Synergistic effect of Korean red ginseng and Pueraria montana var. lobata against trimethyltin-induced cognitive impairment.

Many edible plant extracts exhibit biological activities. For example, the ethanol extract of Pueraria montana var. lobata (P. montana) inhibits acetylcholinesterase (AChE), and red ginseng is well known for promoting health. In this study the authors investigated the synergistic effect of P. montana and red ginseng extracts on AChE activity in vitro and in mouse brain tissues and trimethyltin (TMT)-induced cognitive impairment in a mouse model of TMT-induced neurodegeneration. A diet containing a mixture of P. montana and red ginseng extracts reversed learning and memory impairments in Y-maze and passive avoidance behavioral tests. In addition, the mixture inhibited AChE activity and lipid peroxidation synergistically.

Erucamide from Radish Leaves Has an Inhibitory Effect Against Acetylcholinesterase and Prevents Memory Deficit Induced by Trimethyltin.

In this study, we investigated a potent acetylcholinesterase inhibitor that was isolated from radish leaf (Raphanus sativus L.) extracts. Through sequential fractionation of radish leaf extract, the active constituent was identified as cis-13-docosenamide (erucamide). To validate the potency, erucamide derived from radish leaves was supplemented in diets and then fed to trimethyltin (TMT)-exposed mice. Specifically, mice had free access to a control diet or diets containing different concentrations of erucamide for 3 weeks, followed by an injection of TMT (2.5 mg/kg body weight). Our results showed that pretreatment of mice with erucamide (20 and 40 mg/kg body weight per day) significantly attenuated the TMT-induced learning and memory deficits that were assessed by Y-maze and passive avoidance tests. These findings suggest that radish leaves, and possibly its isolated erucamide, may have preventive effects against memory deficits related to Alzheimer's disease by modulation of cholinergic functions.

2,4-Bis(1,1-dimethylethyl)phenol from Cinnamomum loureirii Improves Cognitive Deficit, Cholinergic Dysfunction, and Oxidative Damage in TMT-Treated Mice.

We previously reported that the extract of Cinnamomum loureirii (C. loureirii) significantly inhibited acetylcholinesterase (AChE), and identified 2,4-bis(1,1-dimethylethyl)phenol (BP) from C. loureirii as a potential AChE inhibitor. The present study, therefore was undertaken to demonstrate the effects of BP from C. loureirii on learning and memory impairment in trimethyltin (TMT)-treated ICR mice. Y-maze and passive avoidance tests were used to test cognitive ability. Further, changes in biochemical parameters in the brain tissue were also assessed in response to TMT injection and BP intervention. BP pre-administration (20, 40 mg/kg/d) in mice significantly protected cognitive dysfunction induced by TMT (p<0.05). Moreover, BP reduced AChE activity and lipid peroxidation but increased acetylcholine levels in the brain. In conclusion, we suggested that BP protected against TMT-induced cognitive dysfunction, and might be a potential agent for alleviating symptoms of neurodegenerative disorders, such as Alzheimer's disease, via modulating cholinergic functions.