Cissus verticillata Leaf Extract Decreases the Production of AGEs and ROS In Vitro

Cissus verticillata (plant-insulin) is used in the Brazilian popular medicine to treat symptoms of diabetes. Studies about its ability to contrast glycoxidative stress is lacking, which may add mechanistic information about its effects on treat diabetic complications. This study investigated the ability of Cissus verticillata leaf hydroethanolic extract (CvExt) to scavenge reactive oxygen species (ROS) and to inhibit the formation of advanced glycation end products (AGEs). ROS scavenging assays were used to test CvExt antioxidant activity. Incubations of bovine serum albumin with glucose (0.5 M) or methylglyoxal (2 mM) and CvExt (250, 125, and 62.5 μg/mL) were used to test the antiglycation activity, by monitoring fluorescent AGEs, markers of amino acid oxidation, and protein carbonyl groups (PCO). The plant extract was submitted to liquid-liquid extractions, fractions were analyzed by liquid chromatography with tandem mass spectrometry, and the data obtained were subjected to partial least-squares discriminant analysis. CvExt scavenged ROS inhibited the formation of AGEs and amino acid oxidation products, and decreased PCO levels. The main metabolites found in CvExt were flavonoids, cinnamic acid derivatives, coumarins, free amino acids, and some lipophilic compounds. CvExt inhibited glycoxidative stress in vitro, which can be associated with its complex chemical composition.