# Study on the Effect of Koumiss Extract in Alleviating Non‐Alcoholic Fatty Liver Disease in Zebrafish Model by Improving Mitochondrial Function and Inhibiting Fat Deposition

## TL;DR

This study shows that koumiss extract and its compounds can reduce liver fat and improve mitochondrial function in a zebrafish model of non-alcoholic fatty liver disease.

## Contribution

The study identifies koumiss extract and its analogs as potential therapeutic agents for NAFLD by modulating mitochondrial complex I assembly proteins.

## Key findings

- Koumiss extract and its compounds reduced triglyceride and lactate dehydrogenase levels in HepG2 cells.
- Treatment with koumiss extract alleviated liver steatosis and reduced cholesterol levels in zebrafish models.
- The compounds downregulated mRNA expression of mitochondrial complex I assembly-related proteins.

## Abstract

Non‐alcoholic fatty liver disease (NAFLD) has emerged as a significant health issue due to the pathological accumulation of fat in the liver in the absence of excessive alcohol intake, with mitochondrial dysfunction being a critical underlying mechanism. This study aimed to evaluate the therapeutic potential of koumiss extract, along with 2‐furanic acid and α, α‐trehalose, in modulating mitochondrial function and mitigating fat deposition in NAFLD. Utilizing molecular docking techniques, we assessed the binding affinities of these compounds to mitochondrial complex I assembly (MCIA) proteins, while establishing both in vitro (HepG2 cell line) and in vivo (zebrafish model) NAFLD models to measure lipid accumulation and related biochemical parameters, including triglyceride (TG), total cholesterol (TC), and lactate dehydrogenase (LDH) levels, alongside the expression profiles of MCIA proteins. Our results demonstrated that koumiss extract, 2‐furanic acid, and α, α‐trehalose significantly decreased TG and LDH levels indicative of steatosis in HepG2 cells, while also reducing the expression of MCIA‐related proteins. In vivo experiments using a zebrafish NAFLD model demonstrated pronounced liver steatosis in the model group. Treatment with koumiss extract, 2‐furanic acid, and α, α‐trehalose significantly alleviated liver steatosis and reduced TG and TC levels. Furthermore, mRNA expression levels of ACAD9, ECSIT, NDUFAF1, and NDUFAF2 were significantly downregulated in the treatment groups. Koumiss extract, 2‐furanic acid, and α, α‐trehalose exhibit significant effects in reducing MCIA‐related proteins and steatosis in NAFLD models. Consequently, these results suggest that koumiss extract and its analogs hold promise as therapeutic agents for NAFLD, potentially enhancing liver lipid homeostasis.

Koumiss extract, 2‐furoic acid, and α,α‐trehalose alleviate NAFLD via modulating MCIA‐related proteins. This study illustrates the proposed mechanism by which koumiss extract and its bioactive analogs—2‐furoic acid and α,α‐trehalose—ameliorate NAFLD. Molecular docking analyses revealed strong binding affinities of these compounds to MCIA proteins. In both HepG2 cellular and zebrafish larval NAFLD models, treatment with the koumiss extract, 2‐furoic acid, and α,α‐trehalose significantly reduced lipid accumulation, TG, TC, and LDH levels. Mechanistically, the compounds downregulated mRNA expression of MCIA‐related factors including ACAD9, ECSIT, NDUFAF1, and NDUFAF2. These findings support the therapeutic potential of koumiss extract and its constituents in restoring mitochondrial function and hepatic lipid homeostasis.