• Journal of Life Science
• /
• v.32 no.1
• /
• pp.11-22
• /
• 2022

N-methyl-D-aspartate (NMDA) receptors have received considerable attention regarding their involvement in glutamate-induced neuronal excitotoxicity. Resveratrol has been shown to exhibit neuroprotective effects against this kind of overactivation, but the underlying cellular mechanisms are not yet clearly understood. In this study, HT-22 neuronal cells were treated with NMDA in Mg²⁺-free buffer and subsequently used as an experimental model of glutamate excitotoxicity to elucidate the mechanisms of resveratrol-induced neuroprotection. We found that NMDA treatment causes a drop in MTT reduction ability, disrupts inside-negative transmembrane potential of mitochondria, depletes cellular ATP levels, and stimulates intracellular ROS production. Double fluorescence imaging studies demonstrated an increased formation of mitochondrial permeability transition (MPT) pores accompanied by apoptotic cell death, while cobalt protoporphyrin and bilirubin showed protective effects against NMDA-induced mitochondrial injury. On the other hand, zinc protoporphyrin IX significantly attenuated the protective effects of resveratrol which was itself shown to enhance heme oxygenase-1 (HO-1) mRNA and protein expression levels. In cells transfected with HO-1 small interfering RNA, resveratrol failed to suppress the NMDA-induced effects on MTT reduction ability and MPT pore formation. The present study suggests that resveratrol may prevent mitochondrial injury in NMDA- treated HT-22 cells and that enhanced expression of HO-1 is involved in the underlying cellular mechanism.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.39 no.6
• /
• pp.843-852
• /
• 2010

Hydroxycinnamic acid derivatives (HADs) and anthocyanins in corn (Zea mays L.) have recently been reported to have anticarcinogenic, anti-hypertensive, antidiabetic, antifungal, antioxidant, and anti-melanogenic activities. Five HADs and anthocyanins in corn were quantified by HPLC according to cultivars and heat processes. In addition, major anthocyanin of a black waxy corn was isolated and identified by several instrumental analysis, and its content was also quantified by HPLC according to heat processes. Of the ten corn cultivars, five waxy corn cultivars had moderate five HADs contents except "Baksa" waxy corn with higher two free cinnamic acids (FCAs), p-coumaric and ferulic acids. In contrast, three dent corn cultivars contained higher levels of three polyamine conjugates (PCs), CFP, DCP and DFP, and especially "P3394" had the highest amount of the three PCs. Two sweet corn cultivars had generally intermediate HADs levels between waxy and dent corn cultivars. Of the three colored-waxy corns, a black Mibaek waxy corn had the highest anthocyanin content. During heat processes, levels of two FCAs in the black waxy corn generally increased, whereas no significant change on three PCs contents was observed except the puffing process. Roasting, retort and puffing processes significantly increased two FCAs and especially, the puffed black waxy corn had the highest amount of FCAs. Meanwhile, most heat treatments except retort process, considerably decreased total anthocyanin contents, and especially the puffed black waxy corn had nearly no anthocyanin. Level of one major anthocyanin, pelargonidin 3-glucoside (P3G) isolated from a black waxy corn was appreciably decreased by heat treatments except retort process, which greatly increased P3G content. These results suggest that the retorted black waxy corn may be a promising high quality functional corn product.

• Journal of Applied Biological Chemistry
• /
• v.60 no.4
• /
• pp.363-372
• /
• 2017

Hypericum ascyron has long been used as medicinal plant and recent studies reported that H. ascyron has anti-diabetic, anti-oxidant, and anti-bacterial effects. In this study, inhibitory effect from H. ascyron on pro-inflammatory responses has been investigated. H. ascyron was extracted at optimal extraction condition. Total phenolic contents in water and 90% ethanol were 29.75 and 31.82 mg/g, respectively. Hyaluronidase inhibitory activity of H. ascyron extracts ($50-200{\mu}g/mL$ phenolics) was 0.00-14.81% and 15.33-47.49%, respectively. In cell viability, cell toxicity was shown at concentration of $100{\mu}g/mL$ and $30{\mu}g/mL$ of water and 90% ethanol extract. Therefore, $10-50{\mu}g/mL$ in water extracts and $5-20{\mu}g/mL$ in ethanol extracts was selected each for further study. Inducible nitric oxide synthase (iNOS) derived nitric oxide (NO) and cyclooxygenase (COX)-2-derived prostaglandin $E_2$ ($PGE_2$) protein expression inhibitory effect of extracts were inhibited in a dose dependent manner, significantly. Also, the pro-inflammatory cytokines inhibitory effect such as tumor necrosis $factor-{\alpha}$, nterleukin (IL)-6 and $IL-1{\beta}$ were decreased in the dose dependent manner. The results indicate that H. ascyron extracts reduced inflammatory responses in lipopolysaccharide-induced 264.7 cells via the regulation of the iNOS, COX-2, NO, $PGE_2$, and pro-inflammatory cytokines. Therefore, H. ascyron extracts have significant anti-inflammatory effect and a source as therapeutic materials.

• Journal of Life Science
• /
• v.29 no.1
• /
• pp.60-68
• /
• 2019

Limonium tetragonum, an edible halophyte that grows on salt marshes in Korea, is thought to possess various health benefits (e.g., antioxidant, antitumor, and hepatoprotective). In the present study, different solvent partitioned subfractions, water ($H_2O$), buthanol (n-BuOH), 85% aqueous methanol (85% aq. MeOH), and hexane (n-hexane), from crude extract of L. tetragonum were tested for their ability to prevent adipogenesis in differentiating 3T3-L1 preadipocytes. The treatment of differentiating 3T3-L1 preadipocytes with L. tetragonum subfractions (LTFs) resulted in suppressed adipogenesis and reduced expression of adipogenesis-related transcription factors such as peroxisome proliferator-activated receptor gamma ($PPAR{\gamma}$), CCAATT/enhancer-binding protein alpha ($C/EBP{\alpha}$), and sterol regulatory element-binding protein 1c (SREBP-1c) at both mRNA and protein levels. In addition, the LTF treatment notably decreased the levels of phosphorylated p38, extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK) of the mitogen-activated protein kinase (MAPK) pathway in association with $PPAR{\gamma}$-linked adipogenesis. Among all the tested LTFs, $H_2O$ and n-hexane were the most effective in lowering lipid accumulation and regulating the adipocyte differentiation via $PPAR{\gamma}$ pathway. Taken together, the results indicated that the $H_2O$ and n-hexane LTFs contain bioactive compounds that may exhibit significant antiadipogenesis activity by downregulation of the $PPAR{\gamma}$ pathway and inactivation of the MAPK signal pathway in 3T3-L1 preadipocytes.