Categories
Healthy People

Nature-Made Medicine

Two recent reports from Linus Pauling Institute scientists demonstrate their ongoing efforts to understand the relationship between health and dietary compounds.

“Orthomolecular medicine is the use of the right molecules or orthomolecular substances that are normally present in the human body in the amounts that lead to the best of health and the greatest decrease in disease. It is the most effective prevention in the treatment of disease.”

—   Linus Pauling, 1983

 

Linus Pauling spent the latter years of his career at Stanford University and at the scientific institute that bears his name exploring the role of micronutrients in health, from the common cold to cancer. By the time he wrote the paragraph above, he had received two unshared Nobel Prizes and had become well known for his advocacy of vitamin C mega-doses. Today, his legacy lives on through the Ava Helen and Linus Pauling Papers Collection, the Linus Pauling Institute (LPI) and a new 105,000-square-foot science center at Oregon State University.

Two recent reports from LPI scientists demonstrate their ongoing efforts to understand the relationship between health and dietary compounds.

Green Tea for the Immune System

Green tea drinkers may be on to something. Scientists have found that a beneficial compound in the ancient beverage has a powerful ability to increase the number of “regulatory T cells” (a type of white blood cell) that play a key role in immune function and suppression of autoimmune disease. This may be one of the underlying mechanisms for the health benefits of green tea, which has attracted wide interest for its ability to help control inflammation, improve immune function and prevent cancer.

Emily Ho's research focuses on naturally occuring compounds that play a role in cell regulation. Better understanding of these processes could lead to treatments for cancer and other diseases. (Photo: Kelly James)
Emily Ho's research focuses on naturally occuring compounds that play a role in cell regulation. Better understanding of these processes could lead to treatments for cancer and other diseases. (Photo: Kelly James)

“This appears to be a natural, plant-derived compound that can affect the number of regulatory T cells, and in the process improve immune function,” says Emily Ho, an LPI principal investigator and associate professor in the OSU Department of Nutrition and Exercise Sciences. “When fully understood, this could provide an easy and safe way to help control autoimmune problems and address various diseases.”

The immune system performs a delicate balancing act between attacking unwanted invaders and protecting normal cells. In autoimmune diseases, which can range from simple allergies to terminal conditions such as Lou Gehrig’s disease, this process goes awry, and the body mistakenly attacks itself.

Some cells exist primarily to help control that problem and dampen or “turn off” the immune system, including regulatory T cells. The number and proper function of those regulatory T cells, in turn, are regulated by other biological processes such as transcription factors and DNA methylation.

In this study, scientists exposed laboratory mice to a compound in green tea called epigallocatechin gallate, or EGCG, which has both anti-inflammatory and anti-cancer characteristics. They found that mice with higher EGCG levels had a higher production of regulatory T cells. Its effects were not as potent as some of those produced by prescription drugs, but it also had few concerns about long-term use or toxicity.

“EGCG may have health benefits through an epigenetic mechanism, meaning we aren’t changing the underlying DNA codes, but just influencing what gets expressed, what cells get turned on,” Ho says. “And we may be able to do this with a simple, whole-food approach.”

The findings were published in Immunology Letters, a professional journal. Co-authors included scientists from OSU, the University of Connecticut and Changwon National University in South Korea. The National Institute of Environmental Health Sciences and the OSU Agricultural Experiment Station supported the work.

Tea consumption was also the focus of one of the LPI’s most frequently cited papers. In 2003, scientists Jane Higdon and Balz Frei, LPI director, published a survey of studies on tea and the incidence of cancer, coronary heart disease and other illnesses.

For the Love of Cauliflower

If you ever needed a reason to eat broccoli, Brussels sprouts or cauliflower, consider sulforaphane. Ho and other LPI scientists have shown for the first time that this phytochemical can selectively target and kill prostate cancer cells while leaving normal cells healthy and unaffected.

The findings are another important step forward for the potential use of sulforaphane in cancer prevention and treatment. Clinical prevention trials are already under way for its use in these areas, particularly prostate and breast cancer.

It appears that sulforaphane, which is found at fairly high levels in cruciferous vegetables, is an inhibitor of histone deacetylase, or HDAC enzymes. HDAC inhibition is one of the more promising fields of cancer treatment and is being targeted from both a pharmaceutical and dietary approach, scientists say.

“It’s important to demonstrate that sulforaphane is safe if we propose to use it in cancer prevention or therapies,” says Ho, lead author on the study. “Just because a phytochemical or nutrient is found in food doesn’t always mean it’s safe, and a lot can also depend on the form or levels consumed,” Ho adds. “But this does appear to be a phytochemical that can selectively kill cancer cells, and that’s always what you look for in cancer therapies.”

The findings were published in Molecular Nutrition and Food Research, a professional journal. The research was supported by the National Cancer Institute, National Institute of Environmental Health Sciences and the OSU Agricultural Experiment Station.

Previous OSU studies done with mouse models showed that prostate tumor growth was slowed by a diet containing sulforaphane.