Globally, approximately 13% of all deaths annually are attributed to cancer. Surgery, radiation and chemotherapy are the current treatment techniques for cancer, however these methods are expensive, have high failure rates and have been associated with detrimental side effects. Plant derived products could be good candidates in alleviating challenges being experienced with these current methods. This study aimed at evaluating the phytochemistry, antiproliferation potential, and probable mechanism of action of Albizia gummifera, Rhamnus staddo and Senna didymobotrya plant extracts. Phytochemical screening was done as per standard procedures. The common 3-(4, 5-dimethylthiazol-2-yl) -2, 5-diphenyltetrazolium (MTT) dye was used in the determination of the antiproliferative activity of the extracts. Extracts induction of VEGF (angiogenesis) and p53 (apoptosis) genes' expression was evaluated using Real Time Polymerase Chain Reaction. Phytochemical screening revealed presence of alkaloids, tannins, glycosides, flavonoids, terpenes, phenolics and saponins in the plants extracts. A. gummifera's stem bark methanol: dichloromethane extract had the highest activity against the cancerous cell lines tested: HCC1395 (IC 50 6.07±0.04µg/ml), DU145 (IC 50 3.34±0.05µg/ml), CT26 (IC 50 5.78±0.08µg/ml) and Hep2 (IC 50 7.02±0.01µg/ml). R. staddo root bark methanol: dichloromethane extract had an IC 50 value of 15.71±0.04µg/ml on HCC, 9.81±0.09µg/ml on Hep2 and 11.14±0.39µg/ml on CT26. S. didymobotrya root bark methanol: dichloromethane extract inhibited HCC with an IC 50 of 65.06±0.07µg/ml, CT26 with an IC 50 of 15.71±0.04µg/ml and Hep2 with an IC 50 of 62.10±0.11µg/ml. From the results obtained, the plants exhibited selective toxicity to cancer cells while sparing the normal cells (SI ≥ 3). A. gummifera and S. didymobotrya and R. staddo plant extracts upregulated p53 and down-regulated VEGF genes. In conclusion, this study confirms that these plant extracts could be potential candidates for development of drugs for the management of breast, prostrate, colorectal and throat cancer.

Incorporation of fruits and vegetables in diet can successfully be used in prevention and treatment of cancer. Annona muricata and Abelmoschus esculentus which belongs to the annonaceae and malvaceae family respectively have commonly been used in traditional medicine to treat various ailments. This study evaluated the phytochemical components of both A. muricata and A. esculentus and their antiproliferative activity on the breast, cervical and prostate cancer cell lines. Both A. muricata and A. esculentus were extracted using methanol and dichloromethane in a ratio of 1:1. Phytochemical screening was done using standard analytical procedures. The MTT assay was used to evaluate the antiproliferative activity of A. muricata and A. esculentus extracts against breast cancer, cervical cancer, prostate cancer and Vero cell lines. Phytochemical screening confirmed that the fruit of A. muricata and the pods of A. esculentus are rich in saponins, tannins, alkaloids, terpernoids, glycosides, flavonoids and phenols. A. muricata had an IC 50 of 23.632±1.3465 µg/ml, 72.5860±1.9819 µg/ml and 93.6233±3.0570 µg/ml on Hela (cervical cancer cells), DU145 (Prostate cancer) and HCC 1395 (Breast cancer) cells respectively. A. esculentus demonstrated antiproliferative activity on Hela cells with an IC 50 of 20.3840±1.2132 µg/ml on DU145 and HCC 1395 cells an IC 50 of 50.013±0.2502 µg/ml and 171.6460±4.7642 µg/ml respectively. The standard drug used had an IC 50 of 21.126 µg/ml on HCC and 24.850 µg/ml on Hela cells. Both plants selectively inhibited the growth of the cancerous cells tested (SI>3) with the highest selectivity observed in HCC 1395 cells. This study authenticates traditional use and suggests potential use of these plants in cancer management and treatment.

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.