Andrographolide exerts an anxiolytic-like effect possibly via regulation of the hypothalamic-orexinergic system

Abstract

Background: Anxiety is a psychiatric disorder that causes many problems in life such as poor concentration, sleep disturbance, and feelings of unease to anticipate future threats. The hypothalamus is a part of the limbic system that regulates stress. The orexinergic system, naturally produced in the hypothalamus, is associated with anxiety and depression which is induced by stress. Andrographolide has antioxidants and anti-inflammation properties that are possibly effective in preventing stress-induced anxiety. Objective: This study was designed to investigate the effect of andrographolide on anxiety-like behaviour and orexinergic systems. Method: The ddY strain mice were exposed to electrical footshock stress for five days. The light was used as a contextual fear conditioning during stress exposure. Exactly 50 mg/kg of Andrographolide was given intraperitoneally, along with stress induction. The anxiety-like behaviour was investigated using two approaches: the duration of the freezing behaviour and the mice’s natural aversion to exploring open space. The hypothalamus was collected to examine the orexinergic systems. Result: Stress induction developed an anxiety-like behaviour in mice while administering andrographolide attenuated this effect. Additionally, andrographolide administration stimulated the hypothalamic orexinergic system. Conclusion: Andrographolide exerts an anxiolytic effect possibly via regulation of the hypothalamic orexinergic system.