IJEScA International Journal of Engineering and Science Application ISSN 2406-9833 IJEScA vol.4, 1, May 2017 1 The Potency of β-Sitosterol Isolated From Hydroid Aglaophenia cupressina Lamoureoux as Antimitotic Agent towards Sea Urchin Tripneustes gratilla Linn. Afriansyah 1 , Sjafaraenan 2 , E. Johannes 2 , M. Litaay 2 1 Graduate Student of Department of Biology, Faculty of Mathematics and Natural Sciences 2 Department of Biology, Faculty of Mathematics and Natural Science Hasanuddin University, Makassar 90245  e-mail: eevreel.teksas01@gmail.com ABSTRACT The potency of β-Sitosterol isolated from hydroid Aglaophenia cupressina Lamoureoux as antimitotic agent towards early cleavage of Sea Urchin Tripneustes gratilla Linn had been conducted. The study aimed to determine β-Sitosterol activity isolated compound from hydroid A. cupressina Lamoureoux as antimitotic compound towards early cleavage of zygote of Sea Urchin T. gratilla Linn. Antimitotic treatments were β-Sitosterol (concentration 1 µg/ml, 10 µg/ml and100 µg/ml), positive control vincristine (concentration 0.01 µg/ml, 0.1 µg/ml, and 1 µg/ml) and negative control. A protozoa-free seawater was used in this assay. The results revealed that β- Sitosterol compound had the highest inhibition activity at concentration of 100 g/ml was 69.22 % with IC-50 on 0.95 µg/ml which could develop as cancer chemotherapy compound. Keywords: Antimitotic, β-Sitosterol, Hydroid Aglaophenia cupressina Lamoureoux, Tripneustes gratilla Linn. 1. INTRODUCTION Hydroids are sea invertebrate that easily found in shallow waters. Hydroids live in colonies, and attached to the sponge or dead coral. The abundance of hydroid in waters making it the source of wealth of new molecular. Hydroid A. cupressina L is known to have a variety of active compounds with β- sitosterol is one of them [1]. Active compound isolated from A cupressina L had been studied extensively, but not β-sitosterol compound [2, 3 & 4]. β-sitosterol is a sterol that has various benefits such as lowering cholesterol, cancer prevention and as a cosmetic raw material [5]. β-sitosterol compound as a cancer chemotherapeutic agent is to be tested through various stages of biopharmacology testing, both in-vivo and in-vitro. As for the in-vitro test include antimitotic assay [6]. Sea Urchin T. gratilla Linn is commonly used in trials because of its sensitivity to exposure in measuring the compound toxicity, the zygote of Sea Urchin T. gratilla Linnis often used as a test medium. Besides its abundance, its easy and inexpensive application in procedure makes it a test media that frequently used. It is important to comprehend the information on β-sitosterol as antimitotic material. Therefore, this study was undertaken. The studies aimed to determine β- Sitosterol activity as the isolated compound from hydroid A. cupressina L as antimitotic