Ethanol extract of Astragali Radix and Salviae Miltiorrhizae Radix, Myelophil, exerts anti-amnesic effect in a mouse model of scopolamine-induced memory deficits

Abstract

Ethnopharmacological relevance: Myelophil, a combination of extracts taken from Astragali Radix and Salviae Miltiorrhizae Radix, is a traditional Chinese medicine used for the treatment of chronic fatigue-associated disorders. Here we examined the ability of Myelophil to alleviate memory impairment in a mouse model. We aimed to investigate whether Myelophil has the pharmacological effects on memory deficits associated with brain dysfunctions using an animal model.

Materials and methods: Ten week-old male C57BL/6N mice were pretreated with Myelophil (50, 100, or 200 mg/kg), or tacrine (10 mg/kg) for 7 days, and then intraperitoneally injected with scopolamine (1 mg/kg). Memory-related behaviors were evaluated using the Morris water maze for 5 days. Levels of biomarkers of oxidative stress, antioxidant activity, acetylcholinesterase (AChE) activity, and extracellular signal-regulated kinase (ERK) were measured in brain tissues.

Results: Scopolamine treatment increased the escape latency time and shortened time spent in the target quadrant; these effects were ameliorated by pretreatment with Myelophil. Scopolamine-induced changes in reactive oxygen species (ROS), malondialehyde (MDA), and AChE activity were significantly attenuated in mice pretreated with Myelophil. Recovery of antioxidant capacities, including total glutathione (GSH) content, and the activities of GSH-reductase, GSH-S-transferase, and catalase was also evident in Myelophil-treated mice. The strongest effects were seen for ERK and muscarinic acetylcholine receptor 1 (mAChR1) at both the protein and gene expression levels, with significant amelioration of expression levels in the Myelophil pretreatment group.

Conclusions: These results suggest that Myelophil confers anti-amnesic properties in a mouse model of memory impairment, driven in part by the modulation of cholinergic activity.

Keywords: Acetylcholinesterase; Antioxidant; Extracellular signal-regulated kinase; Memory; Oxidative stress; Scopolamine.