Pengobatan kanker secara medis dengan kemoterapi ternyata kurang selektif, karena bersifat toksik bagi jaringan normal. Strategi yang potensial adalah penggunaan agen ko-kemoterapi dengan bahan obat dari alam. Salah satu tanaman yang berpotensi sebagai sumber obat baru adalah sirsak (Annona muricata L.). Penelitian ini bertujuan mengetahui efek sitotoksik isolat daun sirsak terhadap sel Raji berdasarkan nilai Lethal Concentration 50 (LC) dan profil kimia isolat aktifnya.
Penelitian dilakukan dengan ekstraksi daun sirsak metode perkolasi menggunakan etanol 96%. Ekstrak difraksinasi menggunakan metode Vacuum Liquid Chromatography (VLC) dengan fase gerak bertingkat dengan pelarut kloroform dan etil asetat. Fraksi yang didapat dimonitor dengan Kromatografi Lapis Tipis (KLT) dengan mengelompokkan fraksi  berdasarkan spot yang sama. Selanjutnya dire-fraksinasi dan dipantau dengan KLT hingga didapatkan satu spot dan diisolasi sebagai isolat. Perlakuan uji dengan menggunakan variasi konsentrasi isolat 10; 20; 30; 40; 60; 70; 90; dan 100 µg/ml ke microplate 96 sumuran. Setiap sumuran berisi sel Raji dengan kepadatan 2 x 10  sel/sumuran. Isolat daun sirsak diuji sitotoksisitasnya terhadap sel Raji dengan metode [3-(4,5dimethylthiazol-2-yl)-2,5- diphenyl tetrazolium  bromide] atau MTT Assay.

Hasil dari penelitian menunjukkan bahwa isolat daun sirsak (Annona muricata L.) memiliki aktivitas sitotoksik dengan nilai LC  sebesar 71,96 µg/ml. Profil kimia isolat aktif daun sirsak diidentifikasi mengandung senyawa terpenoid dengan Retardation factor (Rf) 0,62 dan 0,94 dan senyawa steroid dengan Rf 0,90.

Kata kunci: Annona muricata L., sel Raji, uji sitotoksisitas, MTT Assay,  Kromatografi Lapis Tipis (KLT).

Medical cancer treatment with chemotherapy were less selective, because toxic to normal tissues. Potential strategies is the use of co-chemotherapy agent from nature. One of the plants that have the potential as a source of new drugs is soursop (Annona muricata L.). The purposes of this study are to determine the effect of cytotoxic, Lethal Concentration 50 (LC ) value and the chemical constituents profile of active isolate of soursop leaves.
The study began with extracted of soursop leaves using 96% ethanol. The extract was fractionated using Vacuum Liquid Chromatography (VLC) with a mobile phase stratified with chloroform and ethyl acetate. Fractions obtained were grouped based on the similar spot and they were refractionated to obtain isolates. Further refractionation and monitored by TLC until found one spot and isolated as isolates. Isolates concentration were 10; 20; 30; 40; 60; 70; 90; and 100 µg/ml respectively. They were applied to the microplate 96 wells. Density of Raji cells was 2 x 10 4  cells/well. Cytotoxcity test of soursop leaves isolates was carried out against Raji cells by using MTT [3-(4,5-dimethylthiazol-2-yl)-2.5-diphenyl tetrazolium bromide] method.
The results showed that isolates soursop leaves have cytotoxic activity with LC  value of 71.96 µg/ml. Chemical profile of the soursop leaves active isolates were identified by Thin Layer Chromatography (TLC) and analyze qualitatively.
The result indicated there is a terpenoid compound with Retardation factor (Rf) detected 0.62 and 0.94 and steroid compounds with Rf detected 0.90.

Keywords: Annona muricata L., Raji cells, cytotoxicity assay, MTT Assay, Thin  50
Layer Chromatography (TLC).