Anti-angiogenic and anti-oxidant effects of 2-NTI indole derivative vs. suramin in ex vivo, in vivo, and in vitro studies

Angiogenesis is an intricate pathway that involves the formation of new blood capillaries from old, functioning ones. Improper angiogenesis is a feature of numerous maladies, including malignancy and autoimmune disorders. Indole-related derivatives are believed to interfere with the mitotic spindle, inhibiting the multiplication, and invasion of cancerous human cells. 5-bromo-2-(5-(4-nitrophenyl)-4H-1,2,4-triazol-3-yl)-1H-indole (2-NTI) is one of such compounds with outstanding anti-angiogenic, and anti-proliferative properties. To evaluate 2-NTI’s antiangiogenic and anti-oxidant activities and potential mechanisms of action in comparison with the standard agent, suramin. The rat aortic ring (RAR) and Chick chorioallantois membrane (CAM) assays were employed to determine antiangiogenic efficacy and dose response, while the DPPH assay estimated free radical scavenging activity. Besides, an MTT test was performed to evaluate antiproliferative activity in HUVECs; however, RT-PCR assessed the gene expression level of VEGF in HCT116 cells. 2-NTI displayed a significant and dose-dependent suppression of angiogenesis (83.04%) at 100 μg/mL concentration versus the negative controls in the RAR assay. 2-NTI also showed no toxicity in the HUVEC cell line, with an IC50 of 876.6 μg/mL, but it significantly reduced the formation of free radicals (IC50 of 135.2 µg/mL) and VEGF gene expression (at doses of 200 and 400 µg/mL) versus the negative controls and suramin. In CAM model, 2-NTI generated considerable blood vessel regression as compared to the negative control. 2-NTI possesses potent anti-angiogenic actions, which might be explained by its profound anti-proliferative and free radical detoxifying activities.