Mycotoxin-induced cytotoxicity of commercially available pelleted feline feed in feline peripheral blood mononuclear cells Ex Vivo

Mycotoxin contamination is a major concern in developing countries such as South Africa, with pelleted pet foods often being contaminated with mycotoxins that have a negative impact on pet health. This study investigated the cytotoxicity of some common mycotoxins found in commercial cat food. A total of 12 cat food samples consisting of six samples each from standard grocery store lines (SB) and premium veterinarian lines (PB) were collected from supermarkets and veterinary practices, respectively. Samples of pelleted cat food were extracted for mycotoxins. Cat peripheral blood mononuclear cells (PBMCs) were isolated and treated with various feed extracts for 24 h to determine the oxidative stress and antioxidant status, using the thiobarbituric acid (TBARS) and glutathione assays, mitochondrial integrity and cell death using caspsase 3/7 luminometry and Annexin V flow cytometry assays, respectively. Both PB and SB extracts decreased ATP levels (P<0.05) and increased mitochondrial depolarization (P<0.05) except for the PB acid fraction. Lipid peroxidation was increased in both PB and SB extracts (P<0.05) with a concomitant decrease in glutathione levels (P<0.05). Apoptosis and necrosis of PBMCs were also increased (P<0.05) in PB and SB extracts, with executioner caspases-3/7 elevated (except for the PB acid fraction). Interestingly, initiator caspases were decreased (P<0.05). This study found that both PB and SB display immune toxicity in feline lymphocytes; however, PB fared better by demonstrating lower levels of cytotoxicity.