Are Brazilian bamboo species helpful for cognition and memory?

Abstract

BackgroundBamboo species has been used for centuries in Asian traditional medicine to treat mental disorders resulting from the aging process. Brazil has the greatest diversity of bamboos in the Americas, with a high degree of endemism, but just a few of them has been studied for bioprospecting purposes. PurposeConsidering the previous report on the use of Asian bamboos to treat diseases affecting cognition and memory, a set of Brazilian bamboos species was investigated for similar properties. MethodsLeaves from Olyra glaberrima, Parodiolyra micrantha, Aulonemia aristulata, Filgueirasia arenicola, Filgueirasia cannavieira, and Merostachys pluriflora were investigated to their chemical profiles, free radical scavenging, anticholinesterase properties, toxicological effects on zebrafish larvae (Danio rerio), and protective effect on memory impairment assays (scopolamine-induced assay). ResultsBased on HPLC-ESI-MS/MS data, 70 compounds had their putative structures assigned based on analysis of molecular formula and fragmentation pattern. The most abundant compounds were glycosylated flavonoids, followed by terpenoids and soluble sugars. Overall bamboo leaf extracts showed high antioxidant potential. A moderate potential as an inhibitor of the acetylcholinesterase activity was detected for M. pluriflora. The in vivo assays indicated that aqueous extracts at 0.1 mg/ml are not toxic for zebrafish embryos and do not alter the larval exploratory behavior. The extracts from O. glaberrima, P. micrantha, A. aristulata, and F. arenicola increased the cognitive capacity of zebrafish larvae against an aversive stimulus. In adult zebrafish, the extracts from O. glaberrima, F. cannavieira, and M. pluriflora prevented the cognitive deficit induced by scopolamine treatment. ConclusionsAqueous extracts of the six Brazilian bamboo species showed high in vitro antioxidant potential. Some bamboo extracts increased the cognitive capacity of zebrafish larvae in the face of an aversive stimulus. Furthermore, some of them can reduce the memory loss induced by scopolamine in zebrafish adults. Moreover, many substances that were detected in this study had never been described for bamboos. This was the first study with herbaceous bamboo species; it is also the first study that used zebrafish as an experimental model to test bamboo extracts.