ABSTRACT

This study aims to reveal the effects of acyclovir on angiogenesis and to assess the experimental doses.

In the study, the chick chorioallantoic membrane model was used as an experimental model. Forty fertilized eggs were kept at 85-90% relative humidity, below 37°C until the fifth day post-fertilization, when the vessels in the chick chorioallantoic membrane model appeared and the drugs were applied. Four different concentrations of acyclovir were chosen to determine the mode of action and dose dependence: 3.55 mg/mL, 7.1 mg/mL, 14.2 mg/mL, and 28.4 mg/mL. Each of the 1 mL total acyclovir concentrations were applied to the chick chorioallantoic membrane surfaces. The chick chorioallantoic membranes treated with sterile distilled water were designated as controls. Eight eggs were used for each test group. After applying the drug, all the eggs were covered with transparent tape and kept under the same conditions throughout the experiment. The results were evaluated 48 hours after the drugs were administered and the results were recorded with a digital camera.

In our study, it was observed that 3.55 mg/mL acyclovir concentration shows the reduced density of capillaries around the pellet and no change in the number of capillaries. Both 7.1 mg/mL and 14.2 mg/mL concentrations of acyclovir caused a local reaction that was restricted to the membrane and it was attributed to local crystallization reaction. The concentration of 28.4 mg/mL had a toxic effect on the eggs.

In this study, it was found that acyclovir has a very weak anti-angiogenic effect dose-dependently at the concentrations used. Considering that an observational model was used in our study, quantitative studies are needed for assessing anti-angiogenic effects in the future. There is also a need for further studies to elucidate the effects of acyclovir on vascular endothelial growth factor level and which stage of the angiogenesis-related process it is specifically effective on.

Keywords: Angiogenesis, acyclovir, chorioallantoic membrane, endothelial cells