Stem Cells Offer Alternative to Animals for Skin Tests
Human stem cells can be converted into skin cells and grown in 3-D culture, according to a recent publication in Stem Cell Reports. This may offer another replacement for animal tests. Until now, scientists have used cells from skin samples as an efficient alternative to animal tests for drug development and testing. However, one sample of skin provides a limited number of cells. In this report, researchers state that using stem cells allowed them to produce human skin cell cultures using a technique that can likely be scaled up so that many cultures can be produced from each sample.
This technology may represent a new source of human skin cell cultures, providing researchers with increased access to reliable, human-relevant methods for drug and cosmetics testing.
Petrova A, Celli A, Jacquet L, et al. 3D in vitro model of a functional epidermal permeability barrier from human embryonic stem cells and induced pluripotent stem cells. Stem Cell Reports. 2014;5:675-689.
New Human Liver Cell Line Promises to Increase the Accuracy of Genetic Toxicity Tests
Currently, there are several in vitro genotoxicity assays available to test for a chemical’s potential to damage genetic material. However, these assays tend to be oversensitive, with a high number of positive results that may not truly be positive. They are also often conducted in cells taken from hamsters or mice. This often leads companies to do additional animal tests for genotoxicity. Scientists have introduced a new human liver cell line in the laboratory that is able to closely mimic the metabolic activity of human livers, and they have shown that conducting genotoxicity tests with this cell line improves the tests’ accuracy. This could lead to fewer false positives and eventually replace animal tests for genotoxicity completely.
Le Hégarat L, Mourot A, Huet S, et al. Performance of Comet and Micronucleus Assays in Metabolic Competent HepaRG Cells to Predict In Vivo Genotoxicity. Toxicol Sci. 2014;138(2):300-309.
Rep. Jim Moran
Congress Introduces Landmark Ban on Animal-Tested Cosmetics
In March, Rep. Jim Moran, D-Va., introduced the Humane Cosmetics Act, a landmark bill to ban the testing of cosmetics on animals. This historic legislation would not only end animal testing for cosmetics within the United States but would also prohibit the sale of products that have been tested on animals elsewhere.
Thousands of animals are used in cosmetics tests in the U.S. each year despite the widespread availability of nonanimal alternatives. Rats, mice, guinea pigs, rabbits, and other animals endure endless chemical assaults to their skin, eyes, and internal organs and are never given any pain relief. But nonanimal methods more accurately predict human effects in much less time and at a lower cost.
This important bill would put the U.S. on the same footing as its economic competitors. The European Union has banned both cosmetic testing and the sale of cosmetics tested on animals—requiring even American companies to stop testing on animals if they want to sell to European customers. India, Israel, and parts of Brazil have followed in the EU’s footsteps. Australia has introduced a similar ban.
The Physicians Committee supports this bill and is continuing to monitor all U.S. legislative efforts on cosmetics and meet with allies and congressional staff.
Fiber Extends Life After Heart Attack
Fiber decreases the likelihood of dying after a heart attack, according to a study in the British Medical Journal. A high-fiber diet was associated with a 35 percent reduction in death from heart disease among 4,098 heart attack survivors. Fiber, especially from grains, decreases systemic inflammation, lowers bad cholesterol, improves insulin sensitivity, and enhances healthy gut flora.
Li S, Flint A, Pai JK, et al. Dietary fiber intake and mortality among survivors of myocardial infarction: prospective cohort study. BMJ. 2014;348:2659-2671.
Iron in Meat Linked to Heart Disease
Iron in meat may increase the risk of heart disease, according to a meta-analysis in the Journal of Nutrition. Researchers analyzed data from 21 international studies, which followed 292,454 participants for an average of 10 years. Heme iron (found in meat) increased risk of heart disease by 57 percent. Non-heme iron found in vegetables showed no relationship to heart disease risk or mortality.
Hunnicutt J, He K, Xun P. Dietary iron intake and body iron stores are associated with risk of coronary heart disease in a meta-analysis of prospective cohort studies. J Nutr. 2014;144:359-366.
“Paleo” Diet Bad for Cholesterol
The “Paleo” diet worsens cholesterol levels, according to a study in the International Journal of Exercise Science. Researchers put 44 healthy adults on a “Paleo” diet that included lean meat, fish, eggs, nuts, fruit, and vegetables, as well as on a circuit training program. After 10 weeks, LDL (“bad”) cholesterol increased by 12.5 mg/dL and total cholesterol by 10.1 mg/dL. Triglycerides also increased slightly. The authors noted that any improvements from the exercise program may be negated by the diet.
Smith MM, Trexler ET, Sommer AJ, Starkoff BE, Devor ST. Unrestricted Paleolithic diet is associated with unfavorable changes to blood lipids in healthy subjects. Int J Exerc Sci. 2014;7:128-139.
Fruits and Vegetables May Prevent Early Death
Increased intakes of fruits and vegetables may prevent early death, according to a review in the Journal of Epidemiology and Community Health. Researchers followed 65,226 participants from the Health Surveys for England aged 35 and older for seven years. Those who consumed seven or more servings of fruits and vegetables per day saw a 42 percent decreased risk of death from any cause, compared with those consuming the least. Fruit and vegetable consumption was associated with a 25 percent and 31 percent decreased risk of death from cancer and heart disease, respectively.
Oyebode O, Gordon-Desagu V, Walker A, Mindell JS. Fruit and vegetable consumption and all-cause, cancer and CVD mortality: analysis of Health Survey for England data. J Epidemiol Community Health. Published online March 31, 2014.
High-Fat Diet Increases Breast Cancer Risk
Women who eat diets high in fat and saturated fat increase their risk of developing breast cancer, according to a study published by the National Cancer Institute. Diet records from 337,327 women over a period of 11.5 years were analyzed for fat content. The women who consumed the most fat had a 20 percent increased risk for two breast cancer subtypes (estrogen receptor-positive and progesterone receptor-positive), and women consuming the most saturated fat faced a 28 percent increased risk for the same subtypes, compared with those who consumed the least.
Sieri S, Chiodini P, Agnoli C, et al. Dietary fat intake and development of specific breast cancer subtypes. J Natl Cancer Inst. Published online April 9, 2014.