Vitamin D May Halt Lung Function Decline In Asthma And COPD
Vitamin D May Halt Lung Function Decline In Asthma And COPD
May 20th, 2009 by Valerie ChavezScienceDaily (May 20, 2009) —
Vitamin D may slow the progressive decline in the ability to breathe
that can occur in people with asthma as a result of human airway smooth
muscle (HASM) proliferation, according to researchers at the University
of Pennsylvania.
The group found that calcitriol, a form of vitamin D synthesized
within the body, reduced growth-factor-induced HASM proliferation in
cells isolated from both persons with asthma and from persons without
the disease. The proliferation is a part of process called airway
remodeling, which occurs in many people with asthma, and leads to
reduced lung function over time.
The researchers believe that by slowing airway remodeling, they can
prevent or forestall the irreversible decline in breathing that leaves
many asthmatics even more vulnerable when they suffer an asthma attack.
"Calcitriol has recently earned prominence for its anti-inflammatory
effects," said Gautam Damera, Ph.D., who will present the research at
the American Thoracic Society's 105th International Conference in San
Diego on May 20. "But our study is the first to reveal the potent role
of calcitriol in inhibiting ASM proliferation."
The experiments were conducted with cells from 12 subjects, and the
researchers compared calcitriol with dexmethasone, a corticosteroid
prescribed widely for the treatment of asthma. Although, dexmethasone
is also a powerful anti-inflammatory agent, the researchers found that
it had little effect on HASM growth.
Dr. Damera and his colleagues found calcitriol inhibits HASM in a
dose-dependent manner, with a maximum inhibitory effect of 60 percent ±
3 percent at 100nM.
As part of the University of Pennsylvania's Airway Biology
Initiative, the researchers are planning a randomized control trial of
calcitriol in patients with severe asthma and expect to have data from
the trial in about a year's time.
With its anti-inflammatory qualities and its ability to inhibit
smooth muscle proliferation, Dr. Damera said, calcitriol may become an
important new therapy, used alone or in combination with already
prescribed steroids, for treating steroid-resistant asthma.
Dr. Damera and his colleagues have also conducted experiments to
determine the mechanism by which calcitriol retards HASM proliferation.
They believe the vitamin works by inhibiting activation of distinct set
of proteins responsible for cell-cycle progression.
The investigators have also conducted experiments to determine
whether calcitriol, which is currently used to treat psoriasis, could
be an effective therapy for COPD. Although preliminary, their data
shows that calcitriol appears to reduce pro-inflammatory cytokine
secretions in COPD. As with asthma, the researchers believe, calcitriol
may also have the added benefit of slowing, if not stopping, the
progression of airway remodeling. Others in the field believe
calcitriol may also have the potential to inhibit the development and
growth of several types of cancer.
LINK: http://www.sciencedaily.com/releases/2009/05/090520114657.htm
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