Synthesis and anti-tumor activity of piperonal substituted chalcone

Objectives: Chalcones have been identified as potential antitumor agents with a novel target, the tubulin. The aim of the study was to synthesize a piperonal substituted chalcone and evaluate its in vivo antitumor activity. Materials and Methods: Piperonal substituted chalcone was synthesized using Claisen-Schmidt condensation and characterized using various spectroscopic techniques. The lethal dose (LD50) of the synthesized compound was estimated using OECD-425 guidelines in rats. Antitumor activity of the synthesized compound was evaluated on 1-methyl nitrosourea (MNU)-induced mammary tumor in female Wistar rats. Histological evaluation was used to confirm tumor induction and assess treatment with the synthesized compound. The possible mechanism of action of the synthesized compound was elucidated in silico using molecular docking. Results: The compound was synthesized and named C2. C2 was found to be relatively safe with LD50 >2000 mg/kg orally. Moreover, C2 exhibited remarkable antitumor activity, at all the tested doses in a dose dependent manner. Histological evaluation of the MNU-induced mammary tumor rats treated with C2 displayed fewer signs of hyperplasia and small numbers of connective tissue with larger lobules when compared with the untreated group. In silico tubulin-binding interactions revealed that the kinetics of C2 binding to tubulin was like that of colchicine. Comparison of crystal structures of tubulin-C2 and tubulin-colchicine complexes showed that the binding mode of C2 to tubulin was like that of colchicine to tubulin and produced the same conformational changes on the tubulin structure as colchicine. Conclusion: The synthesized chalcone demonstrated remarkable antitumor activities in MNU-induced mammary tumors in rats possibly through inhibition of tubulin polymerization.