Objective: To study the interaction between α1-antichymotrypsin (ACT) and amyloid peptide Aβ1-42 in vitro, and the effects of their complex on expression of transcription factors PPARγ and NFκB in human neuroblastoma (Kelly) cells. Methods: Aβ1-42 and ACT were mixed at a 10: 1 molar ratio at room temperature, the complex formed in 2 hours and 24 hours were expressed as Aβ1-42/ACT (2 hours), Aβ1-42/ACT (24 hours), respectively. The complexes were studied by using agrose electrophoresis, and their effects on PPAR-γ and NFκB expressions were assessed by electrophoresis mobility shift assay (EMSA) Results: At conditions used, ACT interacted with Aβ1-42 in vitro, the complexes formed and functioned differently according to their interaction period. Compared with unstimulated control cells, Aβ1-42/ACT (2 hours) strongly increased PPAR-κ and NFκB expressions by Kelly cells by 158% (P < 0.05) and 77% (P < 0.05), respectively, while Aβ1-42/ACT (24 hours), or Aβ1-42, ACT alone had no similar effects. Conclusions: PPAR-γ and NFκB should be two transcription factors actively involved in the inflammatory process in human bodies. They have also been found increased in Alzheimer's brains, suggesting they should be a factor of pathology in this disease. The interaction between ACT and Aβ1-42 had an effect on the expression of PPARγ and NFκB, which might be responsible for the imbalanced inflammation in the central nervous system in Alzheimer's disease (AD). The relative status and quantity of ACT and Aβ1-42 in the amyloid deposits might have an impact on the pathogenesis of AD.