Does fumonisin B1 exposure trigger oxidative stress and pro-inflammatory cytokine signaling?

Fumonisin B1 (FB1), a common mycotoxin found in maize, has been extensively studied for its ability to disrupt cellular homeostasis through specific biochemical pathways. Experimental evidence across various animal and cell models confirms that exposure triggers significant oxidative stress and inflammatory responses.

Mechanisms of oxidative stress and DNA damage

Experimental data consistently show that FB1 exposure leads to the accumulation of reactive oxygen species (ROS) and subsequent cellular damage.

• Sphingolipid disruption: FB1's primary mechanism is the inhibition of ceramide synthase. This leads to an accumulation of sphinganine and sphingosine, which disrupts mitochondrial function and serves as a major source of ROS.
• Oxidative biomarkers: Studies in liver, endothelial, and astrocyte models report increased levels of malondialdehyde (MDA), a marker of lipid peroxidation, and alterations in antioxidant enzyme activity.
• Genotoxic effects: The resulting ROS leads to oxidative DNA damage, characterized by elevated levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG), a definitive biomarker for guanine oxidation.

Pro-inflammatory signaling pathways

FB1 exposure activates specific signaling cascades that promote inflammation, although these effects are often tissue-specific.

• Cytokine elevation: Research demonstrates that FB1 increases the production of key pro-inflammatory cytokines, specifically TNF-alpha and IL-6, in hepatocytes and macrophages.
• Signaling cascades: These inflammatory responses are mediated through the activation of the NF-kB and JAK/STAT signaling pathways. In some models, the JNK MAPK pathway is also activated via ROS-dependent mechanisms, primarily driving apoptosis.
• Immunological complexity: While FB1 triggers pro-inflammatory signals, it can simultaneously exert immunosuppressive effects in other contexts, such as reducing IL-12p40 and impairing dendritic cell function.

Bottom line

Experimental studies strongly support that fumonisin exposure triggers oxidative stress and pro-inflammatory cytokine signaling. These effects are driven by the disruption of sphingolipid metabolism and the activation of the NF-kB and JAK/STAT pathways, leading to measurable DNA damage and systemic inflammation.