Nrf2: A Main Responsive Element of the Toxicity Effect Caused by Trichothecene (T-2) Mycotoxin

Overview of T-2 Toxin Enterotoxicity: From Toxic Mechanisms and Detoxification to Future Perspectives

Fusarium species produce a secondary metabolite known as T-2 toxin, which is the primary and most harmful toxin found in type A trichothecenes. T-2 toxin is widely found in food and grain-based animal feed and endangers the health of both humans and animals. T-2 toxin exposure in humans and animals occurs primarily through food administration; therefore, the first organ that T-2 toxin targets is the gut. In this overview, the research progress, toxicity mechanism, and detoxification of the toxin T-2 were reviewed, and future research directions were proposed. T-2 toxin damages the intestinal mucosa and destroys intestinal structure and intestinal barrier function; furthermore, T-2 toxin disrupts the intestinal microbiota, causes intestinal flora disorders, affects normal intestinal metabolic function, and kills intestinal epidermal cells by inducing oxidative stress, inflammatory responses, and apoptosis. The primary harmful mechanism of T-2 toxin in the intestine is oxidative stress. Currently, selenium and plant extracts are mainly used to exert antioxidant effects to alleviate the enterotoxicity of T-2 toxin. In future studies, the use of genomic techniques to find upstream signaling molecules associated with T-2 enterotoxin toxicity will provide new ideas for the prevention of this toxicity. The purpose of this paper is to review the progress of research on the intestinal toxicity of T-2 toxin and propose new research directions for the prevention and treatment of T-2 toxin toxicity.

Betulinic acid attenuates T-2 toxin-induced lung injury by activating Nrf2 signaling pathway and inhibiting MAPK/NF-κB signaling pathway

T-2 toxin, a type-A trichothecene mycotoxin, exists ubiquitously in mildewed foods and feeds. Betulinic acid (BA), a pentacyclic triterpenoid derived from plants, has the effect of relieving inflammation and oxidative stress. The purpose of this study was to investigate whether BA mitigates lung impairment caused by T-2 toxin and elucidate the underlying mechanism. The results indicated that T-2 toxin triggered the inflammatory cell infiltration, morphological alterations and cell apoptosis in the lungs. It is gratifying that BA ameliorated T-2 toxin-caused lung injury. The protein expression of nuclear factor erythrocyte 2-related factor 2 (Nrf2) pathway and the markers of antioxidative capability were improved in T-2 toxin induced lung injury by BA mediated protection. Simultaneously, BA supplementation could suppress T-2 toxin-induced mitogen-activated protein kinase (MAPK)/nuclear factor-kappa B (NF-κB)-dependent inflammatory response and mitochondrial apoptotic pathway. Therefore, T-2 toxin gave rise to pulmonary toxicity, but these changes were moderated by BA administration through regulation of the Nrf2/MAPK/NF-κB pathway, which maybe offer a viable alternative for mitigating the lung impairments caused by the mycotoxin.

Review of neurotoxicity of T-2 toxin

T-2 toxin is a representative trichothecene that is widely detected in corn, wheat and other grain feeds. T-2 toxin has stable physical and chemical properties, making it difficult to remove from food and feed. Hence, T-2 toxin has become an unavoidable pollutant in food for humans and animals. T-2 toxin can enter brain tissue by crossing the blood-brain barrier and leads to congestion, swelling and even apoptosis of neurons. T-2 toxin poisoning can directly lead to clinical symptoms (anti-feeding reaction and decline of learning and memory function in humans and animals). Maternal T-2 toxin exposure also exerted toxic effects on the central nervous system of offspring. Oxidative stress is the core neurotoxicity mechanism underlying T-2 toxin poison. Oxidative stress-mediated apoptosis, mitochondrial oxidative damage and inflammation are all involved in the neurotoxicity induced by T-2 toxin. Thus, alleviating oxidative stress has become a potential target for relieving the neurotoxicity induced by T-2 toxin. Future efforts should be devoted to revealing the neurotoxic molecular mechanism of T-2 toxin and exploring effective therapeutic drugs to alleviate T-2 toxin-induced neurotoxicity.

T-2 toxin induces cardiotoxicity by activating ferroptosis and inhibiting heme oxygenase-1

T-2 toxin, a natural secondary sesquiterpenoid metabolite produced by numerous strains of Fusarium fungi, is prevalent in both contaminated food and the environment. T-2 toxin is known to be highly toxic to the cardiovascular system, but the precise mechanisms that lead to T-2 toxin-induced cardiotoxicity are not yet fully understood. Recent findings indicate that ferroptosis is a pivotal factor in cardiovascular damage and exhibits a strong correlation with the detrimental impacts of T-2 toxin. The present study was designed to examine the involvement of ferroptosis in T-2 toxin-induced cardiac injury. Male mice and human cardiomyocytes were subjected to T-2 toxin for 24 h to induce acute cardiotoxicity for in vivo and in vitro studies, respectively. Our results demonstrated that T-2 toxin increased reactive oxygen species production, malondialdehyde, and decreased glutathione/oxidized glutathione and adenosine triphosphate levels. Furthermore, T-2 toxin was observed to activate ferroptosis, as evidenced by an increase in iron (Fe2+) concentration and upregulation of prostaglandin endoperoxide synthase 2, downregulation of glutathione peroxidase 4 and ferritin heavy chain 1, as well as ferroptotic morphological alterations. Inhibition of ferroptosis by Liproxstatin-1 reversed T-2 toxin-induced cardiac injury. Additionally, the downregulation of heme oxgenase-1 (HO-1) expression by T-2 toxin exacerbates ferroptosis and oxidative damage, which can be further aggravated by HO-1 inhibition with Sn-protoporphyrin. These findings provide novel insights into the mechanism of T-2 toxin-induced cardiotoxicity and suggest that targeting ferroptosis and HO-1 may represent a promising cardioprotective strategy against T-2 toxin.