"We enriched preharvest broccoli with different bioactive components, then assessed the levels of cancer-fighting enzymes in rats that ate powders made from these crops," said Elizabeth Jeffery, a U of I professor of food science and human nutrition.
The highest levels of detoxifying enzymes were found in rats that ate selenium-treated broccoli. The amount of one of the cancer-fighting compounds in broccoli was six times higher in selenium-enriched broccoli than in standard broccoli powder, she said.
Selenium-treated broccoli was also most active in the liver, reaching a level of bioactivity that exceeded the other foods used in the experiment.
"We were intrigued to find that selenium initiated this amount of bioactivity," she said.
Along with garlic and other plants of the allium family, broccoli and other plants of the brassica family are unique in having a methylating enzyme that enables plants to store high concentrations of selenium, she said.
"Our bodies need a certain amount of selenium, but many areas of the world, including parts of the United States and vast areas of China, have very little selenium in the soil," she said.
"Not only could selenium in broccoli deliver this necessary mineral, it also appears to rev up the vegetable's cancer-fighting power," she added.
Jeffery is now working to determine whether selenium compounds are directly responsible for the increase in bioactivity or if selenium acts indirectly by directing new synthesis of the broccoli bioactives called glucosinolates.
In a previous study, Jeffery and U of I colleague John W. Erdman Jr. showed that tomato and broccoli powders eaten together are more effective in slowing prostate cancer in laboratory rats than either tomato or broccoli alone.
In their current research, they are experimenting with ways to increase the bioactive components in these foods in order to test the efficacy of enriched broccoli and tomatoes in a new prostate cancer study.
Rats were fed diets with food powders containing 10 percent of either standard broccoli; standard tomato; lycopene-enriched tomato; tomato enriched with lycopene and other carotenoids; broccoli sprouts, which contain very high levels of cancer-fighting compounds; or broccoli grown on soil treated with selenium.
The scientists found that greater amounts of bioactive components in the food powders translated into increased levels of the compounds in body tissue and increased bioactivity in the animals.
Carotenoid-enriched tomatoes produced more bioactivity in the liver than lycopene-enriched or standard tomatoes, yielding the most cancer-preventive benefits.
"Carotenoids, which are phytochemical pigments found in fruits and vegetables, are thought to be excellent antioxidants and effective in cancer prevention," said Ann G. Liu, a U of I graduate student who worked on the study.
"A good rule is: the brighter the color, the higher the carotenoid content. If you're growing or buying tomatoes, select plants or produce that are a very bright red. High-lycopene tomatoes are now available through garden catalogs," she added.
"This research shows that you can greatly increase a food's bioactive benefits through normal farming practices, without resorting to genetic engineering. Farmers have traditionally been more concerned about yield than nutritional composition. Now we're asking, can we grow more nutritional broccoli and tomatoes? And the answer is a definite yes," said Jeffery.
The study was published in the Journal of Agricultural and Food Chemistry. Liu and Sonja E. Volker co-authored the paper with Jeffery and Erdman.
Phyllis Picklesimer | EurekAlert!
Kakao in Monokultur verträgt Trockenheit besser als Kakao in Mischsystemen
18.09.2017 | Georg-August-Universität Göttingen
Ultrasound sensors make forage harvesters more reliable
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Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
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