The Journal of Phytopharmacology 2026; 15(4):209-217 DOI:10.31254/phyto.2026.15403

Research Article

Exploitation of aqueous Rosmarinus officinalis extract as a protective agent in the hippocampus of lead acetate-exposed rats

Chioma Christabel Onyemechi¹ , John Favour Ehijiagbon Aig-Unuigbe¹ , Frederick Ohiomokhai Tobalu¹ , Akporufuoma Racheal Orheruataa¹ , Osagie Usman Idemudia¹ , Adaze Bijou Enogieru²

Chioma Christabel Onyemechi,John Favour Ehijiagbon Aig-Unuigbe,Frederick Ohiomokhai Tobalu,Akporufuoma Racheal Orheruataa,Osagie Usman Idemudia,Adaze Bijou Enogieru

1. Department of Anatomy, University of Benin, Benin City, Nigeria
2. Department of Anatomy, School of Basic Medical Sciences, University of Benin, Edo State, Nigeria

*Author to whom correspondence should be addressed.

Received: 11th April, 2026 / Accepted: 13th July, 2026 / Published : 31st July, 2026

Abstract

Background: Hippocampal dysfunction can result from defects, degeneration, or toxins like lead (Pb), which crosses the blood-brain barrier, disrupts calcium signaling, and causes oxidative stress, leading to cognitive decline. Dietary antioxidants may help counteract this oxidative injury and protect hippocampal function. Objective: This study investigated the protective activity of aqueous Rosmarinus officinalis leaf extract on lead acetate induced hippocampal toxicity. Materials and Methods: Forty-eight adult Wistar rats were divided into six groups: A (control), B (100 mg/kg Pb only), C (100 mg/kg Pb + 100 mg/kg R. officinalis), D (100 mg/kg Pb + 200 mg/kg R. officinalis), E (100 mg/kg R. officinalis only), and F (200 mg/kg R. officinalis only). All administrations, via an orogastric tube, lasted for twenty-eight (28) days. Neurobehavioral tests (Novel Object Recognition, Y-maze, Elevated Plus Maze) were evaluated, after which hippocampi were collected to assess lead levels, antioxidant activity, lipid peroxidation, acetylcholinesterase (AChE), nitric oxide (NO), histology, and apoptosis.  Results: Pb-exposed rats showed significant (p<0.05) weight loss, cognitive and memory deficits, disrupted antioxidant and AChE activity, increased lipid peroxidation, elevated hippocampal NO and lead levels, along with neuronal atrophy and caspase-3 upregulation, indicating apoptosis. Pretreatment with R. officinalis significantly (p<0.05) mitigated weight loss, oxidative stress, lipid peroxidation, neuronal damage, and levels of hippocampal lead, NO, AChE, and caspase-3, highlighting its antioxidant, metal-chelating, NO-scavenging, anti-cholinesterase, and anti-apoptotic effects against Pb-induced neurotoxicity.  Conclusion: Consequently, this study provides novel evidence supporting R. officinalis as a promising neuroprotective agent with potential for drug development against hippocampal dysfunction.