Novel N-chloroacetyl-2-pyrazoline analogs with 2-naphthyl and ferrocenyl groups: targeting histamine receptor H1 to overcome colorectal cancer drug resistance

Aim: This study investigates the anticancer activity of naphthalene- and ferrocene-based 2-pyrazolines against colorectal cancer (CRC) cell lines and assesses their potential to overcome chemotherapy resistance. Methods: Several 2-pyrazoline derivatives were synthesized and tested for anticancer activity across various cell lines, including p53 wild-type (WT) and knockout (KO) colon cancer cells and vinblastine-resistant KB-V1 cervix carcinoma cells. Compounds Clac10 (5c) and Clac12 (5e) were studied for their effects on colony and spheroid formation, cell cycle, and apoptosis. Molecular docking and cellular thermal shift assays explored their binding to histamine receptor H1 (HRH1). In vivo antitumor efficacy was tested on HCT116 xenografts in NSG mice. Results: Compounds Clac10 and Clac12 significantly inhibited the proliferation of both p53 WT and KO colon cancer cells, as well as drug-resistant KB-V1 cells. When combined with 5-fluorouracil (5-FU), they showed synergistic antiproliferative effects in HCT and DLD1 cells. These compounds reduced colony and spheroid formation, induced cell cycle arrest, and promoted apoptosis by downregulating cyclin D1 and antiapoptotic proteins B-cell lymphoma-extra large (Bcl-XL), B-cell lymphoma 2 (Bcl-2), myeloid cell leukemia 1 (Mcl-1). Molecular docking and thermal shift assays confirmed binding to HRH1, affecting histamine-induced extracellular signal-regulated kinase (ERK) and glycogen synthase kinase 3 beta (GSK3B) signaling. In vivo, Clac10 significantly reduced HCT116 xenograft growth, decreased Ki-67 and phosphorylated-glycogen synthase kinase 3 beta (p-GSK3B) levels, and increased cleaved caspase-3. Conclusion: Naphthalene-based 2-pyrazoline compounds Clac10 and Clac12 showed a potent anticancer activity against colon cancer lines. They inhibit tumor growth by targeting HRH1 signaling, indicating potential as CRC therapies and resistance-overcoming agents. Further studies are needed to explore their clinical potential.