Chiang Mai Journal of Science

 Crocodile blood extracts; serum, plasma, hemoglobin, and crude leukocyte extract were prepared from whole blood of crocodiles (Crocodylus siamensis) by differential sedimentation. In this study, crocodile blood extracts possessed considerable cytotoxic activity. It was evident that, the serum, plasma, hemoglobin, and crude leukocyte extract have not significant cytotoxic potentials by the yellow tetrazolium bromide assay (MTT assay) using a macrophage-like cell, RAW 264.7. The anti-inflammatory effect of crocodile blood extracts, which were evaluated by examining their inhibitory effects on pro-inflammatory mediators in lipopolysaccharide (LPS)-stimulated murine macrophage RAW 264.7 cells. Both plasma and crude leukocyte extract significantly inhibited the anti-inflammation NO production and exhibited cytotoxicity at the whole tested concentration. In addition, crude leukocyte extract reduced the NO production in a dose-dependent manner, also similar pattern was observed in plasma. On the other hand, serum and hemoglobin cannot inhibit the anti-inflammation NO production. Taken together, these findings indicate that the anti-inflammatory properties of plasma and crude leukocyte extract may be due to the inhibition of NO production. Thus crocodile blood extracts, plasma and crude leukocyte extract may provide a potential therapeutic approach for inflammation related diseases.