Anticoagulant, antioxidant and cytotoxic potential of cinnamic acid and derivatives.

INTRODUCTION: Since antiquity, natural products have been widely used to relieve symptoms and prevent numerous diseases. Early treatments for vascular disorders, including thrombosis, relied heavily on plant-derived substances, which later served as prototypes for the development of platelet aggregation inhibitors and coagulation-modulating agents. Among these bioactive constituents, phenolic compounds-abundantly found in various botanical sources-have gained prominence due to their well-established antioxidant properties and reported anticoagulant effects. Recent studies highlight that the structural diversity of phenolic acids, particularly cinnamic acid (CA) and its derivatives, offers a valuable chemical scaffold for developing new therapeutic agents targeting thrombogenesis and oxidative imbalance.

OBJECTIVE: This study aimed to evaluate, in vitro, the pharmacological (anticoagulant and antioxidant) and toxicological (oxidant and cytotoxic) activities of cinnamic acid (CA) and five synthetic derivatives-4HDCN, 4MTCN, 3,4DHCN, 3,4DMCN, and 3H4MCN.

METHODS: Anticoagulant activity was assessed using a semi-automated coagulometer by measuring clotting time after exposure of human plasma to each molecule. Antioxidant, oxidant, and cytotoxic (hemolytic) activities were determined using human erythrocytes from blood groups A, B, and O. Oxidative and antioxidant responses were quantified by spectrophotometry following exposure to phenylhydrazine as a pro-oxidant inducer. Hemolysis was evaluated at concentrations ranging from 0 to 400 mg/dL.

RESULTS: In the anticoagulant assays, the derivative 3,4DHCN exhibited the strongest activity, prolonging clotting time to 176.6 s, slightly surpassing 3,4MTCN (165.6 s). All molecules demonstrated low or negligible oxidizing activity (<7.1%). Regarding antioxidant potential, 4MTCN showed the most effective protection against phenylhydrazine-induced oxidation, reducing oxidative damage to 8.7%. None of the tested compounds induced moderate or high hemolysis at concentrations up to 200 mg/dL. However, at 400 mg/dL, CA and 4HDCN produced high hemolytic rates across erythrocyte types. In type A cells, hemolysis reached 89.4% (CA) and 76.0% (4HDCN); in type B, 64.3% and 60.5%; and in type O, 90.1% and 70.7%, respectively.

CONCLUSION: Dihydroxylated and dimethoxylated cinnamic acid derivatives demonstrated notable anticoagulant activity, minimal oxidative effects, low antioxidant capacity, and an absence of cytotoxicity in human erythrocytes at therapeutically relevant concentrations. These findings indicate that such molecules represent promising candidates for the development of new anticoagulant agents with favorable safety profiles.