The 2011 ASHS Annual Conference

Consumption of neurotoxic phytochemical constitents can pose a serious heath risk to those who are unsuspecting. Chronic consumption of fruits and/or teas made from soursop (Anonna muricata L.) and cherimoya (Annona cherimola Mill.) has been suggested as a culprit of onset of atypical parkinsonism in Guadeloupe. Despite the initial report on the linkage between benzylisoquinoline alkaloids and atypical parkisonism, annonacin and other acetogenic constituents (polyketides) may be actually responsible for the disease. Pawpaw [Asimina triloba (L.) Dunal] is a relative of soursoup and cherimoya, and the edible portion of pawpaw also contains acetogenins, and also been found cytotoxic to a few cancer cell lines. The objective of the study was to investigate the cytotoxicity of pawpaw fruit extract against rat brain tumor cells in vitro. Pawpaw pulp was first extracted in acetone and lyophylized. The lyophlized powder was then reconstituted with double distilled water (DDH₂O) and fractioned with DDH₂O, 50% methanol (MeOH), 100% MeOH, 100% acetone, and then 50% acetone. PC12, a dopamigenic phytochromocytoma cell line was cultured in RPMI-1640 medium containing 5% horse serum and 10% fetal bovine serum. Cultures were incubated in a 37°C humidified chamber with 5% CO₂.  Cells were subjected to various concentrations of pawpaw extracts at 24 hrs., and analyzed 48 hrs. after the treatment. Of all extracts tested, fraction 3 was found to be the most cytotoxic.