Ethanol extract of Chondracanthus tenellus(Harvey)Hommersand attenuates lipopolysaccharide-induced inflammatory and oxidative response by blocking the NF-κB,MAPKs,and PI3K/Akt signaling pathways

Objective:To investigate whether the ethanol extract of Chondracanthus tenellus(Harvey)Hommersand,a type of red algae,could exhibit anti-inflammatory potential in lipopolysaccharide(LPS)-stimulated macrophages.Methods:The ethanol extract of Chondracanthus tenellus was applied to 100 ng/mL LPS-stimulated RAW 264.7 cells,and cell viability,phagocytic ability,levels of pro-inflammatory factors,and the production of reactive oxygen species were measured.To identify the underlying mechanism of the ethanol extract of Chondracanthus tenellus,the expression of inflammation-regulated genes was estimated.Results:The ethanol extract of Chondracanthus tenellus had no cytotoxic effect at concentrations below 300μg/mL,and reduced the LPS-induced production of inflammatory mediators including nitric oxide(NO)and prostaglandin E2.Furthermore,the extract markedly suppressed the expression of inducible NO synthase and cyclooxygenase-2,as well as the production of reactive oxygen species.The LPS-induced up-regulation of pro-inflammatory cytokines was attenuated by treatment with the ethanol extract of Chondracanthus tenellus,reducing their extracellular secretion.The Chondracanthus tenellus extract also inhibited LPS-mediated activation of nuclear factor-kappa B(NF-κB).In addition,the phosphorylation of mitogen activated protein kinases(MAPKs)and phosphatidylinositol 3 kinase(PI3K)/Akt was markedly increased by LPS,which was significantly abolished by the Chondracanthus tenellus extract.Conclusions:Our findings indicate that the ethanol extract of Chondracanthus tenellus exhibited potential anti-inflammatory and antioxidant effects through downregulating the NF-κB,MAPKs,and PI3K/Akt signaling pathways in LPS stimulated RAW 264.7 macrophages.tenellus extract.Conclusions:Our findings indicate that the ethanol extract of Chondracanthus tenellus exhibited potential anti-inflammatory and antioxidant effects through downregulating the NF-κB,MAPKs,and PI3K/Akt signaling pathways in LPS stimulated RAW 264.7 macrophages.

Ethanol extracts of Hizikia fusiforme induce apoptosis in human prostate cancer PC3 cells via modulating a ROS-dependent pathway

Objective:To investigate whether ethanol extracts of Hizikia fusiforme could induce apoptosis in human prostate cancer PC3 cells.Methods:Cell viability was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide.Apoptosis and mitochondrial membrane potential(MMP)were measured using flow cytometry in PC3 cells.DNA damage was assessed by nuclear staining and DNA fragmentation assay.Expressions of apoptosis-associated proteins were determined by Western blotting assays.Activities of caspase-3,-8,and-9 were determined by colorimetric assay.Moreover,intracellular reactive oxygen species(ROS)generation was detected using a flow cytometer and fluorescence microscope.Results:Treatment of PC3 cells with ethanol extracts of Hizikia fusiforme inhibited proliferation,which was associated with induction of apoptosis,and accompanied by increased expression of Fas,Fas-ligand(Fas L),Bax and t Bid,and decreased expression of Bcl-2.In addition,ethanol extracts of Hizikia fusiforme reduced c-Flip expression and activated caspase-8,-9 and-3,resulting in an increase in poly(ADP-ribose)polymerase(PARP)cleavage.However,in the presence of a pan-caspase inhibitor,ethanol extracts of Hizikia fusiforme-mediated growth inhibition and apoptosis were significantly attenuated.Ethanol extracts of Hizikia fusiforme also destroyed the integrity of mitochondria due to the loss of MMP,leading to cytosolic release of cytochrome c.Moreover,the levels of ROS were markedly increased by treatment with ethanol extracts of Hizikia fusiforme,which was significantly suppressed by the ROS scavenger N-acetyl-L-cysteine.Further investigation of whether ethanol extracts of Hizikia fusiforme-induced apoptosis was related to the generation of ROS was conducted and the results showed that N-acetyl-L-cysteine fully blocked ethanol extracts of Hizikia fusiforme-induced apoptotic events including loss of MMP,activation of caspase-3,the cytosolic release of cytochrome c and cytotoxicity.Conclusions:Ethanol extracts of Hizikia fusiforme have chemopreventive potential via induction of ROS-dependent apoptosis.Therefore,ethanol extracts of Hizikia fusiforme may be useful for developing effective and selective natural sources to inhibit cancer cell proliferation.

Immunostimulatory effect of ethanol extract of Chondracanthus tenellus in RAW 264.7 macrophages in vitro

Objective:To investigate whether ethanol extracts of Chondracanthus tenellus(EECT)could improve immunomodulatory property of murine monocyte/macrophage RAW 264.7 cells.Methods:Cell viability,phagocytic ability,and nitric oxide were measured.The levels of prostaglandin E2 and cytokines were determined using enzyme-linked immunosorbent assay kits.Expression of immunoregulatory response protein was detected by Western blotting assay.Results:As the concentration of EECT increased,the morphology of the cells changed to a typical active macrophage shape,and the phagocytic activity increased significantly.EECT also effectively enhanced the production and secretion of immunomodulatory mediators,such as nitric oxide and prostaglandin E2,and cytokines.In addition,compared with the control group,EECT markedly stimulated the expression of Toll-like receptor 4(TLR4)and myeloid differentiation factor 88,one of the TLR4 adapter molecules.Furthermore,EECT promoted the nucleus translocation of nuclear factor-kappa B(NF-κB)by increasing the phosphorylation and degradation of the inhibitor of NF-κB-α,indicating activation of the NF-κB signaling pathway.Meanwhile,similar trends were found in cells treated with lipopolysaccharide as a positive control.Conclusions:Taken together,the results indicate that EECT has an immunomodulatory effect by increasing the production of immunomodulatory mediators and cytokines through activation of the TLR4/NF-κB signaling pathway.EECT could be used as a potential candidate for medication or dietary supplements to increase immune activity.