Bee stings have long been known to relieve some of the symptoms of rheumatoid arthritis, but only now has the reason for this been clarified.

Bee venom contains a number of protein-like compounds, among them a substance called melittin. This substance appears to inactivate a key regulator of several inflammatory genes, researchers report in the journal Arthritis and Rheumatism.

The findings are based on a study of rats with two types of experimentally induced arthritis. Dr. Jin Tae Hong, from Chungbuk National University in South Korea, and colleagues note that bee venom had anti-arthritic effects in both sets of animals.

Both bee venom and melittin decreased the amount of three substances that cause inflammation and which are turned on and off by a cellular regulator called NF-kappa-B.

Further testing showed that bee venom and melittin bind to NF-kappa-B, blocking its ability to turn on production of the inflammatory regulators.

“The extent of the inhibitory effects of melittin in most parameters is similar to or greater than those of bee venom itself,” the researchers write, “suggesting that melittin may be a major causative component in the pharmacologic effects of bee venom.”

SOURCE: Arthritis and Rheumatism, November 2004.