Judul: Isolation and cytotoxicity of theen leaves (ficus carica linn.) flavonoid extract
Abstrak: Penggunaan daun tin (Ficus carica) sebagai obat mulai dikembangkan di Indonesia sejak tahun 2011. Studi mengenai potensi bioaktif tanaman tin telah banyak dilakukan di dunia, tetapi belum banyak dilakukan di Indonesia. Penelitian ini dilakukan untuk menentukan sitotoksisitas ekstrak flavonoid daun tin berdasarkan metode uji letalitas larva udang (BSLT) dan toksisitas embrio ikan zebra (ZFET). Hasil penelitian menunjukkan rendemen ekstrak flavonoid pada sampel sebesar 2.36% dengan nilai LC50 sebesar 422 ppm dengan metode BSLT dan 181 ppm dengan metode ZFET. Hasil ini lebih tinggi dibandingkan dengan ekstrak kasar metanol. Uji kualitatif terhadap ekstrak menunjukkan kandungan flavonoid berupa flavon dan flavonol dalam fraksi etil asetat dari ekstrak metanol. Pemberian ekstrak kasar flavonoid daun tin pada embrio ikan zebra menimbulkan abnormalitas mayor pada sirkulasi darah. Berdasarkan hasil ini ekstrak kasar flavonoid daun tin cukup toksik dan efek toksiknya diduga dominan pada sistem sirkulasi darah makhluk hidup., Theen leaves have been used as traditional medicine in Indonesia since 2011. The bioactivity potential of the leaves has been acknowledged in international research, but lack of information in Indonesia so far. This study aims to examine the cytotoxicity of theen leaves flavonoid extract against brine shrimp (Artemia salina) and zebrafish (Danio rerio) embryo. The result showed that flavonoid in the sample was 2.36% and the 50% lethal concentrations (LC50) were 422 and 181 ppm against brine shrimp and zebrafish embryo, respectively. The qualitative assay for flavonoid class indicated the presence of flavones and flavonols class. The zebrafish embryo test indicated a major malformation on blood circulation. Based on these facts, the flavonoid extract is toxic and has effect to blood circulation of living organism. Key words: brine shrimp lethality test, flavonoid, theen leaves, zebra fish embryo toxicity.
Keyword: daun tin, flavonoid, toksisitas embrio ikan zebra, uji letalitas larva udang

Judul: Toksisitas Akut Ekstrak Daun Ketapang (Terminalia catappa) Pada Larva Udang Dan Embrio Ikan Zebra.
Abstrak: Catappa or ketapang (Terminalia catappa) leaves are known to be rich in bioactive compounds such as polyphenols, tannins, and flavonoids. Usually it has traditionally been used in herbal medicine and aquaculture due to its therapeutic properties. Other than their benefits, the potential toxicity of catappa leaves to aquatic animals is not fully understood yet. This study is aimed to determine the acute toxicity of catappa leaves extract using the median lethal concentration (LC50) on brine shrimp larva and zebrafish (danio rerio) embryos. The Artemia salina larva were used for brine shrimp lethality test (BSLT) and the zebrafish embryos were used for zebrafish embryos acute toxicity test (ZFET) method with 0, 10, 100, 1000 ppm concentration of catappa leaves ethanol extract, in 10 larva/embryo per 2 mL extract (duplo). Additionally, 0, 150, 300, 450, 600, 750 ppm of concentration were used to evaluate hatching rate and abnormality in zebrafish embryos, 1 embryo per well (96-well plates) containing 250 µL egg water. The BSLT result showed an LC50 of 273.62 ppm, considered a moderately toxic to brine shrimp larva. For ZFET, the LC50 was 1890.58 ppm, which means it is low toxic to zebrafish embryos. The result also showed the different extract concentrations showed the different hatching rate and abnormality, up to 300 ppm the hatching rate was still 100% with 5% of abnormalities. In conclusion, the ethanol extract of catappa leaves is considered moderate toxicity to brine shrimp larva and low toxicity to zebrafish embryos., Daun ketapang (Terminalia catappa) diketahui memiliki senyawa bioaktif, seperti polifenol, tanin, dan flavonoid. Daun ketapang secara tradisional telah digunakan dalam pengobatan herbal dan budidaya perairan. Potensi toksisitas daun ketapang terhadap perkembangan hewan air belum sepenuhnya dipahami. Penelitian ini bertujuan untuk mengetahui toksisitas akut ekstrak daun ketapang berdasarkan median lethal konsentrasi (LC50) pada larva udang dan embrio ikan zebra (danio rerio). Brine shrimp lethality test (BSLT) menggunakan larva Artemia salina dan zebrafish embryo acute toxicity test (ZFET) menggunakan embrio ikan zebra dengan konsentrasi ekstrak etanol daun ketapang 0, 10, 100, 1000 ppm untuk menghitung LC50, 10 larva atau embrio/sumur (2 mL), dilakukan duplo. Selanjutnya, konsentrasi ekstrak daun ketapang 0, 150, 300, 450, 600, 750 ppm digunakan untuk mengevaluasi tingkat penetasan (hatching rate) dan abnormalitas, 1 embrio/sumur (96-well plates) (250 µL). Uji BSLT menghasilkan LC50 sebesar 273,62 ppm, yang menunjukkan tingkat toksisitas sedang pada larva udang, sedangkan uji ZFET menghasilkan LC50 sebesar 1890,58 ppm, yang berarti relatif tidak toksisitas pada embrio ikan zebra. Perbedaan konsentrasi ekstrak menunjukkan perbedaan tingkat penetasan dan abnormalitas, hingga konsentrasi 300 ppm tingkat penetasan masih 100% dengan abnormalitas 5%. Sebagai kesimpulan, ekstrak etanol daun ketapang memiliki toksisitas sedang pada larva udang dan relatif tidak toksik pada embrio ikan zebra.
Keyword: acute toxicity, brine shrimp, catappa leaf extract, LC50, zebrafish embryo

Judul: Bifurkasi Hopf pada Model Siklus Bisnis Kaldor Kalecki tanpa dan dengan Waktu Tunda
Abstrak: Business cycle model is one of dynamical system models in economic. One of the business cycles model is Kaldor-Kalecki model. Kaldor-Kalecki business cycle model that is written in delayed defferential equations, is a business cycle model that involves gross product and capital stock of a company. In this paper Kaldor-Kalecki business cycle model is analyzed using both nondelay and delay in time of capital stock. By Taylor expansion for the time delayed model, an analysis of stability around the fixed points has been done. Furthermore, by using Hopf bifurcation theorem, it can be shown that there exists periodic orbits and limit cycle. In the nondelayed model, changing the parameter of goods market could lead to the occurrence of Hopf bifurcation and the existence of limit cycle. Similarly, for the delayed model, it has been shown that changing the time delay parameter may result in the occurrence of Hopf bifurcation and limit cycle.
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