The report was delivered at the 98th General Meeting of the American Society for Microbiology, held May 17-21, 1998, in Atlanta, Georgia, USA.

Over-the-counter toothpastes and mouth rinses may kill bad breath and bacteria, but most are virtually harmless against viruses. In this study researcher Milton Schiffenbauer and colleagues \ added zinc, aloe, or grapefruit seed extract to mouthwashes, rinses, and toothpaste in an effort to prevent disease-causing microorganisms in the mouth.

"Our findings have a significant impact on oral hygiene care and its emerging role in chronic, systemic diseases, due to the fact that many viruses found in the body enter through the mouth," Schiffenbauer said in a May 20th presentation.

Schiffenbauer noted that medical researchers have recently discovered that bacterial infections in the mouth may lead to blood clots that can bring on heart attacks and strokes. The article also noted that several studies conducted since 1989 suggest that people with periodontal disease also have an increased risk of heart disease and stroke.

For the past several years, scientists in Pace University's Biology Department have conducted research on oral microbiology and viruses. Their studies found that most of a variety of oral \ agents tested for their antiviral properties were not effective, and some even protected viruses under certain conditions.

Their research focused on two viruses(bacteriophages T1 and T7, which infect Excheria coli B) that attack bacteria. Extracts of zinc, aloe, and grapefruit were separately added to toothpaste and combined in test tubes with the viruses. The loss of phage titer, as a result of these natural additives, was observed for phage stored at room temperature(25 degrees C.), at refrigeration(4 degrees C.) and at subfreezing (-12 degrees C.) temperatures.

T1 and T7 were totally inactivated after 10 minutes exposure at room temperature to NutriBiotic brand grapefruit seed extract(undiluted and 10% dilution). An appreciable decrease in T1 titer, i.e. 85% loss, was also obtained with a crude extract of grapefruit peelings.

Zinc totally inactivated both phages. T1 inactivation occurred after 10 minutes mixing at room temperature, whereas T7 inactivation occurred after one day storage under refrigeration.

Tom's of Maine toothpaste had no antiviral effect on T1 or T7 and actually protected the phages from inactivation at sub-freezing terperatures. However, in the presence of 1% zinc, the toothpaste had a very significant antiviral effect on both phages; total inactivation occurred after one day storage under refrigeration.

Substantial inactivation of both phages was obtained with purified aloe vera after two days of storage(day one under refrigeration, day two at subfreezing temperature), i.e. 88% and 95% loss of titer for T1 and T7, respectively.

A crude extract of aloe, strained or unstrained, had little, if any, effect on the phages. Tom's of Maine mouthwash which contains purified aloe vera juice totally inactivated T1 and T7 after 10 minutes of mixing at room temperature. After 10 minutes of storage at room temperature, under refrigeration and in sub-freezing conditions, T1 and T7 viruses were virtually inactivated.

"This research serves as a model to investigate viral and bacterial infections of the oral cavity," Schiffenbauer said. "Pace researchers will expand their study to include other common forms of viruses that may weaken the gums and allow entry of harmful bacteria."