The invention deals with a process of obtaining an extract containing multiple ingredients including luteolin from the leaves of Cynodon dactylon and its use in the treatment of Alzheimers diseases. The alcoholic extract of Cynodon dactylon was found to be rich in luteolin and exhibited better efficacy. When tested in animals, the efficacy of the extract, particularly the alcoholic extract was found to be comparable to conventional drugs like Donepezil.