Salivary Peptide Protects Against E. Coli Diarrhea

MedicalResearch.com Interview with:

Esther Bullitt, Ph.D. Associate Professor Dept. of Physiology & Biophysics Boston University School of Medicine Boston, MA  02118-2526

Dr. Bullitt

Esther Bullitt, Ph.D.
Associate Professor
Dept. of Physiology & Biophysics
Boston University School of Medicine
Boston, MA  02118-2526 

MedicalResearch.com: What is the background for this study?

Response:      We know that saliva has properties that allow us to swallow easily, and to help prevent gum disease and infections in the mouth. But is that really the only use for the 1-2 liters (1-2 quarts) of saliva we produce every day?  We decided to test whether a component of saliva, Histatin-5, can help prevent diarrheal disease (Traveler’s Diarrhea by Enterotoxigenic Escherichia coli (ETEC)) that is caused by bacteria commonly found in contaminated food and water.

ETEC are bacteria that have hundreds of thin hair-like fibers on their surface, called pili. These bacteria bind specifically to the surface of the gut using these pili, and the bacteria need to stay bound long enough to initiate disease. Studies by Mike Levine’s group in the 1970’s showed that pili are necessary for enterotoxigenic Escherichia coli (ETEC) to cause disease. No adhesion, no disease.

One aid to remaining bound is the unwinding and rewinding of the pili. These helical fibers can unwind up to 8 times their original length, acting as shock absorbers during fluid flow.   Continue reading

Substances in Spit May Help Wounds Heal Faster

Substances in Spit May Help Wounds Heal Faster

MedicalResearch.com Interview with:
Vicente A. Torres PhD

Associate Professor
Institute for Research in Dental Sciences
Faculty of Dentistry
Universidad de Chile 

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Wounds in the oral cavity heal faster and more efficiently than skin. This is in part due to saliva. However, the reasons underlying these differences remain poorly known. Since blood vessel formation (i.e. angiogenesis) is critical to the success and efficiency of wound healing, we focused our studies on the effects of saliva, and specifically the salivary molecule, histatin-1, on angiogenesis.

Our studies showed that histatin-1 promotes angiogenesis, as observed in experiments performed at three “levels”:

1) using human cell cultures (endothelial cells, which are cells that form blood vessels),

(2) using chicken embryos, as animal models, and

(3) analyzing saliva samples obtained from healthy donors.

With all these models, histatin-1 and saliva were found to increase blood vessel formation. In addition, our studies provide information about the molecular mechanisms (i.e. signaling pathways) whereby endothelial cells respond towards histatin-1, by increasing their migration and adhesion to the extracellular matrix.

Continue reading