World Cancer Day: how the UAE's ancient yusor tree could help kill cancer cells

Researchers found the tree may have anti-cancer properties

The yusor tree, common to the Gulf, has a variety of uses, the next of which could be helping to fight cancer. Photo: supplied

Researchers hope to have made a cancer breakthrough with its roots in nature after discovering that a tree native to the UAE could help the body to stem the spread of the disease.

The yusor tree has been a supportive presence in the region for hundreds of years, providing traditional medicines and a fruitful supply of oil for the ancient Egyptians and Jordan’s Bedouin.

Now the tree — known scientifically as Moringa peregrina — could be a key resource in the modern age because of its potential cancer cell-killing properties.

During laboratory tests, researchers at UAE University in Al Ain found that extracts of the tree were able to prevent breast cancer cells and colon cancer cells from proliferating. The extracts also killed the cancer cells.

One extract from leaves and stems was described by the researchers in the journal Horticulturae as showing a “remarkable” ability to prevent cells proliferating and to cause apoptosis, a programmed form of cell death.

The tests were carried out on cancer cell lines, which are populations of cells, originally derived from human tumours, that proliferate when grown in the laboratory.

“From this current work, it can be concluded that Moringa peregrina possesses strong anti-cancerous activity against breast cancer cells and colon cancer cells, which might be due to the presence of promising anti-cancer compounds in the tuber, leaves and stem of the plant,” the researchers wrote.

Study shows great promise

Dr Abdul Jaleel, an associate professor at UAE University and the study’s senior author, said extensive work went into the study.

“We did the study using various parts of the plant extracted with different solvents to understand the effects of all portions of the plant, and almost all extracts showed the effectiveness, but the chloroform extracts showed tremendous activity against the growth of the cancer cells,” he said.

The scientists carried out the research, which was supported by a grant from UAEU, because a related tree, Moringa oleifera, has previously been found to have anticancer properties.

To further understand the anti-cancer properties of Moringa peregrina, the various chemicals in the extracts need to be separated and analysed.

“To identify the compounds in the crude extract or the fraction will help to identify which compound or group of compounds impacts on the death of the cancer cells. Clinical studies are also required after the isolation of the particular compound,” said Prof Ayesha Al Dhaheri, another lead author in the UAEU study.

Exciting possibilities for research

According to Prof Michael Heinrich, a University College London professor of ethnopharmacology and pharmacognosy (the study of medicinal plants), who is not connected to the new study, “many plant extracts” show an ability to combat cancer cells in the laboratory.

“What will come out of it we don’t know yet, but it’s an interesting starting point — exciting and relevant,” he said of the new research.

“It is not yet a study which can result in therapeutic uses of Moringa peregrina, but one that offers possible leads for future research.”

He said there was wide interest across the globe, including in the Middle East, in researching “bioactive” compounds found in plants.

As reported previously in The National, efforts have been made in the UAE to develop methods to propagate the yusor tree, which could help to preserve a species that has faced pressure from overgrazing and development.

Plants contain a “rich diversity” of chemical substances, said Dr Veronique Seidel, who leads the Natural Products Drug Discovery Group at the University of Strathclyde Glasgow in the UK.

Some, known as secondary metabolites because they are not directly involved in how the plant grows, develops and reproduces, may influence the growth of neighbouring plants, attract pollinators or protect against herbivores, pests and pathogens.

“These secondary metabolites have naturally evolved to interact with biological targets,” said Dr Seidel, who also was not connected to the UAE study.

“This explains why they are exploited for the discovery and development of new medicines, including anti-cancer drugs.”

She said that many plant secondary metabolites were able, simultaneously, to target different mechanisms involved in cancer formation, growth and invasion.

“They have been reported to activate normal cell defences against carcinogens, reduce the production of growth factors, induce cancer cell death, inhibit the formation of blood vessels required for cancerous tissue growth, as well as reduce cancer-associated inflammation,” Dr Seidel added.

Research reaches key stage

The researchers at UAE University are now trying to isolate and identify the substances that may have anti-cancer properties.

In doing so they are following the lead of many other researchers, because there are numerous medicines derived from plants being used to combat the disease.

A well-known example is the anti-cancer medicine Taxol, also called Paclitaxel, which was isolated from a type of yew tree more than half a century ago and approved for medical use in the early 1990s.

It is given intravenously as a chemotherapy medication against ovarian cancer, breast cancer, lung cancer and pancreatic cancer, among other types of cancer.

Although first identified from a plant, Taxol is produced “biosynthetically” using cell cultures, as is often the case with medications of plant origin.

In other instances, said Prof Heinrich, actual plant extracts, rather than a single known substance purified from plants, are used to combat disease.

This may be because it is too expensive to extract the individual substance, because the substance is unstable when extracted or because the extract contains many substances that have effects.

“You have a combination of effects — different compounds [in the plant extract] target different compound in the human body,” he said.

As well as plants, many other organisms, including microbes and marine sponges, have also been sources of useful substances.

“This highlights the importance of preserving the natural world for future generations to be able to exploit it treasures,” Dr Seidel said.