Preventive Effect of Gonggan (Citrus Reticulata Blanco Var. Gonggan) Peel Extract on Ethanol/HCl-Induced Gastric Injury in Mice via an Anti-oxidative Mechanism.

Ya Wu,Hua Jiang,Guangfang Chen,Fang Tan,Xin Zhao,Chengming Hu,Xingxing Chen,Xiaofei Su

doi:10.3389/fphar.2021.715306

Abstract

Gonggan (Citrus reticulata Blanco var. gonggan) is one of the most popular citruses. In this study, the effect of Gonggan peel extract (GPE) on gastric injury was investigated. The components in GPE were analysed by HPLC and the gastric injury model in mice was established by ethanol/hydrochloric acid. After treatment by GPE, the pathological changes of gastric tissue were observed by optical microscope. The levels of oxidative stress and inflammation were measure by kit. And the mRNA expression of related gene was determined by qPCR assay. HPLC result showed GPE mainly contained the flavonoids narirutin, hesperidin, nobiletin, tangeretin and 5-demethylnobiletin. Morphological and pathological analysis of gastric tissue revealed that GPE could relieve gastric injury. Also, GPE increased the levels of SOD, GSH-Px, and CAT and decreased the level of MDA. Moreover, GPE decreased the levels of the inflammatory cytokines TNF-α, IFN-γ, IL-1β, and IL-6 to suppress inflammation. In addition, the q-PCR results showed that GPE upregulated the mRNA expression of SOD1, SOD2, γ-GCS, GSH-Px, CAT, and IκBα and downregulated the mRNA expression of NF-κB. In conclusion, GPE alleviated gastric injury caused by ethanol/hydrochloric acid by inhibiting oxidative stress and the inflammatory response. The mechanism by which GPE protects gastric tissues may involve the antioxidative pathway. Therefore, GPE has great potential to be developed as a product to prevent gastric injury.

Highlights

Citrus is the largest category of fruit in the world, which has a long history of cultivation in China (Liu et al, 2012)
The results showed that the mRNA expression levels of copper/zinc superoxide dismutase (SOD1), manganese superoxide dismutase (SOD2), glutathione peroxidase (GSH-Px), CAT, γ-glutamylcysteine synthetase (γ-GCS) and inhibitor of NF-κB alpha (IκBα) were significantly suppressed, and the mRNA expression of nuclear factor kappa-B (NF-κB) was enhanced in the model mice compared with the normal mice (p < 0.05, Figure 7)
The results showed that Gonggan peel extract (GPE) reduced the levels of the proinflammatory cytokines tumour necrosis factor-α (TNF-α), IL-6, IFN-γ and IL-1β to suppress the inflammatory response

Summary

Introduction

Citrus is the largest category of fruit in the world, which has a long history of cultivation in China (Liu et al, 2012). The peel of citrus fruit contains a variety of bioactive substances, such as essential oil and flavonoids (Gao et al, 2018; Tripoli et al, 2007; Asikin et al, 2012). There are few researches on the application and activity of flavonoids in Gonggan peel, only the study of its antibacterial effect was reported (Deng and Chao, 2013). Related research about the utilization of active ingredients in peel residue needs to be explored, which provides an opportunity for the development of citrus industry and human health (Ledesmaescobar and Castro, 2014)

Methods

Results

Discussion

Conclusion