Aqueous extracts of Phyllanthus amarus leaf mitigate cognitive impairments by enhancing neurotransmitter regulation and antioxidant defense mechanisms.

Abstract

Aims: Phyllanthus amarus (PA, P. amarus), commonly known as stonebreaker, has historically been used in traditional medicine for its medicinal attributes. Cognitive impairment continues to pose a major challenge in neurodegenerative disorders, with natural products being extensively explored as potential therapies. This study examined the effects of aqueous leaf extracts P. amarus on cognitive behaviors and neurochemical markers in scopolamine-induced amnesic rats.

Material and methods: Rats were administered aqueous PA extracts (50 and 500 mg/kg) or donepezil for a duration of 14 days. Cognitive performance was assessed through behavioral tests followed by neurochemical evaluation of cholinesterases (ChEs), monoamine oxidase (MAO), and purinergic enzymes in the cortex and hippocampus of the rats' brains.

Results: Administration of scopolamine impaired learning and memory and disrupted biochemical homeostasis. Treatment with PA extract significantly improved cognitive performance and attenuated scopolamine-induced alterations in neurotransmitter activity and oxidative stress markers.

Conclusion: In conclusion, aqueous leaf extracts of PA treatment may provide a new potential alternative for the treatment and prevention of cognitive impairment and neurochemical changes associated with neurotoxic agents, suggesting its potential to ameliorate scopolamine‑induced cognitive impairment and neurochemical alterations, while further studies are required to establish relevance to Alzheimer's disease pathology.