A method of treating cancer by targeting two proteases, MMP-9 and cathepsin B is provided. Therapeutic compositions comprising one or more plant extracts that inhibit MMP-9 and/or cathepsin B, which are capable of inhibiting neoplastic and/or endothelial cell migration, tumour growth, tumour-induced angiogenesis and/or metastasis are also provided. The therapeutic compositions of the invention can be used in the treatment of cancer, and, methods of inhibiting tumour growth, tumour metastasis, and/or tumour-induced angiogenesis using the therapeutic compositions alone or in combination with an anti-cancer agent are, therefore, also provided.