Protective effect of Citrullus colocynthis (L.) Schard. fruit extract on high glucose-induced neurotoxicity in PC-12 cells

Background: Diabetic neuropathy is a consequence of chronic hyperglycemia that leads to neural damage over time. The fruits of Citrullus colocynthis (L.) Schard. (C. colocynthis) have long been used in Iranian traditional medicine for treatment of diabetes. Objective: In this study, we investigated the protective effects of C. colocynthis against high glucose-induced neurotoxicity in PC-12 cells as a suitable in vitro model for neuronal functions. Methods: The seedless dry fruit powder was extracted with methanol and then dried by rotary evapoartion. Later the obtain extract was fractionated as hexane, chloroform, ethyl acetate, and n-butanol fractions and aqueous residue. HPLC method was used for qualitative analysis of colocynthin in C. colocynthis pulp. The PC-12 cell viability of total extract and fractions of C. colocynthis were evaluated by means of dose and time in high glucose medium in PC-12 cells as a suitable culture model for studying neuronal functions through MTT assay. Results: The PC-12 cell viability significantly decreased in wells containing high glucose, compared with normal glucose treated cells. C. colocynthis extract treatment significantly enhanced the cells viability under toxic high glucose condition in a dose and time depending manner. Methanol extract of C. colocynthis exhibited a protective effect against high glucose-induced cytotoxicity in PC-12 cells. Conclusion: C. colocynthis has neuroprotective properties against high glucose condition in vitro.