Fusaric acid is a mycotoxin produced by several species of Fusarium [1]. Mycotoxins are biologically active secondary fungal metabolites found as contaminants of food- and feedstuff. Mycotoxin is capable of causing disease and death in both humans and animals.

Fusaric acid is a potent inhibitor of dopamine β-hydroxylase. Fusaric acid uncompetitively inhibited the activity of dopamine β-hydroxylase with an IC50 of 30 μM in an. Fusaric acid lowered endogenous levels of norepinephrine and epinephrine in brain, spleen, heart, and adrenal glands. Fusaric acid inhibited dopamine β-hydroxylase activity in adrenal medulla in vivo [2]. Fusaric acid altered brain and pineal neurotransmitters. In the brain and pineal gland of rats, intraperitoneally (100 mg/kg) administration of fusaric acid increased the level of 5HT, 5-hydroxyindoleacetic acid (5HIAA), tyrosine, and dopamine [3].

Exposure to acute doses of fusaric acid caused vomiting and neurochemical changes in swine. Fusaric acid might act synergistically with trichothecene mycotoxins to cause vomiting and feed refusal in pigs consuming trichothecene-contaminated feedstuffs [4].

References:
[1] Hidaka H, NAGATSU T, TAKEYA K, et al.  Fusaric acid, a hypotensive agent produced by fungi[J]. The Journal of antibiotics, 1969, 22(5): 228-230.
[2] Toshiharu N, Hiroyoshi H, Hiroshi K, et al.  Inhibition of dopamine β-hydroxylase by fusaric acid (5-butylpicolinic acid) in vitro and in vivo[J]. Biochemical pharmacology, 1970, 19(1): 35-44.
[3] Porter J K, Bacon C W, Wray E M, et al.  Fusaric acid in Fusarium moniliforme cultures, corn, and feeds toxic to livestock and the neurochemical effects in the brain and pineal gland of rats[J]. Natural Toxins, 1995, 3(2): 91-100.
[4] Smith T K, MacDonald E J.  Effect of fusaric acid on brain regional neurochemistry and vomiting behavior in swine[J]. Journal of animal science, 1991, 69(5): 2044-2049.