Carrageenans and Their Oligosaccharides from Red Seaweeds Ahnfeltiopsis flabelliformis and Mastocarpus pacificus (Phyllophoraceae) and Their Antiproliferative Activity

Abstract

Comparative structural analysis of gelling polysaccharides from A. flabelliformis and M. pacificus belonging to Phyllophoraceae and the effect of their structural features and molecular weight on human colon cancer cell lines (HT-29, DLD-1, HCT-116) was carried out. According to chemical analysis, IR and NMR spectroscopies, M. pacificus produces kappa/iota-carrageenan with a predominance of kappa units and minor amounts of mu and/or nu units, while the polysaccharide from A. flabelliformis is iota/kappa-carrageenan (predominance of iota units) and contains negligible amounts of beta- and nu-carrageenans. Iota/kappa- (Afg-OS) and kappa/iota-oligosaccharides (Mp-OS) were obtained from the original polysaccharides through mild acid hydrolysis. The content of more sulfated iota units in Afg-OS (iota/kappa 7:1) was higher than in Mp-OS (1.0:1.8). The poly- and oligosaccharides up to 1 mg/mL did not show a cytotoxic effect on all tested cell lines. Polysaccharides showed an antiproliferative effect only at 1 mg/mL. Oligosaccharides had a more pronounced effect on HT-29 and HCT-116 cells than the original polymers, while HCT-116 cells were slightly more sensitive to their action. Kappa/iota-oligosaccharides exhibit a greater antiproliferative effect and more strongly decrease the number of colonies forming in HCT-116 cells. At the same time, iota/kappa-oligosaccharides inhibit cell migration more strongly. Kappa/iota-oligosaccharides induce apoptosis in the SubG0 and G2/M phases, while iota/kappa-oligosaccharides in the SubG0 phase.

Carrageenan oligosaccharide alleviates intestinal damage via gut microflora through activating IMD/relish pathway in female Drosophila melanogaster

“…47,48 However, studies focused on COS and CGN are often inconclusive. Kravchenko et al 49 reported that poly-and oligosaccharides of carrageenan did not exhibit any cytotoxic effect on human colon cancer cell lines at concentrations of up to 1 mg/mL. Similarly, female flies fed diet supplemented with 0.625, 1.25, and 2.5 mg/mL COS showed no toxic effect on flies in this study.…”

“…However, studies focused on COS and CGN are often inconclusive. Kravchenko et al 49 . reported that poly‐ and oligosaccharides of carrageenan did not exhibit any cytotoxic effect on human colon cancer cell lines at concentrations of up to 1 mg/mL.…”

Study on isolation methods of natural polysaccharides

“…Phycoidans are abundant in marine life and are recognized as promising active biological biopolymers with antibacterial and antiviral capabilities. Carrageenan is a water-soluble sulfated polysaccharide made up of repeated disaccharide galactose-3,6anhydrogalactose (3,6-AG) units (sulfated and non-sulfated) linked by alternating α-(1,3) and ß-(1,4) glycosidic bonds [31,32,33]. It accounts for approximately 80% of the dry matter in seaweed and mainly replaces cellulose as a structural ingredient.…”

Modulating Ionic Linkages in the Heterocyclic Sulfated Polysaccharide Carrageenan for Enhanced Selectivity Against Amelanotic Melanoma Cells

“…[36] In this pathway, the apoptosome is formed after complexing of an initiator Procaspase 9 with cytochrome-C (a mitochondrial protein) and APAF-1 (apoptotic protease activating factor-1) [37,38] and in extrinsic pathway, it initiate pro-caspase-8 activity to lead the formation of Caspase-8 which cleaves Bid (BH3-interactingdomain death agonist) and tBid (truncated Bid), which cause disruption of mitochondrial outer membrane for the releasing of cytochrome-C as explained in the Figure 9. [39][40][41][42][43] There are other mechanisms, which has been reported for antitumor activity by inducing inflammation such as first mechanism is about the binding of carrageenan with TLR-4 and activation of TLR-4/NfkB pathway. Second one is the induction of oxidative stress via increment in H 2 O 2 .…”

“…Intrinsic apoptosis pathway induced at the mitochondria via binding of carrageenan with death receptors [36] . In this pathway, the apoptosome is formed after complexing of an initiator Pro‐caspase 9 with cytochrome‐C (a mitochondrial protein) and APAF‐1 (apoptotic protease activating factor‐1) [37,38] and in extrinsic pathway, it initiate pro‐caspase‐8 activity to lead the formation of Caspase‐8 which cleaves Bid (BH3‐ interacting‐ domain death agonist) and tBid (truncated Bid), which cause disruption of mitochondrial outer membrane for the releasing of cytochrome‐C as explained in the Figure 9 [39–43] …”