Broccoli als behandeling bij COPD*
Uit een Amerikaanse studie blijkt dat de bioactieve stof sulforafaan in
broccoli kan zorgen voor duidelijk positief effect op het immuunsysteem in de longen en zorgt voor
flink minder ontstekingen van de longen. Sulforafaan kan de longen beschermen tegen negatieve invloeden van buitenaf en helpt het immuunsysteem schadelijke bacteriën uit de longen te verwijderen. Het verergeren van de klachten door een bacteriële longinfectie is een veelvoorkomende klacht bij
COPD. In de longen van COPD patiënten
is minder activiteit door de transcriptiefacor Nrf2 waardoor te weinig
antioxidanten aangemaakt worden door het lichaam om de schade door de bacteriën
te kunnen herstellen. Uit de studie blijkt dat sulforafaan Nrf2 duidelijk doet
activeren. De huidige behandelingen zijn vaak gericht op het bestrijden van symptomen en het ondersteunen van de patiënt. Geen enkele behandeling beïnvloedt het onderliggende defect in de longen, wat de klachten veroorzaakt.
Broccoli compound may combat COPD
In chronic obstructive pulmonary disease (COPD), damage to immune cells limits the lungs’ ability to fight off bacterial infections. According to a new study, boosting the activity of a specific molecule in these cells can restore their defensive powers. In patients with COPD, immune cells called macrophages lose their ability to engulf and remove bacteria, making the lungs more vulnerable to infection. Until now, no one knew how to reverse this damage to the macrophages.
A team of scientists at Johns Hopkins University, led by Drs. Shyam Biswal and Robert Wise, investigated why macrophages don’t work properly in COPD patients. Previous research suggested that a process called oxidative stress might be to blame. Oxidative stress occurs when the body can’t effectively neutralize damaging compounds called peroxides and free radicals.
A molecule called Nrf2 can cause cells to make more antioxidants, which neutralize these harmful compounds. Previous studies found reduced Nrf2 activity in severe COPD. The scientists suspected that increasing Nrf2 activity might restore the ability of macrophages to remove bacteria. To test their theory, the team used a chemical called sulforaphane, which is known to activate Nrf2. A precursor of sulforaphane is found in broccoli. The research was cosponsored by NIH’s National Heart, Lung and Blood Institute (NHLBI) and National Institute of Environmental Health Sciences (NIEHS). The results appeared in the April 13, 2011, issue of Science Translational Medicine.
The researchers first took macrophages from the lungs of patients with moderate COPD. When they treated these macrophages with sulforaphane, they saw higher Nrf2 levels in the cells. Sulforaphane treatment also boosted the ability of cultured macrophages to clear 2 of the major types of bacteria that infect COPD patients. Macrophage uptake of bacteria rose 300% after treatment, whether the cells came from smokers or non–smokers. Experiments in mouse and human cells revealed that sulforaphane, through Nrf2, increases levels of a receptor called MARCO on macrophages. MARCO activity was necessary for macrophages to engulf bacteria after sulforaphane treatment. Mice exposed to smoke had lower levels of MARCO. Furthermore, smoke-exposed mice genetically engineered to lack Nrf2 had more lung inflammation and higher levels of bacteria.
The team gave sulforaphane with a nebulizer to mice exposed to smoke and found that the mice’s lungs showed reduced inflammation and bacterial burden. The researchers also gave human COPD patients broccoli sprout extract enriched with sulforaphane for 2 weeks. The patients taking the extract had higher levels of MARCO and Nrf2–controlled antioxidants in their blood cells. A NHLBI–sponsored clinical trial is now being conducted to test if sulforaphane can provide relief to patients with COPD.
(April 2011)
Reacties:
