Comparative Hepatotoxicity of Aluminum Administered with Maltol and Kojic Acid to Mice

Maltol is a food additive used worldwide, while it enhances the brain toxicity of aluminum (Al). Al injected with maltol is primarily transferred to the liver and so it may also cause hepatic injury. Kojic acid is used as a food additive in Japan and is structurally related to maltol. Therefore, the hepatotoxicity of Al with maltol was compared to that of Al with kojic acid in mice. Al injected intravenously with maltol in a 1 : 4 molar ratio at a dose of 0.25 mmol Al/kg caused an increase in the plasma activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) despite lower hepatic Al concentration than those found after administration in a 1 : 2 molar ratio and with Al only. At the same time, hepatic phosphorus and sulfur (S) levels decreased. The decrease in the S level was ascribed to that in the taurine content. The increase in urinary taurine was also observed. Al alone, maltol alone, or Al : kojic acid at a ratio of 1 : 4 did not alter the plasma activities of AST and ALT or the hepatic element levels. These findings may suggest that tris (maltolato) aluminum (III) (Al (maltol)3) is a hepatotoxin.