Exploring the Therapeutic Potential of Baicalin: Mitigating Anxiety and Depression in Epileptic Rats

Background: Epilepsy is a serious neurological disorder that affects millions of people each year, often leading to cognitive issues and reduced quality of life. Medication is the main treatment, but many patients experience negative side effects. Male Sprague-Dawley (SD) rats were chosen as experimental animals for this experiment due to their physiological and genetic similarities to humans, cost-effectiveness, and ease of handling in a laboratory setting. Aims: The objective of this study was to assess the neuroprotective properties of baicalin (BA) in relation to its impact on anxiety and depressive-like behaviors in the epilepsy model. Methods: Thirty male Sprague-Dawley (SD) rats were selected for this experiment. Pentylenetetrazol (PTZ) kindling (40 mg/kg; i.p.) was utilized to establish an epilepsy model. The effect of BA (50 mg/kg; gavage) on seizure severity (assessed using the Racine scale), anxiety, and depressive- like behaviors (evaluated through open field experiments and forced swimming tests) was examined. Histological examinations, including hematoxylin and eosin (HE) staining and Nissl staining, were conducted to assess neuronal damage. Furthermore, the neuroprotective properties of BA were examined through the analysis of Doublecortin (DCX), MKI67 (KI67), and Brain-Derived Neurotrophic Factor (BDNF) levels in the hippocampus of rats. The inhibitory impact of BA on neuroinflammation was assessed via dual labeling for NOD-like receptor thermal protein domain associated protein 3 (NLRP3) and the microglial marker ionized calcium- binding adapter molecule 1 (Iba-1). The influence of BA on the expression of P2X7 receptor (P2X7R), NLRP3, and Interleukin-1β (IL-1β) was also assessed by reverse transcription quantitative PCR (RT-qPCR) in the brain. Finally, we employed a molecular docking model to assess the extent of receptor-ligand binding. Results: Epilepsy models exhibited significant anxiety and depressive-like behaviors, and BA significantly reduced the severity of seizures in these rats while also alleviating their anxiety and depressive-like behaviors. Moreover, neuronal loss and damage were observed in the hippocampus of epileptic rats, but BA was able to effectively counteract this issue by enhancing BDNF expression and promoting neurogenesis within the hippocampus, especially in the DG region. The co-localization of Iba-1 with NLRP3 indicated the activation of NLRP3 inflammasome in microglia. Subsequent RT-PCR revealed that BA may alleviate anxiety and depressive-like behaviors in epileptic rats by activating the P2RX7/NLRP3/ IL-1β signaling pathway. The final molecular docking results indicated that BA had a good binding affinity with proteins, such as P2RX7, NLRP3, and IL-1β. Conclusion: This study confirmed the effectiveness of BA in improving anxiety and depressivelike behaviors associated with epilepsy. Moreover, it provides theoretical support for the neuroprotective role demonstrated by BA.