August 16, 2013
Flavonoids In Celery And Artichokes Kill Cancer Cells
Brett Smith for redOrbit.com - Your Universe Online
Vegetables like celery and artichokes have long been thought to convey numerous health benefits, and a new study from scientists at University of Illinois at Urbana-Champaign revealed that these foods have two chemical components, apigenin and luteolin, known as flavonoids that are capable of killing off cancer cells.
“Apigenin alone induced cell death in two aggressive human pancreatic cancer cell lines. But we received the best results when we pre-treated cancer cells with apigenin for 24 hours, then applied the chemotherapeutic drug gemcitabine for 36 hours,” said study author Elvira de Mejia, a U of I food chemistry and toxicology professor.
The researchers found that using the two flavonoids as a pretreatment was more effective than applying them together with the chemotherapeutic drug simultaneously. In fact, applying both the drug and the flavonoids at the same time resulted in a highly undesirable effect.
“Even though the topic is still controversial, our study indicated that taking antioxidant supplements on the same day as chemotherapeutic drugs may negate the effect of those drugs,” said Jodee Johnson, a U of I researcher who worked on the study as a doctoral student in de Mejia’s lab.
“That happens because flavonoids can act as antioxidants,” she added. “One of the ways that chemotherapeutic drugs kill cells is based on their pro-oxidant activity, meaning that flavonoids and chemotherapeutic drugs may compete with each other when they’re introduced at the same time.”
In the study, which was published in the journal Molecular Nutrition and Food Research, the Illinois researchers found that apigenin blocked an enzyme called glycogen synthase kinase-3β (GSK-3β), which led to a drop in the production of anti-apoptotic genes in the pancreatic cancer cells. These genes cause a cancer cell to self-destruct because its DNA has been damaged.
In one cell line, the percentage of self-destructing cancer cells went from 8.4 percent in cells that had not been dosed with apigenin to almost 44 percent in cells that had been administered a 50-micromolar dose of the flavonoid. Chemotherapy drugs had not been used on either group of cells.
The researchers also found that apigenin modified gene expression.
“Certain genes associated with pro-inflammatory cytokines were highly upregulated,” de Mejia said.
While pancreatic cancer patients would probably not be able to eat enough celery or artichokes to boost flavonoids in the blood to an effective level, drugs or supplements could be used to achieve the desired concentrations, according to de Mejia.
The Illinois food scientist added that everyone should consider adding foods high in flavonoids to their regular diet.
“If you eat a lot of fruits and vegetables throughout your life, you’ll have chronic exposure to these bioactive flavonoids, which would certainly help to reduce the risk of cancer,” she noted.
Researchers have been looking into the anti-cancer properties of flavonoids for years. A study published in 2008 by UCLA researchers found that smokers who ate foods rich in certain flavonoids, including strawberries, brussel sprouts and apples, may reduce their lung cancer risk.