A research group including Doctoral Student Ryuya Takada at the Graduate School of Pharmacy and Professor Toshio Morikawa of the Pharmaceutical Research and Technology Institute at Kindai University, in collaboration with Oryza Oil & Fat Chemical Co., Ltd., ES Tech Kyoto, Kyoto Organic Chemical Lab., and Research Institute for Production Development, has revealed that momordin Ic, a saponin contained in Akita Prefecture's traditional specialty food "Tonburi" (mountain caviar), inhibits dietary fat absorption and produces anti-obesity and lipid-lowering effects by regulating the rate of delivery of stomach contents into the intestines and modulating hormone secretion. The findings were published in the Journal of Natural Medicines.
Provided by Kindai University
Tonburi (mountain caviar), the fruit of an annual herb Kochia scoparia (Bassia scoparia) belonging to the Amaranthaceae family, has long been used as a medicinal herb for its tonic and revitalizing effects.
The research group has previously demonstrated that extracts of mountain caviar and momordin Ic are capable of inhibiting glucose absorption, indicating their potential as functional food materials effective for blood glucose control.
In this study, the group demonstrated that mountain caviar extract (MCE) and its main component, momordin Ic, exhibit significant anti-obesity and lipid-lowering effects in model mice.
When MCE (125-250 mg/kg) was administered to olive oil-loaded mice, the postprandial (post-meal) rise in plasma triglyceride was significantly suppressed. Meanwhile, momordin Ic, the principal component accounting for 12.6% of MCE, exhibited a significant antihyperlipidemic effect when administered at a dose of 20 mg/kg.
The group found that momordin Ic did not inhibit pancreatic lipase, the principal enzyme that breaks down fat, but rather delayed gastric emptying. Furthermore, momordin Ic enhanced secretion of GLP-1, which promotes insulin secretion and lowers blood glucose levels, suggesting the involvement of gut-derived hormonal signaling in appetite regulation.
In mice fed a high-fat diet, continuous administration of MCE suppressed body weight gain, while administration of momordin Ic (20 mg/kg/day) significantly reduced visceral fat accumulation and blood LDL/VLDL cholesterol levels. These metabolic improvements were not accompanied by an increase in total energy consumption, which was measured using the doubly labeled water (DLW) method.
These results suggest that MCE and momordin Ic ameliorate diet-induced obesity and dyslipidemia by regulating gastrointestinal function and hormonal pathways related to satiety, independent of total energy consumption.
Morikawa stated, "In this study, we demonstrated that 'momordin Ic,' a saponin contained in mountain caviar, influences lipid absorption and metabolism through gastrointestinal regulation, such as delayed gastric emptying and enhanced GLP-1 secretion. This has demonstrated one aspect of the multifaceted biological activity of a naturally occurring product. As our next step, we will assess its efficacy in humans and unravel the detailed mechanism of action, with the goal of developing its application as a functional food material."
Journal Information
Publication: Journal of Natural Medicines
Title: Anti-obesity and lipid-lowering effects of mountain caviar extract and its principal saponin momordin Ic via delayed gastric emptying and GLP-1 secretion independent of energy expenditure
DOI: 10.1007/s11418-026-02052-3
This article has been translated by JST with permission from The Science News Ltd. (https://sci-news.co.jp/). Unauthorized reproduction of the article and photographs is prohibited.