Terminalia ferdinandiana Exell. Fruit and Leaf Extracts Inhibit Proliferation and Induce Apoptosis in Selected Human Cancer Cell Lines

ABSTRACT

Terminalia spp. are characterized by their high antioxidant contents and several species have anticancer activity. This study examined T. ferdinandiana fruit and leaf extracts for antiproliferative and apoptotic activities against a panel of human carcinoma cell lines. All extracts inhibited Caco2, HeLa, Jeg-3, JAR, MC3T3-E1, and MG63 proliferation. The leaf ethyl acetate extract was the most potent inhibitor of proliferation (MC3T3-E1 IC₅₀ = of 6 µg/ml; Caco2 IC₅₀ = 102 µg/ml). Furthermore, IC₅₀'s < 500 µg/ml were determined against all cell lines tested against that extract. The methanolic leaf extract was also a potent inhibitor of cell proliferation (Jeg-3 IC₅₀ = 147 µg/ml; MC3T3-E1 IC₅₀ = 40 µg/ml). The fruit extracts were also good inhibitors of carcinoma cell proliferation. Cell imaging studies detected morphological features consistent with apoptosis in Caco2 cells exposed to the ethyl acetate, methanolic, and aqueous extracts. Caspase 3 activity was significantly elevated in Caco2 cells exposed to these extracts, indicating that apoptosis was induced. The leaf ethyl acetate extract contained a high diversity and relative abundance of tannins and flavonoids. All T. ferdinandiana fruit and leaf extracts displayed either no toxic or low toxicity in the Artemia franciscana bioassay and in a HDF viability assay.

Acknowledgments

The authors are grateful to Professor Ann McDonnell for providing the MC3T3-E1 and MG63 cells used in this study, and to Dr Jenny Di Trapani for the kind gift of the Jeg-3 and JAR cells. We are also most grateful to David Boehme of Northern Territory Wild Harvest for providing the T. ferdinandiana fruit and leaves. Financial support for this work was provided by the Environmental Futures Research Institute, Griffith University.