Rhamnan sulfate attenuates methylmercury cytotoxicity in rat thymic lymphocytes

Rhamnan sulfate, one of sulfated polysaccharides from seaweeds, is considered to have various characteristics such as antioxidant, anticoagulant, anti-inflammatory, antitumor, contraceptive, and antiviral activities, for the treatment of several diseases. We examined the effect of rhamnan sulfate on thymic lymphocytes treated simultaneously with methylmercury chloride, a toxic organometallic compound, using a flow-cytometric techniques with fluorescent probes, fluo-3-AM (an indicator for intracellular Ca2+) and propidium iodide (an indicator for dead cells). Rhamnan sulfate attenuated the methylmercury-induced increase in cell lethality. This effect of rhamnan sulfate is supposed to be due to the attenuation of methylmercury-induced elevation of intracellular Ca2+ levels. Rhamnan sulfate may be useful for the prevention of organometallic intoxication.