POTENTIAL CELL PROLIFERATION INHIBITOR ISOLATED FROM INDONESIAN BROWN ALGAE (PHAEOPHYTA)

Objective: The objective of this study is to determine the toxic activity of n-hexane and ethyl acetate extracts of brown algae as anticancer candidates.Methods: The brown algae were collected from West Java south coast, identified and then dried. The dry algae was then extracted by using n-hexane and ethyl acetate, filtered, then dried. The toxic activity of n-hexane and ethyl acetate extracts of five species brown algae was screened by using the brine shrimp lethality test (BSLT). The detection for chemical compound was carried out by placing the extracts on a Thin Layer Chromatography (TLC) plate and spraying them with several spray reagents such as Dragendorff, Citro boric acid, and vanillin-sulfuric acid.Results: We identified five species of brown algae i.e.: Sargassum sp., Sargassum duplicatum J. G. Agardh, Sargassum myriocystum J. G. Agardh, Turbinaria ornata (Turner) J. G. Agardh, and Turbinaria decurrens Bory. Four of ten extracts had toxic activities, i.e.: n-hexane extract of Sargassum myriocystum J. G. Agardh (LC50= 273.28 µg/ml), n-hexane extract of Turbinaria ornata (Turner) J. G. Agardh (LC50= 320.4 µg/ml), n-hexane extract of Turbinaria decurrens Bory (LC50= 579.33 µg/ml), and the ethyl acetate extract of Sargassum sp. (LC50= 743.98 µg/ml), whereas Sargassum duplicatum J. G. Agardh was found to be less toxic (nontoxic) (LC50>1000 µg/ml). The active compound of this alga was detected in TLC is terpenoid.Conclusions: N-hexane extract of Sargassum myriocystum J. G. Agardh showed the highest toxicity in the brine shrimp assay (LC50= 273.28 µg/ml).Â

Pengaruh Estradiol-17? Dan Kolagen Tipe IV Terhadap Ekspresi Gen PIK3CA Untuk Menginduksi Ekspresi C-erbB2 Pada Lini Sel Kanker Ovarium SKOV-3

Ovarian cancer cell metastasis is induced by signaling pathway activated by the binding of type IV collagen to ?1 integrinreceptor on the surface of cancer cells and estrogen binding to estrogen receptor. However, the role of estradiol-17? andtype IV collagen on the development of ovarian cancer have not been clearly understood. Therefore, this research wasconducted to observe the differential gene expression in SKOV-3 ovarian cancer cells cultured on type IV collagen andtreated with estradiol-17?, and incubated for 12, 24 and 72 hours. Differential display RT-PCR was used to express thedifferential expression gene after treatment. cDNA fragment that expressed differentially was isolated and sequenced.Sequencing result on one of the cDNA fragment showed that PI3K is one of the gene expressed in SKOV-3 ovarian cancercell. To verify this result, cDNA was amplified using PIK3CA specific primer. The increasing level of PIK3CA is inducedby three kinds of receptor activities, those are c-erbB2 receptor bound to estradiol-17?, homodimer receptor of c-erbB2, andthe activity of integrin receptor bound to type IV collagen. The increasing level and activity of PIK3CA can also increasethe expression of c-erbB2 gene. In SKOV-3 cells cultured on type IV collagen for 72 hours, the increasing of PIK3CA andc-erbB2 expression level is very low. The conclusion is that estradiol-17? gives a more significant effect than type IVcollagen to induce the increasing expression of PIK3CA and c-erbB2 genes