Objective To compare the activation of microglia in vitro induced by oligomeric and fibrillar Aβ,and research the effects of Piper Kadsura Ohwi extracts on the microglial activation.Methods Microglia were divided randomly into 4 test groups,intervened by fibrillar Aβ25-35,fibrillar Aβ25-35 + Piper Kadsura Ohwi extracts,oligomeric Aβ25-35 and oligomeric Aβ25-35 + Piper Kadsura Ohwi extracts respectively.Also a blank contrast group was set without any intervention.48 hours later,activation of microglia was tested by immunocytochemistry,using the CD68 molecule as a specific marker of microglial activation and the incidences of active microglia in different groups were compared.Results Each of the 4 test groups had a higher positive incidence of CD68 expression than that of the blank contrast (5.1％ ) (P ＜ 0.05 ) ; positive incidence of fibrillar Aβ + Piper Kadsura Ohwi extracts group (52.1％) was lower than that of the fibrillar Aβ group (60.8％) (P＜0.05) ; positive incidence of oligomeric Aβ + Piper Kadsura Ohwi extracts group (67.0％) was not significantly different with that of the oligomeric Aβ group (71.2％),P=0.101.Conclusion Both fibrillar and oligomeric Aβ has the ability to activate the silent microglia.Piper Kadsura Ohwi extracts could inhibit the activation of microglia induced by fibrillar Aβ25-35,but didn't show significant effects on the activation induced by oligomeric Aβ25-35.

Objectives To explore the impact of Aβ oligomer(Aβo) and fibrillar Aβ( Aβf) on the ethology of model rat and to explore whether or not piper kadsura ohwi(PKO) can ameliorate the ethological changes.Methods AD animal model was made by continuous intracerebroventricular infusion of Aβ through mini-osmotic pump.After surgery,rats of Aβo + PKO group and Aβf + PKO group received intraperitoneal injection of 10％PKO everyday,rats from Aβo + DMSO group and Aβf + DMSO group received intraperitoneal injection of 2.5％ DMSO.The treatment lasted 5 weeks.Morris water maze experiment began on the 31st day after surgery.Results ( 1 ) Acquisition trials:the escape latency was longer in Aβo group ( ( 89.40 ± 7.20 ) s ) than that in Aβf group ( (65.00 ± 10.89 ) s ) ; escape latency was shorter in Aβf + PKO group ( ( 34.00 ± 11.26 ) s) than that in Aβf group and Aβf + DMSO group( (60.6 ± 6.95 ) s) ; escape latency was shorter in Aβ3o + PKO group ( ( 65.33 ±8.89) s) than that in Aβo group and Aβo + DMSO group ( ( 85.60 ± 6.02) s).( 2 ) Robe trial:the times ( 3.00 ±0.71 ) and the proportion of time (0.23 ± 0.02 ) and path(0.23 ± 0.04) spent in the target quadrant in Aβo group was less than that in Aβf group(6.00 ± 1.58,0.25 ± 0.01,0.26 ± 0.03 ) ; the three parameters in Aβf + PKOgroup were more than those in Aβ3f group and Aβf+ DMSO group; the three parameters in Aβo + PKO group were more than those in Aβo group and Aβo + DMSO group.Conclusions Aβ oligomer had a more severe impact on the ethology of AD model rats than fibrillar Aβ did; piper kadsura ohwi may ameliorate the ethological changes of AD model rats.