The Methanolic Extract Of Rhinanthus Songaricus Alleviates Scopolamine-Induced Memory Dysfunction In Rats

Abstract

Rhinanthus songaricus (RS), a hemiparasitic plant belonging to the family Orobanchaceae, is native to Mongolia. This study aimed to evaluate the neuropharmacological effects of a methanol extract from the aerial parts of R. songaricus in a scopolamine-induced rat model of Alzheimer’s disease.

 Phytochemical screening for flavonoids was performed via thin-layer chromatography (TLC) and ultraviolet spectrophotometry. To assess neuropharmacological effects, rats were orally treated with RS methanolic extract (100 or 200 mg/kg, orally) for 14 days. During this treatment period, cognitive impairment was induced by intraperitoneal injection scopolamine (2 mg/kg, i.p.) for 10 consecutive days.

Phytochemical analysis revealed the presence of apigenin and luteolin flavones, with total flavone content equivalent to 16 mg luteolin per gram of extract. Scopolamine significantly induced locomotor deficits, anxiety-like behavior, and memory impairments. Pretreatment with RS extract at 100 and 200 mg/kg significantly reversed these effects in behavioral tests. Scopolamine also significantly increased acetylcholinesterase (AChE) activity in the hippocampus; this increase was significantly attenuated by RS extract at 200 mg/kg, but not at 100 mg/kg. No significant changes were observed in angiotensin-converting enzyme (ACE) activity across all groups.

The methanol extract of R. songaricus exhibited neuroprotective effects, likely mediated by reducing AChE activity in the hippocampus. These findings suggest that RS extract may have potential benefits in alleviating Alzheimer’s-like symptoms.