The neurogenic effects of rosmarinic acid in a mouse model of type 2 diabetes mellitus

Abstract

There is emerging evidence for a dysregulation of insulin signaling in the brains of patients with Alzheimer's disease (AD) with overlapping molecular features to Type 2 Diabetes Mellitus (T2DM). In addition, T2DM is a known risk factor of AD. The goal of this study was to investigate the neurogenic and neuroprotective potential of rosmarinic acid (RA) in a streptozotocin (STZ)induced combined with high fat diet (HFD) mouse model of diabetes. Animals were divided into four experimental groups (control, diabetic, diabetic + RA, RA only). Behavioral analysis was performed to assess spatial learning and anxiety levels of animals, whereas quantitative real time PCR was carried out to assess the gene expression levels of neuronal markers of neurogenesis (Ki67, DCX and NeuN). A significant decrease in memory and spatial learning was observed in the diabetic mice, which was substantially improved by RA treatment. RA also increased the gene expression of NeuN, DCX and Ki67, which were dysregulated in the diabetic model. This study proposes RA as a potential therapeutic agent to mitigate neuronal dysfunction associated with T2DM by promoting adult hippocampal neurogenesis.

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

“…The results obtained from these studies suggested that RA reverses synaptic plasticity dysfunction by promoting neurogenesis and increasing the synaptic strength of hippocampal neurons. In addition, the hippocampal neuroprotective and neurogenesis activity of RA was supported by studies by Khamse et al (2020) and Ali and Zahid (2020). Suggesting that RA contained in the OS extract plays an important role in hippocampal plasticity.…”