| 1. |
- Castro Alves, Victor, 1986-, et al.
(författare)
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Polysaccharides from chayote enhance lipid efflux and regulate NLRP3 inflammasome priming in macrophage-like THP-1 cells exposed to cholesterol crystals
- 2019
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Ingår i: International Journal of Biological Macromolecules. - : Elsevier. - 0141-8130 .- 1879-0003. ; 127, s. 502-510
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Tidskriftsartikel (refereegranskat)abstract
- The contribution of dietary fiber to decrease the risk of atherosclerosis may occur through other mechanisms besides the increased excretion of cholesterol. Although macrophages are crucial for lipid clearance, the excessive uptake of cholesterol crystals (CC) by these cells induce NLRP3 inflammasome and foam cell formation. Thus, we investigated whether the water-soluble DF from chayote (WSP) regulate CC-pretreated macrophage-like THP-1 cells. Linkage analysis indicated that WSP is composed mainly of pectic homogalacturonan and highly branched type I rhamnogalacturonan as well as hemicellulosic material including glucomannan, xyloglucan, and glucurono(arabino)xylan. WSP reduced interleukin (IL)-1β and chemokine release in CC-pretreated macrophages. Notably, WSP also reduced lipid accumulation in cells previously exposed to CC. Furthermore, WSP upregulated liver X receptor alpha expression, which may account for increased lipid efflux, and reduced matrix metallopeptidase 9 expression. WSP also reduced active caspase-1 protein levels, and downregulated NLRP3 and IL-1β gene expression in CC-pretreated cells, suggesting that this polysaccharide fraction regulates the priming signals required for NLRP3 inflammasome activation. Thus, WSP regulate lipid efflux and suppress inflammasome priming in macrophages, suggesting that the health benefits of this dietary fiber could go beyond its physical properties on the gastrointestinal tract.
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| 2. |
- Ramos do Prado, Samira Bernardino, 1990-, et al.
(författare)
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Migration and proliferation of cancer cells in culture are differentially affected by molecular size of modified citrus pectin
- 2019
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Ingår i: Carbohydrate Polymers. - : Elsevier. - 0144-8617 .- 1879-1344. ; 211, s. 141-151
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Tidskriftsartikel (refereegranskat)abstract
- While chemically and thermally modified citrus pectin (MCP) has already been studied for health benefits, it is unknown how size-fractionated oligo- and polysaccharides differentially affect cancer cell behavior. We produced thermally MCP and fractionated it by molecular size to evaluate the effect these polymers have on cancer cells. MCP30/10 (between 30 and 10 kDa) had more esterified homogalacturonans (HG) and fewer rhamnogalacturonans (RG-I) than MCP and MCP30 (higher than 30 kDa), while MCP10/3 (between 10 and 3 kDa) showed higher amounts of type I arabinogalactans (AGI) and lower amounts of RG-I. MCP3 (smaller than 3 kDa) presented less esterified HG and the lowest amount of AGI and RG-I. Our data indicate that the enrichment of de-esterified HG oligomers and the AGI and RG-I depletions in MCP3, or the increase of AGI and loss of RGI in MCP30/10, enhance the anticancer behaviors by inhibiting migration, aggregation, and proliferation of cancer cells.
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| 3. |
- Ramos do Prado, Samira Bernardino, 1990-, et al.
(författare)
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Ripening-induced chemical modifications of papaya pectin inhibit cancer cell proliferation
- 2017
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 7, s. 1-17
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Tidskriftsartikel (refereegranskat)abstract
- Papaya (Carica papaya L.) is a fleshy fruit with a rapid pulp softening during ripening. Ripening events are accompanied by gradual depolymerization of pectic polysaccharides, including homogalacturonans, rhamnogalacturonans, arabinogalactans, and their modified forms. During intermediate phases of papaya ripening, partial depolymerization of pectin to small size with decreased branching had enhanced pectin anti-cancer properties. These properties were lost with continued decomposition at later phases of ripening. Pectin extracted from intermediate phases of papaya ripening markedly decreased cell viability, induced necroptosis, and delayed culture wound closing in three types of immortalized cancer cell lines. The possible explanation for these observations is that papaya pectins extracted from the third day after harvesting have disrupted interaction between cancer cells and the extracellular matrix proteins, enhancing cell detachment and promoting apoptosis/necroptosis. The anticancer activity of papaya pectin is dependent on the presence and the branch of arabinogalactan type II (AGII) structure. These are first reports of AGII in papaya pulp and the first reports of an in vitro biological activity of papaya pectins that were modified by natural action of ripening-induced pectinolytic enzymes. Identification of the specific pectin branching structures presents a biological route to enhancing anti-cancer properties in papaya and other climacteric fruits.
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