Attenuating effect of N-acetyl-L-cysteine against acute cocaine toxicity in rat C6 astroglial cells

Abstract

Astroglial cells are one of the most abundant cell types in the mammalian brain functioning in neuronal survival and in maintenance of fundamental patterns of circuitry. To date, no study has been conducted regarding the short-term impact of cocaine on these cells in cultures. The present study aimed to investigate acute cocaine (1 h) treatment on cell viability in rat C6 astroglial cells. In addition, the potential effect of N-acetyl-L-cysteine (NAC) against cocaine-induced toxicity was studied. It was observed that 1 h of acute cocaine exposure at 2, 3 and 4 mM caused a dose-dependent decrease in cell viability with an LC50 of 2.857 mM. Furthermore, cocaine treatment caused a decrease in glutathione (GSH) levels in the cells. It was found that cocaine did not exhibit pro-oxidant activity during its exposure to cells. Acute cocaine exposure did not induce nitric oxide (NO) release in the cells. A 5-point (1–5 mM) dose-response curve of NAC clearly indicated no adverse effect on astroglial cell viability. Pretreatment of cells with 5 mM NAC for 30 min, followed by its discard, and exposure to cocaine (2–4 mM) for 1 h protected cells against cytotoxicity by 90%. Treatment of cells with NAC-cocaine mixture rendered 100% protection. Further investigations revealed that the protection by NAC was through the increased GSH levels in the cells. Our results indicate that decreased GSH levels may represent one of the underlying pathologies of cell death and that antioxidant compounds which increase the GSH production could protect against cocaine-induced toxicity by promoting a pro-survival role in astroglial cells.

Milk thistle seed extract protects rat C6 astroglial cells from acute cocaine toxicity

“…3C ). Similar observations were recently reported for NAC pretreatment ( 13 ). In addition, we showed that the increased cell viability of cocaine-treated cells is accompanied by an increase in the GSH level.…”

“…Under our experimental conditions, the cocaine LC 50 in C6 astroglial cells was ~3 mM at 1 h exposure. This value is closer to that of a recent report ( 13 ). It is notable that cocaine was not prominently toxic to liver and kidney cells or to living shrimp larvae ( Fig.…”

“…Treatments lasted 1 h and were performed at a 37°C, 5% CO 2 incubator. The duration of cocaine treatment (1 h) was selected based on our earlier study ( 13 ).…”

Targeting redox regulation to treat substance use disorder using N‐acetylcysteine

“…Following uptake of cystine into cells via system xc‐, cystine can be converted back into cysteine to allow for the synthesis of further glutathione. This has been shown in an experiment where incubation of cultured astroglial cells with a cocaine/NAC mixture prevented the cocaine‐induced decrease in cell viability by increasing cellular glutathione levels (Badisa et al ., , ). Furthermore, NAC may also increase the expression of antioxidant enzymes, with a cell culture model of cocaine‐induced hepatotoxicity finding increased manganese‐ and copper, zinc‐superoxide dismutase, catalase and glutathione peroxidase levels following NAC supplementation (Zaragoza et al ., ).…”

S-Glutathionylation and Redox Protein Signaling in Drug Addiction

“…185 In keeping with this, NAC was found to reverse GSH depletion in rat astroglial cells following cocaine-induced oxidative stress. 186,187 Regrettably, clinical trials of NAC efficacy as a treatment for substance use disorders have received mixed results. 188 However, these results do suggest that drugs affecting glutathionylation are valid areas of research in addiction pharmacotherapy.…”