Ethanol Leaf Extract of Newbouldia laevis Attenuates Stress-Induced Prefrontal Cortical Damage by Reducing Lipid Peroxidation and Corticosterone Level in Adult Wistar Rats

Abstract

Introduction: Stress has been recognized as a risk factor for neuropsychiatric and neurodegenerative disorders due to its ability to induce oxidative stress, neuroinflammation, and neuronal damage in vital brain regions.

Aim: This study investigated the effects of ethanol leaf extract of Newbouldia laevis (ELENL) on stress-induced neuronal damage in the prefrontal cortex of male Wistar rats.

Methods: Thirty male Wistar rats weighing between 150 to 200g were randomized into six groups of five rats each.  Group 1: Control (distilled water, 2ml/kg), Group 2: (Chronic unpredictable mild Stress, CUMS, only), Group 3: (Stress + fluoxetine, 20mg/kg), Group 4: (CUMS + ethanol leaf extract of Newbouldia laevis 300mg/kg), Group 5: (CUMS+ ethanol leave extract of Newbouldia laevis 450mg/ kg), Group 6: (Stress + ethanol leaf extract of Newbouldia laevis 600mg/ kg). Newbouldia laevis extracts were administered orally for three weeks (21 days) once daily during the stress period, approximately 30 minutes before stress exposure. At the end of the treatment, the animals were humanely euthanized. Brain tissue were harvested for biochemical assessment of corticosterone and oxidative stress biomarkers, and processed for light microscopy.

Results: Biochemical analysis for oxidative markers revealed a significant decrease in malondialdehyde (MDA) levels in the ethanol leaf extract of Newbouldia laevis (ELENL) administered groups when compared to group II. A significant increase in dopamine (DA) level in Control (distill water), fluoxetine and CUMS+ELENL (450mg/kg) treated groups, when compared to CUMS only group and a statistical significant (p<0.05) decrease in corticosterone level was observed in control distil water, CUMS+ELENL (450 mg/kg) and CUMS+ELENL (600mg/kg) treated groups when compared to CUMS only group. Pyknotic and vacuolations were observed in the CUMS only group as compared to the ELENL treated groups.

Conclusion: The ethanol leaf extract of Newbouldia laevis shows ameliorative potentials against CUMS induced prefrontal cortex damage in Rats.