The Efficacy of Syzygium aromaticum Essential Oil in Cognitive Disorders against Manganese Chronic Exposure in Rats during Development

Abstract

The essential oil of Syzygium aromaticum has been widely used in traditional medicine to treat a variety of diseases, including some neurological disorders. This study aims at testing, in vivo, the possible anxiolytic and antidepressant effects, of the Syzygium aromaticum essential oil against chronic manganese chloride (4.79 mg/l) intoxication during the gestation and lactation period, in Wistar rat pups. Wistar rat pups were exposed to manganese via their dams’ drinking water from postnatal day (PND) 1 to (PND) 21. After their weaning, the rats exposed to manganese received injections of essential oil of Syzygium aromaticum (0.1 ml/kg) for 18 days. The level of anxiety, depression and locomotor activity were studied. Locomotor activity (open field test), anxiety (elevated plus maze tests), and depression (forced swimming test) were evaluated. The results of the present study indicate that Manganese exposure induces, on the one hand, impairments of body (p<0.001) and of brain weight (p<0.05). On the other hand, it increases level of anxiety (p<0.05), depression (p<0.001) and locomotor hyporactivity (p<0.001), when compared to control rats. Administration of essential oil of Syzygium aromaticum leads to a reduction in the level of anxiety (p<0.05), of depression (p<0.001) and corrects locomotor hyporactivity (p<0.05) in rats exposed to manganese beforehand. These results suggest that essential oil of Syzygium aromaticum can employ as a natural, protective agent against neuro-toxicity induced by manganese chloride during the gestation and lactation periods.