Oxidative stress plays an important role in the degeneration of dopaminergic neurons in Parkinson's disease (PD). Nostoc Commune extract (NCE) has been identified as a bioactive compounds in brain disorders, with antioxidant activities. The present study aims to evaluate the effects of NCE on 6-OHDA-induced cognitive disorders in a rat model of Parkinson's disease. In this research study, rats were divided into four groups: control, lesioned , NCE 50, and NCE 100. The Parkinson's model was induced by 6-OHDA injection unilaterally (AP: +1 mm; L: +2.5 mm; D: +4.5 mm). Intrastriatal 6-OHDA-lesioned rats received NCE (50 and 100 mg/kg) orally for three weeks. Apomorphine-induced rotation on day 21 and novel object recognition test (NORT) on day 22 were carried out. The results showed that injection of 6-OHDA decreased discrimination Index in the NORT (p < 0.001). NCE 50 and NCE 100 treatment reduced apomorphine-induced rotational asymmetry and enhanced the time spent with the new object in the novel object recognition test (p < 0.001) compared with the lesioned group. Besides, NCE 100 showed better therapeutic effects than NCE 50. In conclusion, the beneficial effect of NCE on learning and memory improvement may be attributed to antioxidant activities. Thus, using this extract may be useful by modulating the level of antioxidant activity and protecting the nervous system against 6-OHDA toxicity in pharmacological alleviation of cognitive deficits.
