Nav: Home

Coffee bean extracts alleviate inflammation, insulin resistance in mouse cells

October 11, 2019

URBANA, Ill. - When coffee beans are processed and roasted the husk and silverskin of the bean are removed and unused, and often are left behind in fields by coffee producers.

Food science and human nutrition researchers at the University of Illinois are interested in the potential of inflammation-fighting compounds found in the silverskin and husk of coffee beans, not only for their benefits in alleviating chronic disease, but also in adding value to would-be "waste" products from the coffee processing industry.

A recent study, published in Food and Chemical Toxicology, shows that when fat cells of mice were treated with water-based extracts from coffee beans skins, two phenolic compounds--protocatechuic acid and gallic acid--in particular reduced fat-induced inflammation in the cells and improved glucose absorption and insulin sensitivity.

The findings show promise for these bioactive compounds, when consumed as part of the diet, as a strategy for preventing obesity-related chronic illnesses, such as Type 2 diabetes and cardiovascular disease.

"In my lab we have studied bioactive compounds from different foods, and have seen the benefits for the prevention of chronic diseases," says Elvira Gonzalez de Mejia, professor of food science in the College of Agricultural, Consumer and Environmental Sciences at U of I, and co-author of the study. "This material from coffee beans is interesting mainly because of its composition. It's been shown to be non-toxic. And these phenolics have a very high anti-oxidant capacity."

For the study, the researchers looked at two types of cells, macrophages (immune response cells) and adipocytes (fat cells), and the effect of the combined compounds from the extracts, as well as the individual pure phenolics, on adipogenesis--the production and metabolism of fat cells in the body--and the related hormones. They also looked at the effect on inflammatory pathways.

When obesity-related inflammation is present, the two types of cells work together--stuck in a loop--to increase oxidative stress and interfere with glucose uptake, worsening the situation.

In order to block this loop and prevent chronic disease, the researchers' goals are to eliminate or reduce as much inflammation as possible in order to allow glucose uptake to be facilitated, as well as to have healthy cells that will produce adequate insulin.

Miguel Rebollo-Hernanz, a visiting scholar in de Mejia's lab, and lead author of the study, explains how the results provide insights into the mechanism of action of these extracts and pure compounds, and their potential efficacy for future studies in humans or animals.

For the study, the fat cells and immune cells were cultured together to recreate the "real-life" interaction between the two cells.

"We evaluated two extracts and five pure phenolics, and we observed that these phenolics, mainly protocatechuic acid and gallic acid, were able to block this fat accumulation in adipocytes mainly by stimulating lipolysis [the breakdown of fats], but also by generating 'brown-like' or 'beige' adipocytes," Rebollo-Hernanz explains.

Significantly, these "brown-like" cells are known as fat burners, and they contain more mitochondria, an important organelle in cells that turns nutrients into energy. In the study, the researchers observed that some phenolics were able to stimulate browning of the fat cells, increasing the content of mitochondria in adipocytes, or fat cells.

"Macrophages are present in the adipose tissue and when adipose tissue grows excessively, there are interactions that stimulate inflammation and oxidative stress," Rebollo-Hernanz says. "We saw that these phenolics were able to reduce and decrease the secretion of inflammatory factors, but also decrease oxidative stress."

When macrophages interact with fat cells, the cells have fewer mitochondria. Having less mitochondria, they lose the capacity of burning lipids. Using these phenolics, the researchers found that this impact of macrophages on the fat cells was completely blocked. The fat cells maintained their function.

"The compounds we tested were able to inhibit inflammation in the macrophage. That means inhibiting many markers that produce inflammation to the adipocytes. Those were blocked," de Mejia says. "Coming to the adipocytes themselves, we saw inhibition of different markers related to inflammation as well. Absorption of glucose was improved because the glucose transporters were present. And this went back and forth.

"Now we know that in the presence of these compounds we can reduce inflammation, reduce adipogenesis, and decrease the 'loop' that helps the two types of cells grow and develop bad compounds that will negatively affect the whole system," she adds.

The researchers also stressed the positive impact on the environment of using the coffee bean by-products.

During coffee processing, the bean is separated from the husk, the external outer layer of the bean. After the bean is roasted, the silverskin layer is separated. "It's a huge environmental problem because when they separate this husk after processing, it usually stays in the field fermenting, growing mold, and causing problems," de Mejia explains. Worldwide 1,160,000 tons of husk are left in fields per year, potentially causing contamination.

Additionally, 43,000 tons of silverskin is produced each year, which, de Mejia adds, may be easier to utilize because it stays with the bean as it is exported to different countries to be roasted.

"Once producers see the value, they will treat these materials as an ingredient instead of a waste," de Mejia says. "It will require good collaboration between academic institutions, industry, and the public sector to solve this problem, but the market is there for these products."
-end-
The paper, "Phenolic compounds from coffee by-products modulate adipogenesis-related inflammation, mitochondrial dysfunction, and insulin resistance in adipocytes, via insulin/PI3K/AKT signaling pathways," is published in Food and Chemical Toxicology [DOI: 10,1016/j.fct.2019.110672]. Co-authors of the study include Miguel Rebollo-Hernanz, Qiaozhi Zhang, Yolanda Aguilera, Maria A. Martin-Cabrejas, and Elvira Gonzalez de Mejia. Also, a continuation of this research was published in Antioxidants 2019, 8, 279. https://www.mdpi.com/2076-3921/8/8/279.

De Mejia is a professor in the Department of Food Science and Human Nutrition, and director of the Division of Nutritional Sciences, all in the College of ACES at University of Illinois.

Funding was provided by the USDA-NIFA HATCH (project 1014457) and the Ministry of Economy and Competitiveness, SUSCOFFEE project (AGL2014-57239-R).

University of Illinois College of Agricultural, Consumer and Environmental Sciences

Related Mitochondria Articles:

Unexpected insights into the dynamic structure of mitochondria
As power plants and energy stores, mitochondria are essential components of almost all cells in plants, fungi and animals.
Mitochondria are the 'canary in the coal mine' for cellular stress
Mitochondria, tiny structures present in most cells, are known for their energy-generating machinery.
Master regulator in mitochondria is critical for muscle function and repair
New study identifies how loss of mitochondrial protein MICU1 disrupts calcium balance and causes muscle atrophy and weakness.
Oxygen deficiency rewires mitochondria
Researchers slow the growth of pancreatic tumor cells.
Self-cannibalizing mitochondria may set the stage for ALS development
Northwestern Medicine scientists have discovered a new phenomenon in the brain that could explain the development of early stages of neurodegeneration that is seen in diseases such as ALS, which affects voluntary muscle movement such as walking and talking.  The discovery was so novel, the scientists needed to coin a new term to describe it: mitoautophagy, a collection of self-destructive mitochondria in diseased upper motor neurons of the brain that begin to disintegrate from within at a very early age.
Uncovering the presynaptic distribution and profile of mitochondria
In a recent study published in the Journal of Neuroscience, scientists from the MPFI and the University of Iowa CCOM have provided unprecedented insight into the presynaptic distribution and profile of mitochondria in the developing and mature calyx of Held.
Temple researchers identify new target regulating mitochondria during stress
Like an emergency response team that is called into action to save lives, stress response proteins in the heart are activated during a heart attack to help prevent cell death.
Runaway mitochondria cause telomere damage in cells
Targeted damage to mitochondria produces a 'Chernobyl effect' inside cells, pelting the nucleus with harmful reactive oxygen species and causing chromosomal damage.
Interplay between mitochondria and nucleus may have implications for new treatment
Mitochondria, the 'batteries' that produce our energy, interact with the cell's nucleus in subtle ways previously unseen in humans, according to research published today in the journal Science.
Dissolving protein traffic jam at the entrance of mitochondria
Researchers from Freiburg discovered a novel mechanism that ensures obstacle-free protein traffic into the powerhouse of the cell.
More Mitochondria News and Mitochondria Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Teaching For Better Humans 2.0
More than test scores or good grades–what do kids need for the future? This hour, TED speakers explore how to help children grow into better humans, both during and after this time of crisis. Guests include educators Richard Culatta and Liz Kleinrock, psychologist Thomas Curran, and writer Jacqueline Woodson.
Now Playing: Science for the People

#556 The Power of Friendship
It's 2020 and times are tough. Maybe some of us are learning about social distancing the hard way. Maybe we just are all a little anxious. No matter what, we could probably use a friend. But what is a friend, exactly? And why do we need them so much? This week host Bethany Brookshire speaks with Lydia Denworth, author of the new book "Friendship: The Evolution, Biology, and Extraordinary Power of Life's Fundamental Bond". This episode is hosted by Bethany Brookshire, science writer from Science News.
Now Playing: Radiolab

Dispatch 3: Shared Immunity
More than a million people have caught Covid-19, and tens of thousands have died. But thousands more have survived and recovered. A week or so ago (aka, what feels like ten years in corona time) producer Molly Webster learned that many of those survivors possess a kind of superpower: antibodies trained to fight the virus. Not only that, they might be able to pass this power on to the people who are sick with corona, and still in the fight. Today we have the story of an experimental treatment that's popping up all over the country: convalescent plasma transfusion, a century-old procedure that some say may become one of our best weapons against this devastating, new disease.   If you have recovered from Covid-19 and want to donate plasma, national and local donation registries are gearing up to collect blood.  To sign up with the American Red Cross, a national organization that works in local communities, head here.  To find out more about the The National COVID-19 Convalescent Plasma Project, which we spoke about in our episode, including information on clinical trials or plasma donation projects in your community, go here.  And if you are in the greater New York City area, and want to donate convalescent plasma, head over to the New York Blood Center to sign up. Or, register with specific NYC hospitals here.   If you are sick with Covid-19, and are interested in participating in a clinical trial, or are looking for a plasma donor match, check in with your local hospital, university, or blood center for more; you can also find more information on trials at The National COVID-19 Convalescent Plasma Project. And lastly, Tatiana Prowell's tweet that tipped us off is here. This episode was reported by Molly Webster and produced by Pat Walters. Special thanks to Drs. Evan Bloch and Tim Byun, as well as the Albert Einstein College of Medicine.  Support Radiolab today at Radiolab.org/donate.