Si-Kyung Kim

Anti-adipogenic activity of blue mussel (Mytilus edulis) extract by regulation of 3T3-L1 adipogenesis through Wnt/β-catenin signaling pathway

The blue mussel (Mytilus edulis) is widely distributed in European waters but it is little consumed. Although several studies have been reported biological activities of mussels, the anti-adipogenic activity of blue mussel and the molecular mechanism in anti-obese activity remain unknown. Here, we prepared a water extract of blue mussel (BME) and its anti-adipogenic activity was assessed in 3T3-L1 cells. BME treatment dose-dependently inhibited 3T3-L1 lipid accumulation, as judged by Oil Red O staining and microscopic analysis. Consistent with this, BME treatment markedly suppressed mRNA expression levels of adipogenic genes, such as C/EBPβ, PPARγ, C/EBPα, and FAS, in 3T3-L1 mature adipocytes. BME-inhibited lipid accumulation in 3T3-L1 adipocytes was limited with treatment after adipocyte differentiation, particularly in the early and intermediate stages. We also showed that the Wnt/β-catenin signaling pathway is required in BME-inhibited 3T3-L1 adipogenesis. These finding may provide scientific evidence for the development of functional foods against obesity.

Antioxidant activity of water extracts of persimmon flower buds

Fresh, naturally dried, and artificially dried persimmon (Diospyros kaki cv. Fuyu) flower buds (PFBs) were extracted with deionized water (1 g/100 mL) at five temperatures (60, 70, 80, 90, and 100°C) for 4 soaking times (30, 60, 120, and 180 s). DPPH and ABTS radical scavenging activities were enhanced with increasing extraction time and temperature. Extraction time and temperature in fresh PFB extract led to little differences in total phenolic contents (TPCs). However, naturally and artificially dried PFB extracts significantly changed TPCs. The extracts of artificially dried PEB for 180 s at 100°C contained the highest TPC: 43.07 μg gallic acid equivalents/g. These results suggest that the drying method and soaking condition are important for the application of PFBs to a functional food material.

Anti-oxidant and anti-adipogenic effects of acorn (Quercus acutissima CARR.) shell extracts via regulation of wnt signaling in 3T3-L1 cells

Acorn (Quercus acutissima CARR.) is a nut from the Fagaceae family that has been used in traditional medicine for many years. However, shells from acorns are regarded as a by-product and are mostly discarded. Anti-adipogenic activities of acorn shells were investigated using 3T3-L1 cells and methanol shell extracts (AE-M). AE-M demonstrated Cu2+-chelation activities and anti-oxidant activities via reduction of oxidative stress levels induced using AAPH. Six days after adipocyte differentiation, 50 and 100 μg/mL AE-M completely suppressed 3T3-L1 adipogenesis and the anti-adipogenic effect was stronger than for the positive control 50 μM quercetin. Treatment with AE-M in 3T3-L1 cells reduced mRNA expression levels of adipogenic genes. AE-M-inhibition was found in pre-adipogenic, early, and intermediate stages of adipogenesis in 3T3-L1 cells. The Wnt/β-catenin signaling pathway is required for AE-M-inhibition of 3T3-L1 adipogenesis.

Antimicrobial and ACE Inhibitory Activities of Citrus unshiu Fermented with Lactic Acid Bacteria

To develop high quality citrus products, seven lactic acid bacteria were innoculated onto ground citrus (Citrus unshiu) and cultured for 10 days. On culture days 0, 3, 5, 7, and 10, citrus ferments were withdrawn, and their antimicrobial and angiotensin-I converting enzyme (ACE) inhibitory activities were evaluated. Citrus ferments innoculated with CL-1 and CL-2, which were isolated from kimchi, showed relatively higher antimicrobial activities against food poisoning bacteria. Citrus ferments innoculated with CL-1 and CL-2 also showed stronger ACE inhibitory activities than other ferments. CL-1 and CL-2 showed more than 99% homogeny with Pediococcus acidilactici and Lactobacillus sakei, respectively, by 16S rRNA gene analysis. These results indicate that fermentation with P. acidilactici and L. sakei might contribute to the increased antimicrobial and anti-hypertensive activities of citrus.