Fucoidan Induces Apoptosis in A2058 Cells through ROS-exposed Activation of MAPKs Signaling Pathway

Fucoidan, a natural component of brown seaweed, has various biological activities such as anticancer activity, anti-oxidant, and anti-inflammatory against various cancer cells. However, the fucoidan has been implicated in melanoma cells via apoptosis signaling pathway. Therefore, we investigated apoptosis with fucoidan in A2058 human melanoma cells with dose- and time-dependent manners. In our results, A2058 cells viability decreased at relatively short-time and low-concentration through fucoidan. This effects of fucoidan on A2058 cells appeared to be mediated by the induction of apoptosis, as manifested by morphological changes through DNA-binding dye Hoechst 33342 staining. When a dose of 80 µg/mL fucoidan was treated, the cells were observed: crescent or ring-like structure, chromatin condensation, and nuclear fragmentation. With the increase at 100 µg/mL fucoidan, the cell membrane is intact throughout the total process, including membrane blebbing and loss of membrane integrity as well as increase of sub-G1 DNA. Furthermore, to understand the exact mechanism of fucoidan-treated in A2058 cells, western blotting was performed to detect apoptosis-related protein expression. In this study, Bcl-2 family proteins can be regulated by fucoidan, suggesting that fucoidaninduced apoptosis is modulated by intrinsic pathway. Therefore, expression of Bcl-2 and Bax may result in altered permeability, activating caspase-3 and caspase-9. And the cleaved form of poly ADP-ribose polymerase was detected in fucoidan-treated A2058 cells. These results suggest that A2058 cells are highly sensitive to growth inhibition by fucoidan via apoptosis, as evidenced by activation of extracellular signal-regulated kinases/ p38/Bcl-2 family signaling, as well as alteration in caspase-9 and caspase-3.

Induction of Apoptosis with Moringa oleifera Fruits in HCT116 Human Colon Cancer Cells Via Intrinsic Pathway

Moringa oleifera Lam (M. oleifera, Moringaceae) is a tree of the Moringaceae family that can reach a height of between 5 and 10 m. The current paper presents cytotoxic effect of M. oleifera fruits and its flavonoids 1 and 2. The viability of HCT116 human colon cancer cells were 38.5% reduced by 150 µg/mL of ethanolic extracts in a concentration-dependent manner; in addition, we observed the apoptotic features of cell shrinkage and decreased cell size. Bcl-2 family proteins were regulated as determined by Western blotting analysis, suggesting that M. oleifera fruits and their flavonoids 1 and 2 induced apoptosis through an intrinsic pathway. Based on our findings, 70% ethanolic extracts of M. oleifera fruits and flavonoids 1 and 2 might be useful as cytotoxic agents in colorectal cancer therapy.

Induction of Apoptosis with Kigelia africana fruits in HCT116 Human Colon Cancer Cells via MAPKs Signaling Pathway

Kigelia africana (Lam.) Benth. (Bignoniaceae) is a flowering plants in South, Central and West Africa and commonly known as the sausage tree (Eng.); worsboom (Afr.); umVunguta, umFongothi (Zulu); Modukguhlu (North Sotho); Muvevha (Venda). The dried, powdered fruits are used as dressing for wounds and ulcers, haemorrhoids, rheumatism, purgative, skin-firming, lactation in breast-feeding mothers. The aim of this study is to investigate the cytotoxic and apoptotic potentials of 70% ethanolic extracts of Kigelia africana fruits in HCT116 human colon cancer cells. Treatment of Kigelia africana fruits with various concentrations resulted in a sequence of characteristic of apoptosis, including loss of cell viability and morphological changes. Flow cytometry analysis showed Kigelia africana fruits increased the sub-G1 phase (apoptosis) population. Apoptosis confirmed by annexin V-fluorescein isothiocyanate and propidium iodide double staining in HCT116 human colon cancer cell lines. Moreover, analysis of the mechanism indicated that Kigelia africana fruits showed an increased Bax and Bcl-2 expressions in a dose-dependent manner, resulting in activation of hallmarks of apoptotic events, caspase-3, caspase-9 and cleaved poly-ADP-ribose polymerase. This is the first report to demonstrate the cytotoxicity of Kigelia africana fruits on HCT116 human colon cancer cells.

Anti-inflammatory Activity of Fucoidan with Blocking NF-kappaB and STAT1 in Human Keratinocytes Cells

Fucoidan, a sulfated polysaccharide is found in several types of edible brown algae. It has shown numerous biological activities; however, the molecular mechanisms on the activity against atopic dermatitis have not been reported yet. We now examined the effects of fucoidan on chemokine production co-induced by TNF-alpha/IFN-gamma, and the possible mechanisms underlying these biological effects. Our data showed that fucoidan inhibited the TNF-alpha/IFN-gamma-induced production of thymus and activation-regulated chemokine (TARC) and macrophagederived chemokine (MDC) mRNA in human keratinocytes HaCaT cells. Also, fucoidan suppressed phosphorylation of nuclear factor kappa B (NF-kappaB) and activation of signal transducer and activator of transcription (STAT)1 in a dose-dependent manner. In addition, fucoidan significantly inhibited activation of extracellular-signal-regulated kinases (ERK) phosphorylation. These data indicate that fucoidan shows anti-inflammatory effects by suppressing the expression of TNF-alpha/IFN-gamma-induced chemokines by blocking NF-kappaB, STAT1, and ERK1/2 activation, suggestive of as used as a therapeutic application in inflammatory skin diseases, such as atopic dermatitis.