The major challenge concerning tumours and cancers is that they currently do not have a cure. The side effects from the available treatment options have made research gravitate towards phytotherapy. Annona muricata is one of the highly recommended plants due to its usage albeit in crude form in treating several diseases especially, tumours and cancer inclusive. However, the fraction of its extracts responsible for these effects, is still unknown. This study was designed to investigate the anti-tumour and anti-inflammatory effects of Hexane, ethyl-acetate, butanol and aqueous fractions of A. muricata leaves in dimethylbenzanthracene-induced (DMBA) mammary tumours. Forty-two female Wistar rats were divided into 7 groups of 6 animals each. Group 1 was Control and were on basal diet; Groups 2 to 7 were tumour-induced with 0.05mg/g DMBA subcutaneously with soy oil as vehicle. Group 2 was untreated; Group 3 was treated with doxorubicin (0.0125mg/g); Groups 4 to 7 were treated orally with the four fractions respectively at 12.5mg/g for 14 days. Data obtained were subjected to Analysis of Variance using Bonferroni post-hoc test. P<0.05 was taken as statistically significant. Annona muricata fractions reduced the TNF-α and CRP concentrations which were elevated in response to tumour induction, with the butanol fraction having the highest reduction potential, with a value of 0.02 ± 0.08 and 0.15 ± 0.04 respectively. However, these reductions were not statistically significant across all treatment groups. This study shows that all four fractions of A. muricata are potent inhibitors of inflammation, particularly in DMBA-induced mammary tumours. However, the butanol fraction proves to be the most potent in altering the process of inflammation via the TNF-α and the CRP signalling pathways.

Key words: Tumour, Cancer, Annona muricata, dimethylbenzanthracene, doxorubicin.