Assessment of the no-observed-adverse-effect level (NOAEL) of gallic acid in mice

Gallic acid is a naturally occurring plant phenol obtained by the hydrolysi s of tannins and is known to show some pharmacological activities. The purp ose of this paper is to establish the safety of gallic acid in mice. In thi s study, acute administration of gallic acid even at a dose as high as 5 g/ kg body weight did not produce any signs of toxicity or mortality. In the s ubacute study, gallic acid at a dose of 1000 mg/kg body weight did not sign ificantly alter the hematological parameters. Further, no appreciable chang e was noted in the various biochemical parameters such as SGOT and SGPT, as well as many serum constituents such as protein, cholesterol, urea and bil irubin. Therefore, from this study, it may be concluded that gallic acid is non-toxic up to a level of 5000 mg/kg body weight, when given orally. In a ddition, the subacute study indicated the absence of cumulative toxicity, a s reflected by the non-significant alterations in the parameters investigat ed. The NOAEL was 5000 mg/kg body weight, the highest dose tested. (C) 2001 Elsevier Science Ltd. All rights reserved.