Scientists at The University of Texas Health Science Center have reported that a combination of resveratrol, grape seed extract, calcium D-glucarate and ellagic acid may suppress damage that can cause skin cancer. The scientists believe that this research can be used in the future to develop supplements, creams and sunscreens to prevent skin cancer.
The materials, which were derived from natural plant sources according to the scientists, included: resveratrol from the skin of red grapes; grape seed extract; calcium D-glucarate, a salt of D-glucaric acid, which is present in the human bloodstream and in many fruits and vegetables; and ellagic acid from a host of berries and walnuts. It was noted in the study that the combination was needed due to the different mechanisms of action for each substance.
The substances were tested on mice that had been genetically manipulated to be sensitive to skin cancer initiation and promotion/progression.Thomas Slaga, PhD, the team leader, developed SENCAR, the mouse model of skin cancer. He and colleagues Zbigniew Walaszek, PhD, and Magdalena Kowalczyk, PhD, found that the combination of substances, even at low doses protected the skin from skin cancer formation.
The scientists administered the agents both topically and in a diet. In one study, the team induced skin cancer by shaving the backs of rodents and applying a chemical that produces a genetic mutation. This was done twice a week for four weeks. At the same time, researchers applied topical resveratrol and fed the mice diets supplemented with various combinations of the plant substances.
The team evaluated several outcomes, including thickness in the outer layer of the skin. An increase in thickness indicates that precancerous cells are multiplying. Researchers also monitored mutations in Ha-ras, an oncogene that is a biomarker of cancer initiation, and inflammation, which is important in tumor promotion. Even low doses of plant agent combinations produced protective effects, while the plant substances given individually produced markedly less benefit.
The researchers noted that the substances can be effective on cancers other than skin cancer such as lung cancer. They found that the substances can aid in the prevention of skin cancer and other epithelial cancers in humans, specifically those that have smoked or sunbathed.
The team continues to look for the best combinations of the natural agents in suppressing different events during skin cancer development. They are going to use an UVB light model of skin cancer initiation and confirm their results. The ongoing work is supported by two grants from the National Institutes of Health.