The vasculo-toxic effect of meglumine antimoniate (MA) was confirmed in our previous investigation. The current study investigates the association of this effect with altered VEGF-A and VEGF-R2 expression. Additional mechanisms by which MA causes vascular toxicity are not clearly understood. We hypothesized that MA may alter normal expression of apoptotic genes and cause vascular toxicity. The current investigation was designed to address this issue using a chick embryo model. Fertile chicken eggs were treated with MA and the extra-embryonic membrane (EEM) vasculature was evaluated by morphometric, molecular and immunohistochemistry assays. The results showed that MA not only altered apoptotic gene expression, but that this alteration may disturb the normal development of the vascular network and cause embryo malformation. The relative expression level of the CASP3, CASP7, CASP9, APAF1, AIF1 and TP53 genes increased in drug-exposed EEMs. In addition, IHC assay confirmed the low expression BCL2 and increased expression of Bax, which are associated with a high rate of apoptosis. We suggest that induction of an apoptotic signaling pathway can lead to vascular defects during embryo development and the consecutive cascade of events can lead to the embryo malformation. (C) 2018 Elsevier Inc. All rights reserved.