Alzheimer’s disease (AD) is a neurodegenerative disorder that features declines of judgment, cognition, memory, and behavior. AD is the leading cause of dementia, becoming one of the largest public health concerns. Currently, 30 million people suffer from AD, and the World Health Organization has reported that the number of patients will triple over the next 20 years.
Owing to the steady growth of the aging population; an increasing prevalence of dementia is expected in both developing and developed countries.As spring arrives in the northern hemisphere; many people are cursing ragweed, a primary culprit in seasonal allergies. But scientists might have discovered a promising new use for some substances produced by the pesky weed. In ACS’ Journal of Natural Products; researchers have identified and characterized ragweed compounds that could help nerve cells survive in the presence of Alzheimer’s disease (AD) peptides.
Amyloid precursor protein
The accumulation of Aβ peptide into senile plaques has considered one of the major causes of AD.3 Two types of Aβ peptides, Aβ40 and Aβ42, can exist outside as well as inside nerve cells. Aβ has been found to be a normal metabolite of amyloid precursor protein (APP), produced by the cleavage of APP by β-secretase and γ-secretase.4 The senile plaque mainly consists of Aβ40 and Aβ42; which can produce several types of oligomeric structures such as protofibrils, fibrils, and plaques according their extent of oligomerization.
Those with AD, a neurodegenerative disorder, often have impaired judgment, cognition; memory and behavior. Scientists have linked AD to the accumulation of amyloid-β (Aβ) peptides in the brain; which form plaques that kill nerve cells. Unfortunately, the five drugs currently approved for AD treatment only delay disease progression for a short time. When Won Keun Oh and colleagues screened 300 natural plant extracts for activity against AD in a preliminary study, they found a surprising candidate: Ambrosia artemisiifolia (common ragweed).
The neuroprotective activity
Therefore This invasive weed, native to North America, has now spread to South America, Asia and much of Europe. Oh and colleagues decided to isolate and characterize the structures of ragweed compounds responsible for this neuroprotective activity. The researchers isolated 14 compounds from whole ragweed plants that appeared to protect neurons from Aβ-induced toxicity.
They determined the structures of the compounds with nuclear magnetic resonance; mass spectrometry and other analytical techniques. Seven of the chemicals, including terpenoids and spermidine conjugates, had described previously, but the remainder newly identified terpenoids. When the researchers added the two most active new compounds to a lab dish that contained neurons producing Aβ, about 20 % more cells survived than without treatment.