Background: Scutellarein, a bioactive flavone derived from Scutellaria barbata D. Don—a herb widely used in Traditional Chinese Medicine (TCM)—is known for its neuroprotective, neurogenic, and anti-inflammatory properties. Our previous research demonstrated that the hydroethanolic extract of S. barbata (HSBE) exhibits robust antidepressant-like activity, supported by behavioral, neurochemical, and biochemical alterations in rodent models. Furthermore, a validated High-Performance Thin-Layer Chromatography (HPTLC) method confirmed the presence of scutellarein in significant amounts within the extract. Based on these findings and existing literature, the present study was designed to investigate the antidepressant-like potential of scutellarein and elucidate its molecular mechanisms. Method: Swiss albino mice were orally administered scutellarein at doses of 20 and 40 mg/kg body weight for three weeks. The CUMS method was employed to induce depression for 21 days. On the 21st day, TST, FST, and OFT were used to evaluate antidepressant-like potential. On the 22nd day, 5-HT, NE, and DA levels were quantified in the cortex, hypothalamus, and hippocampus. MAO-A and B activity, as well as levels of antioxidant enzymes, were assessed in the brain. Additionally, plasma corticosterone and nitrite levels were also measured to elucidate the mechanisms of action. Results: Scutellarein exhibited dose-dependent antidepressant-like effects in both TST and FST, with enhanced locomotor activity observed in the OFT, indicating improved mood and mobility. Furthermore, scutellarein significantly modulated levels of NE, 5-HT, and DA in key brain regions. Additionally, it regulated MAO-A and B activity, as well as antioxidant enzyme levels, potentially affecting neurotransmitter levels and mitigating oxidative stress. Scutellarein also affected plasma nitrite and corticosterone levels, indicating systemic impact on nitric oxide signaling and the HPA axis, which are key in stress responses. Discussion: The findings suggest that scutellarein exerts antidepressant-like effects through a multimodal mechanism involving monoaminergic regulation, attenuation of oxidative and nitrosative stress, inhibition of MAO activity, and modulation of HPA axis function. These combined actions support the neurobiological relevance of scutellarein in stress-induced depression. Conclusion: Scutellarein demonstrates significant antidepressant-like activity in vivo and may represent a promising phytochemical candidate for further development as a novel antidepressant agent.
Pannu et al. (Wed,) studied this question.