Anti-Inflammatory Activity of AF-13, an Antioxidant Compound Isolated from the Polar Fraction of Allomyrina dichotoma Larva, in Palmitate-Induced INS-1 Cells.

Kyong Kim ,Choul‐Young Kim ,Dong-Jae Baek ,Eun‐Young Park ,Yoon Sin Oh

doi:10.3390/life11060470

Kyong Kim , Choul‐Young Kim + Show 3 more

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https://doi.org/10.3390/life11060470

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Abstract

This study was conducted to evaluate the fractions isolated from Allomyrina dichotoma larva extract (ADLE) that exhibited anti-apoptotic and anti-inflammatory effects. A total of 13 fractions were eluted from ADLE by centrifugal chromatography (CPC), and the polar AF-13 fraction was selected, which exerted a relatively protective effect against fat-induced toxicity in INS-1 cells. AF-13 treatment of palmitate-treated INS-1 cells decreased the expression level of apoptosis-related proteins and DNA fragmentation. AF-13 also significantly inhibited the production of nitric oxide and reactive oxygen species and the triglyceride content induced by palmitate, and the effect was found to be similar to that with ADLE treatment. Palmitate upregulated the expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) through the activation of NF-κB p65; however, this effect was significantly attenuated by AF-13 treatment. In conclusion, AF-13 is one of the major components of ADLE responsible for anti-apoptotic and anti-inflammatory activities.

Highlights

Inflammation causes insulin resistance, the primary trigger of type 2 diabetes, and may be a major cause of fatal diabetes-related complications
We recently showed that A. dichotoma larvae (ADL) alleviated hepatic insulin resistance in high-fat-diet-induced diabetic mice [11] and prevented free fatty acid (FFA)induced lipotoxicity in pancreatic beta cells [12]
Fractionation of Allomyrina dichotoma larva extract (ADLE) was performed by a linear-gradient centrifugal partition chromatography (CPC) using three ternary solvent systems

Summary

Introduction

Inflammation causes insulin resistance, the primary trigger of type 2 diabetes, and may be a major cause of fatal diabetes-related complications. Palmitate triggers a typical event, i.e., the induction of nitric oxide synthase (iNOS), an enzyme that catalyzes the intracellular generation of the cytotoxic free radical NO. Oxidative stress due to an increase in intracellular reactive oxygen species (ROS) levels plays a central role in insulin resistance and pancreatic β-cell death during the progressive deterioration in glucose tolerance and development of type 2 diabetes [3,4,5,6]. Living organisms have their own natural antioxidants and substances that defend against ROS [7]. The horn beetle Allomyrina dichotoma has been used in various folk remedies in several countries and is believed to contain useful biologically active substances

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