Turmeric, also known as “the golden spice,” has been around for more than 4,000 years. In India, where Radha Ayyagari, Ph.D., grew up, it’s used widely as both a food spice and an herbal medicine for treating a variety of diseases, including cancer, arthritis, urinary-tract infections and digestive disorders. It has been scientifically established that curcumin, the active ingredient in turmeric, is a potent antioxidant. So it’s perhaps no surprise that Dr. Ayyagari, a professor of ophthalmology at the University of California, San Diego, is developing an extract from turmeric that may be useful in slowing retinal degeneration.
Years ago, while reviewing scientific literature, Dr. Ayyagari discovered that curcumin is a catalyst for producing heat shock proteins, or HSPs, which play an important role in ensuring proper cell function. As so-called cellular chaperones, HSPs help prevent the misfolding of other proteins that occurs in the photoreceptors of people with autosomal dominant retinitis pigmentosa (adRP).
Photoreceptors, or rods and cones, are the retinal cells that enable us to see properly. With adRP, usually one parent is affected and has a mutated gene that causes the disease. In turn, his or her child has a 50 percent chance of inheriting the mutated gene. Dr. Ayyagari, an FFB-funded researcher who’s also a member of the Foundation’s Scientific Advisory Board, believes that curcumin may be able to help slow the vision loss associated with adRP.
Not long ago, she tested her hypothesis in a lab by adding curcumin to cultured cells that have the P23H mutation of the rhodopsin gene. Also known as RHO, it’s the gene that provides instructions for making a protein called rhodopsin, which is needed for normal vision. The P23H dominant mutation is one of the most common causes of adRP. Dr. Ayyagari also administered curcumin to a rodent model of the disease, and results from both studies were positive, showing that curcumin helps stall vision loss.