Protective effect of Insect tea primary leaf (Malus sieboldii (Regal) Rehd.) extract on H2O2-induced oxidative damage in human embryonic kidney 293T cells

Jing Zhang,Yue Huang,Huazhi Liu,Hong Wang,Xin Zhao,Weifeng Li,Sha Yi,Zemei Guo

doi:10.1186/s13765-020-00516-y

Abstract

In this study, Insect tea primary leaf (Malus sieboldii (Regal) Rehd.) was used as the research object to investigate the protective effect of Insect tea primary extract (ITPLE) on hydrogen peroxide (H2O2)-induced oxidative damage in human embryonic kidney 293T cells (HEK 293T cells) and the mechanism of action of the main active components. The 3-(4,5-dimethyl-2-thiazolyl)- 2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay was used to determine the toxicity of ITPLE to HEK 293T cells in vitro as well as its protective effect against (H2O2)-induced oxidative damage in HEK 293T cells. In addition, various assay kits were used to measure oxidation-related indicators in HEK 293T cells, and quantitative polymerase chain reaction (qPCR) analysis was used to determine the mRNA expression levels of oxidation-related genes in HEK 293T cells. High performance liquid chromatography (HPLC) analysis was used to characterize active components in ITPLE. The experimental results revealed that the ITPLE had no toxic effect on cells in the range of 0–200 μg/mL, and, in this range, exhibited a concentration-dependent protective effect against H2O2-induced oxidative damage in HEK 293T cells. It was also found that the ITPLE can reduce the malondialdehyde (MDA) level and increase the levels of superoxide dismutase (SOD), glutathione (GSH), glutathione peroxidase (GSH-Px), and catalase (CAT)in oxidative damage HEK 293T cells. The qPCR analysis results also showed that the ITPLE upregulated the mRNA expression levels of SOD, CAT, GSH and GSH-Px in HEK 293T cells damaged by H2O2-induced oxidative stress. The HPLC analysis identified 7 bioactive components in the ITPLE, including neochlorogenic acid, cryptochlorogenic acid, rutin, kaempferin, isochlorogenic acid B, isochlorogenic acid A and hesperidin. This study reveals that ITPLE is rich in active compounds and has good antioxidant effect in vitro, thus it has the potential to be developed into a traditional Chinese medicine and functional drinks.

Highlights

Insect tea is a traditional health drink in southern China
Determination of MDA, superoxide dismutase (SOD), GSH, GSH‐Px and CAT in HEK 293T cells subjected to oxidative damage As described in ITPLE toxicity determination section, after treating the cells with ITPLE for 48 h, cells in the culture plate were washed with phosphate-buffered saline
QPCR analysis of mRNA expression levels in HEK 293T cells subjected to oxidative damage Total RNA was isolated from HEK 293T cells treated as described in sub-Sect

Summary

Introduction

Insect tea is a traditional health drink in southern China. The production process of Insect tea is very special, in particular, the Insect tea primary leaves are fed to insect larvae, and the excreta of the larvae are processed into tea like drinks [1]. Besides the influence of insects, the species of raw primary leaves (material leaves) play an important role in the quality and function of Insect tea. The plant leaves used to make Insect tea mainly include Kuding tea The toringo leaves used for preparing Insect tea need to go through certain processing procedures. Afterwards, the composition and bioactivity of the leaves of toringo will change, but the research on the composition and function of the processed leaves is still lacking

Objectives

Methods

Results

Conclusion