Phytochemical, antioxidant and mitochondrial permeability transition analysis of fruit skin ethanolic extract of Annona muricata Linn. (Soursop)

Question: Annona muricata Linn. contains a group of bioactive long chain fatty acid derivatives called Annonaceous acetogenins, which have shown selective cytotoxicity against several cancer cell lines and other abnormal cells by a known mechanism. The current study analyzed the phytochemical and antioxidant properties of the fruit skin ethanolic extract of Annona muricata (ESA) and its effect on the opening of rat liver mitochondrial membrane permeability transition (MMPT) pore in vitro.Methods: Tests for the phytochemical constituents of the extract and antioxidant assays were carried out following standard protocols while the opening of the MMPT pore in the presence of varying concentrations of the extract was spectrophotometrically assayed under succinate-energized conditions. Calcium chloride (CaCl2) solution and spermine at specified concentrations were employed to trigger and inhibit MMPT pore opening respectively. Results: The results show that terpenoids, steroids and glycosides were found present in the fruit skin ethanolic extract and the extracts were found to have very low antioxidizing properties at the tested concentrations based on the diphenyl-1-picryhydrazy (DPPH) radical scavenging activity assay. Lipid peroxidation was induced in a concentration-dependent manner on both the cytosolic and mitochondrial hepatocyte fractions in vitro. In the absence of triggering agent, 0.84mg/ml concentration of ESA induced the opening of the pore by 129% whereas the other three lower concentrations (0.12mg/ml, 0.36mg/ml and 0.60mg/ml) did not induce MMPT pore opening. In the presence of the triggering agent, the extracts showed no inhibitory activity; rather there was a greater increase in the induction with increasing concentration of extracts. Conclusions: From the foregoing, the fruit skin ethanolic extract of Annona muricatamaypossibly contain bioactive components that are likely to induce apoptosis thereby adding to the growing list of naturefriendly chemopreventive and curative therapy of cancer.