Preliminary evaluation of intraperitoneal injection in mice as a realistic assessment for microcystin’s toxicological effects in mammals

Cyanobacteria are increasingly becoming major concerns in freshwater bodies throughout the world. Microcystins (MCs) are a diverse group of heptapeptide cyanobacterial toxins that affect the liver. Rodent studies have been conducted over the years to study the effects of MCLR, primarily through intraperitoneal (IP) injection. It is known that MCs are 150 to 200 times more toxic when administered by the IP route than when administered by the environmentally appropriate oral route. However, it is difficult to obtain the quantities of toxin necessary for oral route studies, so it is important to evaluate the usefulness of data obtained using the IP route. The objective of this study, therefore, was to determine if IP administration of eight microcystin congeners is predictive of the relative toxicity shown in another study of the same toxins after administration by the oral route.

Impact/Purpose

Given the difficulty in obtaining sufficient quantities of algal toxins to test in vivo by the appropriate oral route, the question of the relevance of intraperitoneal dosing in smaller quantities is an important one, as the intraperitoneal route requires much lower amount of toxin to achieve the same degree of toxicity. This is a preliminary study reporting the effects of eight microcystin congeners when administered in mice via intraperitoneal route. This study also compares these effects with the effects from the same congeners in mice but instead administered by the appropriate oral route. The data indicates that the intraperitoneal route is a reasonable approximation of the data from the appropriate oral route. Further data using a higher dose for intraperitoneal administration is underway to increase the relevance of the data.

Citation

Huang, H., J. Lang, J. Schmid, D. Jenkins-Hill, AND N. Chernoff. Preliminary evaluation of intraperitoneal injection in mice as a realistic assessment for microcystin’s toxicological effects in mammals. North Carolina Society of Toxicology Regional Chapter (NCSOT) Annual Meeting, Raleigh, NC, October 07, 2019.