Jin-Sik Nam

Butanol extract of Ecklonia cava prevents production and aggregation of beta-amyloid, and reduces beta-amyloid mediated neuronal death.

Beta-amyloid (Aβ) is a major pathogenic peptide for Alzheimers disease (AD) and is generated by the processing of amyloid precursor protein (APP). The Aβ monomers aggregate into oligomeric and fibrillar forms which have been implicated as the toxic species inducing the neuronal dysfunction. Brown algae Ecklonia cava is known for its anti-oxidant and anti-inflammatory functions. Therefore, we tested the effect of E. cava extract on the production and aggregation of Aβ peptides. The butanol extract of E. cava reduced Aβ secretion from HEK293 cells expressing APP with Swedish mutation and increased soluble APPα and C-terminal fragment-α (CTFα), of which activity was similar to BACE (β-site of APP cleaving enzyme) inhibitors. Furthermore, the extract inhibited Aβ oligomerization, particularly mid-size oligomer formation, confirmed by the ultrastructural morphology. Congo red, thioflavin T assays, and electron microscopy showed that the extract inhibited Aβ fibril formation effectively. Finally, the extract protected primary cortical neurons from various Aβ-induced cell deaths, especially oligomer-induced death. Although further study is needed to test the effectiveness of the extract in vivo, our results demonstrate, for the first time, that the butanol extract of E. cava could be used as an anti-Aβ agent for AD therapeutics.

Comparison of Physicochemical Properties and Antioxidant Activities between Lentinula edodes and New Cultivar Lentinula edodes GNA01

The new cultivar Lentinula edodes, which is named ‘Lentinula edodes GNA01’, was bred by mating strains isolated from ‘L26’ and ‘Kyoungwon9015’ obtained from Sammyungjin Research Institute, Fujian, China. L. edodes GNA01 does not have stipes like L. edodes, although it generally has a similar spherical shape. Moisture and crude protein contents of L. edodes GNA01 were lower than those of L. edodes. Meanwhile, L. edodes GNA01 contained higher levels of crude ash, crude lipid, crude fiber, and carbohydrates than L. edodes. The β-carotene content (19.05 μg/100 g) of L. edodes GNA01 was about three times higher than that of L. edodes. In addition, vitamin D content (118.53 μg/100 g) of L. edodes GNA01 was more than twice that of L. edodes. L. edodes GNA01 was a good source of mineral elements, with K and Mg contents of 2,277.50 mg/100 g and 203.15 mg/100 g, respectively. The major fatty acids of L. edodes GNA01 were C16:0 and C18:2, and L. edodes GNA01 had the highest linoleic acid (C18:2) content of 1,087.66 mg/100 g. Total phenol content of L. edodes GNA01 was 12.52 mg GAE/g, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities and ferric reducing antioxidant power (FRAP) values of L. edodes GNA01 were lower than those of L. edodes at all concentrations. However, DPPH radical scavenging activities and FRAP values of L. edodes GNA01 were above 80% and 0.9 at a concentration of 10 mg/mL, respectively.

Nutritional compositions in roots, twigs, leaves, fruit pulp, and seeds from pawpaw (Asimina triloba [L.] Dunal) grown in Korea

Pawpaw (Asimina triloba L.) roots, twigs, leaves, fruit, and seeds were analyzed for their nutritional compositions. Seeds exhibited significantly higher levels of crude protein, lipid, fiber, and dietary fiber than those of the other parts. Sucrose in fruit was 9321.24 mg%, which was the highest among the samples. The total essential amino acid to total amino acid ratio was highest in the leaves, and the leaves contained the highest amount of potassium. The calcium content ranged between 8.15-153.41 mg%. Oleic and linoleic acids in seeds were 5905.11 and 8045.56 mg%, respectively, which were the highest among the pawpaw parts. The highest amount of linolenic acid was measured in the leaves, and β-carotene, vitamin C, and vitamin E were also the most abundant in the leaves. These results suggest that every part of pawpaw is a good source of an important food item. Additionally, this study provides basic data for improving the sitological value of pawpaw.

Changes in the phenolic compounds and antioxidant activities of mustard leaf (Brassica juncea) kimchi extracts during different fermentation periods

This study was conducted to investigate the changes in the total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activities of 80% methanol and water extracts from mustard leaf kimchi during different fermentation periods. The methanol extract exhibited higher TPC and TFC than the water extract. Both extracts from kimchi fermented for two months showed the highest antioxidant effects against the scavenging activities of 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radicals and 2,2-azino-bis diammonium salt (ABTS) radicals. Moreover, the methanol extract from kimchi fermented for two months showed the highest nitrite scavenging activity. The highest metal (Fe2+) chelating effect of the methanol extract and water extract was observed after three months and one month, respectively. Caffeic acid showed the highest increase with fermentation. These findings suggest that the antioxidant activities of kimchi depend on the fermentation period. Accordingly, this study provides basic data for improving the antioxidant activity of mustard leaf kimchi through the establishment of their fermentation period.