Abstract:

Objective  To explore the inhibitory effect of Piper Kadsura Ohwi extracts on the releases of proinflammatory cytokines, IL-1β and TNF-α, in microglia cells which were activated by Aβ1-42 with different aggregation state. Methods   Mice microglia cell line BV2 was cultured in vitro. Consistent soluble oligomeric and fibrillar Aβ1-42 were prepared. The cytotoxicity of different extracts from Piper Kadsura Ohwi was assessed by methyl thiazolyl tetrazolium(MTT). BV2 cells were divided into 4 experimental groups，intervened respectively by oligomeric Aβ1-42, oligomeric Aβ1-42 + Piper Kadsura Ohwi extracts, fibrillar Aβ1-42 and fibrillar Aβ142+ Piper Kadsura Ohwi extracts. Besides, a blank control group was set up without any intervention. Expressions of IL-1β and TNF-α were assessed by Realtime PCR. Results   There was no effect on the survival of BV2 cells with various concentrations(10-80g/L) of Piper Kadsura Ohwi extracts. Real-time PCR showed that each of the 4 experimental groups had higher expressions of IL-1β and TNF-α, compared with blank control group. The oligomeric Aβ1-42 + Piper kadsura Ohwi extract group had lower expressions of IL-1β and TNF-α than the oligomeric Aβ1-42 group; likewise, the fibrillar Aβ1-42 + Piper Kadsura Ohwi extract group had lower expressions of IL-1β and TNF-α than the fibrillar Aβ1-42  group. Conclusion   Both fibrillar and oligomeric Aβ1-42 can activate the microglia cell BV2, and their activating effects can be inhibited by Piper Kadsura Ohwi extracts.

Key words: Piper Kadsura Ohwi extracts； Microglia； Alzheimer’s disease； β-amyloid； IL-1β； TNF-α