0000000000538858
AUTHOR
Michael Nöldner
KA-672 inhibits rat brain acetylcholinesterase in vitro but not in vivo.
Abstract KA-672, a lipophilic benzopyranone derivative which is currently under development as a cognitive enhancer and antidementia drug, has previously been shown to have facilitatory effects on learning and memory in rats at doses of 0.1–1 mg/kg. We now report that KA-672 inhibited the activity of acetylcholinesterase (AChE), measured in vitro in rat brain cortical homogenate, with an IC 50 value of 0.36 μ M indicating that KA-672 may improve cognitive functions as a consequence of AChE inhibition. However, when we employed the microdialysis procedure to monitor acetylcholine (ACh) release from rat hippocampus, no effect of KA-672 (0.1–10 mg/kg) was found, indicating a lack of inhibition…
Neurotrophic Properties of Silexan, an Essential Oil from the Flowers of Lavender-Preclinical Evidence for Antidepressant-Like Properties.
Abstract Background Silexan, a special essential oil from flowering tops of lavandula angustifolia, is used to treat subsyndromal anxiety disorders. In a recent clinical trial, Silexan also showed antidepressant effects in patients suffering from mixed anxiety-depression (ICD-10 F41.2). Since preclinical data explaining antidepressant properties of Silexan are missing, we decided to investigate if Silexan also shows antidepressant-like effects in vitro as well as in vivo models. Methods We used the forced swimming test (FST) in rats as a simple behavioral test indicative of antidepressant activity in vivo. As environmental events and other risk factors contribute to depression through conve…
Hypericum Extract and Hyperforin: Memory-Enhancing Properties in Rodents
Effects of a Hypericum extract in therapeutic use and hyperforin sodium salt were evaluated in rat and mouse avoidance tests. In a conditioned avoidance response (CAR) test on the rat, oral daily administration of hyperforin (1.25 mg/kg/day) or of the extract (50 mg/kg/day) before the training sessions considerably improved learning ability from the second day onwards until the day 7. In addition, the memory of the learned responses acquired during 7 consecutive days of administration and training was largely retained even after 9 days without further treatment or training. The observations made using different doses indicate that these learning-facilitating and/or memory-consolidating effe…