Immunological effects ofChondrus armatuscarrageenans and their low molecular weight degradation products

Ability of high molecular weight (HMW) kappa- and lambda-carrageenans of the red marine algaeChondrus armatusand their low molecular weight degradation products (LMWDPs) (0.7-20 and 10-170 kDa respectively) to influence functional properties (motility and phagocytosis) of murine peritoneal macrophages was assessed in this study as an in vitro and a weeklong feeding experiment. We demonstrated that, with an exception of one, all carrageenan samples at 100 mu g/ml increased cellular motility and dose-dependently decreased phagocytic activity; LMWDPs of lambda-carrageenan suppressed motility and had no effect on phagocytosis. Oral administration of all the carrageenan samples at 100 mu g/kg/day for 7 days to mice had no effect on their clinical appearance, body weight, weight of their liver, spleen or thymus or development of noticeable changes to their inner organs. All samples induced a shift of the cell composition of the peritoneal cavity towards macrophages. Consumption of LMWDPs of kappa-carrageenan resulted in development of leukopenia, however, no changes to relative WBC count were introduced by either of the samples. All samples decreased murine peritoneal macrophages phagocytic activity, with lambda-samples possessing higher efficacy than their kappa-counterparts; all LMWDPs stimulated peritoneal macrophages motility, with kappa-samples possessing higher efficacy than their lambda-counterparts In conclusion, we have shown that kappa- and lambda-carrageenans of theC. armatusand their LMWDPs suppress phagocytotic activity of peritoneal macrophages under both in vitro and in vivo conditions. This allows them to be viewed as pharmacologically active substances andpropagates the need for their further investigation as such.

Automated summary

This study evaluated the effects of high molecular weight kappa- and lambda-carrageenans and their low molecular weight degradation products on murine peritoneal macrophages in both in vitro and in vivo conditions. The results showed suppression of phagocytic activity of macrophages, indicating the potential pharmacological activity of these substances. Further research is needed to explore their effects and mechanisms.