FIG 5.

Activity of HMW chitosan against L. major-infected BMMs after 24 h in the presence or absence of an NO inhibitor at pH 6.5. Infected macrophages were preincubated with the NO inhibitor L-NMMA (0.4 mM) for 2 h, following 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 24 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 24 h, there was no significant difference in the activity of chitosan after inhibition of NO (P > 0.05 by t test). Experiment was conducted in quadruplicate cultures, and data are expressed as mean values ± SD. Experiment was reproduced a further two times and the results were confirmed (data not shown). Initial macrophage infection rate was >80% after 24 h.