Methods: In the current study, new ester 3-hydroxyoctyl -5- trans-docosenoate (compound-1) was isolated from the chloroform soluble fraction of A. anchusa using column chromatography. Using MTT assay, the anticancer effect of the compound was determined in human hepatocellular carcinoma cells (HepG-2) compared with normal epithelial cell line (Vero). DPPH and ABTS radical scavenging assays were performed to assess the antioxidant potential. The Molecular Operating Environment (MOE-2016) tool was used against tyrosine kinase.
Results: The structure of the compound was elucidated based on IR, EI, and NMR spectroscopy technique. It exhibited a considerable cytotoxic effect against HepG-2 cell lines with IC50 value of 6.50 ± 0.70 µg/mL in comparison to positive control (doxorubicin) which showed IC50 value of 1.3±0.21 µg/mL. The compound did not show a cytotoxic effect against normal epithelial cell line (Vero). The compound also exhibited significant DPHH scavenging ability with IC50 value of 12 ± 0.80 µg/mL, whereas ascorbic acid, used as positive control, demonstrated activity with IC50 = 05 ± 0.15 µg/mL. Similarly, it showed ABTS radical scavenging ability (IC50 = 130 ± 0.20 µg/mL) compared with the value obtained for ascorbic acid (06 ± 0.85 µg/mL). In docking studies using MOE-2016 tool, it was observed that compound-1 was highly bound to tyrosine kinase by having two hydrogen bonds at the hinge region. This good bonding network by the compound might be one of the reasons for showing significant activity against this enzyme.
Conclusion: Our findings led to the isolation of a new compound from A. anchusa which has significant cytotoxic activity against HepG-2 cell lines with marked antioxidant potential.
METHODS: α-Mangostin (AM) was isolated from C. arborescens and its cell death mechanism was investigated. AM-induced cytotoxicity was observed with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Acridine orange/propidium iodide staining and annexin V were used to detect cells in early phases of apoptosis. High-content screening was used to observe the nuclear condensation, cell permeability, mitochondrial membrane potential, and cytochrome c release. The role of caspases-3/7, -8, and -9, reactive oxygen species, Bcl-2 and Bax expression, and cell cycle arrest were also investigated. To determine the role of the central apoptosis-related proteins, a protein array followed by immunoblot analysis was conducted. Moreover, the involvement of nuclear factor-kappa B (NF-κB) was also analyzed.
RESULTS: Apoptosis was confirmed by the apoptotic cells stained with annexin V and increase in chromatin condensation in nucleus. Treatment of cells with AM promoted cell death-transducing signals that reduced MMP by downregulation of Bcl-2 and upregulation of Bax, triggering cytochrome c release from the mitochondria to the cytosol. The released cytochrome c triggered the activation of caspase-9 followed by the executioner caspase-3/7 and then cleaved the PARP protein. Increase of caspase-8 showed the involvement of extrinsic pathway. AM treatment significantly arrested the cells at the S phase (P<0.05) concomitant with an increase in reactive oxygen species. The protein array and Western blotting demonstrated the expression of HSP70. Moreover, AM significantly blocked the induced translocation of NF-κB from cytoplasm to nucleus.
CONCLUSION: Together, the results demonstrate that the AM isolated from C. arborescens inhibited the proliferation of MDA-MB-231 cells, leading to cell cycle arrest and programmed cell death, which was suggested to occur through both the extrinsic and intrinsic apoptosis pathways with involvement of the NF-κB and HSP70 signaling pathways.
METHODS: Here, we tested effects from sera of Asian water monitor lizard (Varanus salvator), python (Malayopython reticulatus) and tortoise (Cuora kamaroma amboinensis) against cancer cells. Sera were collected and cytotoxicity assays were performed using prostate cancer cells (PC3), Henrietta Lacks cervical adenocarcinoma cells (HeLa) and human breast adenocarcinoma cells (MCF7), as well as human keratinized skin cells (Hacat), by measuring lactate dehydrogenase release as an indicator for cell death. Growth inhibition assays were performed to determine the effects on cancer cell proliferation. Liquid chromatography mass spectrometry was performed for molecular identification.
RESULTS: The findings revealed that reptilian sera, but not bovine serum, abolished viability of Hela, PC3 and MCF7 cells. Samples were subjected to liquid chromatography mass spectrometry, which detected 57 molecules from V. salvator, 81 molecules from Malayopython reticulatus and 33 molecules from C. kamaroma amboinensis and putatively identified 9 molecules from V. salvator, 20 molecules from Malayopython reticulatus and 9 molecules from C. kamaroma amboinensis when matched against METLIN database. Based on peptide amino acid composition, binary profile, dipeptide composition and pseudo-amino acid composition, 123 potential Anticancer Peptides (ACPs) were identified from 883 peptides from V. salvator, 306 potential ACPs from 1074 peptides from Malayopython reticulatus and 235 potential ACPs from 885 peptides from C. kamaroma amboinensis.
CONCLUSION: To our knowledge, for the first time, we reported comprehensive analyses of selected reptiles' sera using liquid chromatography mass spectrometry, leading to the identification of potentially novel anticancer agents. We hope that the discovery of molecules from these animals will pave the way for the rational development of new anticancer agents.