Inhibition of Toll Like Signaling Pathway Is Associated With Genomic Instability in Rat Liver Exposed to Crack Cocaine.

BACKGROUND/AIM: The aim of the present study was to investigate the biological effects of subacute crack cocaine exposure in rat liver. MATERIAL AND METHODS: A total of 32 rats were distributed into four groups (n=8): Experimental group 1 (G1) and Experimental group 2 (G2): rats received 18 mg/kg of body weight (b.w) of crack cocaine for 5 days, once a day, group G2 remained 72 h without exposure after the experimental period (5 days)(abstinence); Experimental group 3 (G3): rats received 36 mg/kg of body weight (b.w) of crack cocaine for 5 days, once a day; Control Group (CTRL): rats received only the vehicle (DMSO) administered by the intraperitoneal (i.p) route for 5 days, once a day. RESULTS: All groups exposed to crack cocaine had an increase in the number of micronucleated hepatocytes and binucleated cells only in the highest tested dose (36 mg/kg). Karyolysis had an increase in the 18 mg/kg dose, in the abstinence group (G2), and 36 mg/kg group (G3); whereas pyknotic nuclei had an increase in the G2 group. The group exposed to 18 mg/kg of crack cocaine also showed high 8 OHdG expression. The p-NF-κB p65 protein decreased in the groups exposed to crack cocaine at doses of 18 and 36 mg/kg, as well as in the abstinence group. MyD88 was also found decreased in the group exposed to crack cocaine at 18 mg/kg. CONCLUSION: Crack cocaine inhibited toll like signaling pathway whilst being associated with genomic instability in rat liver cells.