Synthesis, toxicity and immunomodulating activity of Co(II), Ni(II), Cu(II) and Zn(II) complexes of L(-)-2,3,5,6-tetrahydro-6-phenylimidazo[2,1-b]thiazole (levamisole).

Co(II), Ni(II), Cu(II) and Zn(II) complexes of levamisole (LMS) were prepared and characterized by elemental analyses, IR spectroscopy, 1H and 13C NMR and mass spectrometry. The following general formula was derived: M(LMS)2Cl2, where M = Co, Ni, Cu, Zn. It was established that LMS behaved as a monodentate ligand and the coordination was accomplished through the N-7 atom. The toxicity and the immunomodulating activity of the complexes on mice and rats in comparison with uncomplexed LMS was assayed. The metals in the complexes exerted different changes in the toxicity of LMS. The complex containing Zn(II) was less toxic and manifested higher immunomodulating activity than LMS.

The effects of the anti-enteroviral agent PTU-23 on immune response in normal mice.

The anti-enteroviral agent PTU-23 (N-phenyl-N'-3-hydroxyphenyl carbamide) was tested for an effect on humoral and cellular immune response in normal BD2F1 hybrid mice. Humoral immune response was assessed by hemolytic plaque technique and cellular immunity--by the delayed type hypersensitivity reaction and by the rate of activated lymphocytes in the mesenteric lymph nodes. PTU-23 was administered subcutaneously in doses of 200, 400 and 800 mg/kg body weight during 6 consecutive days. The immune response was recorded on day 1, 7 and 14 after the treatment. The changes observed in humoral and cellular immunity were found to be dependent on the time interval between the administration of the drug and of the antigen (sheep red blood cells), as well as dose-dependent. On day 1 a considerable suppression of humoral and cellular immune response was recorded at the three dose levels used. On day 7 the inhibition of humoral and cellular immunity was less. On day 14 the immune response in the animals treated with 400 and 800 mg/kg of the tested substance approached the control values, whereas it was observed that the dose of 200 mg/kg results in a certain stimulation of humoral and cellular immune response.