Judul: Antiproliferation activity of psidium guajava leaf exctract on breast cancer MCF-7 Cells
Abstrak: Ekstrak daun jambu biji memiliki bahan aktif yang diharapkan mampu menghambat proliferasi sel kanker dan tidak bersifat toksik terhadap sel yang normal. Oleh karena itu, penelitian ini bertujuan mengevaluasi efek antiproliferasi dari ekstrak daun jambu biji terhadap sel kanker payudara MCF-7. Evaluasi hambatan ditentukan dengan menggunakan uji 3-(4,5-dimetiltiazol-2-il)-2,5-difenil-tetrazolium bromida (MTT). Hasil penelitian menunjukkan kandungan metabolit sekunder simplisia daun jambu biji adalah flavonoid, saponin, tanin, dan triterpenoid. Nilai IC50 dari ekstrak kasar etanol 70% terhadap sel MCF-7 sebesar 35 ppm. Ekstrak menghambat pertumbuhan sel kanker payudara MCF-7 secara maksimal pada konsentrasi 100 ppm tanpa menghambat pertumbuhan sel normal Chang. Fraksionasi dengan eluen terbaik campuran kloroform dan metanol (6:4) menghasilkan fraksi 4 yang memiliki sifat toksisitas selektif paling baik dengan nilai IC50 sebesar 378 ppm. Berdasarkan analisis gugus fungsi menggunakan spektrofotometer infra merah terhadap fraksi 4, terdapat serapan C=C aromatik, ulur –CH2 asimetrik, C–O eter, dan –OH. Kata kunci: daun jambu biji, sel MCF-7, spektrofotometer infra merah, uji MTT, Guava leaf extract contains active compound that could inhibit the proliferation of cancer cells and non-toxic to normal cells. Therefore, the purpose of this study was to evaluate the antiproliferation effect of guava leaf extract on breast cancer MCF-7 cells. MTT (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide) assay was used to test the anticancer effect. The result showed that guava leaf contained secondary metabolites as flavonoids, saponins, tannins and triterpenoids. The IC50 value of 70% ethanol extract to MCF-7 cells was 35 ppm. The ethanol extract inhibited the proliferation of MCF-7 at 100 ppm without inhibited Chang cells. Further fractionation with chloroform and methanol (6:4) as eluent gave a fourth fraction showing excellent selective toxicity with IC50 value of 378 ppm. Based on functional group identification on this particular fraction using infra-red spectrophotometer, there were aromatic C=C, asymmetric –CH2 stretching, C–O ether, and –OH absorptions. Keywords: Psidium guajava leaves, MCF-7 cell, infra-red spectrophotometer, MTT assay
Keyword: daun jambu biji, sel MCF-7, spektrofotometer infra merah, uji MTT

Judul: Kuersetin dari Ekstrak Daun Jambu Biji Merah (Psidium guajava) dan Kinerjanya sebagai Penghambat Proliferasi Sel Kanker
Abstrak: Red guava leaf (Psidium guajava) extract has been known to inhibit cancer cell proliferation. However, further studies on the activity of flavonoids in red guava leaves as an anticancer agent has not been done. This study aims to test the inhibitory activity on Raji cells (ATCC CCL-86) by quercetin in guava leaves. Methanol crude extract was fractionated using vacuum liquid chromatography and column chromatography techniques to obtain fraction rich of quercetin. Fractionation of the crude methanol extract gave a fraction which shows a spot at Rf 0.675, which is similar to that of standard quercetin. Identification of quercetin fraction with liquid chromatography-mass spectrometry showed the fragment ion spectra of the quercetin (m/z 150, 151, 152). The quercetin fraction has been tested for its activity toward Raji cells and Vero cells. The quercetin fraction inhibited proliferation of Raji cells by 60%, at a concentration of 100 mg mL-1, but only inhibits the proliferation of Vero cells by 10%. This result indicates the quercetin fraction of guava leaf is able to inhibit the proliferation of Raji cells, but not toward Vero cells.
Keyword: quercetin, Psidium guajava, flavonoids, cancer cells proliferation

Judul: The impact and contribution of the tourism sector to the Indonesian economy : an I-O and SAM approach
Abstrak: Tourism is an important and strategic sector for the Indonesian economy. The sector has been growing for the last two decades to enhance its contribution to the GDP, employment, regional, local economy, and to strengthen the balance of payment. In particular, a planned economy was introduced to provide substantial opportunities to utilize tourism as a mechanism for national development. As a service-based sector, tourism as also considered to be a vehicle of converting the manufacturing economy to a service economy which makes the delivery of the product rather than the creation of the product the most important thing.
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