Antioxidants May `Filter' Smoking Damage

BOSTON--Adding antioxidants to cigarette filters may reduce the amount of free radical damage incurred by the smoker, according to two in vitro studies presented by Theodore Hersh, M.D., and Wendy Barkin of Atlanta-based Thione International at the American Association for the Advancement of Science (AAAS) annual meeting. The antioxidant blend, called Thione Antioxidant Complex(TM), is a proprietary blend manufactured by Thione International (www.thione.com).

Free radical damage caused by cigarette smoke affects proteins, DNA and lipids, and can lead to atherosclerosis, chronic lung disease and cancer, according researchers from the University of California, Berkeley. However, the intake of antioxidants may prevent smoking-related diseases by combating this oxidative damage (Cancer Epidemiol Biomarkers Prev, 11, 1:7-13, 2002).

According to two studies conducted by Hersh, president of Thione International, and colleagues, there may be a way to limit the amount of damage caused by cigarette smoke. "We're in a pilot right now whereby our patented complex is being manufactured through tobacco filters for cigarettes so that as the cigarette is consumed, the smoke from the tobacco basically enters through that filter," explained Gary Falconbridge, vice president of marketing at Thione International. "The complex actually absorbs many of these harmful chemicals."

The first study presented at the AAAS meeting indicated that treating smoke with Thione Antioxidant Complex--which is comprised of L-glutathione, N-acetyl-L-cysteine and L-selenomethionine microencapsulated in liposomes--may reduce human cell death after exposure to cigarette smoke. The in vitro study indicated that fetal fibroblasts survived 95 percent and 100 percent of the time after 24 and 48 hours of exposure to antioxidant-treated smoke, as compared to 60 percent and 77 percent survival after exposure to untreated smoke. In addition, human lymphocyte survival averaged 100 percent and 15 percent after 20 and 80 minutes of exposure to antioxidant-treated smoke as compared to 65 percent and 8 percent survival after exposure to untreated smoke.

The second in vitro study presented at the AAAS meeting indicated that cigarette smoke treated with the same antioxidant complex may reduce the amount of damage done to human salivary proteins, which may be responsible for oral cancer. Researchers collected saliva samples from non-smokers and exposed it to treated and untreated cigarette smoke. Damage to the saliva proteins exposed to untreated smoke was significantly higher than the damage incurred by saliva proteins exposed to treated smoke. Researchers concluded that antioxidant complex in the filter of a cigarette can neutralize oxidants and damaging agents to salivary proteins.

"As a physician, I know that people can't or won't quit [smoking]," Hersh said. "If you can't get them to quit, one of my responsibilities as a physician is at least to lessen their risks of developing diseases related to tobacco. ... Knowing that smokers develop millions of free radicals, and the person smoking inhales many of these free radicals, we opted to see whether we could reduce the harmful effects of these free radicals even before they're inhaled by the smoker."