Abstract

Annona senegalensisis a plant wide-spread in tropical regions including the sub-saharian region of theAfrican continent. Generally, all the different parts of the plant are used in traditional medicine. It had been previously reported to contain cytotoxic, antibacterial, antiparasitic and antibiotic compounds. In the present report, we have evaluated the antitumor activity of the Annona senegalensisplant in vitro by targeting with different extracts of this plant the ribosomal protein (rp) eL42 in the human 80S ribosomesin situ. In fact, rp eL42 had been shown to bind most of the anticancer drugs targeting the ribosomes. Since this protein had been found to be crosslinked in situon human 80S ribosomes with periodate-oxidized tRNA, a reactive analogue of the tRNA molecule, we took advantage of the fact that any anticancer natural product targeting this protein would prevent the crosslinking reaction. Our results reveal that the crude extract, as well as the methanol and butanol fractions at 10μg/μL contain bioactive molecules that bind to the Lys-53 residue of the eL42 protein and prevent the crosslinking reaction with tRNAox.

Finally, Annona senegalensiswas shown to exhibit a dose-dependent cytotoxic effect on breast cancer MDA-MB-231 cells. Altogether, the results in the present report suggest that Annona senegalensis is likely to contain a very effective molecule targeting the ribosomal protein eL42 with a potent anticancer effect on breast cancer cells in vitro.

Keywords

Annona senegalensis, human 80S ribosomes, ribosomal protein eL42, Lys-53 residue of rp eL42, periodate-oxidized tRNA, affinity labeling in situ of eL42 on 80S ribosomes, anticancer natural products