Researchers have figured out how fly larvae works as a healing balm that’s been used by battlefield surgeons for centuries to close wounds.
The scientists published their findings in the journal Wound Repair and Regeneration. Maggots suppress the immune system. They consume dead tissue, leaving healthy tissue practically unscathed. Physicians have been using larvae to clean wounds for a long time. The use of penicillin in the 1940s made clinical maggots less useful, but in the 1990s, when antibiotic-resistant bacteria arose, it created a new demand for alternative treatments. In 2004, the FDA approved maggot therapy as a prescription treatment.
Until now, no one had scientifically tested the idea that maggots curb inflammation. A team in the Netherlands siphoned samples of maggot secretions from disinfected maggots in the lab. Then, they were added to blood samples from four healthy adults. The levels of complement proteins were measured. These are involved in the body’s inflammatory response.
Every blood sample treated with maggot secretions showed lower levels of complement proteins than control samples. It was up to 99.9% in the best cases. The researchers also found the broken-down remnants of two complement proteins, C3 and C4, in the secretion-treated samples, suggesting that the secretions had ripped the proteins apart.
When the researchers tested blood samples from postoperative patients, they discovered that maggot secretions reduced the levels of complement proteins by 19% to 55%. The team tested the maggot secretions again after a day, a week and a month to test their shelf life. They also boiled some. The secretions were more effective after boiling, and lost no potency even after a month.
If the secretions didn’t suppress the immune system, the larvae would probably be attacked by the body. The team is now working on isolating the complement-inhibiting compounds.
Reference: “Maggot excretions affect the human complement system” by Gwendolyn Cazander MD, PhD; Marco W. J. Schreurs PhD; Lennaert Renwarin; Corry Dorresteijn; Dörte Hamann PhD and Gerrolt. N. Jukema MD, PhD, 30 October 2012, Wound Repair and Regeneration.