Thursday September 18 2014
Chokeberries are found in woods and swamps in North America
“Wild berries native to North America may have a role in boosting cancer therapy,” BBC News reports.
It has been found – in a laboratory study using pancreatic cancer cells – that chokeberry extract may help increase the powers of chemotherapy drugs in treating pancreatic cancer.
Researchers tested an extract of chokeberry – a plant found on the eastern side of the continent – on pancreatic cancer cells. They examined what happened to these cells in the laboratory when they were treated with chemotherapy alone, chokeberry extract alone, or with a combination of both.
Researchers found that adding the chokeberry extract to gemcitabine (a chemotherapy drug used in the treatment of pancreatic cancer) was more effective at halting the growth of cancer cells than the drug alone.
Pancreatic cancer is a condition with notoriously poor prognosis, and the possibility of any new treatment on the horizon is encouraging. However, it is uncertain whether these positive lab results would translate to a real-world setting. It is expected that, based on these promising results, further studies will look into the possibility of human trial(s).
For now, people with pancreatic cancer should not consider taking these chokeberry extracts or supplements, based on this very early-stage research. "Herbal remedies" should never be assumed to be safe, and some can react unpredictably with chemotherapy drugs.
Where did the story come from?
The study was carried out by researchers from Middlesex University, University of Southampton, Portsmouth University and Kings College Hospital. It was funded by the Malaysian Ministry of Higher Education and a US charitable organisation called Have a Chance Inc.
The study was published in the peer-reviewed Journal of Clinical Pathology.
The BBC’s coverage was fair, pointing out that research was at an early stage and including independent comments from cancer experts on the need for human trials. The Daily Telegraph’s coverage only included comments from the study’s authors.
What kind of research was this?
This was a laboratory study, with scientists having conducted various experiments examining the effect of adding extracts of chokeberry to pancreatic cancer cells.
The researchers point out that pancreatic cancer has a very poor outlook and a high mortality rate, with only 1-4% of those with the cancer surviving to five years. Only 10-20% of people with pancreatic cancer are suitable for surgery, and pancreatic cancer cells are resistant to both chemotherapy and radiotherapy.
Researchers say that many studies have explored the use of dietary agents, particularly antioxidant substances called polyphenols, found in fruits and vegetables. This is because of their ability to promote apoptosis – programmed cell death – in a variety of cancer cells. Previous studies have also shown that a number of polyphenols, including those from chokeberry extracts, have potential anticancer properties in malignant brain tumours.
Chokeberry (aronia melanocarpa) is a shrub found in North American wet woods and swamps. Extracts and supplements are popular for their apparent health-giving qualities, including their high level of antioxidants.
What did the research involve?
Researchers used a line of pancreatic cancer cells called AsPC-1, which were cultured in the laboratory. In a number of experiments, they assessed how well the cells grew when treated with:
- the chemotherapy drug gemcitabine alone at different doses (gemcitabine is one of the drugs sometimes given to people after they have had surgery to remove their pancreatic cancer, to try and prevent it returning)
- differing levels of chokeberry extract
- a combination of gemcitabine with chokeberry extract
They also carried out experiments to examine how chokeberry extract might cause the death of cancer cells, and at what concentration it caused cell death. As a control, they also tested chokeberry extract on the healthy cells that line blood vessels. These are taken from the veins of the umbilical cord and are often used in laboratory studies.
What were the basic results?
Researchers found that gemcitabine in combination with chokeberry extract was more effective at killing cancer cells than gemcitabine by itself. This difference in effect was also present when using lower doses of gemcitabine.
The analysis indicated that when incubated with gemcitabine for 48 hours, a concentration of one microgram per millilitre of chokeberry extract was required to induce cell death. Generally, the higher the concentration of chokeberry extract used in combination with gemcitabine, the more cancer cells were killed.
However, chokeberry extract alone without gemcitabine was not effective at killing the cancer cells at the concentrations tested.
Healthy cells were unaffected by chokeberry extract up to a concentration of 50 micrograms per millilitre.
How did the researchers interpret the results?
The researchers say that chokeberry extract and other micronutrients should be considered as part of cancer therapy. More specifically, they suggest that elements in chokeberry extract may have “supra-additive effects” when used in combination with at least one conventional anti-cancer drug.
In an accompanying press release, Bashir Lwaleed, at the University of Southampton, comments: "These are very exciting results. The low doses of the extract greatly boosted the effectiveness of gemcitabine when the two were combined. In addition, we found that lower doses of the conventional drug were needed, suggesting either that the compounds work together synergistically [where the whole is greater than the sum of its parts], or that the extract exerts a "supra-additive" effect. This could change the way we deal with hard-to-treat cancers in the future. "
It is now commonly thought that the antioxidants found in fruits and vegetables may have many health benefits, including reducing the risk of some cancers.
Pancreatic cancer is a condition with notoriously poor prognosis, and the possibility of any new treatment on the horizon is encouraging. This study found that when pancreatic cancer cells in the laboratory were directly treated with a combination of the chemotherapy drug gemcitabine and chokeberry extract, adding the extract enhanced the cancer-killing potential compared to the chemotherapy drug alone.
However, directly adding an extract to cells in the laboratory is a lot different from people actually taking chokeberry extracts themselves. Though these are promising findings, it is too early to say whether the micronutrients found in this extract could be effective in the treatment of pancreatic cancer. Further scientific study will be needed before initial developments could progress to the next stage of trials in people with pancreatic cancer, to see whether chokeberry extract might enhance the effects of chemotherapy.
For now, as experts importantly highlight, people with pancreatic cancer should not consider taking these chokeberry extracts in the form of a herbal remedy or supplement, based on this very early-stage research.
Herbal remedies, just like pharmaceutical medicines, will have an effect on the body and can be potentially harmful.
They should therefore be used with the same care and respect as pharmaceutical medicines. Being "natural" doesn't necessarily mean they're safe to take.
Read more about herbal medicines and supplements.
Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.