Genomic Instability in Human Lymphocytes from Male Users of Crack Cocaine

Abstract

Recent research suggests that crack cocaine use alters systemic biochemical markers, like oxidative damage and inflammation markers, but very few studies have assessed the potential effects of crack cocaine at the cellular level. We assessed genome instability by means of the comet assay and the cytokinesis-block micronucleus technique in crack cocaine users at the time of admission to a rehabilitation clinic and at two times after the beginning of withdrawal. Thirty one active users of crack cocaine and forty control subjects were evaluated. Comparison between controls and crack cocaine users at the first analysis showed significant differences in the rates of DNA damage (p = 0.037). The frequency of micronuclei (MN) (p < 0.001) and nuclear buds (NBUDs) (p < 0.001) was increased, but not the frequency of nucleoplasmic bridges (NPBs) (p = 0.089). DNA damage decreased only after the end of treatment (p < 0.001). Micronuclei frequency did not decrease after treatment, and nuclear buds increased substantially. The results of this study reveal the genotoxic and mutagenic effects of crack cocaine use in human lymphocytes and pave the way for further research on cellular responses and the possible consequences of DNA damage, such as induction of irreversible neurological disease and cancer.

Genotoxic and Cytotoxic Potential of Smoke Crack Cocaine on the Epithelium of the Human Oral Mucosa

“…The results showed that the frequency of micronuclei and karyorrhexis increased significantly. Our results corroborate the findings of some authors, such as Webber et al and de Freitas et al 18,25 These authors observed a frequency of micronuclei and nuclear buds was significantly increased in peripheral blood lymphocytes and oral mucosa. In 2014, das Graças Alonso de Oliveira et al 26 have investigated the frequency of micronucleus in oral mucosa of crack cocaine users too.…”

Genotoxicity and mutagenicity induced by acute crack cocaine exposure in mice

“…For example, some studies have demonstrated significant effect on DNA content, increasing the degree of aneuploidy, with the action of crack being much more potent and rapid than that of cocaine hydrochloride (Narvaez et al, 2013). Crack cocaine was able to induce genetic damage in peripheral blood and buccal mucosa cells of users (de Freitas et al, 2014;das Graças Alonso de Oliveira et al, 2014). However, to the best of our knowledge, no studies have addressed if crack cocaine induces genetic damage in multiple organs so far.…”

Genotoxic changes in peripheral lymphocytes after therapeutic exposure to crude coal tar and ultraviolet radiation

“…A standard version of alkaline comet assay detects DNA single strand breaks (DNASSBs), alkali-labile sites and incomplete excision repair sites 31 . In the presented study we used the standard version with modifications according to Buchynska 32 and de Freitas 33 . We analysed the percentage of DNA in the tail (designated as tail DNA or tail intensity; % tDNA) expressed as the ratio between amount of DNA in the head and amount of DNA in the tail 34 .…”