February 24, 2004
Early Vitamin E Supplements Stem Development of Hallmark Alzheimer’s Symptoms in Mice
Source: University of Pennsylvania Health System
(Philadelphia, PA) - Vitamin E, a well-known antioxidant, has been used to treat Alzheimer’s disease, but with mixed results, especially in patients with advanced symptoms. A risk factor for Alzheimer’s is oxidative stress, a clinical condition characterized by an excessive production of reactive chemicals in the brain, which can damage important regions of this organ.
Domenico Praticò, M.D., assistant professor of pharmacology at the University of Pennsylvania School of Medicine, and colleagues tested the idea that timing of vitamin E supplementation for treating Alzheimer’s might be an important factor in its effectiveness. They found that vitamin E given to young transgenic mice before the formation of telltale plaques reduces by up to half the levels of amyloid deposited in the brain over time compared to aged mice on the same regimen. This study appears in the February edition of The FASEB Journal.
Early Vitamin E Supplements Stem Development of Hallmark Alzheimer’s Symptoms in Mice
Source: University of Pennsylvania Health System
(Philadelphia, PA) - Vitamin E, a well-known antioxidant, has been used to treat Alzheimer’s disease, but with mixed results, especially in patients with advanced symptoms. A risk factor for Alzheimer’s is oxidative stress, a clinical condition characterized by an excessive production of reactive chemicals in the brain, which can damage important regions of this organ.
Domenico Praticò, M.D., assistant professor of pharmacology at the University of Pennsylvania School of Medicine, and colleagues tested the idea that timing of vitamin E supplementation for treating Alzheimer’s might be an important factor in its effectiveness. They found that vitamin E given to young transgenic mice before the formation of telltale plaques reduces by up to half the levels of amyloid deposited in the brain over time compared to aged mice on the same regimen. This study appears in the February edition of The FASEB Journal.
“Our findings indicate that an antioxidant is important to cure or prevent disease only if given at a very early stage,” says Praticò. “If given when the disease is already established the chances of a positive effect are very small.”
The researchers used a well-characterized transgenic mouse that expresses a mutant gene present in humans and forms Alzheimer’s plaques (similar to the ones found in humans) in the brain starting at about 11 to 12 months. One group of mice received vitamin E at five months, before plaques start to form. Another group started at 14 months--a time when much plaque had already been deposited--with the same amount of vitamin E. They followed each group for eight months and compared their outcome with controls that did not receive vitamin E. The young group showed a 50 percent reduction in the number of plaques deposited in brain tissue as compared to the older mice. “This group didn’t show any significant difference in plaque reduction as compared to controls, suggesting that once the plaque is deposited there’s very little that an antioxidant can do,” says Praticò. This finding also indicates that other mechanisms may play a role in the disease once established.
The immediate implications of these findings are simple, especially for patients diagnosed with mild cognitive impairment (MCI), a possible precursor to Alzheimer’s: Start taking vitamin E early. “They will benefit the most,” says Praticò. “ Considering that up to 50 percent of patients with MCI will develop Alzheimer’s within four years, and the fact that recent epidemiological studies have clearly shown that intake of antioxidants, in particular vitamin E, lowers the risk of Alzheimer’s, MCI patients will be the most appropriate target for this therapy.”
Penn scientists also contributing to this research are Syuan Sung, Yuemang Yao, Kunihiro Uryu, Hengxuan Yang, Virginia M-Y Lee, and John Q. Trojanowski. This study was funded by the National Institutes of Health, The Alzheimer Association, and the American Heart Association.
Dr. Pratico, can be contacted at domenico@spirit.gcrc.upenn.edu or 215-898-6446.
For a printer friendly version of this release, click here.
# # #
PENN Medicine is a $2.2 billion enterprise dedicated to the related missions of medical education, biomedical research, and high-quality patient care. PENN Medicine consists of the University of Pennsylvania School of Medicine (founded in 1765 as the nation’s first medical school) and the University of Pennsylvania Health System (created in 1993 as the nation’s first integrated academic health system).
Penn’s School of Medicine is ranked #2 in the nation for receipt of NIH research funds; and ranked #4 in the nation in U.S. News & World Report’s most recent ranking of top research-oriented medical schools. Supporting 1,400 fulltime faculty and 700 students, the School of Medicine is recognized worldwide for its superior education and training of the next generation of physician-scientists and leaders of academic medicine.
Penn Health System consists of four hospitals (including its flagship Hospital of the University of Pennsylvania, consistently rated one of the nation’s “Honor Roll” hospitals by U.S. News & World Report), a faculty practice plan, a primary-care provider network, three multispecialty satellite facilities, and home health care and hospice.
The researchers used a well-characterized transgenic mouse that expresses a mutant gene present in humans and forms Alzheimer’s plaques (similar to the ones found in humans) in the brain starting at about 11 to 12 months. One group of mice received vitamin E at five months, before plaques start to form. Another group started at 14 months--a time when much plaque had already been deposited--with the same amount of vitamin E. They followed each group for eight months and compared their outcome with controls that did not receive vitamin E. The young group showed a 50 percent reduction in the number of plaques deposited in brain tissue as compared to the older mice. “This group didn’t show any significant difference in plaque reduction as compared to controls, suggesting that once the plaque is deposited there’s very little that an antioxidant can do,” says Praticò. This finding also indicates that other mechanisms may play a role in the disease once established.
The immediate implications of these findings are simple, especially for patients diagnosed with mild cognitive impairment (MCI), a possible precursor to Alzheimer’s: Start taking vitamin E early. “They will benefit the most,” says Praticò. “ Considering that up to 50 percent of patients with MCI will develop Alzheimer’s within four years, and the fact that recent epidemiological studies have clearly shown that intake of antioxidants, in particular vitamin E, lowers the risk of Alzheimer’s, MCI patients will be the most appropriate target for this therapy.”
Penn scientists also contributing to this research are Syuan Sung, Yuemang Yao, Kunihiro Uryu, Hengxuan Yang, Virginia M-Y Lee, and John Q. Trojanowski. This study was funded by the National Institutes of Health, The Alzheimer Association, and the American Heart Association.
Dr. Pratico, can be contacted at domenico@spirit.gcrc.upenn.edu or 215-898-6446.
For a printer friendly version of this release, click here.
# # #
PENN Medicine is a $2.2 billion enterprise dedicated to the related missions of medical education, biomedical research, and high-quality patient care. PENN Medicine consists of the University of Pennsylvania School of Medicine (founded in 1765 as the nation’s first medical school) and the University of Pennsylvania Health System (created in 1993 as the nation’s first integrated academic health system).
Penn’s School of Medicine is ranked #2 in the nation for receipt of NIH research funds; and ranked #4 in the nation in U.S. News & World Report’s most recent ranking of top research-oriented medical schools. Supporting 1,400 fulltime faculty and 700 students, the School of Medicine is recognized worldwide for its superior education and training of the next generation of physician-scientists and leaders of academic medicine.
Penn Health System consists of four hospitals (including its flagship Hospital of the University of Pennsylvania, consistently rated one of the nation’s “Honor Roll” hospitals by U.S. News & World Report), a faculty practice plan, a primary-care provider network, three multispecialty satellite facilities, and home health care and hospice.
