Figure 2.

Antioxidant activity of C. siliqua extracts. (A–C) Comparative assessment of the radical-scavenging activity of akin extracts, from both varieties, based on the inhibition of 2,2-Diphenyl-1-Picrylhydrazyl (DPPH) absorbance 35 min postaddition (n ≥ 2); 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox) (200 μM) served as the positive radical scavenger. (D,E) Intracellular antioxidant activity of carob extracts, based on 2′,7′-dichlorofluorescein (DCF) fluorescence quenching; in (D), basal intracellular reactive oxygen species (ROS) levels of normal human fibroblasts (AG01523) 210 min after 2′,7′-dichlorodihydrofluorescein diacetate (DCFH-DA) addition are depicted (n = 3); in (E), elevated ROS levels an hour after H₂O₂ addition, at a final concentration of 160 μΜ, are shown (n = 2); in both (D,E), vehicle (DMSO) served as negative control (C) and Trolox (T) at 100 μM served as positive control. (F) Intracellular glutathione (GSH) levels of human fibroblasts pretreated with carob extracts at the highest noncytotoxic dose of 200 μg/mL (Table S1) under normal oxygen tension and hypoxic conditions, respectively (n ≥ 3); vehicle (DMSO) served as negative control (C) and N-acetylcysteine (NAC) at 10 mM served as positive control. Bars represent mean values ± SD. * p < 0.05; ** p < 0.01 (Student’s t-test). Control values were set to 100%.