Jae Kyeom Kim

Protective Effects of Kaempferol (3,4',5,7-tetrahydroxyflavone) against Amyloid Beta Peptide (Aβ)-Induced Neurotoxicity in ICR Mice

To determine the effects of kaempferol, rat pheochromocytoma cells (PC12) and Institute of Cancer Research (ICR) mice were utilized as neuronal models. Using in vitro assays, kaempferol was shown to have protective effects against oxidative stress-induced cytotoxicity in PC12 cells. Administration of kaempferol also significantly reversed amyloid beta peptide (Aβ)-induced impaired performance in a Y-maze test. Taken altogether, the results reported here suggest that further investigation is warranted of the influence of kaempferol on pathways related to Alzheimer’s disease.

Effects of Methoxsalen from Poncirus trifoliata on Acetylcholinesterase and Trimethyltin-Induced Learning and Memory Impairment

Previously, we identified methoxsalen (8-methoxy-2′,3′,6,7-furocoumarin) as the bioactive compound probably responsible for acetylcholinesterase (AchE) inhibition achieved by feeding crude extract of Poncirus trifoliate. To confirm the activity of methoxsalen, Institute of Cancer Research (ICR) mice were fed a control or a methoxsalen-supplemented diet for 4 weeks, and then learning and memory enhancing effects with respect to trimethyltin (TMT)-induced neurotoxicity were evaluated. The brain tissues of ICR mice were dissected after completion of the behavioral tests for biochemical analysis. Methoxsalen effectively reversed TMT-induced memory impairment on both Y-maze and passive avoidance tests. Brain AchE activity was inhibited by the oral consumption of all concentrations of methoxsalen. Moreover, the level of oxidative stress was significantly ameliorated in the groups on methodsalen containing diets. This is the first in vivo study conducted with methoxsalen in the field of AD research, and it indicates that further investigation of methoxsalen is warranted.

Quality Evaluation on Use of Camellia Oil as an Alternative Method in Dried Seaweed Preparation

The fatty acid and volatile compound compositions of camellia oil were analyzed in this study. The impacts of the replacement of conventional vegetable oil with camellia oil on the sensory attributes of dried seaweed were also determined. C18:1 (83.59%), followed by C16:0 and C18:2, were the most abundant fatty acids in camellia oil. A total of 11 and 32 volatile compounds were identified in camellia oil and sesame oil, respectively. In the preference test, the camellia oil samples received a higher, although insignificant, liking rating in overall acceptability of appearance. Overall, there were no differences between the sensory attributes of camellia oil and sesame oil. This finding, combined with the unique fatty acid composition, thermal stability, and health benefits of camellia oil indicate that further study into the use of camellia oil in foods is warranted.

Comparison of nutritional quality and thermal stability between peanut oil and common frying oils

The aim of this work was to compare the performances and nutritional characteristics of peanut oil to common frying oils during repetitive frying. The peanut oil had the highest color stability, the lowest initial, and final total polar compounds (TPC) levels among all other oil samples throughout the frying of potato slices. The TPC levels increased in all oils over the course of frying, being impacted more by the initial quality rather than the type of oils. In tocopherol analysis, as a consequence of frying, γ-tocopherol decreased most among the other six tocopherol isomers. Owing to the lack of data on the repetitive frying of peanut oil, this work provides basic information for peanut oil to use for frying purposes.

Antioxidant and cognitive-enhancing activities of Arctium lappa L. roots in Aβ1-42-induced mouse model

Many studies have shown that oxidative stress induced by hydrogen peroxide can lead to neuronal cell death. In this study, protective effects of the ethanol extract of A. lappa L. roots against oxidative stress in PC12 cells were measured by 2′, 7′-dichlorofluorescein diacetate and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays. Oxidative stress contributes to the memory deficits induced by Beta-amyloid1-42 in mice. Treatment with the ethanol extract of A. lappa L. roots improved working and reference memory in mice in the Y-maze and passive avoidance tests. To detect the lipid peroxidation levels, malondialdehyde was measured. To purify the bioactive compound, active fractions and components of A. lappa L. roots were isolated by partitioning, open column chromatography, TLC, high-performance liquid chromatography, electron ionization mass spectrometry, and 1H/13C-nuclear magnetic resonance. We identified the bioactive compound as quinic acid, which is a powerful antioxidant agent. Ultimately, the roots of A. lappa L. may become available as an antioxidant food for Alzheimer’s disease patients and those with other oxidative stress-induced disorders.

Characterization of Nutritional Composition, Antioxidative Capacity, and Sensory Attributes of Seomae Mugwort, a Native Korean Variety of Artemisia argyi H. Lév. & Vaniot.

Few studies have investigated Seomae mugwort (a Korean native mugwort variety of Artemisia argyi H. 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 of Seomae mugwort and the commonly consumed species Artemisia princeps Pamp. In comparison with A. princeps, Seomae mugwort had higher contents of polyunsaturated fatty acids, total phenolic compounds, vitamin C, and essential amino acids. In addition, Seomae mugwort had better radical scavenging activity and more diverse volatile compounds than A. princeps as well as favorable sensory attributes when consumed as tea. Given that scant information is available regarding the Seomae mugwort 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.

Composition of Fatty Acids in Commercially Available Tree Nuts and Their Relationship with Protective Effects against Oxidative Stress-induced Neurotoxicity

Fatty acid profiles of commercially available tree nuts were analyzed and association between fatty acid composition and protective effects against oxidative stress was investigated. Among commercially available tree nuts, walnuts showed the most potent protective effects for both cell viability and 2′,7′-dichlorofluorescein (DCF) formation. Neuronal cell viability and inhibition of intracellular oxidative stress were inversely related to saturated fatty acid contents in tree nuts. Eigen analysis revealed that principal component (PC) 1 was mainly contributed by 2′,7′-dichlorofluorescin diacetate (DCF-DA), DPPH, and C18:2 and C18:3. PC2 was contributed by MTT assay, and saturated fatty acids. Walnuts exhibited the highest potency against oxidative stress closely related with C18:3, based on principal component analysis (PCA) and Pearson’s correlation analyses. A combination of fatty acid profiling using chromatographic analysis and PCA is a promising method to evaluate oxidative stress.

Perilla frutescens Extract Ameliorates Acetylcholinesterase and Trimethyltin Chloride-Induced Neurotoxicity

One of the critical features of Alzheimers disease is cognitive dysfunction, which is, in part, due to decreases in acetylcholine (ACh). The ethanol extract of Perilla frutescens was selected for isolating the acetylcholinesterase (AChE) inhibitor based on preliminary screening. In vivo behavioral tests were performed to examine the effects of the P. frutescens extract on trimethyltin chloride-induced impairment of learning and memory in mice. A diet containing P. frutescens extract effectively reversed learning and memory impairment on the Y-maze and passive avoidance tests. To isolate the active compound from the P. frutescens extract, solvent partitioning, silica gel open column chromatography, thin-layer chromatography, and high-performance liquid chromatography were used. The AChE inhibitor was identified as rosmarinic acid.

Cinnamomum loureirii Extract Inhibits Acetylcholinesterase Activity and Ameliorates Trimethyltin-Induced Cognitive Dysfunction in Mice.

The pathogenesis of Alzheimers disease (AD) has been linked to the deficiency of neurotransmitter acetylcholine (ACh) in the brain, and the main treatment strategy for improving AD symptoms is the inhibition of acetylcholinesterase (AChE) activity. In the present study, we aimed to identify potent AChE inhibitors from Cinnamomum loureirii extract via bioassay-guided fractionation. We demonstrated that the most potent AChE inhibitor present in the C. loureirii extract was 2,4-bis(1,1-dimethylethyl)phenol. To confirm the antiamnesic effects of the ethanol extract of C. loureirii, mice were intraperitoneally injected with the neurotoxin trimethyltin (2.5 mg/kg) to induce cognitive dysfunction, and performance in the Y-maze and passive avoidance tests was assessed. Treatment with C. loureirii extract significantly improved performance in both behavioral tests, suggesting that this extract may be neuroprotective and therefore beneficial in preventing or ameliorating the degenerative processes of AD, potentially by restoring cholinergic function.

Chemical Characterization and Oxidative Stability of Medium- and Long-Chain Fatty Acid Profiles in Tree-Borne Seed Oils

This study was undertaken to evaluate chemical characteristics and oxidative stability of tree-borne seed oils. A total of 15 different fatty acids were identified in six tree-borne seed oils, which included seven types of saturated fatty acids, four types of monounsaturated fatty acids, and four types of polyunsaturated fatty acids. Japanese camphor tree (JCT) had a high content of medium-chain fatty acids (97.94 ± 0.04%), in which fatty acid composition was distinct from those of the other five plant seed oils. Overall, contents of tocopherols, a type of fat-soluble vitamin, ranged between 3.82 ± 0.04 mg/100 g and 101.98 ± 1.34 mg/100 g, respectively. Phytosterol contents ranged from 117.77 ± 1.32 mg/100 g to 479.45 ± 4.27 mg/100 g, respectively. Of all tree-borne seed oils, β-sitosterol was the phytosterol at the highest concentration. Contents of unsaponifiables were between 0.13 ± 0.08 and 2.01 ± 0.02, and values of acid, peroxide, and p-anisidine were between 0.79 ± 0.01 and 38.94 ± 0.24 mg KOH/g, 3.53 ± 0.21 and 127.67 ± 1.79 meq/kg, and 2.07 ± 0.51 and 9.67 ± 0.25, respectively. Oxidative stability of tree-borne seed oils was assessed through measurement of oxidation-induction periods. These results should serve as a foundation to identify the potential of tree-borne seed oils in industrial application as well as in providing fundamental data.