An overview of main effects of LTs in helminth infections. LTs participate of expulsion of T. spiralis in the intestine. The inhibition of LTs resulted in increases of parasitemia and decreases IgE levels, eosinophil numbers and IL-5 concentrations in mice infected with S. venezuelensis. LT inhibition also reduced the eosinophil recruitment to tissues and on blood eosinophilia in experimental T. canis infection. LTB₄ enhanced the ability of neutrophils and eosinophils to kill the schistosomula of S. mansoni. LTs play important roles in the penetration of the skin by the schistosome cercariae. CysLTs are involved in the proliferation and activation of hepatic stellate cells from S. mansoni granulomas.