Modulation of acetylcholinesterase activity exerts anti-inflammatory effect in spleen and immune cells of fish fed with a diet contaminated by aflatoxin B1

Abstract Suitable control of immune and inflammatory responses is a critical determinant of fish health, and the cholinergic system, through the enzyme acetylcholinesterase (AChE), displays an important role in these responses by regulation on acetylcholine (ACh) levels. In fish, exposure to aflatoxin B 1 (AFB 1 ) is associated with reduced immune responsiveness and immunosuppression, but the pathways involved on the impairment of fish immune system during AFB 1 exposure remains poorly understood. Thus, the aim of this study was to evaluate whether AChE activity in splenic tissue and immune cells is able to modulate the inflammatory and immune responses in silver catfish ( Rhamdia quelen ) fed with a diet contaminated by AFB 1 . AChE activity in spleen tissue, as well as in peripheric and splenic lymphocytes were lower on days 14 and 21 post-feeding in animals fed with AFB 1 contaminated feed compared to the control group. Based on these evidences, the results indicate that AChE activity is capable to modulate immune and inflammatory responses in tissue and immune cells of fish fed with a diet containing AFB 1 , leading to the development of an anti-inflammatory profile in an attempt to improve immune response and reduce or prevent tissue damage due to the inflammatory response.