In Vivo genotoxicity of a commercial C.I. Disperse Red 1 dye.

Color Index (C.I.) Disperse Red 1 (DR1) is a widely used textile azo dye found in rivers. As it may not be completely removed by conventional treatments, humans can be exposed through drinking water. Studies have supported in vitro toxicity and mutagenicity of commercial DR1. This study aimed to investigate the mutagenic and toxicogenomic effects of commercial DR1 in multiple tissues/organs of Swiss male mice. For that, animals were orally exposed to the dye (by gavage), at single doses of 0.0005, 0.005, 0.5, 50, or 500 mg/kg bw. The two lowest doses were equivalent to the ones found in two Brazilian rivers receiving influx of textile discharges. Cytotoxicity, micronucleated cell frequencies (for all doses tested), primary DNA damage (comet assay), and gene expression profiling of (0.0005 and 0.005 mg/kg of bw) were investigated 24 hr after animal exposure to commercial DR1. Data showed increased frequencies of micronucleated polychromatic erythrocytes in bone marrow cells after treatment with 0.5 and 50 mg/kg bw. At 0.005 mg/kg bw, commercial DR1 induced an increase of primary DNA damage in liver, but not in kidney cells. Additionally, upregulation of genes involved in the inflammatory process (IL1B) (0.0005 and 0.005 mg/kg bw) and cell-cycle control (CDKN1A) in liver cells, and apoptosis (BCL2 and BAX) in leukocytes (0.005 mg/kg bw) were also detected. In conclusion, the commercial DR1 was genotoxic (chromosome aberrations and primary DNA damage) and modulated gene expression in mice, and such effects were dependent on the doses and tissues analyzed. Environ. Mol. Mutagen. 59:822-828, 2018. © 2018 Wiley Periodicals, Inc.

Chemopreventive effects of rosmarinic acid on rat colon carcinogenesis.

Rosmarinic acid (RA) is a polyphenolic compound that shows a number of interesting biological activities, such as antiapoptotic, antifibrotic, antioxidant, hepatoprotective, antineurodegenerative, and anti-inflammatory properties. The aim of this study was to investigate the ability of RA to prevent 1,2-dimethylhydrazine (DMH)-induced primary DNA damage and aberrant crypt foci (ACF) in Wistar rat colon. The animals were treated by gavage with doses of 4, 8, and 16 mg/kg body weight/day. Next, the animals received a single subcutaneous injection of 40 mg/kg DMH and were killed 4 h later for the evaluation of DNA damage using the comet assay. In addition, two doses of 40 mg/kg DMH were administered weekly for 2 weeks and the animals were killed 2 weeks after the last injection for the evaluation of ACF formation in rat colon. The results showed that RA exerted no genotoxic/carcinogenic effects. Treatment with different doses of RA combined with DMH led to a significant reduction in the extent of DNA damage and in the frequency of ACF compared with animals treated with DMH alone. These findings suggest that RA reduces DNA damage and suppresses the formation of ACF.

Inhibitory effects of Baccharis dracunculifolia on 1,2-dimethylhidrazine-induced genotoxicity and preneoplastic lesions in rat colon.

Baccharis dracunculifolia (Asteraceae), the main botanical source of green propolis, also known as 'alecrim-do-campo' and 'vassourinha', is a shrub of the Brazilian 'cerrado' and is native to the South and Southeast of Brazil. The effects of B. dracunculifolia ethyl acetate extract (Bd-EAE) were evaluated on the 1,2-dimethylhydrazine (DMH)-induced DNA damage and aberrant crypt foci (ACF) in the colon of male Wistar rats by the comet and ACF assays, respectively. The animals were treated by gavage with doses of 6, 12, and 24 mg/kg body weight/day. Animals were also administered a single subcutaneous injection of 40 mg/kg DMH and were killed after 4 h for evaluation of DNA damage. Also, two doses of 40 mg/kg of DMH were administered weekly for 2 weeks, and animals were killed 2 weeks after the last injection for evaluation of ACF development in the colon. The results showed a significant reduction in the frequency of DNA damage and ACF in the group treated with the Bd-EAE plus DMH in comparison with those treated with DMH alone, suggesting that Bd-EAE reduced DNA damage and suppressed the formation of ACF and also exerted a protective affect against colon carcinogenesis.