K V Rao1, C L Fernandes. 1. Cellular Carcinogenesis Laboratory, Cancer Research Institute, Tata Memorial Centre, Parel, Bombay, India.
Abstract
AIMS AND BACKGROUND: Malachite green (MG) is a triarylmethane textile dye which is banned for use as a food colour. However, despite the ban it is used unscrupulously as a food colouring agent. It is also used extensively for dyeing silk, wool, jute, leather, cotton and also as a laboratory reagent, in view of its multipurpose utility, MG may pose a potential environmental health hazard. The purpose of this study was to evaluate the dose-dependent effects of malachite green on the development of pre-neoplastic lesions during N-nitrosodiethylamine (DEN)-induced hepatocarcinogenesis in comparison with phenobarbitone (PB) in male Wistar strain rats. METHODS: Rats were administered 200 p.p.m. DEN in drinking water for a period of one month. Following an interval of two weeks the animals were given MG at concentrations of 25, 50 and 100 p.p.m. through drinking water for 7 months. PB at a concentration of 500 p.p.m. served as the standard tumour promoter. The dose dependent tumour enhancing effects of MG were monitored on the basis of morphological appearance of the livers, liver weight profile, histological pattern and quantitative GGT activity. RESULTS: MG tested at all the three concentrations and PB were found to enhance liver carcinogenesis to a significant extent when compared to either with their corresponding controls or only the DEN treated animals. CONCLUSIONS: A dose-dependent tumour enhancing effect of MG on DEN-induced hepatic preneoplasia in rats was observed. The enhancing effects at 25, 50 and 100 p.p.m. were found to be comparable with PB at 500 p.p.m.
AIMS AND BACKGROUND:Malachite green (MG) is a triarylmethane textile dye which is banned for use as a food colour. However, despite the ban it is used unscrupulously as a food colouring agent. It is also used extensively for dyeing silk, wool, jute, leather, cotton and also as a laboratory reagent, in view of its multipurpose utility, MG may pose a potential environmental health hazard. The purpose of this study was to evaluate the dose-dependent effects of malachite green on the development of pre-neoplastic lesions during N-nitrosodiethylamine (DEN)-induced hepatocarcinogenesis in comparison with phenobarbitone (PB) in male Wistar strain rats. METHODS:Rats were administered 200 p.p.m. DEN in drinking water for a period of one month. Following an interval of two weeks the animals were given MG at concentrations of 25, 50 and 100 p.p.m. through drinking water for 7 months. PB at a concentration of 500 p.p.m. served as the standard tumour promoter. The dose dependent tumour enhancing effects of MG were monitored on the basis of morphological appearance of the livers, liver weight profile, histological pattern and quantitative GGT activity. RESULTS:MG tested at all the three concentrations and PB were found to enhance liver carcinogenesis to a significant extent when compared to either with their corresponding controls or only the DEN treated animals. CONCLUSIONS: A dose-dependent tumour enhancing effect of MG on DEN-induced hepatic preneoplasia in rats was observed. The enhancing effects at 25, 50 and 100 p.p.m. were found to be comparable with PB at 500 p.p.m.