Chemical composition and toxicity of Taiwanese betel quid extract

In this genotoxic study, the Ames Salmonella microsome test showed that an aqueous extract of betel quid did not induce mutagenicity in Salmonella typ himurium strains TA98 and TA100. Mammalian cell studies (Chinese hamster ov ary K1 cell; CHO-K1 cell) revealed that only higher concentrations (100 and 1000 mu g/ml) of aqueous extract weekly increased the frequencies of siste r-chromatid exchange (SCE) in the absence of S9. Animal (male Sprague-Dawle y rat) studies showed that low-dose feeding (0.53 g dry aqueous extract/kg diet) significantly increased the activities of glutathione (GSH) peroxidas e and cytoplasmic glutathione S-transferase (cGST) of liver, high-dose feed ing (26.5 g dry aqueous extract/kg diet) lowered the contents of GSH and to tal glutathione. The effect of an aqueous extract of betel quid on the oxid ation of 2'-deoxyguanosine (2'-dG) to 8-hydroxy-2'-deoxyguanosine (8-OH-dG) evaluated that this aqueous extract may act as a pro-oxidant at lower dosa ge and may be dependent on the iron ions in the model system. However, the aqueous extract of betel quid showed antioxidant activity at higher doses b y the ability of the scavenging effect of the hydroxyl radicals. (C) 1999 P ublished by Elsevier Science Ltd. All rights reserved.