Neuroprotective Effects of Empagliflozin Against Methamphetamine-Induced Withdrawal Syndrome in Mice: Involvement of Bdnf, Tlr4, and JNK Signaling Pathways and Oxidative Stress Biomarkers

Abstract

Background Methamphetamine withdrawal is associated with reduced dopaminergic neurotransmission, oxidative stress, neuroinflammation, and structural brain changes, which are linked to cognitive impairment, memory deficits, and psychological distress. Objectives This study investigated whether empagliflozin, a sodium-glucose cotransporter 2 inhibitor, mitigates behavioral, molecular, and histopathological alterations induced by chronic methamphetamine (METH) exposure. Methods Eighty male NMRI mice were allocated to 8 groups (n = 10). Methamphetamine dependence was induced by administering 2 mg/kg intraperitoneally, twice daily, for 14 days. During METH withdrawal, mice received empagliflozin (0.5, 1, 2, or 10 mg/kg, orally) or saline for 10 days. From days 25 to 28, the open-field test, forced swimming test, elevated plus maze, and novel object recognition test were conducted to assess depression-like behavior, anxiety-like behavior, and cognition. On day 28, the hippocampi were isolated and evaluated for oxidative and antioxidant biomarkers, nitric oxide (NO), and the expression of toll-like receptor 4 (Tlr4), brain-derived neurotrophic factor (Bdnf), and c-Jun N-terminal kinase (JNK). Histopathological studies of the hippocampus and prefrontal cortex were also performed using hematoxylin and eosin staining. Results Methamphetamine withdrawal induced pronounced anxiety-like and depression-like behaviors, recognition memory impairment, redox imbalance, upregulation of Tlr4 and JNK, suppression of Bdnf, and inflammation. However, post-withdrawal empagliflozin ameliorated affective and cognitive deficits, restored glutathione and ferric-reducing antioxidant power, reduced malondialdehyde and protein carbonyl levels, normalized tissue NO levels, increased Bdnf expression, downregulated Tlr4 and JNK expression, and markedly reversed histopathological damage. These findings suggest that empagliflozin confers robust behavioral, antioxidant, anti-inflammatory, and neuroprotective effects during methamphetamine withdrawal. Conclusions The results of this animal study support empagliflozin as a potential treatment for neuropsychiatric dysfunction associated with METH withdrawal. Further clinical studies are needed to confirm the effects of empagliflozin.