In vitro anticancer assessments of Annona muricata fractions and in vitro antioxidant profile of fractions and isolated acetogenin (15-acetyl guanacone)

Annona muricata has been attributed with numerous health benefits – including anticancer properties. The aim of this study was to carry out anticancer investigations of fractions of Annona muricata, by isolating a key compound and assessing antioxidant properties. The anticancer properties of fractions of Annona muricata were assessed using cell lines, and the potent fractions were subjected to isolation procedures. The isolated compound was examined using standard spectroscopies and further assayed with fractions for antioxidant properties. The cell viability of the most potent fractions revealed that ethyl acetate fruit (EAF, 10.62%) and ethyl acetate leaf (EAL, 10.83%) had the highest anticancer abilities, followed by ethyl acetate root-bark (11.44%), crude methanol leaf extract (16.21%) and crude methanol fruit extract (53.50%). The bi-phasic effect was observed for ethyl acetate fruit. The “reverse cycle S-G2 phase disproportionation” pattern was also observed with EAF and EAL. EAF caused a significant reduction of integrins leading to a decline in cell – cell interactions and increased cell death. The isolated compound demonstrated the presence of α, β-unsaturated γ-lactone and hydroxyl functional groups and molecular weight, 662.4 arriving at a molecular formula of C39H66O8 and elucidated as 15-acetyl guanacone. The observations from antioxidant assays suggested that 15-acetyl guanacone possessed a better antioxidant potential compared to fractions. The superior antioxidant properties of EAF compared to EAL correlated significantly with 15-acetyl guanacone (r = 0.563 and r = 0.682, respectively). Thus, the possible in vitro anticancer mechanisms of Annona muricata could be attributed to pro-apoptotic, bi-phasic and karyokinesis effects, “reverse-cycle S-G2 phase disproportionation”, and inhibition of integrin and antioxidant capacity.