This study shows that the Artemia assay, which is usually performed by incubation for a 24-hour period in artificial sea water, can also be performed in phosphate buffered saline (PBS) at pH 7.2, or in a cell culture medium, both of which are used in toxicity assays employing mammalian cells. Thus, by using the equivalent media for incubation, toxic effects in the Artemia assay and toxic mechanisms can more accurately be compared with results obtained in mammalian cell toxicity. Survival of control animals is good for 72 hours, provided that infection can be avoided. A pH greater than 6 is essential for good survival of Artemia Salina, and a pH greater than 10.5 should be avoided. Because of the risk of infection at low saline concentrations, a decreased incubation time of 16 or 12 hours is recommended. The lethal concentrations (LC10 and LC50) in the 24-hour Artemia assay of the first ten chemicals in the MEIC programme were measured in PBS, and the results compared with those from a previous study of the effects in a 10-minute acute ATP leakage assay, specifically indicating lesions in the cell membrane. The EC10 and EC50 values for the alcohols in the Artemia assay were 35–75% of the corresponding values in the ATP leakage assay. For paracetamol and amitriptyline, the EC10 and EC50 values in the Artemia assay were 2–16% of the corresponding values in the ATP-leakage assay. The greatly increased toxicity of the two compounds in the animals may be related to systemic effects. FeSO4 was very toxic to Artemia salina at a concentration of lug/ml, but it did not cause leakage of ATP from cultured cells, even at a concentration of 8,000μg/ml, showing that widely different mechanisms of interaction with FeSO4 are measured by the two assays. A lower toxicity of polygodial, a sesquiterpenoid unsaturated dialdehyde, in cell culture medium, was obvious in the Artemia assay. Thus, some factors in cell culture medium must, by interacting with the toxic molecule, protect the animals against the toxicity of polygodial, as was previously found in cultured cells.
Defined MSC exosome with high yield and purity to improve regenerative activity
