Methylsulfonylmethane (MSM), a white, tasteless crystalline powder, is already a favored supplement in the horse industry. Years before any scientific evidence supported its use, it had earned a reputation for helping alleviate many of the symptoms of muscle soreness and arthritis in horses.
As researchers began to examine MSM more closely, it appeared increasingly likely that this simple compound (essentially, dimethyl sulfoxide, or DMSO, with one extra oxygen atom attached) really did have the ability to assist athletic horses.

Wendy O’Neill, president of the Nutraceutical Alliance (NA), called on one of Guelph’s orthopedic researchers to more closely examine MSM’s effects on equine joints. Mark Hurtig, DVM, MVSc, Dipl. ACVS, presented the results of his study on the use of natural-source MSM for the maintenance and protection of equine articular cartilage at the recent NA symposium.

Hurtig used equine joint cartilage samples maintained in an explant culture (living tissue from an organism transferred to an artificial medium), and exposed them to inflammatory processes simulating what happens when arthritis starts to degrade a joint. Half of the samples were cultured in the presence of Alavis-brand MSM, and half were given no MSM. Several parameters of the inflammatory process were measured, including the production of a hormone called prostaglandin E2 (PGE2), the release of glycosaminoglycans (GAGs, components of cartilage in the cartilage matrix of a healthy joint), and the production of nitric oxide (a free radical, the reduction of which would indicate that MSM acts as an antioxidant).

“There are many claims for the efficacy of MSM in various disease processes,” he said. “What they have in common is inflammation. MSM’s chemical relative, DMSO, is known for its anti-inflammatory properties, so we wanted to see whether MSM had the ability to protect cartilage from known inflammatory triggers or mediators. And if so, we wanted to see just how it reduced the inflammation.”

According to the results, MSM did nothing to suppress nitric oxide production, and had only a mild ability to inhibit cartilage GAG loss. But when it came to the prostaglandin PGE2, MSM clearly showed an ability to suppress its production. “It had a significant effect,” Hurtig said. “Based on these results, I’d say there’s good evidence for MSM having a preventive effect on the development of arthritis in the joints, as well as a therapeutic effect on existing inflammation.”

An interesting note to Hurtig’s work was that MSM had surprising efficacy at very low concentrations, on the scale of 1-100 nanograms per milliliter. Noted Hurtig, “There aren’t many drugs with an effect at a level as small as that.” This information might eventually lead to revisions in dosage recommendations for horses.