In this study we investigated the effects of
glycine on angiogenesis during embryogenesis, wound healing and
tumor growth. In chorioallantoic membrane (CAM) assay,
glycine (100 microM) inhibited angiogenesis by more than 50%. We studied dietary
glycine's effect on
fibrin induced wound healing response in a novel (
Fibrin Z-chamber) assay.
Fibrin within the chamber triggers the healing cascade leading to formation of granulation tissue (GT) rich in blood vessels and stroma. GT was reduced by more than 30% (p < 0.0001) in dietary
Glycine groups as compared to control. We found that microvessel density dropped significantly (15%, p < 0.0003) with dietary
glycine whereas the other components of GT were unaffected. We evaluated
tumor growth delay utilizing
Tumor Z-Chamber (
fibrin with R3230 mammary
adenocarcinoma cells) since
tumors take advantage of angiogenesis and matrix formation. We observed that
tumor growth decreased by 15% (p < 0.03) and
tumor microvessel density dropped by 20% (p < 0.03) with dietary
glycine compared to controls. We found that iNOS
protein levels were decreased significantly in both GT (24%-57%) and
tumor tissue (19-75%). In conclusion, we found that dietary
glycine is a potent anti-angiogenic agent that can reduce wound healing and
tumor growth through reduction of iNOS expression.