Melinjo seed extract could improve obesity, diabetes

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An extract from seeds of the Melinjo tree activates the physiologically beneficial substance adiponectin, which improves obesity and diabetes, according to a new study published in the journal Scientific Reports.

In Southeast Asia, the fruit, flowers, and leaves of Indonesia's Melinjo tree are traditional foods. Melinjo fruit have high antioxidant and antibacterial qualities and are known to contain large amounts of polyphenols. One such compound, resveratrol, has been shown to induce adiponectin and may improve lifestyle-related diseases like metabolic syndrome. Gnetin C, a type of resveratrol abundant in Melinjo seed extract, is known to have higher antioxidant activity and stays in the body longer than resveratrol. However, the detailed mechanism by which these compounds exert their biological activity is still unknown.

For the study, researchers from Kumamoto University in Japan conducted a double-blind, placebo-controlled, randomized controlled trial where 42 healthy adult men took Melinjo seed extract supplements orally for 14 days. They found that taking 300 milligrams of Melinjo seed extract per day activated adiponectin in human males. They also found that effects varied depending on the differences in the type of DsbA-L gene (G/G, G/T, T/T) possessed by the individual. Melinjo seed extract effects were large in G/T or T/T genotype carriers whose gene expression level was presumed to be low, according to the study.

Following the results of the clinical trials, the researchers tested the compound in a high-fat diet mouse model with obesity-induced diabetes. By measuring the effects of Melinjo seed extract on DsbA-L expression and blood adiponectin concentration in various tissues, they found that daily oral administration of Melinjo seed extract over a period of four weeks increased the expression of DsbA-L and the amount of activated adiponectin in the body. Diabetic pathologies, in muscle tissue also improved. Symptoms such as increased fat accumulation and fasting blood sugar levels significantly improved.

These research results show that Melinjo seed extract promotes DsbA-L expression, increases the amount of activated adiponectin, and may improve obesity and diabetic symptoms in living organisms, especially in mice.

"We believe that our findings can benefit human health through the treatment of obesity and diabetes by focusing on the induction of the DsbA-L gene using [Melinjo seed extract]," said Tsuyoshi Shuto, PhD, lead author of the study and associate profession, in a statement. "We hope that this work contributes to a healthier society through the creation of innovative medicines and products from plants and other natural resources."