Experimental Study on Regulation of Nrf2/HO-1 by Linalool to Inhibit Hepatic Injury Induced by Aflatoxin B1 / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo investigate the effect of linalool against acute liver injury induced by aflatoxin B1（AFB1） in rats and explore its protective mechanism. MethodTwenty male SPF SD rats were randomly divided into three groups： Control （n=6）， AFB1 （n=7）， and linalool （n=7） groups. Linalool solution （200 mg·kg-1） was administered preventatively for 14 days， while the control and AFB1 groups intragastrically received an equivalent volume of double distilled water. After preventative administration of linalool， AFB1 solution （1 mg·kg-1， dissolved in saline） was intraperitoneally injected for two consecutive days to induce acute liver injury in rats. Samples were collected and processed 14 days after model establishment. Pathological changes in liver tissue of rats were observed using Hematoxylin-eosin（HE） staining and Masson staining. Biochemical detection was performed to measure the levels of alanine transaminase（ALT）， aspartate transaminase（AST）， γ-glutamyl transferase（GGT）， lactate dehydrogenase（LDH）， alkaline phosphatase（ALP）， total bilirubin（TBil）， direct bilirubin（DBil）， indirect bilirubin（IBil）， malondialdehyde（MDA）， superoxidedismutase（SOD）， catalase（CAT） ， glutathione（GSH）， Fe3+， and Fe2+ in the liver tissue. Western blot was adopted to assess protein expression levels of nuclear factor-erythroid 2-related factor 2（Nrf2） and heme oxygenase-1（HO-1）. Molecular docking was performed to verify the binding between linalool and key proteins of the Nrf2/HO-1 signaling pathway. Molecular dynamics techniques were used to confirm the stability and affinity of linalool binding with key proteins of the Nrf2/HO-1 signaling pathway. ResultPathological results showed that compared to that in the AFB1 group， the liver structure in the linalool group tended to be normal， with a significant decrease in blue collagen fibers. The linalool group exhibited significantly reduced levels of ALT， AST， GGT， LDH， ALP， TBil， DBil， and IBil （P<0.01）， Fe3+ and Fe2+ content， and oxidative stress marker MDA （P<0.01）. The levels of antioxidants SOD， CAT， and GSH significantly increased （P<0.01）. Molecular docking showed a molecular docking energy between linalool and Nrf2 and HO-1 targets of -5.495 6 and -5.199 4 kcal·mol-1（1 cal≈4.186 J）， respectively. Molecular dynamics results indicated strong affinity in the binding of linalool with Nrf2 and HO-1. Western blot revealed a significant increase in Nrf2 protein expression （P<0.05） and a decrease in HO-1 protein expression （P<0.01） in the linalool group. ConclusionLinalool may protect against AFB1-induced acute liver injury by modulating the Nrf2/HO-1 ferroptosis signaling pathway to inhibit liver cell ferroptosis and regulate hepatic oxidative stress levels.