Figure 12.

Possible mechanism of action of polysaccharides extracted from macroalgae inducing apoptosis. It represents the mechanism of action of some compounds such as fucoidan, laminarin, carrageenan, and ulvan in the extrinsic and intrinsic apoptosis pathway, modulating target molecules involved in them. The polysaccharides generate an overproduction of ROS and Ca²⁺ intracellular, which causes mitochondrial dysfunction allowing the release of pro-apoptotic compounds to the cytosol, triggering apoptosis. Brown arrows indicate positive or negative regulation of crucial proteins by such polysaccharides. Apaf-1: apoptotic protease activating factor-1; ATM: Ataxia-telangiectasia-mutated; Bax: Bcl-2-associated X protein; Bcl-2: B-cell lymphoma; Bcl-xL: B-cell lymphoma-extra-large; Bid: BH3- interacting domain death agonist; Caspase -3, -6, -7, -8, -9, -10: Cysteinyl aspartic acid-protease -3, -6, -7, -8, -9, -10; DNA-PK: DNA-dependent protein kinase; DR 4/5: Death receptor 4/5; FADD: Fas-associated death domain; Fas: FLIP: (FADD-like IL-1β-converting enzyme)-inhibitory protein; HtrA2: High-temperature requirement protein A2; IAP: Inhibitors of Apoptosis Proteins; MOMP: Mitochondrial Outer Membrane Permeabilization; NF-κB: nuclear factor kappa-light-chain-enhancer of activated B cells; PARP: poly (ADP-ribose) polymerase; RIP: Receptor interacting protein; SMAC/DIABLO: Second mitochondrial activator of caspases/direct IAP binding protein with low PI; tBid: Truncated Bid.