FIG 3.

Activity of HMW chitosan against L. major amastigotes in BMMs after 4 h, with and without ROS scavenger at pH 6.5. Infected macrophages were preincubated with 5 mM NAC for 2 h, after which HMW chitosan at a concentration of 1.64, 4.9,14.8, 44.4, 133.3, or 400 μg/ml was added and the cells were incubated for a further 4 h. Chitosan activity against intracellular amastigotes was evaluated as described in Materials and Methods. Values are expressed as percentages of inhibition of infection relative to the results for untreated controls. After 4 h, there was no significant difference in the antileishmanial activities of chitosan after scavenging of ROS (P > 0.05 by t test). Experiment was conducted in quadruplicate, and data are expressed as mean values ± SD. Experiment was reproduced a further two times with similar results (data not shown). Initial macrophage infection rate was >80% after 24 h.