Butylated hydroxyanisole specifically inhibits tumor necrosis factor-induced cytotoxicity and growth enhancement

Abstract

The effect of commonly used food antioxidants on recombinant tumor necrosis factor α (rTNF-α)-induced cytotoxicity, growth enhancement and adhesion has been evaluated. Butylated hydroxyanisole (BHA) and 4-hydroxymethyl-2,6-di-t-butylphenol (HBP) were the only two of nine antioxidants that completely inhibited rTNF-α-induced cytotoxicity in L929 and WEHI 164 fibrosarcoma cells. Ethoxyquin, propyl gallate and butylated hydroquinone only partially inhibited rTNF-α-induced cytotoxicity, while the antioxidants butylated hydroxytoluene (BHT), α-tocopherol, ascorbic acid and thiodipropionic acid had minimal effects. The only difference between the molecular structure of the efficient HBP and the non-efficient BHT, is a hydroxymethyl group instead of a hydroxyl group on the phenolic ring. Neither BHA nor BHT inhibited the activation of NF _ϰB after 10 or 60 min challenge with rTNF-α in L929 cells. BHA also inhibited rTNF-α-induced, but not rIL-1β-induced growth enhancement in FS-4 fibroblasts. Further, BHA blocked both rTNF-α-induced and rIL-1β-induced prostaglandin E₂ synthesis in FS-4 fibroblasts. BHA inhibited the rTNF-α-induced release of arachidonic acid in both FS-4 and L929 cells, suggesting that BHA inhibits cellular phospholipase(s). Neither α-tocopherol nor BHA inhibited rTNF-α-induced adhesiveness of human endothelial cells. The results indicate that BHA is a specific and potent inhibitor of rTNF-α- and rTNF-β-induced cytotoxicity, as well as of rTNF-α-induced growth enhancement.