Objective: To find new compounds in order to overcome the mainstay of metastatic breast cancer due to the adverse side effects from, and increasing resistance to, current chemotherapeutic agents. Methods: α-Mangostin and apigenin were reported in comparison to doxorubicin, a chemotherapeutic drug. Ductal carcinoma (BT474) cell line and non-tumorigenic epithelial tissue from mammary gland (MCF-10A) were used. Cell viability assessment was calculated by the standard 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. Cell morphology was investigated by light microscopy. By flow cytometry analysis, programmed cell death was observed using annexin V and propidium iodide staining while cell-cycle arrest was observed using propidium iodide staining. Change in transcriptional expression was evaluated by real-time quantitative reverse transcription PCR. Results: In 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, the result revealed α-mangostin and apigenin were more cytotoxic to BT474 cells. Longer exposure times to α-mangostin and apigenin caused more floating cells and a lower density of adhered cells with more vacuoles present in the colonies in BT474 only. α-Mangostin and apigenin caused necrosis in BT474 cells in a 24 h exposure, but a small amount of early apoptotic cells could also be detected at 24, 48 and 72 h exposure, whereas doxorubicin caused early apoptosis to BT474 cells at 24 h. Transcript expression and activity analysis supported caspase-3 was involved in the death of BT474 cells treated by all compounds. Moreover, α-mangostin and apigenin arrested the cell-cycle at the G

Objective: To screen crude extracts of propolis, bee pollen and honey from four stingless bee species [Trigona incisa (T. incisa)], Timia apicalis, Trigona fusco-balteata and Trigona fuscibasis) native to East Kalimantan, Indonesia for cytotoxic activity against five human cancer cell lines (HepG2, SW620, ChaGo-I, KATO-III and BT474). Methods: All samples were extracted with methanol, and then subpartitioned with n-hexane and ethyl acetate. Each crude extract was screened at 20 μg/μL for in vitro cytotoxicity against the cell lines using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. In addition, four previously shown bioactive components from propolis (apigenin, caffeic acid phenyl ester, kaempferol and naringenin) and two chemotherapeutic drugs (doxorubicin and 5-fluorouracil) were used to evaluate the sensitivity of the cell lines. Results: Overall, crude extracts from propolis and honey had higher cytotoxic activities than bee pollen, but the activity was dependent upon the extraction solvent, bee species and cell line. Propolis extracts from T. incisa and Timia apicalis showed the highest and lowest cytotoxic activity, respectively. Only the HepG2 cell line was broadly sensitive to the honey extracts. For pure compounds, doxorubicin was the most cytotoxic, the four propolis compounds the least, but the ChaGo-I cell line was sensitive to kaempferol at 10 μg/mL and KATO-III was sensitive to kaempferol and apigenin at 10 μg/mL. All pure compounds were effective against the BT474 cell line. Conclusions: Propolis from T. incisa and Trigona fusco-balteata contain an in vitro cytotoxic activity against human cancer cell lines. Further study is required, including the isolation and characterization of the active antiproliferative agent(s).

OBJECTIVETo screen crude extracts of propolis, bee pollen and honey from four stingless bee species [Trigona incisa (T. incisa)], Timia apicalis, Trigona fusco-balteata and Trigona fuscibasis) native to East Kalimantan, Indonesia for cytotoxic activity against five human cancer cell lines (HepG2, SW620, ChaGo-I, KATO-III and BT474).

METHODSAll samples were extracted with methanol, and then subpartitioned with n-hexane and ethyl acetate. Each crude extract was screened at 20 µg/mL for in vitro cytotoxicity against the cell lines using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. In addition, four previously shown bioactive components from propolis (apigenin, caffeic acid phenyl ester, kaempferol and naringenin) and two chemotherapeutic drugs (doxorubicin and 5-fluorouracil) were used to evaluate the sensitivity of the cell lines.

RESULTSOverall, crude extracts from propolis and honey had higher cytotoxic activities than bee pollen, but the activity was dependent upon the extraction solvent, bee species and cell line. Propolis extracts from T. incisa and Timia apicalis showed the highest and lowest cytotoxic activity, respectively. Only the HepG2 cell line was broadly sensitive to the honey extracts. For pure compounds, doxorubicin was the most cytotoxic, the four propolis compounds the least, but the ChaGo-I cell line was sensitive to kaempferol at 10 µg/mL and KATO-III was sensitive to kaempferol and apigenin at 10 µg/mL. All pure compounds were effective against the BT474 cell line.

CONCLUSIONSPropolis from T. incisa and Trigona fusco-balteata contain an in vitro cytotoxic activity against human cancer cell lines. Further study is required, including the isolation and characterization of the active antiproliferative agent(s).