Shikonin reduces hematopoietic stem cells and immune cells in zebrafish embryos by activating the AMPK signaling pathway.

Shikonin, a natural bioactive compound isolated from the root of Lithospermum erythrorhizon, has been shown to possess significant pharmacological activities, including anticancer and antiviral properties. Despite these findings, the pharmacological effects of shikonin on hematopoietic stem cells and the immune system remain underexplored. In this study, zebrafish were used as a model organism to systematically investigate the potential effects of shikonin on hematopoiesis and the immune system. Using zebrafish as a model, we investigated the impact of shikonin on hematopoiesis and immune function across concentrations of 0, 0.125 mg/L, 0.25 mg/L, and 0.50 mg/L. The results revealed that exposure to shikonin led to a gradual reduction in the number of hematopoietic stem cells(HSCs), thymic T cells, neutrophils, and macrophages in zebrafish compared to the control group. Additionally, the expression of genes related to innate immunity was significantly downregulated. This was accompanied by developmental abnormalities in embryos and an increased mortality rate. At the mechanistic level, exposure to shikonin can activate the AMPK pathway and upregulate oxidative stress. Moreover, this immune cells and HSCs could be rescued by the AMPK inhibitor (Vidarabine) and astaxanthin (ATX). These research results indicate that shikonin induces damage to the hematopoietic and immune systems of zebrafish by activating the AMPK pathway and oxidative stress, which highlights the potential risks of shikonin and provides a basis for its safe use in clinical practice.