Testing performed on both human subjects and rats found that modified compounds derived from the rue plant (PAP-1) and a Cuban sea anemone extract (SL5) hindered the effect of autoimmune T-cells. T-cells are lymphocytes (white blood cells) that can either regulate immune response or attack and kill invading organisms or cancer cells, depending on the type of T-cell. There are three types of T-cells, generally known as killer T cells, helper T cells, and suppressor T cells. The researchers hope that the results of this study will be helpful in developing new treatments from these compounds that will target specific cells called effector memory T lymphocytes while allowing other white blood cells in the immune system to function normally. The compounds from the sea anemone and rue plant both selectively block an ion channel, shutting down the destructive T-cells. This ion channel prevents the cells from proliferating and producing chemicals called cytokines that attack the body during autoimmune activity.
In the human study, the researchers tested blood samples from type-1 diabetes patients and joint fluid from people with rheumatoid arthritis. They found that both compounds suppressed the function of the autoimmune T-cells without affecting other T-cells that fight infections. In another set of tests using rats, the nontoxic compound from the rue shrub plant delayed the onset and reduced the incidence of disease in diabetic rats. The nontoxic sea anemone venom compound stopped the progression of the disease and improved the joint function of rats with experimental autoimmune arthritis.
This laboratory performed these studies after previously finding that the SL5 compound from the sea anemone was effective in treating rats with an experimental model of multiple sclerosis. Preclinical safety studies on PAP-1 and SL5 are under way in collaboration with AIRMID, a biotech company in the San Francisco Bay Area. The work began years ago after finding a study report describing the beneficial effect of a scorpion sting on a patient with multiple sclerosis. The researchers also noted the importance of protecting the planet’s plant and animal biodiversity as science is constantly discovering new substances and new sources to fight disease.
Heike Wulff from University of California, Davis is a co-lead author with other authors from UCI, UC Davis, Johns Hopkins University, Bachem Biosciences and the Benaroya Research Institute in Seattle. The National Institutes of Health, American Diabetes Association, Juvenile Diabetes Research Foundation, National Multiple Sclerosis Society, Arthritis National Research Foundation and David Israelsky provided support for the study.