Comparison of pancreatic lipase inhibitory isoflavonoids from unripe and ripe fruits of Cudrania tricuspidata

Yang Hee Jo,Bang Yeon Hwang,Seon Beom Kim,Mi Kyeong Lee,Seon-Gil Do,Qing Liu,Keiko Abe

doi:10.1371/journal.pone.0172069

Abstract

The composition and content of the active constituents and their biological activity vary according to diverse factors including their maturation stages. A previous study showed that the fruits of Cudrania tricuspidata inhibited pancreatic lipase activity, a key enzyme in fat absorption. In this study, we investigated the chemical composition and pancreatic lipase inhibitory activity of unripe and ripe fruits of C. tricuspidata. Unripe fruits of C. tricuspidata have a higher content of total phenolic and flavonoids and exhibited stronger pancreatic lipase inhibition compared to ripe fruits. HPLC analysis revealed the different chemical compositions of the unripe and ripe fruits. Further fractionation resulted in the isolation of 30 compounds including two new isoflavonoids. Analysis of the chemical constituents of the unripe and ripe fruits revealed that a 2,2-dimethylpyran ring, a cyclized prenyl, was the predominant side chain in the unripe fruits, whereas it was a linear prenyl group in the ripe fruits. In addition, a new isoflavonoid (19) from the unripe fruits showed the most potent inhibition on pancreatic lipase. Taken together, the maturation stage is an important factor for maximum efficacy and that unripe fruits of C. tricuspidata are a good source of new bioactive constituents for the regulation of obesity

Highlights

A global rise in obesity has become a widespread issue due to its association with diverse pathological disorders, including atherosclerosis, diabetes, hypertension, and cancer [1,2]
We investigated the difference in the chemical composition of unripe and ripe fruits of C. tricuspidata
The unripe fruits had a higher content of total phenolics and flavonoids and exhibited stronger pancreatic lipase inhibition compared to the ripe fruits

Summary

Introduction

A global rise in obesity has become a widespread issue due to its association with diverse pathological disorders, including atherosclerosis, diabetes, hypertension, and cancer [1,2]. High consumption of saturated fats in Western diets is suggested as one of the main contributors to obesity, as demonstrated by the correlation between the amount of dietary fat and obesity in epidemiological study. Fat is an ester of three fatty acid and glycerol and absorbed after digestion into monoglyceride and fatty acids by lipase. Lipase is a key enzyme in lipid absorption and pancreatic lipase, a main lipase of the human, is responsible for the hydrolysis of 50–70% of total dietary fats. A reduction in fat absorption by the inhibition of pancreatic lipase is suggested to be beneficial for the regulation of obesity [3,4].

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Results

Conclusion