Hyeon Ju Kim

Blueberry (Vaccinium virgatum) Leaf Extracts Protect Against Aβ-Induced Cytotoxicity and Cognitive Impairment

The ethylacetate (EtOAc) fraction of blueberry leaf extract was investigated to examine the in vivo antiamnesic effects against amyloid β protein (Aβ)-induced learning and memory deficit. The fraction showed the highest antioxidant activities, and the generation of intracellular reactive oxygen species was significantly decreased. Cell viability assays revealed the in vitro cytoprotective effects of the fraction, and the cytoplasmic lactate dehydrogenase release into the medium was dose-dependently inhibited. In addition, a chlorogenic acid was identified as a predominant phenolic compound by high-performance liquid chromatography analysis. Antiamnesic effects were evaluated by using in vivo the Y-maze and passive avoidance tests, and preadministration of the fraction attenuated Aβ-induced memory impairment in both in vivo experiments. Acetylcholinesterase prepared from mice brain was inhibited by the fraction, and malondialdehyde generation in the brain homogenate was also decreased. These findings suggest that the EtOAc fraction of blueberry leaf extract could possess a wide range of physiological effects against neurodegenerative diseases.

An investigation into the ameliorating effect of black soybean extract on learning and memory impairment with assessment of neuroprotective effects

BackgroundThe physiological effects of the non-anthocyanin fraction (NAF) in a black soybean seed coat extract on Aβ-induced oxidative stress were investigated to confirm neuroprotection. In addition, we examined the preventive effect of NAF on cognitive defects induced by the intracerebroventricular (ICV) injection of Aβ.MethodsLevels of cellular oxidative stress were measured using 2′,7′-dichlorofluorescein diacetate (DCF-DA). Neuronal cell viability was investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assay. To investigate in vivo anti-amnesic effects of NAF by using Y-maze and passive avoidance tests, the learning and memory impairment in mice was induced by Aβ. After in vivo assays, acetylcholinesterase (AChE) activity and level of malondialdehyde (MDA) in the mouse brain were determined to confirm the cognitive effect. Individual phenolics of NAF were qualitatively analyzed by using an ultra-performance liquid chromatography (UPLC) Accurate-Mass Quadrupole Time of-Flight (Q-TOF) UPLC/MS.ResultsA NAF showed cell protective effects against oxidative stress-induced cytotoxicity. Intracellular ROS accumulated through Aβ1–40 treatment was significantly reduced in comparison to cells only treated with Aβ1–40. In MTT and LDH assay, the NAF also presented neuroprotective effects on Aβ1–40-treated cytotoxicity. Finally, the administration of this NAF in mice significantly reversed the Aβ1–40-induced cognitive defects in in vivo behavioral tests. After behavioral tests, the mice brains were collected in order to examine lipid peroxidation and AChE activity. AChE, preparation was inhibited by NAF in a dose-dependent manner. MDA generation in the brain homogenate of mice treated with the NAF was decreased. Q-TOF UPLC/MS analyses revealed three major phenolics from the non-anthocyanin fraction; epicatechin, procyanidin B1, and procyanidin B2.ConclusionsThe results suggest that the NAF in black soybean seed coat extracts may improve the cytotoxicity of Aβ in PC12 cells, possibly by reducing oxidative stress, and also have an anti-amnesic effect on the in vivo learning and memory deficits caused by Aβ. Q-TOF UPLC/MS analyses showed three major phenolics; (-)-epicatechin, procyanidin B1, and procyanidin B2. Above results suggest that (-)-epicatechins are the major components, and contributors to the anti-amnesic effect of the NAF from black soybean seed coat.

Protective Effects of Black Soybean Seed Coat Extracts against Oxidative Stress-induced Neurotoxicity

Rat pheochromocytoma cells (PC12) and mice were utilized as in vitro and in vivo models to determine the neuroprotective effects of a 70% acetone extract of black soybean seed coat (BSSCE). BSSCE showed higher total phenolic contents than other extracts. Intracellular reactive oxygen species accumulation from H₂O₂ treatment of PC12 cells was significantly reduced when BSSCE was present in the media compared to PC12 cells treated with H₂O₂ only. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium-bromide (MTT) reduction assay and lactate dehydrogenase assay also showed significantly increased protective effects in PC12 cells. In addition, BSSCE improved the in vivo cognitive ability against amyloid beta peptide-induced neuronal deficits.

Black Soybean Extract Protects Against TMT-Induced Cognitive Defects in Mice

To find a neuroactive compound with a potent inhibitory effect on acetylcholinesterase (AChE) and in vivo anti-amnesic activity from natural resources, we evaluated anthocyanins and nonanthocyanins from black soybean extract. Nonanthocyanins from black soybean extract were the most potent and dose-dependent AChE inhibitors. Intracellular reactive oxygen species accumulation resulting from H₂O₂ treatment was significantly decreased compared with cells treated with H₂O₂ only. Nonanthocyanins were also neuroprotective against H₂O₂ treated neurotoxicity by 3-[4,5-dimethythiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assay. Finally, nonanthocyanins from black soybean in the preadministration group attenuated trimethyltin (TMT)-induced memory injury in both in vivo tests. AChE, prepared from mice brain tissues, was inhibited by nonanthocyanins from black soybean in a dose-dependent manner. Malondialdehyde generation in the brain homogenates of mice treated with nonanthocyanins from black soybean was decreased. We concluded that nonanthocyanins from black soybean had an efficacious in vitro AChE inhibitory activity, and protected against H₂O₂-induced neurotoxicity. In addition, our findings suggest that nonanthocyanins from black soybean may improve the TMT-induced learning and memory deficit because of AChE inhibition of mice brain tissue. Consequently, these results demonstrate that the nonanthocyanins from black soybean could possess a wide range of beneficial activities for neurodegenerative disorders.

Effect of anthocyanins from rabbit-eye blueberry (Vaccinium virgatum) on cognitive function in mice under trimethyltin-induced neurotoxicity

Extracts of rabbit-eye blueberries (Vaccinium virgatum) were investigated for in vitro neuroprotective and in vivo learning and memory effects in mice under trimethyltin (TMT)-induced neurotoxicity. Blueberry anthocyanins showed high in vitro antioxidant activities in ABTS and 2’,7’-dichlorofluorescein diacetate (DCF-DA) assays. In a cell viability assay using MTT, anthocyanins showed protective effects, and lactate dehydrogenase release into the medium was effectively inhibited. Drug-induced cognitive deficits, examined in vivo using Y-maze and passive avoidance testing, were ameliorated by the anthocyanin fraction. HPLC analysis showed that delphinidin was the predominant anthocyanin. After behavioral testing, acetylcholinesterase (AChE) activities and lipid peroxidation in the mouse brain were investigated for biochemical changes. Administration of blueberry anthocyanins reduced the level of TMT-induced memory injury via inhibition of the AChE activity and lipid peroxidation.

Nutritional Composition and Cytoprotective Effect of Moringa oleifera Lam.

The cytoprotective effect of Moringa oleifera Lam. (drumstick tree) on neuronal cells was investigated to confirm the physiological benefits associated with this natural food resource. First, the drumstick tree extract was chemically analyzed to determine inherent nutritional constituents. Calcium and potassium were identified as the major mineral constituents, and palmitic acid (C16:0, 16.33%) and gadoleic acid (C20:01, 66.34%) were detected as the major fatty acids. Moreover, drumstick tree extract contained 94.78 mg/100 g vitamin E and 112.61 mg/100 g niacin. PC12 cells were used to study the cytoprotective effects of drumstick tree extract. Intracellular accumulation of reactive oxygen species was significantly reduced when H 2 O 2 treated-neuronal cells were cultured in a medium containing the methanolic extract of drumstick tree, compared to cells treated with only H 2 O 2 . Cell viability assay using MTT showed that the extract protected cells against H 2 O 2 -induced neurotoxicity and inhibited LDH leakage from the cell membrane. Caspase assay showed that the extract exerted cytoprotective effect against apoptosis. Consequently, these data suggest that drumstick tree is a useful natural resource with positive effects on human health.

Effect of Daebo (Castanea crenata) Inner Skin Extract on TMT-induced Learning and Memory Injury

The aim of this study was to investigate the anti-amnesic effect of daebo (Castanea crenata) extract on trimethyltin chloride (TMT)-induced learning and memory impairment, in vivo. The inner skin of daebo was extracted using distilled water under reflux conditions. At the end of the adaptation period, ICR mice were divided into a control group, a TMT injection group (negative control), and a sample group (C5: 5 mg/kg body weight; C10: 10 mg/kg body weight; and C20: 20 mg/kg body weight), and were tested with learning and memory tests. The ethylacetate fraction of the daebo inner skin extract was found to increase TMT-induced memory deficit in the Y-maze and passive avoidance test. Brain tissue analysis showed that the ethylacetate fraction of daebo extract lowered the acetylcholine esterase (AChE) activity and malondialdehyde (MDA) content of neuronal cells, both of which are indicative of lipid peroxidation.