Protective Effects of Gnetin C from Melinjo Seed Extract against High-Fat Diet-Induced Hepatic Steatosis and Liver Fibrosis in NAFLD Mice Model.

Nonalcoholic fatty liver disease (NAFLD), the most common form of chronic liver disease, can progress to hepatic steatosis, inflammation, and advanced fibrosis, increasing the risk of cirrhosis. Resveratrol, a natural polyphenol with antioxidant and anti-inflammatory properties, is beneficial in treating multiple metabolic diseases. Gnetin C, a resveratrol derivative obtained from Melinjo seed extract (MSE), shares similar health-promoting properties. We investigated the role of gnetin C in preventing NAFLD in a mouse model and compared it with resveratrol. Male C57BL/6J mice were fed a control diet (10% calories from fat), a high-fat choline-deficient (HFCD) diet (46% calories from fat) and HFCD diet supplemented with gnetin C (150 mg/kg BW·day-1) or resveratrol (150 mg/kg BW·day-1) for 12 weeks. Gnetin C supplementation reduced body and liver weight, and improved blood glucose levels and insulin sensitivity. Both gnetin C- and resveratrol reduced hepatic steatosis, with gnetin C also decreasing liver lipid content. Gnetin C and resveratrol ameliorated HFCD diet-induced hepatic fibrosis. The mRNA expression results, and western blot analyses showed that gnetin C and, to some extent, resveratrol downregulated fibrosis markers in the TGF-ß1 signaling pathway, indicating a possible safeguarding mechanism against NAFLD. These results suggest that gnetin C supplementation may protect against lipid deposition and hepatic fibrosis.

[Attitude Survey Data on Interaction between Dietary Supplements and Medicines].

Since "Foods with Function Claims" system was established in 2015, the percentage of people taking health foods and supplements is gradually increasing. The number of people taking both dietary supplements and medicines is also increasing. Therefore, providing information on interaction between dietary supplements and medicines has become increasingly important. We have conducted a study for understanding the awareness of the consumers on the interaction of health foods and supplements with medicines. The ratio of those who do not consult with an informed opinion on the interaction between health foods and supplements with medicines was 76% and 55.2% admitted that they did not experience any side effects as a result of this interaction. In conclusion, the understanding of the interaction between health foods and medication among consumers is still limited and most of them do not consult with specialized physicians. It has been revealed that efforts to expanding the consumers understanding on the risk of interaction between supplements and medicines are necessary. It was suggested that the "Database for guiding the interaction between medicines and health foods" could be a useful tool for providing this type of information.

Royal Jelly Delays Motor Functional Impairment During Aging in Genetically Heterogeneous Male Mice.

Aging is associated with motor disorders that decrease the quality of life (QOL). Royal jelly (RJ), used as a dietary supplement, has shown various health benefits and, therefore, it has the potential to improve the QOL during aging. We have previously developed protease enzyme-treated RJ to avoid the anaphylactic response induced by RJ supplementation. However, the effects of a lifelong treatment with RJ on normal aging have not been fully clarified. In this study, we investigated the effects of enzyme-untreated RJ (NRJ) and enzyme-treated RJ (ERJ) on the aging process focusing on motor functions, by using a genetically heterogeneous (HET) mouse model experimentally endowed with genetic diversity. We performed four different physical performance tests (grip strength, wire hang, horizontal bar, and rotarod). We showed that the age-related impairment of the motor functions was significantly delayed in RJ-treated mice. Both NRJ and ERJ were similarly effective against these types of aging-associated declines. Histological analyses revealed that the RJ treatment affected the muscle fiber size at an advanced age. We also demonstrated that age-related changes in muscle satellite cell markers and catabolic genes were affected in RJ-treated mice. These results suggest that non-protein components of RJ improved the motor function in aging mice. These findings indicate that RJ has the potential to change the QOL during aging by regulating the motor function.

Resveratrol derivative-rich melinjo (Gnetum gnemon L.) seed extract improves obesity and survival of C57BL/6 mice fed a high-fat diet.

Melinjo (Gnetum gnemon L.) seed extracts (MSEs) are rich in resveratrol dimers (gnemonoside A, C, D, gnetin C), trans-resveratrol, and other resveratrol derivatives. trans-Resveratrol is a widely studied caloric restriction mimetic. In mice fed a high-fat diet (HFD), trans-resveratrol protects against obesity, type 2 diabetes, and premature death. Here, treatment of HFD-fed mice with 2.0% MSE significantly reduced body weight gain (p < 0.001), blood insulin (p < 0.01), and HOMA-IR (p < 0.05) after 8 weeks compared with untreated HFD-fed mice. Additionally, 0.2% MSE treatment of HFD-fed mice significantly improved physiological activity (p < 0.05) at 18 months of age and reduced risk of death due to HFD by 25% (hazard ratio = 0.75, p = 0.036). These data show that MSE can improve several aspects of metabolic syndrome and survival in mice and may have health benefits as a dietary supplement.

Melinjo (Gnetum gnemon L.) Seed Extract Decreases Serum Uric Acid Levels in Nonobese Japanese Males: A Randomized Controlled Study.

Melinjo (Gnetum gnemon L.) seed extract (MSE) containing trans-resveratrol (3,5,4'-trihydroxy-trans-stilbene) and other derivatives exerts various beneficial effects. However, its mechanism of action in humans remains unknown. In this study, we aimed to investigate beneficial effects of MSE in healthy adult males. In this double-blind, randomized controlled study, 30 males aged 35-70 years with ≤10% flow-mediated dilatation received placebo or 750 mg MSE powder for 8 weeks, and twenty-nine males (45.1 ± 8.8 years old) completed the trial. There was a significant difference in the melinjo and placebo groups. Compared with the placebo control, MSE significantly reduced serum uric acid at 4 weeks and 8 weeks (n = 14 and 15, resp.). HDL cholesterol was significantly increased in the melinjo group. To clarify the mechanism of MSE for reducing uric acid, we investigated xanthine oxidase inhibitory activity, angiotensin II type 1 (AT1) receptor binding inhibition rate, and agonistic activities for PPAR α and PPAR γ . MSE, trans-resveratrol, and a resveratrol dimer, gnetin C (GC), significantly inhibit AT1 receptor binding and exhibit mild agonistic activities for PPAR α and PPAR γ . In conclusion, MSE may decrease serum uric acid regardless of insulin resistance and may improve lipid metabolism by increasing HDL cholesterol.