Protective effect of saffron extract and crocin on reactive oxygen species-mediated high glucose-induced toxicity in PC12 cells.

Diabetic neuropathy is one of the most frequent complications of diabetes. Despite some studies, the exact mechanism of glucose neurotoxicity has not been fully elucidated. Increased reactive oxygen species (ROS) has proposed as a possible mechanism. Crocus sativus L. (saffron) has been known as a source of antioxidants. Therefore, neuroprotective effect of saffron extract, its active component crocin and gamma-glutamylcysteinylglycine (GSH) was studied in glucose-induced neurotoxicity, using PC12 cells as a suitable in vitro model of diabetic neuropathy. Cell viability was quantitated by MTT assay. ROS was measured using DCF-DA by flow cytometry analysis. The result showed that glucose (13.5 and 27 mg/ml) reduced the cell viability of PC12 cells after 4 days. Saffron extract (5 and 25 mg/ml), crocin (10 and 50 muM) and GSH (10 muM) could decrease this toxicity. Glucose toxicity was consistent with increased ROS production which reduced by saffron, crocin and GSH pretreatment. These results suggest saffron and its carotenoid crocin could be potentially useful in diabetic neuropathy treatment.