In this study, the protective effect of sweet potato extract against hydrogen peroxide-induced oxidative stress and cytotoxicity on the pheochromocytoma cell line (PC12) was investigated. The active component of the sweet potato extract was purified and determined to be 2,4-di-tert-butylphenol. The antioxidant capacity of 2,4-di-tert-butylphenol was measured by using 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid (ABTS) radical. To examine the effects of 2,4-di-tert-butylphenol on amyloid-beta peptide (Aβ1₁₋₄₂)-induced learning and memory impairment in mice, in vivo behavioral tests were performed. Administration of 2,4-di-tert-butylphenol increased alternation behavior in mice injected with Aβ₁₋₄₂. These results suggest that sweet potato extract could be protective against Aβ-induced neurotoxicity, possibly due to the antioxidative capacity of its constituent, 2,4-di-tert-butylphenol.

Amyloid beta peptide (Aβ)-induced oxidative stress may be linked to neurodegenerative disease. Ethanol extracts of Rosa laevigata protected PC12 cells from hydrogen peroxide-induced oxidative stress. (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) reduction assays revealed a significant increase in cell viability when oxidatively stressed PC12 cells were treated with R. laevigata extract. The effect of R. laevigata on oxidative stress-induced cell death was further investigated by lactate dehydrogenase release assays and trypan blue exclusion assays. Administration of 1,2-benzenedicarboxylic acid dinonyl ester from R. laevigata extract to mice infused with Aβ significantly reversed learning and memory impairment in behavioural tests. After behavioural testing, the mice were sacrificed and brains were collected for the examination of lipid peroxidation, catalase activity and acetylcholinesterase (AchE) activity. These results suggest that 1,2-benzenedicarboxylic acid dinonyl ester from R. laevigata extract may be able to reduce Aβ-induced neurotoxicity, possibly by reducing oxidative stress. Therefore, R. laevigata extract may be useful for the prevention of oxidative stress-induced neurodegenerative disorders.

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.

Few studies have investigatedSeomaemugwort (a Korean native mugwort variety ofArtemisia argyiH. Lév. & Vaniot), exclusively cultivated in the southern Korean peninsula, and the possibility of its use as a food resource. In the present study, we compared the nutritional and chemical properties as well as sensory attributes ofSeomaemugwort and the commonly consumed speciesArtemisia princepsPamp. In comparison withA. princeps, Seomaemugwort had higher contents of polyunsaturated fatty acids, total phenolic compounds, vitamin C, and essential amino acids. In addition,Seomaemugwort had better radical scavenging activity and more diverse volatile compounds thanA. princepsas well as favorable sensory attributes when consumed as tea. Given that scant information is available regarding theSeomaemugwort and its biological, chemical, and sensory characteristics, the results herein may provide important characterization data for further industrial and research applications of this mugwort variety.

The amyloid beta (Aβ) peptide is known to increase free radical production in nerve cells, leading to cell death. To investigate the effect of Rosa laevigata against Aβ-induced oxidative damage, in vitro assays and in vivo behavioral tests were performed. R. laevigata showed cell protective effects against oxidative stress-induced cytotoxicity. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) reduction assay exhibited significant increase in cell viability when rat pheochromocytoma (PC 12) cells were treated with R. laevigata extracts. Administration of R. laevigata extracts to mice significantly reversed the Aβ-induced learning and memory impairment in in vivo behavioral tests. These results suggest that R. laevigata extracts can reduce the cytotoxicity of Aβ in PC 12 cells, possibly by the reduction of oxidative stress, and these extracts may be useful in the prevention of Alzheimer's disease.