Central microinjection of phytohormone abscisic acid changes feeding behavior, decreases body weight, and reduces brain oxidative stress in rats

Objectives: Natural products have a potential role on food intake in mammals. It has been reported that phytohormone abscisic acid (ABA) has a regulatory role on metabolic processes. Here, the effects of ABA on feeding behavior and brain oxidative stress were investigated in male Wistar rats. Methods: ABA was injected intracerebroventricularly. Experimental groups were included (n = 9): control (received no injection), ABA vehicle (received normal saline), and ABA-treated groups were injected with different doses of ABA (2.5, 5, and 10 μg/rat for 7 days). Daily cumulative daytime and nighttime food consumption, meal frequency, meal duration, and alteration in body weight were recorded. At the end of behavioral experiment, catalase and peroxidase activity and malondialdehyde (MDA) and hydrogen peroxide (H2O2) levels were assayed. Results: The results showed that ABA (5 and 10 μg) increased the meal frequency. Moreover, ABA could decrease body weight and MDA and H2O2 levels and increased the catalase and peroxidase activities in diencephalon. It also decreased the MDA concentration in the brain stem. Discussion: Taken together, ABA has an important effect on feeding behavior and body weight in rats likely via increasing antioxidant capacity. However, further studies are still required to determine the underlying mechanisms of ABA on the feeding behavior.