Abstract
Methyloxantines are present in many herbs and vegetal foods, among them in tea, coffee and chocolate. Previous studies revealed that theophylline and theobromine have anti-angiogenic properties. Anti-tumor properties of theobromine were also described. Pentoxifylline (3,7-dimethyl-1-(5-oxohexyl)xanthine, PTX) is a synthetic xanthine derivative. It is a phosphodiesterase inhibitor and has various anti-inflammatory abilities. Pentoxifylline is widely used in therapy of inflammatory arterial diseases such as intermittent claudication of upper and lower limbs as well as in coronary heart disease. The aim of our research was to evaluate the effect of pentoxifylline (individually and in combination with non-steroidal anti-inflammatory drug sulindac), on L-1 sarcoma angiogenic activity and tumor formation in syngeneic Balb/c mice. Pre-incubation of tumor cells for 90 min with various PTX concentrations resulted in dose-dependent decrease of their ability to induce newly-formed blood vessels after transplantation into the skin of recipient mice. Administration of PTX to mice, recipients of tumor cells, slows tumor growth and reduces its volume. Synergistic inhibitory effect of PTX and sulindac, expressed as % of tumors sixth and thirteen day after subcutaneous grafting of L-1 sarcoma into syngeneic Balb/c mice, was observed.