Abstract: The purpose of this study was to observe the antitumor effect and toxic and side effect of lithium carbonate (Li2CO3) on cyclophosphamide (CP) . All mice were inoculated tumors (hepatocarcinoma H22 or sarcoma S180) according to the standard method. Li2CO3 20 or 40 mg/(kg. d) was administered for 10 da ys. CP (90 or 180 mg/ kg) was administered once by ip. It was shown that combinated application of Li2CO3 and CP significantly enhanced the inhibition rates of tumors (H22 , S180) in mice , and remarkably increased the number of white blood cell (WBC) of the tumor2bearing mice (H22 , S180) , and remarkably decreased the f requency of micronucleus (MNF) of bone marrow polychromatic erythrocyte (PCE) of the tumor2bearing mice. These result s indicated that Li2CO3 could enhance significantly the effect s of CP to inhibite tumor in mice , and remarkably reduce the toxic and side responses of decreasing WBC and increasing MNF caused by CP.

Key words: Lithium carbonate, cyclophosphamide, antitumor effect, toxic and side response