In vitro hemolysis and lipid peroxidation-inducing activity of the tentacle extract of the sea anemone (Paracondylactis indicus Dave) in rat erythrocytes

Objective : In vitro hemolytic activity of the tentacle extract of Paracondylactis indicus (Dave), a sea anemone found in the eastern coastal region of West Bengal (India), was determined in rat erythrocytes.
Materials and Methods : Acute toxicity study was carried out with the tentacle extract followed by detailed biochemical studies to evaluate the direct and indirect hemolytic activities of the extract. The effects of pH, temperature, divalent cations and chelating agents on hemolysis were also evaluated. Efforts were also made to elucidate the mechanism of the hemolytic activity of the extract.
Results : The tentacle extract of P. indicus (Dave) produced significant hemolysis (both direct and indirect) in washed rat erythrocytes. The direct hemolytic activity of the tentacle extract was found to be both temperature- and pH-dependent. Divalent cations (Ca²⁺ , Mg²⁺ ) produced significant enhancement of direct hemolytic activity. Hemolysis (both direct and indirect) was significantly diminished in the presence of Zn²⁺ , EDTA and p-bromophenacyl bromide. The tentacle extract was found to induce lipid peroxidation in washed erythrocytes, which was inhibited by chlorpromazine. The tentacle extract demonstrated significant proteolytic activity, which was found to decrease in the presence of protease inhibitors (EDTA, EGTA and PMSF).
Conclusion : P. indica tentacle extract (and in particular, the 60% cut fraction) probably contains enzymatic components like phospholipase(s) along with proteases, which may be the contributing factors for its observed hemolytic activity.