Nurul Farah Aina MD Fauzi - Faculty of Medicine, University of Sultan Zainal Abidin (UniSZA), ۲۰۴۰۰ City Campus Kuala Terengganu, Terengganu Darul Iman, Malaysia
Nor Hidayah Abu Bkar - Faculty of Medicine, University of Sultan Zainal Abidin (UniSZA), ۲۰۴۰۰ City Campus Kuala Terengganu, Terengganu Darul Iman, Malaysia
Nasir Mohamad - Faculty of Medicine, University of Sultan Zainal Abidin (UniSZA), ۲۰۴۰۰ City Campus Kuala Terengganu, Terengganu Darul Iman, Malaysia
Liyana Hazwani Mohd Adnan - Faculty of Medicine, University of Sultan Zainal Abidin (UniSZA), ۲۰۴۰۰ City Campus Kuala Terengganu, Terengganu Darul Iman, Malaysia
Nor Suliana Mustafa - Faculty of Medicine, University of Sultan Zainal Abidin (UniSZA), ۲۰۴۰۰ City Campus Kuala Terengganu, Terengganu Darul Iman, Malaysia
Nor Zidah Ahmad - Faculty of Medicine, University of Sultan Zainal Abidin (UniSZA), ۲۰۴۰۰ City Campus Kuala Terengganu, Terengganu Darul Iman, Malaysia

Background: Amphetamine (AT) is a potent central nervous system stimulant that is capable of producing damaging effects to the central dopaminergic pathway; used both for medical purposes and also abused recreationally. One of the potential naturally occurring compounds is thymoquinone (TQ), an active compound of Nigella sativa; which is known for its cellular protective effects. The objectives of this study were to determine the IC۵۰ values of AT and TQ on differentiated SH-SY۵Y neuronal cells and to evaluate the changes of dopamine (DA) level in the cells exposed to AT after co-administering with TQ.Materials and Methods: Differentiated SH-SY۵Y cells were grown in a cell culture flask containing DMEM/F۱۲ medium supplemented with ۱۰% (v/v) fetal bovine serum and ۱% (v/v) penicillin/streptomycin. The IC۵۰ value of TQ and AT in differentiated SH-SY۵Y cells was determined by using ۳-(۴,۵-dimethylthiazol-۲-yl)-۲,۵-diphenyl tetrazolium bromide (MTT) assay. The DA level was determined by using the Enzyme-Linked Immunosorbent Assay (ELISA) kit.Results: The IC۵۰ values of AT and TQ were ۱۵۹۶ μM and ۹۲۶ μM, respectively. Co-administration of ۴۰ μM of AT and ۳۰ μM of TQ demonstrated a significant increase in DA level at ۴۸ hours of exposure when compared to the administration of AT group (P≤۰.۰۵).Conclusion: These findings suggested that TQ has a role in maintaining the DA activity after long-term AT exposure.

amphetamine, thymoquinone, differentiated SH-SY۵Y cells, dopamine, lactate dehydrogenase activity