Rosmarinic acid-rich ethanolic extract of Orthosiphon stamineus ameliorates cognitive and hippocampal long-term potentiation in chronic cerebral hypoperfusion rat model

Zurina Hassan, Kesevan Rajah Kumaran, Nelson Jeng Yeou Chear, Siti Najmi Syuhadaa Bakar, Thaarvena Retinasamy, Saatheeyavaane Bhuvanendran, Amin Malik Abdul Majeed, Mohd Farooq Shaikh, Iekhsan Othman

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Chronic cerebral hypoperfusion (CCH) is one of the main causes of vascular dementia caused by the reduced blood flow to the brain. Orthosiphon stamineus (OS) is a medicinal herb exhibiting pronounced neuroprotective, anti-oxidant and anti-inflammatory activities due to its high rosmarinic acid content. This study investigated the nootropic effect of OS ethanolic extract on cognitive functions in CCH rats. CCH was developed by permanent bilateral occlusion of the common carotid artery (PBOCCA). Passive avoidance task (PAT) and Morris water maze (MWM) test were conducted to evaluate cognitive functions followed by in vivo long-term potentiation (LTP) for assessing neuroplasticity. The rosmarinic acid content of OS ethanolic extract was quantified using a validated HPLC-PDA. Treatment with OS ethanolic extract significantly increased step-through latency in the PAT, decreased escape latency at a low dose of OS extract in the MWM and rescued the LTP impairment at the highest dose in CCH rats. These results strongly support the effectiveness of rosmarinic acid-rich OS extract (5.088 % w/w) in treating pathological vascular dementia caused by CCH.

Original languageEnglish
Article number196
Number of pages16
JournalNeuroscience Research Notes
Volume6
Issue number3
DOIs
Publication statusPublished - 27 Aug 2023

Keywords

  • chronic cerebral hypoperfused rats
  • cognitive function
  • Morris-water-maze
  • O. stamineus
  • passive avoidance task

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