Shuzo Fujita

Lignophenols Decrease Oleate-Induced Apolipoprotein-B Secretion in HepG2 Cells

Lignin is one of the components in the plant cell wall, after cellulose, making up 20-30% of the global plant biomass. Lignophenols (LPs) are derivatives of lignin with high phenolic function and antioxidant properties. However, their medicinal property is not well characterised. Apolipoprotein-B (apo-B) is an essential component in very low-density lipoprotein, and high levels of serum apolipoprotein-B (apo-B) are a major factor for coronary heart disease. In this study, we examined the effect of lignophenols on apo-B secretion in HepG2 cells. HepG2 cells were treated with varying concentrations of LPs and 0.8 mm sodium oleate. LPs decreased oleate-induced apo-B secretion in a dose-dependent manner. LPs also decreased oleate-induced microsomal triglyceride transfer protein (MTTP) mRNA expression and cellular total cholesterol, suggesting that lipid bioavailability and lipidation of lipoprotein are likely involved in the decreased secretion of apo-B. Furthermore, LPs decreased oleate-induced mature sterol regulatory element binding protein 2 (SREBP-2), a transcription factor that activates cholesterol biosynthesis. This is the first study to show that LPs can decrease oleate-induced apo-B secretion in HepG2 cells. The modulations of MTTP mRNA expression, cellular total cholesterol metabolism and mature SREBP-2 expression may be important factors in the regulation of apo-B secretion by LPs.

Lignin-derived lignophenols attenuate oxidative and inflammatory damage to the kidney in streptozotocin-induced diabetic rats

Abstract This study investigated the effects of lignin-derived lignophenols (LPs) on the oxidative stress and infiltration of macrophages in the kidney of streptozotocin (STZ)-induced diabetic rats. The diabetic rats were divided into four groups with 0%, 0.11%, 0.33% and 1.0% LP diets. The vehicle-injected controls were given a commercial diet. At 5 weeks, superoxide (O2−) production, macrophage kinetics, the degree of fibrosis in glomeruli and mRNA expression for monocyte chemoattractant protein-1 (MCP-1) were examined. The NADPH-stimulated O2− levels in the kidney of the diabetic rats treated with 1.0% LP were significantly lower than those in untreated diabetic rats. The number of macrophages, levels of MCP-1 mRNA expression and degree of glomerular fibrosis increased in untreated LP and these levels were significantly lower in 1.0%LP-treated rats. The results suggested that LPs suppress the excess oxidative stress, the infiltration and activation of macrophages and the glomerular expansion in STZ-induced diabetic kidneys.

Video-endoscopic comparison of swallowing waxy rice mochi and waxy wheat mochi: improvement of a traditional Japanese food that presents a choking hazard

Mochi is highly cohesive and adhesive, and easy to choke on. Many of the fatal suffocation accidents with mochi occur in the elderly aged 65 years or older. These circumstances prompted us to investigate a special property of waxy wheat which is similar in texture to waxy rice, but is less cohesive and adhesive. We compared the differences in chewing and swallowing movements associated with eating waxy rice mochi and waxy wheat mochi between healthy adults and healthy elderly. Healthy elderly chewed mochi more and longer than healthy adults. Although there was no difference in the number of chewing cycles or total duration of chewing between the two types of mochi, waxy wheat mochi was easier to chew and left less pharyngeal residue. These findings lead us to suggest that waxy wheat mochi is promising as a food that is easy to swallow and difficult to choke on. Graphical Abstract This is the image which observed a chewing state of the Waxy wheat mochi by video-endoscopy. A green coloring agent was added to one set of samples to yield green and white mochi, allowing easy identification by video-endoscopy. Each bolus of waxy wheat and waxy rice mochi consisted of both white and green mochi.

Effect of lignin-derived lignophenols on hepatic lipid metabolism in rats fed a high-fat diet

The effect of lignin-derived lignophenols on lipid metabolism in the livers of rats fed a high-fat diet was investigated. Rats fed a diet providing 45% of energy from fat were divided into 2 groups, namely 0% and 0.5% lignophenols-containing diets. The controls were fed a diet providing 10% of energy from fat. Plasma blood parameters, protein expression of acetyl-CoA carboxylase (ACC) and sterol regulatory element-binding protein (SREBP)-1, and SREBP-1c mRNA expression in the livers were examined. The plasma triglyceride levels in the rats fed lignophenols-containing diets were decreased. SREBP-1c mRNA expression in the rats fed lignophenols-containing diets was significantly reduced compared with the rats fed high-fat diets, and phosphorylated ACC protein in the rats fed lignophenols-containing diets was significantly increased. Our results suggested that lignophenols suppress the expression of SREBP-1c mRNA and the phosphorylation of ACC in the liver, and may lead to a decrease in plasma triglyceride levels.