Modified chemical extracts from the Laminaria hyperborea algae (shown here) have the potential to counter joint cartilage breakdown, a new study suggests.
Image credit: Sergey S. Dukachev
Currently, osteoarthritis (OA) is considered to be the most common joint disease across the United States, affecting more than 30 million adults. It usually affects people later in life, and its symptoms are stiff, swollen, and painful joints, as well as increasing difficulty in moving.
At the moment, there is no cure for OA, and treatments only target the management of symptoms. Management strategies often include minding weight gain, physical therapy, and prescription and over-the-counter painkillers. Sometimes, surgery is required to replace over-damaged joints.
New research led by Prof. Marcy Zenobi-Wong, from the Eidgenössische Technische Hochschule (ETH), and Dr. Katharina Maniura, from Empa - both in Zürich, Switzerland - now suggests that we should look at brown algae for a cure.
The researchers' findings were published in the journal Biomaterials Science.
Extract from algae could stall arthritis
Experiments in vitro have revealed that polysaccharide alginate derivatives extracted from stems of brown algae called Laminaria hyperborea, also known as "tangle" or "cuvie," might be able to put a stop to joint cartilage deterioration. The properties of these derivatives are similar to those of extracellular cartilage molecules.
"Alginate, which is derived from brown algae, has been used as a culture system for cartilage cells for many years. In our study alginate has been chemically modified ("sulfated") to be a better mimic of the body's natural polysaccharides that are also present in cartilage," Dr. Maniura explained for Medical News Today.
The team experimented with sulfated alginate derivatives to see how they would act on relevant cell cultures. They noticed that alginate sulfate has antioxidant properties, meaning that it can counter oxidative stress, which leads to cell death. Alginate molecules to which more sulphate groups had been attached, the scientists saw, were more effective in reducing oxidative stress.
Alginate sulfate also exhibited immune-modulatory properties, allowing it to regulate inflammatory triggers at cell level. The researchers observed that alginate sulfate could decrease the expression of genes that promote inflammatory reactions in chondrocytes, which are cartilaginous cells, as well as in macrophages, which are immune system cells that "eat" cellular debris and foreign bodies.
In the case of immunomodulation, once more, the alginate molecules were more effective if they had more sulphate groups attached to them.
These antioxidant and immune-modulatory properties suggest that sulfated alginate derivatives are able to stall the deterioration of joint cartilage. "The hope is that they can even stop this degeneration," suggests co-author Dr. Markus Rottmar, of Empa.
Still a long way to go
"Traditional therapies for treating OA are based on the non-targeted administration of general anti-inflammatory molecules, such as non-steroidal anti-inflammatory drugs (NSAIDs), steroids, and hyaluronic acid, which can limit the pain but do not affect the disease outcome," explain the researchers.
The development of a clinical solution targeting the disease itself, rather than its symptoms, would greatly improve quality of life and allow people diagnosed with this condition to avoid complications that might lead to disability and joint replacement surgery.
A potential alginate treatment, as envisaged by the researchers, would be fairly uncomplicated and would significantly impact the evolution of the disease.
"We envision, if further research is successful, that [the alginate] would be applied in a similar way as currently used viscosupplementation [supplementation of the natural lubricating fluid in the knee joint], namely injected into the affected joint."
Dr. Katharina Maniura
Nevertheless, the scientists warn that this is only the beginning of a long and demanding research journey. Experiments in vivo will be necessary to duplicate the in vitro results, so the researchers would like to continue testing alginate sulfates on animals. They hope that they may then be able to proceed to clinical trials.
But the researchers add that even if all the experiments are successful, it will still be a matter of years until sulfated alginate derivatives will be available to treat people diagnosed with OA.