Cytotoxicity of methanol extracts of Prochloron didemni originated from ascidians Lissoclinum patella and Didemnum molle collected from Manado Bay, North Sulawesi

Abstract

Among coral reef ascidians inhabiting Manado Bay, North Sulawesi, Lissoclinum patella and Didemnum molle were found housing symbiotic microbe in their tunics. These tunicates benefit from the association by feeding directly on the microbial cells, and in turn the microbe were facilitated to produce functional compounds such as anticancer cyclic peptides. Preliminary screening for these compounds were conducted by cytotoxicity assays against human blood cells. The symbiotic microbe was molecularly identified as Prochloron didemni. Microbial samples were obtained by squeezing colonial tissues from the two newly collected host ascidians. Crude extracts were prepared by extraction in 80% methanol, and followed by in vitro cytotoxic assayed against human blood cells using May-grunwald-Giemsa method. The extract of the D. molle derived Prochloron showed more cytotoxic effects than the one of the L. patella. However, the cultivation of Prochloron cells originated from D. molle was not established compared to those of L. patella. Therefore for further production of anticancer potential compounds, cultivation of the L. patella derived Prochloron is being developed.