Nine methanol extracts were proved to reduce the tau aggregation in vitro. Extracts from leaves of Psidium guajava, Artocarpus altilis and Nelumbo nucifera impressively inhibited the tau aggregation with IC50 at mg/mL, mg/mL and mg/mL, respectively. Methylene blue was used as a positive control, with IC50 at µM. The five examined fractions of guava leaf were proved to inhibit the tau aggregation ranging from % to %, except the 100 % of hexane fraction showed almost no effect on the tau aggregation inhibitor. | TAÏP CHÍ PHAÙT TRIEÅN KH&CN, TAÄP 20, SOÁ T2- 2017 Study on tau-aggregation inhibitors in Alzheimer’s disease of methanol extracts of several medicinal plants collected in the Mekong Delta, Vietnam Nguyen Kim Dua Dai Thi Xuan Trang Can Tho University (Received on 27 th July 2016, accepted on 26 th April 2017) ABSTRACT Nine herbs were collected, dried and Tau protein and Aβ-amyloid have been extracted with methanol. The half maximal studied as pathological aggregations, which form inhibitory concentration (IC50) of methanol neurofibrillary tangles and amyloid plaques in extracts was measured by Thioflavin T assay at Alzheimer’s disease brain. Tau protein plays a various concentrations. Silica gel column critical role in neuron that binds to microtubules chromatography was employed to fractionate the and assists with their formation and stabilization. Psidium guajava leaf crude extract. Nine However, unbinding of hyperphosphorylated tau methanol extracts were proved to reduce the tau and microtubules leads to unstable and aggregation in vitro. Extracts from leaves of disintegrating state of neuron. The free tau Psidium guajava, Artocarpus altilis and Nelumbo the tau proteins form neurofibrillary tangles. The purpose nucifera impressively inhibited of this study is to screen in vitro the the tau- aggregation with IC50 at mg/mL, mg/mL aggregation inhibitory activity of nine methanol and mg/mL, respectively. Methylene blue was extracts of Psidium guajava leaf, Nelumbo used as a positive control, with IC50 at µM. nucifera leaf; wild Ipomoea aquatic, Cleome The five examined fractions of guava leaf were rutidosperma aerial parts, Artocarpus altilis leaf, proved to inhibit the tau aggregation ranging cultivated Ipomoea aquatic, Centella asiatica leaf, from % to %, except the 100 % of Mimosa pudica L. aerial parts, Nelumbo nucifera hexane fraction showed almost no effect on the tau aggregation inhibitor. seed pod collected in the .
