ABSTRACT
Nasopharyngeal carcinoma (NPC) in BALB/c nude mice (NM) was re-produced by hypodermic implanting human CNE-2 cell to the right-side of neck-backposi-tion. The changes of plasma malondialdehyde (MDA) and cAMP/cGMP ratio in NM bea-ring human NPC were examined. Meanwhile, we observed that tumor's size, plasma MDAand cAMP/cGMP ratio in NM bearing human NPC were affected by polysacchoridopetide(PSP). Results indicated that in comparison with the control group, NM bearing humanNPC showed a marked increase in plasma MDA(18.25?1.37 nmol/ml),cAMP/cGMP ratio(4.55?0.35), a marked decrease in plasma, cAMP (71.83?8.51 pM/ml) and cGMP(15.77?0.65 pM/ml), both high or low-concentration PSP inhibited NPC growth.Rate of inhibition was between 59.58 to 95.53 percent. PSP decreased plasma MDA,elevated cAMP, cGMP's levels and recovered cAMP/cGMP ratio. Our results suggestedthat the elevated level of MDA in NM bearing human NPC was closely associated withthe presence of NPC. PSP had antitumor effect, probably by means of decreasing freeradicals and recovering cAMP/cGMP ratio.