Phytohormone abscisic acid ameliorates cognitive impairments in streptozotocin-induced rat model of Alzheimer's disease through PPARβ/δ and PKA signaling

Abstract

Aim: Alzheimer's disease (AD) is characterized by oxidative stress, neuroinflammation and progressive cognitive decline. Abscisic acid (ABA) is produced in a variety of mammalian tissues, including brain. It has anti-inflammatory and antioxidant effects and elicits a positive effect on spatial learning and memory performance. Here, the possible protective effect of ABA was evaluated in streptozotocin (STZ)-induced AD rat model which were injected intracerebroventriculary (i.c.v.) with STZ (3 mg/kg).

Material and Methods: The STZ-treated animals received ABA (10 μg/rat, i.c.v.), ABA plus PPARβ/δ receptor antagonist (GSK0660, 80 nM/rat) or ABA plus selective inhibitor of PKA (KT5720, 0.5 μg/rat) for 14 d. Learning and memory were determined using Morris water maze (MWM) and passive avoidance (PA) tests.

Results: The data showed that STZ produced a significant learning and memory deficit in both MWM and PA tests. ABA significantly prevented the learning and memory impairment in STZ-treated rats. However, ABA effects were blocked by GSK0660 and KT5720.

Conclusion: The data indicated that ABA attenuates STZ-induced learning and memory impairment and PPAR-β/δ receptors and PKA signaling are involved, at least in part, in the ABA mechanism.

Keywords:

• Abscisic acid
• Alzheimer’s disease
• cognitive impairment
• PKA
• PPARβ/δ receptors
• streptozotocin

Acknowledgements

The authors would like to thank the financial support (grant to M. Abbasnejad, 1396) from Shahid Bahonar University of Kerman, Kerman, Iran.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study was financially supported by Shahid Bahonar University of Kerman, Kerman, Iran.