Viability Analysis of Biomphalaria glabrata Hemocytes During Schistosoma mansoni Infection And Glyphosate-Based Herbicide Exposure

Pesticides are chemical agents that have a range of harmful effects on human health and the environment. They can cause drastic changes in natural communities, such as macroinvertebrates, plankton and fish. Snails, including Biomphalaria glabrata, are often present in aquatic communities and have multiple roles in limnic ecosystems. B. glabrata is an intermediate host of several species of helminths of medical and veterinary importance, such as Schistosoma mansoni, the etiological agent of schistosomiasis. The original Roundup® herbicide can affect snails and directly affects S. mansoni hemocytes, cells that act in the snails’ immune defense. Here we analyzed the effect of herbicide exposure on B. glabrata hemocytes divided into four groups: control group, infected-only group, treated-only group and infected+treated group. For this, flow cytometry and Neubauer-chamber counting were used to determine the morphology, viability and lectin expression profiles of hemocytes. We observed that the group infected by S. mansoni and treated with herbicide had a higher concentration of dead hemocytes in relation to the other groups. The treated group showed similar results to the control group, suggesting that the herbicide (Roundup™) alone does not interfere with the snails’ immune system. Regarding cellular-morphological-characterization analysis, hyalinocytes were the cells most commonly found in all groups studied. These findings suggest that S. mansoni infection and exposure to pesticides directly the immune system of the snails, stimulating the production of hemocytes, especially hyalinocytes, which have a high phagocytic power to quell the infection, but with toxic effects on the snail.