Newswise – For centuries people around the world have used herbal remedies to fight infections, stimulate wound healing, and for religious ceremonies. And for centuries, scientists have tried to identify the active substances of these plants in order to use them in modern medicine.
Today, researchers at the University of Copenhagen studied an Australian desert plant and found a substance that appears to counteract resistance to a specific type of chemotherapy.
âCancer cells sometimes develop an ability to fight off the drug, chemotherapy, used to treat patients. We have found a substance in a plant that appears to inhibit the ability of cancer cells to defend themselves against chemotherapy, that is, to develop resistance to chemotherapy. The plant is only found in Australia and is traditionally used by indigenous people, âsays Malene J. Petersen, PhD student, Department of Drug Design and Pharmacology.
The natural substance isolated by researchers is a so-called flavonoid. In the laboratory, they tested the substance on human cancer cells in combination with SN-38, which is the active substance of the drug Irinotecan used to fight for example against aggressive lung cancer and colon cancer. The results showed that a combination of the natural substance and chemotherapy was able to inhibit the ability of cancer cells to fight the drug.
âCancer cells resistant to SN-38 produce a large amount of a protein responsible for transporting the drug out of the cancer cell, a so-called efflux pump. This natural substance isolated from the Australian plant is able to inhibit this pump, which makes it difficult for the cancer cell to eliminate the drug effectively, âexplains Professor Dan StÃ¦rk, who supervised the project.
The plant in the new study belongs to the eremophile genus, comprising about 230 species, found only in the Australian deserts. The name eremophile precisely means love the desert.
âAn impressive collaboration across continents made this research project possible. We got help from a retired Australian botanist, who traveled 55,000 kilometers across dry western Australia to collect plants. And a colleague from the University of Melbourne helped us perform DNA analysis of the plans to help us predict which plants were worth studying. Finally, colleagues from the University of Copenhagen explored the potential to sustainably produce bioactive substances in the future using synthetic biology, âexplains Dan StÃ¦rk.
Many anti-cancer drugs come from plants
70 percent of all cancer drugs come directly from nature or are derived from substances found in nature. Therefore, the new finding does not surprise the researchers behind the study.
Nine out of ten cancer deaths are due to resistance to cancer drugs. When a cancer patient does not respond to treatment or experiences a so-called relapse after treatment, it is most often because cancer cells have learned to defend themselves against the drug by producing a large number of efflux pumps.
âWe already have products that inhibit the efflux pump. But they don’t work optimally because they aren’t specific enough and can have a lot of side effects. We also believe that we can find compounds that work even better than the substance we discovered here. That is why we are now going to start looking for similar substances in other plants, âexplains Professor Dan StÃ¦rk.
âInterestingly, antibiotic resistant bacteria, for example, appear to produce large amounts of nearly identical efflux pumps, making them extremely efficient at pumping antibiotics out of cells. This natural substance, the flavonoid, targets this specific pump protein, which makes us speculate whether it may also play a role in the treatment of antibiotic resistance, âexplains Malene J. Petersen.
Growing interest in the sustainable production of natural medicines
The chemicals used to produce the majority of modern medicines are made from fossil fuels. Therefore, interest in nature’s active substances is steadily increasing. The United States Food and Drug Administration still approves many natural products or analogues as drugs. The latter are synthetic substances which are almost identical to the natural substance.
âThe idea is to take the knowledge of traditional medicine, which has been passed down from generation to generation over thousands of years, and use cutting-edge technology to determine which substances are active and which genes in plants. which code for the production of these active substances. In the long term, this will allow us to sustainably produce future drugs through synthetic biology, âexplains Professor Dan StÃ¦rk.