Alzheimer’s Disease: A Review

Abstract

Alzheimer's disease (AD) is an age-related, non-reversible neurodegenerative disease. AD is characterized by cognitive and behavioral problems. It is the most common cause of dementia among people aged 65yrs and older. It is the third leading cause of death in developed countries Alzheimer disease accounts for 60-70% cases of progressive cognitive impairment in elderly patients. The disease is more common among women than men by a ratio of 1.2 to 1.5. Two basic types of AD are familial and sporadic. While familial AD (FAD) is a rare form of AD, affecting less than 10 percent of AD patients, sporadic AD comprises the remaining 85-90%. However, no effective therapy exists till date. Because of the increased safety concerns about the synthetic drugs, cheaper and safer sources of drugs based on natural origin are the focus of current research. The traditional medicine all over the world is nowadays revalued by an extensive research activity on different plant species and their therapeutic applications. Since they have a relatively higher therapeutic index, lesser side effects and are economical, herbal drugs have gained a lot of acceptance and popularity in the recent years. These plants may show beneficial effects in animal models of AD. Pooja Arora* 1 , Harjeet Singh 2 1. Department of Pharmacology, H.R. Institute of Pharmacy, 7th km stone, Delhi-Meerut Road, Morta, Ghaziabad, U.P.-201003 2. Department of Pharmaceutics, H.R Institute of Pharmacy, 7th km stone, Delhi-Meerut Road, Morta, Ghaziabad, U.P.-201003 Submission: 19 August 2017 Accepted: 27 August 2017 Published: 30 September 2017 www.ijppr.humanjournals.com Citation: Pooja Arora et al. Ijppr.Human, 2017; Vol. 10 (2):218-230. 219 INTRODUCTION Alzheimer's disease (AD) is an age-related, non-reversible neurodegenerative disease. AD is characterized by cognitive and behavioral problems. It is the most common cause of dementia among people aged 65yrs and older. It is the third leading cause of death in developed countries (Ewbank, 1991). Alzheimer disease accounts for 60-70% cases of progressive cognitive impairment in an elderly patients. The total prevalence of AD in the United States is estimated at 2.3 million (range, 1.09 4.8 million) (Brookmeyer et al, 1998). The prevalence of AD doubles every 5 years after the age of 60yrs, increasing from a prevalence of 1% among those 60-64 years-old to up to 40% of those aged 85 years and older (Von Strauss et al, 1999). The disease is more common among women than men by a ratio of 1.2 to 1.5 (Gao et al, 1998). Two basic types of AD are familial and sporadic. While familial AD (FAD) is a rare form of AD, affecting less than 10 percent of AD patients, sporadic AD comprises the remaining 85-90 %. FAD is frequently observed in younger people while sporadic AD is related to advancing age and ultimately affects almost half of the population over the age 85 (Yaffe, 1998). It leads to death within an average of 8 years after diagnosis, the last 3 of which are typically spent in an institution. Besides memory loss, Alzheimer's patients show dramatic personality changes, disorientation, declining physical coordination, and an inability to care for themselves. In the final stages, victims are bedridden, lose urinary and bowel control, and suffer epileptic attacks. Death is usually due to pneumonia, bedsores or urinary tract infection. The diagnosis of AD can only be confirmed by the presence of amyloid plaque, neuro-fibrillary tangles, neuronal & synaptic loss and brain atrophy in specific brain areas. Dementia is diagnosed in a living patient (with at least 85% accuracy) on the basis of cognitive tests (especially delayed recall) and exclusion of other conditions such as stroke, hypothyroidism or nutritional deficiency. However, no effective therapy exists till date. Because of the increased safety concerns about the synthetic drugs, cheaper and safer sources of drugs based on natural origin are the focus of current research. The traditional medicine all over the world is nowadays revalued by an extensive activity of research on different plant species and their therapeutic applications. Since they have a relatively higher therapeutic index, lesser side effects and are economical, herbal drugs have gained a lot of acceptance and popularity in the recent years. Curcumin has been shown to possess potent anti-amyloidogenic effects (Ono et al, 2004). Certain other plants like Ginkgo biloba, St John's wort, Kava-kava, Valerian, Bacopa monniera and www.ijppr.humanjournals.com Citation: Pooja Arora et al. Ijppr.Human, 2017; Vol. 10 (2):218-230. 220 Convolvulus pluricaulis have shown beneficial effects in diseases of the nervous system (Kumar, 2006). These plants may show beneficial effects in animal models of AD.