Tag: trace elements

Categories : Cancer Diet and NutritionTags : Leave a comment

‘Eating the Rainbow’ Found to Reduce Prostate Cancer Risk and Improve Treatment

On By ModernMedia
Photo by Brad West on Unsplash

New research by scientists at the University of South Australia suggests that consumption of colourful fruits and vegetables on a regular basis reduces the risk of a prostate cancer (PC) diagnosis. These foods, rich in micronutrients, also help speed up recovery from radiotherapy for the disease.

The findings, from two studies published in the journal Cancers, highlight the importance of a Mediterranean or Asian diet that includes these foods. For the first study, researchers compared micronutrient plasma concentrations of prostate cancer patients with a healthy control group, revealing low levels of lutein, lycopene, alpha-carotene, and selenium in PC patients and high levels of iron, sulphur, and calcium in the same group, relative to controls.

The second study found increased DNA damage after radiation exposure was also associated with low lycopene and selenium in blood plasma.

Men with plasma concentrations lower than 0.25ug/mL) for lycopene and/or lower than 120ug/L for selenium have an increased risk of prostate cancer and are likely to be more sensitive to the damaging effects of radiation.

Foods that are rich in lycopene include tomatoes, melons, papayas, grapes, peaches, watermelons, and cranberries. Selenium-rich foods include white meat, fish, shellfish, eggs, and nuts.

Study co-author Dr Permal Deo says that studies show that eating foods rich in lycopene and selenium is preferable to taking supplements, where the benefits are limited.

“Our recommendation is to adopt a Mediterranean diet enlisting the help of a dietician because people absorb nutrients in different ways, depending on the food, the digestive system, the person’s genotype and possibly their microbiome,” Dr Deo says.

Prostate cancer remains one of the most common and fatal cancers in men, but the nutritional deficiencies associated with it remain largely unknown, hence this study. Other risk factors, such as ethnicity, family history and age have previously been linked to prostate cancer.

“There is strong evidence that being overweight and tall increases the risk of prostate cancer. Diets high in dairy products and low in vitamin E may also increase the risk but the evidence is less clear.”

Source: University of South Australia

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Scientists Lift the Lid on The Secret Life of Manganese

On By ModernMedia
Photo by Louise Reed on Unsplash

A new biosensor engineered by Penn State researchers offers scientists the first dynamic glimpses of the elusive – and vital – manganese ion. The researchers engineered the sensor from a natural protein called lanmodulin, which binds rare earth elements with high selectivity and was discovered five years ago by some of this study’s researchers. Their findings are published in the Proceedings of the National Academy of Sciences.

The researchers genetically reprogrammed the protein to favour manganese over other common transition metals like iron and copper, unlike most transition metal-binding molecules. The sensor could have broad applications in biotechnology to advance understanding of photosynthesis, host-pathogen interactions and neurobiology.

Like iron, copper and zinc, manganese is an essential metal for plants and animals. Its function is to activate enzymes. In humans, manganese is linked to neural development. Accumulation of excess manganese in the brain induces Parkinsonian-like motor disease, whereas reduced manganese levels have been observed in association with Huntington’s disease, the researchers explained.

“We believe that this is the first sensor that is selective enough for manganese for detailed studies of this metal in biological systems,” said Jennifer Park, a graduate student at Penn State and lead author on the paper. “We’ve used it – and seen the dynamics of how manganese comes and goes in a living system, which hasn’t been possible before.”

She explained that the team was able to monitor the behaviour of manganese within bacteria and are now working to engineer even tighter binding sensors to potentially study how the metal works in mammalian systems.

Scientific understanding of manganese has lagged behind that of other essential metals, in part because of a lack of techniques to visualise its concentration, localisation and movement within cells. The new sensor opens the door for all kinds of new research, explained Joseph Cotruvo, associate professor of chemistry at Penn State and senior author on the paper.

“There are so many potential applications for this sensor,” said Cotruvo. “Personally, I am particularly interested in seeing how manganese interacts with pathogens.”

He explained that the body works hard to restrict the iron that most bacterial pathogens need for survival, and so those pathogens instead turn to manganese.

“We know there is this tug-of-war for vital metals between the immune system and these invading pathogens, but we haven’t been able to fully understand these dynamics, because we couldn’t see them in real time,” he said, adding that with new capabilities to visualise the process, researchers have tools to potentially develop new drug targets for a range of infections for which resistance has emerged to common antibiotics, like staph (MRSA).

Designing proteins to bind to particular metals is an intrinsically difficult problem, Cotruvo explained, because there are so many similarities between the transition metals present in cells. As a result, there has been a lack of chemical biology tools with which to study manganese physiology in live cells.

“The question for us was, can we engineer a protein to only bind to one thing, a manganese ion, even in the presence of a huge excess of other very similar-looking things, like calcium, magnesium, iron, and zinc ions?” Cotruvo said. “What we had to do was create a binding site arranged in just the right way, so that this protein bond was more stable in manganese than any other metal.”

Having successfully demonstrated lanmodulin is capable of such a task, the team is now planning to use it as a scaffold from which to evolve other types of biological tools for sensing and recovering many different metal ions that have biological and technological importance.

“If you can figure out ways of discriminating between very similar metals, that’s really powerful,” said Cotruvo. “If we can take lanmodulin and turn it into a manganese-binding protein, then what else can we do?”

Source: Penn State