Exploring the Antidepressant-like Effects of Wogonin: Analysis of Behavioural, Neurochemical, and Biochemical Parameters
Authors: Pannu Arzoo , Goyal Ramesh K. 
Published: September 2024

Background:
Wogonin, a bioactive compound isolated from S. barbata D. Don, has
been identified in the literature as a potential inhibitor of monoamine oxidase (MAO), a key enzyme
involved in the degradation of neurotransmitters associated with mood regulation. This
study aims to investigate the antidepressant-like activity of wogonin in vivo, utilizing a preclinical
model. The rationale for selecting wogonin stems from its documented MAO inhibitory properties,
suggesting a potential role in modulating neurotransmitter levels implicated in depressive
disorder.

Method:
The study employs a multifaceted approach, incorporating behavioural, neurochemical,
and biochemical assessments. The Chronic Unpredictable Mild Stress model is utilized to induce
depression-like behavior in rodents for 21 days. Two doses of wogonin (20 and 40 mg/kg per
orally) and standard (fluoxetine, 20 mg/kg, and imipramine, 15 mg/kg) were administered to albino
mice. Behavioural paradigms, including the Tail Suspension Test, Forced Swim Test, and
Open Field Test, are employed to assess the impact of wogonin on depressive-like symptoms on
the 21st day. Neurochemical analyses focus on alterations in 5-HT, NE, and DA levels within relevant
brain regions, and MAO activity is quantified to ascertain wogonin's potential as an MAO
inhibitor on the 22nd day. Biochemical assessments emphasize wogonin's antioxidant properties
and its ability to mitigate oxidative stress, a significant factor in depression pathophysiology.
Plasma nitrite levels are measured to elucidate wogonin's impact on nitric oxide signalling. Plasma
corticosteroid levels are also quantified to delineate wogonin's effect on the hypothalamicpituitary-
adrenal (HPA) axis, a central regulator of stress response.

Results:
Wogonin demonstrates significant antidepressant effects in a dose-dependent manner in
the behavioural assessments, showing a marked reduction in depressive-like behaviours across all
paradigms. Neurochemical analyses revealed a significant (p ≤ 0.05) restoration of monoamine
neurotransmitter levels in the relevant brain regions as compared to CUMS-induced stress group.
Additionally, wogonin exhibits a potent (p ≤ 0.05) inhibitory effect on MAO activity. Biochemical
assessments demonstrate a significant (p ≤ 0.05) increase in antioxidant capacity and a reduction
in oxidative stress markers. Plasma nitrite levels indicate an enhancement of nitric oxide signalling.
Corticosteroid levels showed a modulation of the HPA axis, suggesting a regulatory effect
on stress response.

Conclusion:
This comprehensive study establishes wogonin as a promising MAO inhibitor with
notable antidepressant potential. The findings provide crucial insights into its mechanisms of action,
indicating a multifaceted approach to alleviating depression. Wogonin's demonstrated efficacy
across behavioural, neurochemical, and biochemical parameters presents a strong foundation
for further research and development of wogonin-based antidepressant interventions.