Secretase inhibitors for the treatment of Alzheimer's disease: Long road ahead.

Alzheimer's disease (AD) is a neurodegenerative disease, characterized by progressive loss of memory which is associated with other cognitive deficits. The two protein structures in the brain i.e. neurofibrillary tangles and senile plaques are considered to hamper the normal cognitive activity of the brain. There are various therapeutic interpolations under investigation to thwart and treat AD. Secretases inhibitors are important agents that inhibit the development of senile plaques. β-secretase (BACE) inhibitors are in lime light for the drug development of AD. BACE initiates the production of Aβ, so its inhibition provides a valid target for the AD. BACE inhibitors viz. LY2811376, LY2886721, E2609 are in different phases of clinical trials. However, chemical study of MK8931 was discontinued due to lack of chances of finding a positive clinical effect. AREAS COVERED: The review incorporates exhaustive literature reports on secretase inhibitors, γ-secretase modulators (GSMs) and α-secretase enhancers. The recent studies on the natural products as GSMs have also been included.