivo."
"The good news is that fisetin is readily available in strawberries but the bad news is that because of its natural product status there may be little fin