The medicinal plants Annona senegalensis Pers. and Allophylus africanus P Beauv. are used in Tanzania traditional medicine for the treatment of cancer. However, there is no scientific documentation on their therapeutic effectiveness. The present study evaluated antiproliferative potential as an indicator of anticancer activity of A. senegalensis and A. africanus plant species from Tanzania. A. senegalensis and A. africanus were collected from Ugweno village at Kilimanjaro, Tanzania. Different types of extracts were prepared in dichloromethane/methanol (DCM:MeOH), petroleum ether, DCM, ethyl acetate (EtOAc), MeOH and water respectively. Antiproliferative activity against HCC 1396 (breast), HEp-2 (throat) and CT 26 (colon) cancer cell lines was assessed by the MTT cell viability assay. The results of the present study showed that the antiproliferative activity varied between plant extracts and the cancer cell lines. The highest antiproliferative activity was achieved with petroleum ether extract of A. senegalensis against HEp-2 with an IC 50 value of 0.42 ± 0.09 μg/ml. This also depicted the highest selectivity to cancerous cells (SI value 94.19) compared to the other extracts. A. africanus also depicted good antiproliferative activity against HEp-2 with IC 50 values of 1.00 ± 0.41 and 2.37 ± 1.45 μg/ml for DCM:MeOH and petroleum ether extracts, respectively. The findings validate the traditional use of A. senegalensis and A. africanus in the treatment of cancer. Results also support previous studies which demonstrated the effect of extraction solvent used in extraction of bioactive agents from medicinal plants. Further studies involving the isolation of pure antiproliferative compounds against cancer cells from the two plants are recommended to elucidate bioactive molecules.

The medicinal plants Annona senegalensis Pers. and Allophylus africanus P Beav. are traditionally used for the treatment of cancer in Tanzania. However, there is no scientific documentation on their therapeutic effectiveness. To evaluate the anticancer potential of A. senegalensis and A. africanus plant species from Tanzania, stem bark of the two plants were collected from Ugweno village at Kilimanjaro, Tanzania. Pulverized plant materials were soaked in dichloromethane/methanol (DCM:MeOH), petroleum ether (PE), DCM, ethyl acetate (EtOAC), MeOH and water to obtain DCM-MeOH, PE, DCM, EtOAC and MeOH extracts respectively. Anticancer activity against breast (HCC 1396), throat (HEp- 2) and colon (CT 26) cancer cell lines was assessed by the MTT cell viability assay. Results showed that anticancer activity varied between plant extracts and the cancer cell lines. The highest anticancer activity was achieved with A. senegalensis petroleum ether extract against HEp-2. The findings justify traditional use of A. senegalensis and A. africanus in treatment of cancer. This study found petroleum ether extract of A. senegalensis to have high potential for development of an anticancer agent against throat cancer. Further studies involving the isolation of pure anticancer compounds from the two plants are recommended to elucidate bioactive molecules with anticancer activity.