Background:Fucoxanthin is a potential tumor cytotoxic compound. However, mechanisms underlying the activities are unclear.Aim:This in silico study aimed to predict the main mechanism of fucoxanthin; whether with its binding to p53 gene, CDK2, or tubulin.Materials and Methods:In silico was studied by using Autodock-Vina's algorithms. The mechanisms being analyzed by comparison of fucoxanthin and native ligands binding energies in p53 gene (1RV1), CDK2 (1AQ1), and three binding sites of tubulin (1JFF-paclitaxel, 1SA0-colchicine, and 1Z2B-vinblastine site).Results:Autodock-Vina's algorithms were valid, as re-docking the native ligands to their receptors showed a RSMD value less than 2 A with binding energies of -11.5 (1RV1), -14.4 (1AQ1), -15.4 (1JFF), -9.2 (1SA0), and -9.7 (1Z2B) kcal/mol. Docking of fucoxanthin to subjected receptors were -6.2 (1RV1), -9.3 (1AQ1), -8.1 (1JFF), -9.2 (1SA0), and -7.2 (1Z2B) kcal/mol. Virtual analysis of fucoxanthin and tubulin binding structure showed the carboxyl moiety in fucoxanthin make a hydrogen bound with 355Val (2.61 A) and 354Ala (2.79 A) at tubulin.Conclusion:The results showed that binding energy of fucoxanthin could only reach the same level as with colchicine ligand in tubulin. Therefore, it may predict that the most probable fucoxanthin main mechanism is to bind tubulin, which causes microtubules depolimerization and cell cycle arrest.

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 57  LC-MS metabolomic analysis of environmental stressor impacts on the metabolite diversity in Nephthea spp.Abstract Context: The soft coral Nephthea spp. is a source of terpenoid class that potentially has pharmaceutical properties. However, metabolite diversity and cytotoxic activity of this species are varied among coral reefs from various sites. Aim: To analyze the water quality in Nephthea spp. environment as a possible factor causing a difference in its metabolite diversity. Settings and Design: Nephthea spp. from seven sites were taken in October 2010 at the Alor District of Marine Protected Area, Indonesia. Materials and Methods: Water quality assessment was analyzed in situ and indexed by Canadian Council of Ministry Environment-Water Quality Index (CCME-WQI) method. Meanwhile, metabolite diversity was analyzed by a LC-MS metabolomic method, using C18 reversed phase and gradient water-acetonitrile system. Statistical Analysis Used: Spearman's rho and regression analysis were applied to correlate the water quality index to ecological index (richness, diversity, and evenness) from LC-MS results. Results: The water quality index had a significant positive correlation and strong linear regression determinant to the total metabolite (R 2 = 0.704), particularly to semipolar metabolite richness (R 2 = 0.809), the area of terpenoid class in the organism. Conclusion: It can be concluded that water quality may serve as a major factor that affects the amount of richness in Nephthea spp. metabolites. When the water quality is lower, as environment stresses increases, it may affect the metabolite richness within direct disrupt of metabolite biosynthesis or indirect ecological means. Terpenoids are known as a soft coral antipredator (coral fishes), the amount of which depends on the water quality.

Microalgae is a photoautotroph organism capable of producing various photosynthetic pigments with diverse beneficial properties. Rhodomonas salina, a Cryptophyte cell, contains only phycoerythrin as its phycobiliprotein pigment. The effects of salinity on growth and phycoerythrin concentration were investigated. Microalgae R. salina were grown in natural sea water with salinity of 33‰ and 50‰.The microalgae was batch-cultured in f/2 medium at light irradiation of 1100 lux, temperature of 24-26 o C, and photoperiode of 12 h : 12 h. The microalgae cell density was directly calculated using haemacytometer. The concentration of phycoerythrin was determined by spectrophotometric method. The cell density and phycoerythrin concentration were monitored every 4 days for 20 days of cell growth. Results showed that salinity did not affect significantly both on growth and phycoerythrin concentration extracted from R. salina biomass (p>0.05;  = 0.05). At both salinity, maximum phycoerythrin concentration were reached on day 8. There was a positive correlation between cell density and phycoerythrin concentration from day 1 to day 8 of cell growth. Microalgae R. salina which was grown in natural seawater with salinity of 33‰ achieved the highest cell density of 8.4 x 10 5 cells/mL and the phycoerythrin concentration of 0.19 g. 10 -5 cell on day 8 of the culture. The highest phycoerythrin concentration was obtained on day 16 of the culture i.e 0.27 g. 10 -5 cell.

Recently, research to explore marine bioactive compounds especially marine medicines and cosmetics shows increasing trend due to the diversity of the chemical structures and their bioactivities. 9 In the

Key words: fucoidan, brown seaweed, bioactivity, L-fucose ABSTRAK Fukoidan adalah senyawa polisakarida yang secara substansional terdiri atas L-fukosa dan golongan ester sulfat, terutama terdapat pada rumput laut coklat. Dalam jangka waktu sepuluh tahun terakhir, bioaktivitas dari fukoidan telah banyak diteliti. Bahkan belakangan ini telah diteliti aplikasi fukoidan untuk obat. Dalam beberapa tahun terakhir, struktur fukoidan telah berhasil diidentifikasi dan bioaktivitasnya berhasil diketahui. Fukoidan mempunyai banyak bioaktifitas antara lain sebagai antikoagulan, antioksidan, antikomplementari, anti pembengkakan, pelindung lambung, dan pengatur kadar lipid darah. Review ini memberikan ringkasan beberapa kemajuan penelitian isolasi dan bioaktivitas fukoidan dari beberapa jenis rumput laut coklat penghasil fukoidan.

ABSTRAKRiset mengenai bioaktivitas ekstrak makroalga Turbinaria decurrens terhadap proliferasi sel limfosit dan sitotoksisitas terhadap sel lestari tumor HeLa dan T47D telah dilakukan. Uji toksisitas dilakukan dengan metode Brine Shrimp Lethality Test (BSLT), sedangkan uji sitotoksisitas terhadap sel tumor HeLa dan T47D dilakukan dengan metode 3- (4,5-dimethylthiazol-2yl ekstrak kasar >1.000 ppm). Fraksi n-heksana T. decurrens merupakan fraksi yang menunjukkan aktivitas sitotoksisitas terbaik terhadap sel tumor HeLa dengan LC 50 sebesar 15,1 ppm. Ekstrak kasar, fraksi metanol, fraksi etil asetat, dan fraksi n-heksana dari makroalga T. decurrens mampu meningkatkan proliferasi sel limfosit manusia. Metabolit sekunder dari fraksi n-heksana T. decurrens sangat prospektif dikembangkan sebagai senyawa antitumor. ABSTRACT: Bioactivity of Turbinaria decurrens extract as an antitumor (HeLa and T47D) and its effects on lymphocyte proliferation. By: Nurrahmi Dewi Fajarningsih, Muhammad Nursid, Thamrin Wikanta, and Endar Marraskuranto Studies to determine the bioactivity of macroalga Turbinaria decurrens extract againts HeLa and T47D tumors and its effect on human lymphocite proliferation have been carried out. Toxicity assay was conducted using Brine Shrimp Lethality Test (BSLT) method while cytotoxicity assay against HeLa, T47D cell lines and for lymphocite proliferation were carried out using 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide]) assay (MTT method). The results of BSLT test showed that T. decurrens n-hexane fraction has the highest toxicity with Lethal

Spons merupakan hewan invertebrata laut yang kaya akan kandungan senyawa bioaktif. Senyawa bioaktif dari spons banyak dieksplorasi sebagai bahan obat antitumor. Penelitian ini bertujuan untuk mengetahui aktivitas sitotoksik, induksi apoptosis dan ekspresi gen p53 fraksi metanol spons Petrosia cf. nigricans terhadap sel tumor HeLa. Uji aktivitas pendahuluan dan sitotoksik masing‑masing dilakukan dengan metode Brine Shrimp Lethality Test (BSLT) dan MTT ([3‑(4,5‑dimethylthiazol‑2yl)‑2,5‑diphenyltetrazolium bromide]) assay. Induksi apoptosis dilakukan dengan metode pengecatan menggunakan akridin oranye dan etidium bromida. Analisis PCR menggunakan primer p53 dilakukan untuk mengetahui ekspresi gen p53. Hasil uji BSLT memperlihatkan bahwa ekstrak kasar P. cf nigricans memiliki aktivitas tahap awal yang sangat baik dengan LC50 = 23,4 µg/mL. Hasil uji MTT menunjukkan bahwa fraksi metanol memiliki aktivitas sitotoksik terhadap sel HeLa dengan nilai LC50 sebesar 11,9 µg/mL. Berdasarkan uji induksi apoptosis metode pengecatan dapat dinyatakan bahwa fraksi metanol mampu menginduksi peristiwa apoptosis pada sel HeLa. Fraksi metanol juga mampu meningkatkan ekspresi gen p53.