The Role of GRP78/ATF6/IRE1 and Caspase-12 Signaling Pathways in the Protective Effects of n-Hexane Oil Extract of Black Soldier Flies' Larvae (Hermetia illucens) Against Aflatoxin-Induced Hepatotoxicity in Rats.

Abstract

Background: Global contamination of agricultural products with aflatoxin (AF) is one of the most important concerns in the field of food safety and quality. Aflatoxin, when entering the food chain, can cause oxidative stress and hepatotoxicity. Black soldier fly larvae (BSFL) are an environmentally friendly insect whose extract is rich in valuable bioactive compounds with antioxidant properties.

Objectives: This study aimed to investigate the protective effect of the n-hexane extract of BSFL on oxidative stress, inflammation, and histopathological changes caused by Aflatoxin B1 (AFB1)-induced hepatotoxicity in rats.

Methods: Thirty-five male Wistar rats with a weight range of 200 to 250 g were randomly divided into 5 equal groups including Control, AFB1 (75 μg/kg), BSFL (360 mg/kg), BSFL 180 mg/kg+AFB1, and BSFL 360 mg/kg+AFB1. At the end of the treatment on the twenty-eighth day, the animals were euthanized and samples were taken for liver enzymes, oxidative stress, inflammation, endoplasmic reticulum (ER) stresses, apoptosis marker, histopathology, and expression of ER stress-related proteins analyses. Data were analyzed by one-way ANOVA followed by Tukey's post-hoc test, with P < 0.05 considered statistically significant.

Results: According to the results of the study, AFB1 administration significantly increased the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), nitric oxide (NO), malondialdehyde (MDA), tumor necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1β), and interleukin 6 (IL-6) (P < 0.001) and also decreased the levels of superoxide dismutase (SOD), reduced glutathione (GSH), glutathione peroxidase (GPx), and catalase (CAT) compared to the control group (P < 0.001). These biochemical and inflammatory abnormalities caused by AFB1 were confirmed by histopathological observations of liver tissue. Administration of BSFL extract (at the higher dose of 360 mg/kg) resulted in significant reversal of biochemical, inflammatory, and hepatic markers and modulated GRP78/ATF6/IRE1 signaling in AF-poisoned rats. Our histological results showed that BSFL extract (360 mg/kg) could reduce steatosis, cellular swelling, and lobular inflammation induced after AF exposure.

Conclusions: The results of this study indicate that BSFL extract, as a valuable bioactive substance with antioxidant properties, may attenuate biochemical indices, oxidative stress, and inflammation caused by AF-induced hepatotoxicity.