Ameliorative Effects of Olea europaea Oil on Morphine Withdrawal: Behavioural, Biochemical and Histological Evidence in Rats

Abstract

INTRODUCTION: Prolonged morphine use can trigger dependence and addiction leading to severe withdrawal symptoms upon cessation. Oxidative stress is a key factor in its pathogenesis. Olea europaea (olive) oil, rich in polyphenols and oleuropein, exhibits antioxidant, anti-inflammatory and neuroprotective properties. Thus, this study aimed  to evaluate the effects of Olea europaea oil in alleviating morphine withdrawal symptoms in morphine-dependent rats. MATERIALS AND METHODS: A total of eighteen rats were randomly divided into three groups. The control group received normal saline, while the positive control group received intraperitoneal injections of morphine sulphate (2.5 mg/kg to 50 mg/kg) for seven days. The treatment group received the same morphine doses followed by oral administration of 250 mg/kg Olea Europaea oil for twenty-one days during morphine withdrawal period. Spontaneous morphine  withdrawal behaviours of rats were observed. Subsequently the rats were sacrificed and the brain tissue was stained with H&E for histological markers. Blood serum and brain tissue were collected for Glutathione (GSH) level measurement using an ELISA kit. The findings were analysed using GraphPad Prism. RESULTS: The administration of Olea Europaea oil significantly reduced (p<0.05) spontaneous withdrawal symptoms. Findings show that Olea Europaea oil ameliorated histological brain signs of morphine toxicity and GSH levels in the brain tissue of the treated group were significantly higher (p<0.05) compared to the no treatment group. CONCLUSION: This study demonstrates that Olea Europaea oil supplementation significantly alleviates morphine withdrawal symptoms and restores antioxidant capacity likely due to its potent antioxidant and neuroprotective properties.