Isoechinulin B, a natural product from Antarctic fungus, attenuates acute liver injury by inhibiting excessive cell adhesion

Abnormal cell adhesion between leukocytes and endothelial cells is closely associated with the development of numerous inflammation-related diseases, with adhesion molecules playing a crucial role. The disruption of cell adhesion directly or indirectly inhibits excessive cell adhesion and thus produces a therapeutic effect. However, there are only a few clinically available antagonists of cell adhesion. One of the biggest challenges is the development of novel and efficient cell adhesion inhibitors. Recently, the anti-inflammatory pharmacological activity of natural products of microbial origin has also received increasing attention. Here, we obtained a potential cell adhesion inhibitor isoechinulin B, an indole diketopiperazine derivative, from the Antarctic fungus Aspergillus sp. CPCC 401072, which is active against cell adhesion. Isoechinulin B decreased the expression of vascular endothelial adhesion molecule 1 (VCAM-1) and intercellular adhesion molecule 1 (ICAM-1) by inhibiting the activation of the NF-κB signaling pathway, thereby inhibiting cell adhesion between leukocytes and endothelial cells to reduce macrophage infiltration in the liver and significantly attenuate lipopolysaccharide-induced acute liver injury in mice. Conclusion Isoechinulin B is a novel cell adhesion inhibitor derived from fungi found in extreme environments.