INS and Parkinson disease: An in vitro model of PD, using rat glioblastoma cell line C6, showed that one hour pre-treatment with insulin (100 nM) protects against 24 h MPP + (500 μM) stimulation-induced toxicity, as demonstrated by significantly decreased LDH and nitric oxide (NO) media release and iNOS and COX2 expression when compared to MPP + stimulated only cells (Ramalingam et al., 2017).