scholarly journals Degradation of Sargassum crassifolium Fucoidan by Ascorbic Acid and Hydrogen Peroxide, and Compositional, Structural, and In Vitro Anti-Lung Cancer Analyses of the Degradation Products

Marine Drugs ◽  
2020 ◽  
Vol 18 (6) ◽  
pp. 334 ◽  
Author(s):  
Tien-Chiu Wu ◽  
Yong-Han Hong ◽  
Yung-Hsiang Tsai ◽  
Shu-Ling Hsieh ◽  
Ren-Han Huang ◽  
...  

Fucoidans possess multiple biological functions including anti-cancer activity. Moreover, low-molecular-weight fucoidans are reported to possess more bioactivities than native fucoidans. In the present study, a native fucoidan (SC) was extracted from Sargassum crassifolium pretreated by single-screw extrusion, and three degraded fucoidans, namely, SCA (degradation of SC by ascorbic acid), SCH (degradation of SC by hydrogen peroxide), and SCAH (degradation of SC by ascorbic acid + hydrogen peroxide), were produced. The extrusion pretreatment can increase the extraction yield of fucoidan by approximately 4.2-fold as compared to the non-extruded sample. Among SC, SCA, SCH, and SCAH, the chemical compositions varied but structural features were similar. SC, SCA, SCH, and SCAH showed apoptotic effects on human lung carcinoma A-549 cells, as illustrated by loss of mitochondrial membrane potential (MMP), decreased B-cell leukemia-2 (Bcl-2) expression, increased cytochrome c release, increased active caspase-9 and -3, and increased late apoptosis of A-549 cells. In general, SCA was found to exhibit high cytotoxicity to A-549 cells and a strong ability to suppress Bcl-2 expression. SCA also showed high efficacy to induce cytochrome c release, activate caspase-9 and -3, and promote late apoptosis of A-549 cells. Therefore, our data suggest that SCA could have an adjuvant therapeutic potential in the treatment of lung cancer. Additionally, we explored that the Akt/mammalian target of rapamycin (mTOR) signaling pathway is involved in SC-, SCA-, SCH-, and SCAH-induced apoptosis of A-549 cells.

Author(s):  
Deepa Priya Ramadoss ◽  
Nageswaran Sivalingam

Objective: The main aim of the study was to investigate the bioactive compound vanillin extracted from proso millet (compound 1), and barnyard millet (compound 2) induces apoptotic cell death and whether it is mediated through mitochondrial pathway in HT-29 and MCF-7 cell line.Methods: The cells were treated with 250 μg/ml and 1000 μg/ml concentration of extracted vanillin for 48 hrs. Cytochrome c release and expression level of pro-apoptotic protein Bax and caspase-9 were detected by western blot analysis.Results: The results reveal that extracted compounds increased the release of cytochrome c and upregulating the expression of Bax and caspase-9 as concentration increases in a dose-dependent manner.Conclusion: The study suggests that the vanillin compound extracted from these millets induces apoptotic cell death through a mitochondria-dependent pathway.


2003 ◽  
Vol 284 (5) ◽  
pp. G821-G829 ◽  
Author(s):  
Wenlin Deng ◽  
De-An Wang ◽  
Elvira Gosmanova ◽  
Leonard R. Johnson ◽  
Gabor Tigyi

We previously showed ( Gastroenterology 123: 206–216, 2002) that lysophosphatidic acid (LPA) protects and rescues rat intestinal epithelial cells (IEC-6) from apoptosis. Here, we provide evidence for the LPA-elicited inhibition of the mitochondrial apoptotic pathway leading to attenuation of caspase-3 activation. Pretreatment of IEC-6 cells with LPA inhibited campothecin-induced caspase-9 and caspase-3 activation and DNA fragmentation. A caspase-9 inhibitor peptide mimicked the LPA-elicited antiapoptotic activity. LPA elicited ERK1/ERK2 and PKB/Akt phosphorylation. The LPA-elicited antiapoptotic activity and inhibition of caspase-9 activity were abrogated by pertussis toxin, PD 98059, wortmannin, and LY 294002. LPA reduced cytochrome c release from mitochondria and prevented activation of caspase-9. LPA prevented translocation of Bax from cytosol to mitochondria and increased the expression of the antiapoptotic Bcl-2 mRNA and protein. LPA had no effect on Bcl-xl, Bad, and Bak mRNA or protein expression. These data indicate that LPA protects IEC-6 cells from camptothecin-induced apoptosis through Gi-coupled inhibition of caspase-3 activation mediated by the attenuation of caspase-9 activation due to diminished cytochrome c release, involving upregulation of Bcl-2 protein expression and prevention of Bax translocation.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3415-3415
Author(s):  
Paul J. Shami ◽  
Vidya Udupi ◽  
Margaret Yu ◽  
Swati Malaviya ◽  
Joseph E. Saavedra ◽  
...  

Abstract NO induces differentiation and apoptosis in Acute Myelogenous Leukemia (AML) cells. Glutathione S-Transferases (GST) play an important role in multidrug resistance and are upregulated in 90% of AML cells. We have designed a novel prodrug class that releases NO on metabolism by GST. O2-(2,4-Dinitrophenyl) 1-[(4-ethoxycarbonyl)piperazin-1-yl]diazen-1-ium-1,2-diolate (JS-K, a member of this class) has potent antileukemic activity. We have previously shown that JS-K induces apoptosis in HL-60 cells by a caspase dependent mechanism (Molecular Cancer Therapeutics2:409-417,2003). The purpose of this study was to determine the pathway through which JS-K induces apoptosis. Western blot analysis showed that treatment of HL-60 cells with JS-K (0 – 1 μM) for 6 hours results in release of Cytochrome c from mitochondria in a dose dependent fashion. Treatment with JS-K resulted in a dose dependent activation of Caspase 9. Sixteen and 24 hours after exposure to 1 μM JS-K, Caspase 9 activity was induced by 393 ± 93% and 237 ± 13% of control, respectively (p = 0.03 at the 24 hours time point). Treatment with JS-K resulted in a dose dependent activation of Caspase 3. Twenty four hours after exposure to 1 μM JS-K, Caspase 3 activity was 208 ± 3.4 % of control (p = 0.02). Treatment with JS-K also resulted in a dose dependent activation of Caspase 8, but to a lesser extent than Caspase 9 and 3. Twenty four hours after exposure to 1 μM JS-K, Caspase 8 activity was 144 ± 5.3 % of control (p = 0.04). We conclude that JS-K activates the intrinsic pathway of apoptosis in leukemia cells by inducing the release of Cytochrome c from mitochondria. (NO1-CO-12400).


2001 ◽  
Vol 281 (5) ◽  
pp. C1596-C1603 ◽  
Author(s):  
Ricky Malhotra ◽  
Zhiwu Lin ◽  
Claudius Vincenz ◽  
Frank C. Brosius

Glucose uptake and metabolism inhibit hypoxia-induced apoptosis in a variety of cell types, but the underlying molecular mechanisms remain poorly understood. In the present study, we explore hypoxia-mediated cell death pathways in Jurkat cells in the presence and absence of extracellular glucose. In the absence of extracellular glucose, hypoxia caused cytochrome c release, caspase 3 and poly(ADP-ribose)polymerase cleavage, and DNA fragmentation; this apoptotic response was blocked by the caspase 9 inhibitor z-LEHD-FMK. The presence of extracellular glucose during hypoxia prevented cytochrome c release and activation of caspase 9 but did not prevent apoptosis in Jurkat cells. In these conditions, overexpression of the caspase 8 inhibitor v-FLIP prevented hypoxia-mediated cell death. Thus hypoxia can stimulate two apoptotic pathways in Jurkat cells, one dependent on cytochrome c release from mitochondria that is prevented by glucose uptake and metabolism, and the other independent of cytochrome c release and resulting from activation of the death receptor pathway, which is accelerated by glucose uptake and metabolism.


FEBS Letters ◽  
1998 ◽  
Vol 437 (1-2) ◽  
pp. 163-163 ◽  
Author(s):  
Hélène Stridh ◽  
Monica Kimland ◽  
Dean P. Jones ◽  
Sten Orrenius ◽  
Mark B. Hampton

2013 ◽  
Vol 109 (03) ◽  
pp. 532-539 ◽  
Author(s):  
Jeannine Winkler ◽  
Margaret Rand ◽  
Markus Schmugge ◽  
Oliver Speer

SummaryAlthough platelets possess the hallmarks of apoptosis such as activation of caspases, cytochrome c release and depolarisation of the mitochondrial transmembrane potential (ΔΨm), their entire apoptotic-signalling pathway is not totally understood. Therefore we studied the expression of various apoptotic proteins and found that platelets contain the pro-apoptotic proteins Omi/HtrA2 and Smac/Diablo, as well as their target the X-linked inhibitor of apoptosis XIAP. Omi/HtrA2 and Smac/Diablo were released from mitochondria into the platelet cytosol together with cytochrome c after induction of apoptosis by the Ca2+ ionophore A23187 or the BH3 mimetic ABT-737, and to a lesser extent, after platelet stimulation with collagen and thrombin. Inhibition of Omi/HtrA2 led to decreased levels of activated caspase-3/7 and caspase-9, but did not abolish loss of ΔΨm or prevent release of Omi/HtrA2 from mitochondria. These results indicate that platelets have a functional intrinsic apoptotic-signalling pathway including the pro-apoptotic protease Omi/HtrA2 and its target protein XIAP.


2002 ◽  
Vol 282 (6) ◽  
pp. C1290-C1297 ◽  
Author(s):  
Qing Yuan ◽  
Ramesh M. Ray ◽  
Leonard R. Johnson

C1297, 2002; 10.1152/ajpcell.00351.2001.We have shown previously that depletion of polyamines delays apoptosis induced by camptothecin in rat intestinal epithelial cells (IEC-6). Mitochondria play an important role in the regulation of apoptosis in mammalian cells because apoptotic signals induce mitochondria to release cytochrome c. The latter interacts with Apaf-1 to activate caspase-9, which in turn activates downstream caspase-3. Bcl-2 family proteins are involved in the regulation of cytochrome c release from mitochondria. In this study, we examined the effects of polyamine depletion on the activation of the caspase cascade, release of cytochrome cfrom mitochondria, and expression and translocation of Bcl-2 family proteins. We inhibited ornithine decarboxylase, the first rate-limiting enzyme in polyamine synthesis, with α-difluoromethylornithine (DFMO) to deplete cells of polyamines. Depletion of polyamines prevented camptothecin-induced release of cytochrome c from mitochondria and decreased the activity of caspase-9 and caspase-3. The mitochondrial membrane potential was not disrupted when cytochrome c was released. Depletion of polyamines decreased translocation of Bax to mitochondria during apoptosis. The expression of antiapoptotic proteins Bcl-xL and Bcl-2 was increased in DFMO-treated cells. Caspase-8 activity and cleavage of Bid were decreased in cells depleted of polyamines. These results suggest that polyamine depletion prevents IEC-6 cells from apoptosis by preventing the translocation of Bax to mitochondria, thus preventing the release of cytochrome c.


2003 ◽  
Vol 285 (5) ◽  
pp. G980-G991 ◽  
Author(s):  
Sujoy Bhattacharya ◽  
Ramesh M. Ray ◽  
Mary Jane Viar ◽  
Leonard R. Johnson

Intracellular polyamine homeostasis is important for the regulation of cell proliferation and apoptosis and is necessary for the balanced growth of cells and tissues. Polyamines have been shown to play a role in the regulation of apoptosis in many cell types, including IEC-6 cells, but the mechanism is not clear. In this study, we analyzed the mechanism by which polyamines regulate the process of apoptosis in response to tumor necrosis factor-α (TNF-α). TNF-α or cycloheximide (CHX) alone did not induce apoptosis in IEC-6 cells. Significant apoptosis was observed when CHX was given along with TNF-α, as indicated by a significant increase in the detachment of cells, caspase-3 activity, and DNA fragmentation. Polyamine depletion by treatment with α-difluoromethylornithine significantly reduced the level of apoptosis, as judged by DNA fragmentation and the caspase-3 activity of attached cells. Apoptosis in IEC-6 cells was accompanied by the activation of upstream caspases-6, -8, and -9 and NH2-terminal c-Jun kinase (JNK). Inhibition of JNK activation prevented caspase-9 activation. Polyamine depletion prevented the activation of JNK and of caspases-6, -8, -9, and -3. SP-600125, a specific inhibitor of JNK activation, prevented cytochrome c release from mitochondria, JNK activation, DNA fragmentation, and caspase-9 activation in response to TNF-α/CHX. In conclusion, we have shown that polyamine depletion delays and decreases TNF-α-induced apoptosis in IEC-6 cells and that apoptosis is accompanied by the release of cytochrome c, the activation of JNK, and of upstream caspases as well as caspase-3. Polyamine depletion prevented JNK activation, which may confer protection against apoptosis by modulation of upstream caspase-9 activation.


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