Effectiveness of aronia berries for reduction of mild fibrosis and gene expression analysis in livers from mice fed a high-fat diet with aronia berries

Abstract

Background: Aronia berries have many potential effects on health, including an antioxidant effect, effect for antimutagenesis, hepatoprotection and cardioprotection, an antidiabetic effect and inhibition of cancer cell proliferation. Previous human studies have shown that aronia juice may be useful for treatment of obesity disorders.

Objective: To reveal relationship between beneficial effect and the gene expression change by aronia berries, we analyzed mice livers using RNA sequencing and RT-qPCR.

Method: At 28 days after starting a normal diet, a high fat diet and a high-fat diet containing 10% freeze-dried aronia berries, serum was obtained from veins of mice after isoflurane anesthesia, and liver tissues were isolated and weighed. Triglyceride, total cholesterol and LDL cholesterol levels were measured and total RNAs were extracted. cDNA libraries were prepared according to Illumina protocols and sequenced using an Illumina HiSeq2500 to perform 100 paired-end sequencing. RNA-sequence reads mapping was performed using a DNA nexus. Gene expression analysis was performed. The liver tissue specimens were fixed and embedded in paraffin. After 5-mm-thick paraffin sections had been cut, they were stained with hematoxylin-eosin using the standard procedure and also with Sirius Red.

Results: In this study, we found that mild fibrosis induced by a high-fat diet was reduced in livers of mice fed a high-fat diet containing aronia berries. RNA sequencing and RT-qPCR analyses revealed that gene expression levels of Igfbp1 and Gadd45g were increased in livers from mice fed a high-fat diet containing aronia berries. Furthermore, results of an enzyme-linked immunoassay showed that a secreted protein levels of FABP1 and FABP4 were reduced in serum from mice fed a high-fat diet containing aronia berries. The results suggest that aronia berries have beneficial effects on mild fibrosis in liver.

Conclusion: Aronia berries have a beneficial effect on liver fibrosis. The recovery from liver fibrosis is associated with expression levels of Gadd45g and Igfbp1 in the liver. The beneficial effects of aronia berries on liver fibrosis reduce the risk of liver cancer diseases and insulin resistance, resulting in reduction of serum FABP1 and FABP4 levels.

Keywords: aronia; fibrosis; liver; Igfbp1; Gadd45g