spider venom: cytotoxic fractions against human lung adenocarcinoma (A549) cells.

BACKGROUND

Spider venom is a potential source of pharmacologically important compounds. Previous studies on spider venoms reported the presence of bioactive molecules that possess cell-modulating activities. Despite these claims, sparse scientific evidence is available on the cytotoxic mechanisms in relation to the components of the spider venom. In this study, we aimed to determine the cytotoxic fractions of the spider venom extracted from and to ascertain the possible mechanism of toxicity towards human lung adenocarcinoma (A549) cells.

METHODS

Spider venom was extracted by electrostimulation. Components of the extracted venom were separated by reversed-phase high performance liquid chromatography (RP-HPLC) using a linear gradient of 0.1% trifluoroacetic acid (TFA) in water and 0.1% TFA in 95% acetonitrile (ACN). Cytotoxic activity was evaluated by the MTT assay. Apoptotic or necrotic cell death was assessed by microscopic evaluation in the presence of Hoechst 33342 and Annexin V, Alexa Fluor 488 conjugate fluorescent stains, and caspase activation assay. Phospholipase A (PLA) activity of the cytotoxic fractions were also measured.

RESULTS

We observed and isolated six fractions from the venom of collected from Aurora, Zamboanga del Sur. Four of these fractions displayed cytotoxic activities. Fractions AT5-1, AT5-3, and AT5-4 were found to be apoptotic while AT5-6, the least polar among the cytotoxic components, was observed to induce necrosis. PLA activity also showed cytotoxicity in all fractions but presented no relationship between specific activity of PLA and cytotoxicity.

CONCLUSION

The venom of spider, an endemic tarantula species in the Philippines, contains components that were able to induce either apoptosis or necrosis in A549 cells.