A new cytotoxic quinolone alkaloid and a pentacyclic steroidal glycoside from the stem bark of Crataeva nurvala: study of anti-proliferative and apoptosis inducing property

Synthesis and crystal structures of D-annulated pentacyclic steroids: looking within and beyond AR signalling in prostate cancer

Carbocyclic steroids D-annulated at 16α and 17α positions with a 5-membered ring E are easily accessible via the interrupted Nazarov cyclization. Three steroid series have been structurally studied: chlorine-containing D-annulated...

Tamarix articulata Inhibits Cell Proliferation, Promotes Cell Death Mechanisms and Triggers G0/G1 Cell Cycle Arrest in Hepatocellular Carcinoma Cells

Research background

From ancient times plants have been used for medicinal purposes against various ailments. In the modern era, plants are a major source of drugs and are an appealing drug candidate for the anticancer therapeutics against various molecular targets. Here we tested methanolic extract of dry leaves of Tamarix articulata for anticancer activity against a panel of hepatocellular carcinoma cells.

Experimental approach

Cell viability of hepatocellular carcinoma cells was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay after a dose-dependent treatment with the extract of T. articulata. Phase-contrast microscopy and 4՛,6-diamidino-2-phenylindole (DAPI) staining served to analyse cellular and nuclear morphology. Immunoblotting was performed to determine the expression of proteins associated with autophagy, apoptosis and cell cycle. However, flow cytometry was used for the quantification of apoptotic cells and the analysis of cells in different phases of the cycle after the treatment with various doses of T. articulata. Additionally, acridine orange staining and 2՛,7՛-dichlorofluorescein diacetate (DCFH-DA) dye were used to analyse the quantification of autophagosomes and reactive oxygen species.

Results and conclusion

Our results demonstrate that T. articulata methanolic extract exhibits promising antiproliferative activity with IC₅₀ values (271.1±4.4), (298.3±7.1) and (336.7±6.1) µg/mL against hepatocellular carcinoma HepG2, Huh7D12 and Hep3B cell lines, respectively. Mechanistically, we found that T. articulata methanolic extract induces cell death by activating apoptosis and autophagy pathways. First, T. articulata methanolic extract promoted autophagy, which was confirmed by acridine orange staining. The immunoblotting analysis further confirmed that the extract at higher doses consistently induced the conversion of LC3I to LC3II form with a gradual decrease in the expression of autophagy substrate protein p62. Second, T. articulata methanolic extract promoted reactive oxygen species production in hepatocellular carcinoma cells and activated reactive oxygen species-mediated apoptosis. Flow cytometry and immunoblotting analysis showed that the plant methanolic extract induced dose-dependent apoptosis and activated proapoptotic proteins caspase-3 and PARP1. Additionally, the extract triggered the arrest of the G₀/G₁ phase of the cell cycle and upregulated the protein expression of p27/Kip and p21/Cip, with a decrease in cyclin D1 expression in hepatocellular carcinoma cells.

Novelty and scientific contribution

The current study demonstrates that T. articulata methanolic extract exhibits promising anticancer potential to kill tumour cells by programmed cell death type I and II mechanisms and could be explored for potential drug candidate molecules to curtail cancer in the future.

Synthesis and Investigation of the Role of Benzopyran Dihydropyrimidinone Hybrids in Cell Proliferation, Migration and Tumor Growth

BACKGROUND

Cancer is the second leading cause of mortality worldwide after heart diseases, and lung cancer is the topmost cause of all cancer-related deaths in both sexes. Dihydropyrimidinones (DHPMs) are medicinally important class of molecules with diverse pharmacological activities including anticancer activity. The present study focuses on the molecular hybridization of novel Benzopyran with Dihydropyrimidinone and evaluation of the resulting hybrids for cancer cell proliferation, migration and tumor growth.

METHODS

We have synthesized a focused library of dihydropyrimidinone benzopyran hybrids (compounds 1-11) by joining the aromatic as well as pyran portions of the benzopyran core with dihydropyrimidinone. All the synthesized hybrid molecules were evaluated for their cytotoxic activities against a panel of four human cancer cell lines of diverse tissue origin, viz: A549 (lung carcinoma), MCF7 (mammary gland adenocarcinoma), HCT-116 (colorectal carcinoma), and PANC-1 (pancreatic duct carcinoma) with the help of MTT cell viability assay. A structure-activity relationship was made on the basis of IC50 values of different hybrids. Effect on cell proliferation was examined through colony formation assay, reactive oxygen species generation and mitochondrial membrane potential studies. Wound healing assays and cell scattering assays were employed to check the effect on cell migration. Western blotting experiments were performed to find out the molecular mechanism of action and anti-tumor studies were carried out to evaluate the in vivo efficacy of the selected lead molecule.

RESULTS

Two types of novel hybrids were synthesized efficiently from benzopyran aldehydes, ethylacetoacetate and urea under heteropolyacid catalysis. Compound 3 was found to be the most potent hybrid among the synthesized compounds with consistent cytotoxic activities against four human cancer cell lines (IC50 values: 0.139 - 2.32 μM). Compound 3 strongly inhibited proliferation abilities of A549 cells in colony formation assay. Compound 3 exerted oxidative stress-mediated mitochondrial dysfunction, in which mitochondrial reactive oxygen species (ROS) generation as a mechanism of its anti-proliferative effects was analysed. Further, the molecule abrogated migration and cell scattering properties of aggressive PANC-1 cells. Mechanistic studies revealed that compound 3 modulated NF-kB expression and its downstream oncogenic proteins involved in cancer cell proliferation and invasion. Finally, compound 3 confirmed its in vivo anti-tumor efficacy; there observed 41.87% tumor growth inhibition at a dose of 30 mg/kg/body weight against a mouse model of Ehrlich solid tumor.

CONCLUSION

Our study unravels a potential anticancer lead (compound 3) from DHPMs that have opened up new research avenues for the development of promising anticancer therapeutic agents.