Edy Meiyanto

Curcumin and its analogues (PGV-0 and PGV-1) enhance sensitivity of resistant MCF-7 cells to doxorubicin through inhibition of HER2 and NF-kB activation.

Chemoresistance of breast cancer to doxorubicin is mediated mainly through activation of NF-kB and over expression of HER2. Curcumin and its analogues (PGV-0 and PGV-1) exert cytotoxic effects on T47D breast cancer cells. Suppression of NF-kB activation is suggested to contribute to this activity. The present study aimed to explore the effects of curcumin, PGV-0, and PGV-1 singly and in combination with doxorubicin on MCF-7/Dox cells featuring over-expression of HER2. In MTT assays, curcumin, PGV-0, and PGV-1 showed cytotoxicity effects against MCF-7/Dox with IC50 values of 80 μM, 21 μM, and 82 μM respectively. These compounds increased MCF-7/Dox sensitivity to doxorubicin. Cell cycle distribution analysis exhibited that the combination of curcumin and its analogues with Dox increased sub G-1 cell populations. Curcumin and PGV-1 but not PGV-0 decreased localization of p65 into the nucleus induced by Dox, indicating that activation of NF- kB was inhibited. Molecular docking of curcumin, PGV-0, and PGV-1 demonstrated high affinity to HER2 at ATP binding site. This interaction were directly comparable with those of ATP and lapatinib. These findings suggested that curcumin, PGV-0 and PGV-1 enhance the Dox cytotoxicity to MCF-7 cells through inhibition of HER2 activity and NF-kB activation.

Combinational effects of hexane insoluble fraction of Ficus septica Burm. F. and doxorubicin chemotherapy on T47D breast cancer cells

OBJECTIVE To evaluate the effects of n-hexane insoluble fraction (HIF) of Ficus septica leaves in combination with doxorubicin on cytotoxicity, cell cycle and apoptosis induction of breast cancer T47D cell lines. METHODS The in vitro drugs-stimulated cytotoxic effects were determined using MTT assay. Analysis of cell cycle distribution was performed using flowcytometer and the data was analyzed using ModFit LT 3.0 program. Apoptosis assay was carried out by double staining method using ethydium bromide-acridin orange. The expression of cleaved-poly (ADP-ribose) polymerase (PARP) on T47D cell lines was identified using immunocytochemistry. RESULTS The combination exhibited higher inhibitory effect on cell growth than the single treatment of doxorubicin in T47D cells. In addition, combination of doxorubicin and HIF increased the incidence of cells undergoing apoptosis. HIF could improve doxorubicin cytotoxic effect by changing the accumulation of cell cycle phase from G2/M to G1 phase. The combination also exhibited upregulation of cleaved-PARP in T47D cells. CONCLUSIONS Based on this results, HIF is potential to be developed as co-chemotherapeutic agent for breast cancer by inducing apoptosis and cell cycle arrest. However, the molecular mechanism need to be explored further.

Hesperidin as a preventive resistance agent in MCF-7 breast cancer cells line resistance to doxorubicin

OBJECTIVE To evaluate of hesperidin to overcome resistance of doxorubicin in MCF-7 resistant doxorubicin cells (MCF-7/Dox) in cytotoxicity apoptosis and P-glycoprotein (Pgp) expression in combination with doxorubicin. METHODS The cytotoxic properties, 50% inhibition concentration (IC50) and its combination with doxorubicin in MCF-7 cell lines resistant to doxorubicin (MCF-7/Dox) cells were determined using MTT assay. Apoptosis induction was examined by double staining assay using ethidium bromide-acridine orange. Immunocytochemistry assay was performed to determine the level and localization of Pgp. RESULTS Single treatment of hesperidin showed cytotoxic activity on MCF-7/Dox cells with IC50 value of 11 µmol/L. Thus, combination treatment from hesperidin and doxorubicin showed addictive and antagonist effect (CI>1.0). Hesperidin did not increase the apoptotic induction, but decreased the Pgp expressions level when combined with doxorubicin in low concentration. CONCLUSIONS Hesperidin has cytotoxic effect on MCF-7/Dox cells with IC50 of 11 µmol/L. Hesperidin did not increased the apoptotic induction combined with doxorubicin. Co-chemotherapy application of doxorubicin and hesperidin on MCF-7/Dox cells showed synergism effect through inhibition of Pgp expression.

Gynura procumbens modulates the microtubules integrity and enhances distinct mechanism on doxorubicin and 5-flurouracil-induced breast cancer cell death

Recent studies both in vitro and in vivo of G. procumbens exhibits chemopreventive properties for tumor inhibition on several types of cancer. Our study was carried out to observe the anticancer property of ethyl acetate fraction of G. procumbens leaves (FEG) on breast cancer cells as well as the co-chemotherapeutic potential, and to investigate its molecular mechanisms. 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to measure the growth inhibitory effect of FEG, doxorubicin (DOX), and 5-fluorouracil (5-FU) and their combination. Flowcytometry, 4′,6-diamidino-2-phenylindole (DAPI) staining, and immunobloting were used to explore the mechanism of cell cycle arrest and apoptosis. FEG inhibited cell proliferation, induced G1 phase arrest and apoptosis. The inhibitory effect of FEG was enhanced when combined with Dox and 5-FU. The apoptosis induction was related to the increase of c-PARP expression after combination treatment of FEG and Dox or 5-FU on MCF-7 cells. However, treatment of DOX, 5-FU, and FEG on T47D cells, resulting no significance DNA fragmentation and nuclei condensation evidance. Only combination treatment of 5-FU + FEG showed c-PARP expression in T47D cells. In T47D cells, The FEG treatment also caused the decrease of microtubule expression as shown by Western blotting assay. The decreasing level of microtubul expression might be caused by protein aggregation, as shown by immunostaning using α-tubulin antibody. All these results suggest that FEG potentiates the DOX and 5-FU efficacy on MCF-7 and T47D cells. FEG induces T47D cell death through different mechanism than MCF-7 that proposed to be mitotic catastrophe. The FEG may have specific targeted on microtubule integrity modulation leading to the cell cycle arrest and proliferation inhibition. Further FEG could be developed as a co-chemotherapeutic agent for reducing side effect and have specific molecular target for breast cancer.

Antiproliferative effect of gynura procumbens (lour.) Merr. Leaves etanolic extract on 7,12-dimethylbenz(a)antracene induced male rat liver

PURPOSE The leaves of Gynura procumbens (Lour.) Merr. has been traditionally used as anticancer. Ethanolic extract of G. procumbens leaves (EGP) showed cytotoxic activity and anticancer activity in animal cancer model. This study was conducted to observe antiproliferative effect using male rats liver cells induced by 7,12-dimethylbenz(a)antracene (DMBA). METHODS Forty days old Sprague Dawley male rats were divided into 4 groups, (1) 0.5 % CMC Na, (2) 20 mg/kg BW DMBA p.o ten times in three weeks, (3) DMBA+300 mg/kg BW of EGP, and (4) DMBA+750 mg/kg BW of EGP. The extract was dissolved into 0.5 % CMC-and administered daily per oral one week before, during and terminated 1 week after the DMBA induction. After sixthteen week experiment, rat livers were sectioned and stained with Haematoxyllene and Eosin (H&E) and AgNOR. RESULTS Histopatology profile showed no primary liver tumor on DMBA group. mAgNOR value of DMBA+300 mg/kg BW EGP showed significant antiproliferative effect compared to DMBA group. CONCLUSION Ethanolic extract of G. procumbens leaves showed antiproliferative activity on male rats liver induced by DMBA.

Immunomodulatory effects of hexane insoluble fraction of ficus septica burm.F. In doxorubicin-treated rats

The use of chemotherapeutics induces cardiotoxicity and affects immune functions, therefore development of combinatorial agents against cardiotoxicity and immunosuppression needs to be explored. Previous studies of the hexane insoluble fraction (HIF) of an ethanolic extract of Ficus septica leaves showed anticancer effects singly and in combination with doxorubicin on T47D breast cancer cells. In this present study, it was evaluated for its immunomodulatory activities in doxorubicin-treated rats. Thirty male Sprague Dawley rats were divided into five groups consisting of six rats each as follows: Group 1, receiving oral saline 10 ml/kg BW (control group); Group 2, receiving HIF dose 750 mg/kg BW orally, once daily; Group 3, receiving HIF dose 1.500 mg/kg BW orally, once daily; Group 4, given oral saline 10 ml/kg BW (normal group); Group 5, receiving HIF dose 1.500 mg/kg BW orally, once daily. The rats of group 1-3 were intramuscularly administered with doxorubicin at a dose of 4.67 mg/kg BW at the days 1 and 4 to suppress immune functions. Concomitantly, the rats were treated with saline or HIF for seven consecutive days (1 to 7). Treatment of HIF succeeded in reducing side effects of doxorubicin based on increasing lymphocyte density and phagocytosis activity and capacity of macrophages, as well as increasing the CD8+blood level and decreasing spleen IL-10 expression. Hexane insoluble fraction of of ethanolic extract of Ficus septica leaves has potential as a protective agent combined with doxorubicin.

Hesperidin increase cytotoxic effect of doxorubicin in MCF-7 cells

Hesperidin, a flavonoid, shows strong cytotoxic effect in several cancer cell lines. The aim of this research was to investigate cytotoxic activities of hesperidin alone and in combination with doxorubicin. Cell viability assay of hesperidin, doxorubicin, and combination treatments were carried out by using MTT assay. Apoptosis assay was done using double staining method using Ethidium Bromide-Acridine Orange. Hesperidin did not show cytotoxic effect but doxorubicin showed cytotoxic effect with IC50 467 nM. Hesperidin (5, 50 and 100 μM) increased cytotoxic effect of doxorubicin compared with doxorubicin alone. The strongest cytotoxic activity was showed by the combination of 200 nM doxorubicin and 100 μM hesperidin. Combination treatment of doxorubicin 200 nM and hesperidin 100 μM induced apoptosis in MCF-7 cells. Hesperidin is potentially to be developed as co-chemotherapeutic agent for breast cancer, while molecular mechanism need to be explored.

Curcumin targets multiple enzymes involved in the ROS metabolic pathway to suppress tumor cell growth

Curcumin has been reported to exhibit anti-tumorigenic activity; however, since its precise actions remain unclear, its effects are considered to be deceptive. In the present study, we confirmed the anti-tumorigenic effects of curcumin on CML-derived leukemic cells in a xenograft model and in vitro culture system. In vitro pull-down and mass analyses revealed a series of enzymes (carbonyl reductase, glutathione-S-transferase, glyoxalase, etc.) that function in a reactive oxygen species (ROS) metabolic pathway as curcumin-binding targets, the expression of which was up-regulated in human leukemia. Curcumin increased ROS levels over the threshold in leukemic cells, and the antioxidant, glutathione (GSH) and overexpression of curcumin-binding enzymes partially mitigated the up-regulation of ROS and growth inhibition caused by curcumin. These results show that curcumin specifically inhibits tumor growth by increasing ROS levels over the threshold through the miscellaneous inhibition of ROS metabolic enzymes. Curcumin has potential in therapy to regulate ROS levels in tumor cells, thereby controlling tumor growth.

Two Active Compounds from Caesalpinia sappan L. in Combination withCisplatin Synergistically Induce Apoptosis and Cell Cycle Arrest on WiDr Cells

Purpose: The aim of this study is to observe the synergistic effect of two active compounds of secang, brazilin and brazilein, combined with cisplatin on WiDr colon cancer cells. Methods: Cytotoxic activities of brazilin (Bi) and brazilein (Be) in single and in combination with cisplatin (Cisp) were examined by MTT assay. Synergistic effect was analyzed by combination index (CI) parameter. Apoptosis and cell cycle profiles were observed by using flow cytometry. Results: The result of MTT assay showed that IC50 value of brazilin and brazilein on WiDr cancer cells were 41 µM and 52 µM respectively. The combination of ½ IC50 of Bi-Cisp reduced cells viability up to 64% and showed synergistic effect with CI value less than 1 (CI = 0.8). The combinations of ½ IC50 of Be-Cisp also reduced cells viability up to 78% and showed synergistic effect (CI=0.65). Combination of Bi-Cisp and Be-Cisp induced apoptosis higher than the single treatments. Further analysis on the cell cycle progression showed that single treatment of ½ IC50 of Be and Bi induced S-phase and G2/M-phase accumulation, while combination of Be-Cisp and Bi-Cisp enhanced S-phase accumulation. Conclusion: Both combination of Bi-Cisp and Be-Cisp showed synergistic effect on WiDr cells through induction of apoptosis and halted the cell cycle progression, thus, WiDr cells growth were significantly reduced.

Curcumin Analog Pentagamavunon-1 (PGV-1) Sensitizes Widr Cells to 5-Fluorouracil through Inhibition of NF-κB Activation

Cell cycle regulation and the NF-κB pathway in cancer cells are important in mediating resistance to 5-Fluorouracil (5-FU). Pentagamavunon-1 (PGV-1), a curcumin analog, is known to exhibit stronger growth inhibitory effects than curcumin itself in several cancer cells. In this study, we evaluated the potency of PGV-1 in combination with 5-FU in WiDr colon cancer cells. In MTT assays, PGV-1 did not only exhibit stronger growth inhibitory effects than both 5-FU and curcumin, but also enhanced the cytotoxicity of 5-FU. Flow cytometry demonstrated that single treatments with PGV-1 and 5-FU resulted in different effects on cell cycle profiles. PGV-1 induced G2/M arrest while 5-FU caused S-phase arrest at low concentration (1 μM) and G1-phase arrest at high concentration (100 μM). Interestingly, the combination of 5-FU and PGV-1 enhanced cell accumulation in S-phase. Although a single treatment with either 5-FU or PGV-1 increased cyclin D1 at the protein level, the combination treatment resulted in significant suppression. In addition, PGV-1 inhibited activation of NF-κB and suppressed the expression of cyclooxygenase-2, an NF-κB downstream protein. In conclusion, PGV-1 increased the cytotoxic effect of 5-FU on WiDr cells through inhibition of NF-κB activation.