Hepatoprotective effects of flavonoids from common buckwheat hulls in type 2 diabetic rats and HepG2 cells.

Hai Wang,Yang Guo,Xiujuan Wang,Shuyan Liu,Junmei Liu,Chunhong Piao,Yue Wang,Yang Cui

doi:10.1002/fsn3.2390

Abstract

Flavonoids from common buckwheat hulls (BHFs) show significant antioxidant and antidiabetic potential. However, their hepatoprotective property is yet to be defined. This study aims to examine the hepatoprotective effect of BHFs in type 2 diabetes mellitus (T2DM) rats and chronic high glucose‐damaged HepG2 cells. Results showed that BHF treatment significantly relieves the state of insulin resistance, thereby reducing blood glucose and improving oxidative stress in T2DM rats. It is worth mentioning that BHF treatment improved diabetes‐induced liver damage disorders, manifested as the clearance of liver fat and the decline of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities. In vitro, HepG2 cells pretreated with BHFs maintained higher superoxide dismutase (SOD), glutathione peroxidase (GSH‐px), and catalase (CAT) activities than the unprotected group. In parallel, compared with the unprotected group, BHFs significantly reduced the leakage of ALT and AST in pre‐protected group dose‐dependently. These results indicated that BHFs had considerable antioxidant and hepatoprotective potential and could be promising to be used as nutraceuticals and dietary supplements to prevent and/or protect against liver disorders.

Highlights

Common buckwheat is one of the most commonly cultivated grain species across the globe
The type 2 diabetes mellitus (T2DM) rat model was established by multiple intraperitoneal injections of streptozotocin (STZ, 30 mg/kg.b.wt) after high-sugar and high-fat diets (Composition: 10% lard, 10% sucrose and 5% cholesterol) for 4 weeks with some modifications according to Zhang et al (2008)
Rats with a fasting blood glucose (FBG) above 11.1 mmol/L were considered as T2DM, where they were randomly divided into three groups

Summary

Introduction

Common buckwheat is one of the most commonly cultivated grain species across the globe. Numerous studies reveal that buckwheat hulls are embedded with rich amounts of flavonoids, which include but are not limited to, rutin, vitexin, quercetin, isoorientin, and hyperoside (Cui et al, 2020; Dziadek et al, 2016; Zhang et al, 2017). Flavonoids are the most studied subclass of polyphenolic compounds that are present in almost all parts of flowering plants, such as grains, fruits, vegetables, and teas (Cassidy & Minihane, 2017; Swallah et al, 2020), with more than 9,000 identified different structures bearing similar diphenol propane skeleton in nature (C6-C3-C6) (Swallah et al, 2020). Numerous studies demonstrated that flavonoids are beneficial to human's health due to their powerful pharmacological activities, including antidiabetic, antioxidant, anti-inflammatory, anticancer, and antihypertensive. Flavonoids are regarded as a unique class of therapeutic molecules and valued by the scientific community (Cassidy & Minihane, 2017; Maaliki et al, 2019; Zaragozá et al, 2020)

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