Antiamnesic effect of Mesua ferrea (L.) flowers on scopolamine-induced memory impairment and oxidative stress in rats

Mesua ferrea Linn. flowers have been used in Ayurveda as a brain tonic and as an ingredient in memory-enhancing formulations such as Brahma Rasayan and Chyawanprash. However, this ethnomedicinal use has not been investigated scientifically. This study evaluated the effect of the ethanolic extract of Mesua ferrea flowers (MFE) on memory in scopolamine-induced models of cognitive dysfunction. MFE was administered to rats (100, 200 and 400 mg/kg, p.o) for a period of 14 days, after which amnesia was induced by giving scopolamine (1 mg/kg, s.c) on the 14^th day. Piracetam (200 mg/kg, p.o) was given as a positive control. The models employed to assess memory in the rats were the T-maze continuous alternation task (T-CAT) and novel object recognition test (NORT). Pretreatment with MFE ameliorated the memory deficit caused by scopolamine; which was evidenced by a significantly greater relative proportion of spontaneous alternation percentage in the T-CAT, and a significant increase of discrimination index in the NORT. Further, MFE significantly inhibited anticholinesterase activity in the brain, elevated the levels of reduced glutathione and catalase, and decreased malondialdehyde and nitrite levels in the brain. The results of this study show that MFE exhibited significant anticholinesterase and antioxidant activities in scopolamine treated rats, which could be the possible underlying mechanism of its memory-enhancing activity and of its ethnomedicinal use as a brain tonic.