Nitrovanillin derivative ameliorates AGE-RAGE nexus associated inflammation: A step towards the amelioration of vascular complications under diabetic environment

Introduction: Advanced glycation endproducts (AGEs) are implicated in various pathological conditions, including diabetes, inflammation, and cardiovascular diseases. Methylglyoxal (MGO), a potent glycation agent, leads to the formation of MGO-derived AGEs, which promote structural and functional anomalies in various cellular and tissues proteins. AGEs stimulate the proliferation of monocytes, and induce a pro-inflammatory state through AGE-RAGE interactions, triggering oxidative stress, and inflammatory condition that contribute to the progression of atherosclerosis, and other diabetic complications. Objective: The current study was aimed to explore the antioxidant and anti-inflammatory properties of a series of novel antiglycation compounds, nitrovanillin derivatives, by modulating the AGEs-stimulated intracellular signaling pathways involved in inflammation. Methods: The preliminary safety profile of nitrovanillin derivatives was assessed by using human hepatocytes (HepG2), and monocytes (THP-1) cell lines via MTT, and WST-1 assays, respectively. Antioxidant activity of the compounds was determined by using DCFH-DA technique. Western blotting, immunocytochemistry, and ELISA methods were employed to assess the levels of pro-inflammatory markers (RAGE, COX-1, COX-2, NF-kappa B, and PGE2) in MGO-AGEs stimulated THP-1 monocytes. Result: Among the nitrovanillin derivatives 1-11, only compound 2, ((E)-2-methoxy-6-nitro-4-(((2-(tri- fluoromethyl)phenyl)imino)methyl)phenol), was found non-toxic to HepG2, and THP-1 cells. Compound 2 lowered the MGO-AGEs-induced reactive oxygen species (ROS) production by inhibiting the upstream signaling of NADPH oxidase and MAPK-p38, which subsequently inhibited the NF-kappa B activation in THP-1 monocytes. Compound 2 also reversed the AGEs-mediated COX-1 suppression, COX-2 upregulation, and PGE2 production by blocking the AGE-RAGE ligation in THP-1 monocytes. Conclusion: In conclusion, nitrovanillin 2 ((E)-2-methoxy-6-nitro-4-(((2-(trifluoromethyl)phenyl)imino)methyl) phenol) is a potential candidate for mitigating MGO-AGEs mediated vasculopathy by the inhibition of AGERAGE-p38/NF-kappa B nexus in THP-1 monocytes. It may offer a therapeutic option for the patients with diabetes and chronic inflammatory vascular complications, and thus offering new avenues for treatment development.