Effects of 2,3,5,6-Tetramethylpyrazine on alcohol-induced injury in liver cells and on the early life stages of zebrafish (Danio rerio Hamilton, 1822)

Abstract

Background: Alcoholic liver disease (ALD) is a major health problem referring to the collection of liver damage caused by excessive alcohol intake. The search for effective and safe alternatives for compounds from plants to protect the liver from extensive damages and delay the progress to a disease is still a big effort done in the scientific community. 2,3,5,6-Tetramethylpyrazine (TMP) is a compound found in a Chinese herbal medicinal plant, Ligusticum chuanxiong Hort and in some other plants.

Objective: This study was done to assess the hepatoprotective effects of TMP against ALD using
histopathological analysis of zebrafish livers subjected to different exposure groups. TMP has been mainly used for the treatment of cardio- and cerebrovascular diseases due to its antioxidant, anti-inflammatory, and antiapoptotic properties.

Methodology: Adult male zebrafish were exposed to three TMP concentrations (40, 60, and 80 mg/L TMP) and to 1% v/v of ethanol. The dissected livers of the zebrafish were processed for fixing on glass slides using the H&E stains and were observed under the light compound microscopes for scoring. The safety of the TMP to the early life stages of the zebrafish was tested using the Zebrafish Embryotoxicity Test (ZFET).

Results: Results showed that TMP was able to dose-dependently decrease mean scores for the four parameters diagnostic of ALD, i.e., steatosis, inflammation, cell death, and ballooning degeneration. These scores were comparable to those of the untreated group (no ethanol + no treatment) and positive control (ethanol + Hepasil DTXTM), with all groups' scores being statistically different from those of the negative control group (ethanol + no treatment) (p<0.05). Results for the ZFET showed that incidence of embryo mortality as well as teratogenic malformations of embryos exposed to TMP were significantly lower compared to the positive control group.

Conclusion: The hepatoprotective role of TMP was implied because anomalies such as cholestasis, vessel
congestion, and hemorrhage were only observed in the ethanol-treated group and not in the other groups. In the analysis of the early development of the embryos using the Zebrafish Embryotoxicity Test (ZFET), TMP was found to be non-toxic and non-teratogenic at concentrations used for liver treatment. These initial findings on TMP provided justification for its plausibility as a hepatoprotective compound against alcoholic liver diseases (ALD).

Published online: November 5, 2021