A parasitic fungus could offer an improved treatment for osteoarthritis.
This is a chronic condition, and while it is currently incurable, treatments can address some of the symptoms.
A person with osteoarthritis may benefit from taking anti-inflammatory drugs, undergoing physical therapy, and making some lifestyle changes. These interventions can help reduce pain and inflammation and improve a person's physical flexibility.
Now, researchers from the University of Nottingham in the UK have turned to a parasitic fungus that, they believe, could lead to new and better treatments for osteoarthritis.
The fungus — called Cordyceps militaris — colonizes the caterpillars of Haepialus moths, as well as other insects. Traditionally, and according to some research, C. militaris can bring many health benefits, including by acting as an anti-inflammatory.
The University of Nottingham researchers have focused, specifically, on the potential benefits of cordycepin, a compound derived from this fungus, which, they say, has a unique anti-inflammatory effect that makes it an important candidate in the treatment of osteoarthritis.
"The natural compound cordycepin is derived from a caterpillar fungus which is famous in the Far East for its medicinal properties," explains the study's lead author, associate professor Cornelia de Moor, Ph.D.
In the new research — the results of which appear in the journal Scientific Reports — de Moor and colleagues studied the effects of cordycepin in mouse and rat models of osteoarthritis and found that it can both reduce pain and stop the condition from progressing.
"Intriguingly," the researcher adds, "[the compound] does this by a different mechanism than any other known anti-inflammatory painkiller," which, she contends, "means that medicines derived from cordycepin may help patients for whom other treatments have failed."
'The founder of a new class of painkillers'
In osteoarthritis, the synovial membrane — which lines certain joints, including knee joints — becomes inflamed, which causes pain and discomfort.
Moreover, synovial inflammation happens as a result of the loss of cartilage surrounding the bones that come together in the joint, meaning that those bones become more exposed to damage.
In the current study, the research team found that, in osteoarthritis, individuals see increased expression of a protein called polyadenylation factor CPSF4, which is linked with synovial inflammation.
Essentially, CPSF4, in conjunction with other proteins, calls for the activation of macrophages, a type of immune cell that contributes to inflammation.
When the scientists administered cordycepin, orally, to the rodents with osteoarthritis, they saw that the compound blocked the mechanism set into motion by excess CPSF4 levels, and thus it suppressed inflammation.
Moreover, cordycepin also appeared to reduce pain and prevent further damage related to the progression of osteoarthritis.
Stephen Simpson, Ph.D., a researcher who specializes in immunology and inflammation and who works for Versus Arthritis, a UK-based registered charity that funded the current study, notes that the current findings may just be the game-changer that people with osteoarthritis need.
"Persistent pain is life-changing for people with arthritis. This is not good enough, and so we are delighted to support this research that has led to these fascinating findings," says Simpson.
"Although in its early stages, the study has great potential for helping people suffering [the] pain of musculoskeletal conditions, and [it] demonstrates the high value and impact of novel discovery-led research on understanding and treating diseases," he adds.
The study's authors concur, expressing hope that the compound they are studying may eventually provide better treatments with fewer side effects.
"We hope that cordycepin will prove to be the founder of a new class of painkiller: the polyadenylation inhibitors. There is a long way to go before a cordycepin-derived medicine reaches patients, but our work is very promising — we are very excited about the prospects."
Cornelia de Moor, Ph.D.