# Anticancer Effects of Seaweed-Derived Bioactive Compounds
## 3 Seaweed Polysaccharide  
Brown seaweeds are more highly enriched with polysaccharides than other seaweeds, such as yellow and green seaweeds. These polysaccharides from brown seaweeds have attracted great attention owing to their therapeutic effects on cancers. The structures of polysaccharides are shown in Figure 1. Polysaccharides are composed of laminarin (**1**), al \begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline
**Seaweed** & **Active Ingredient(s)** & **Activity** \\ \hline _Undaria pinnatifida_ & Fucoxanthin (**25**) extracts & Trigger apoptosis in PC-3 cells via caspase-3 \\ \hline _Leuthesia nana_ & Bromo phenol derivatives (**18–23**) & Cytotoxicity in various human cancer cells, including MCF-7A549, BGC823, HCT-8 cell lines \\ \hline _Fucus serartus, luminaria digital,_ _asophyllm nodsum, pelvicial caliculata_ & Astaxanthin, \(\beta\)-carotene, zeaxanthin & Agent for cerebrovascular disease, photoproduction of eye, and anticancer agent \\ \hline _Cystoseira abies-marina_ & Cystoazorones A (**30**) and B (**31**) & Anticancer activity against HeLa cells \\ \hline _Dilophus liquidatus_ & Diterpenoids (**33–36** and **37**) & Cytotoxic activity against murine leukemia cells (p-388) and p-388 doxorubicin-resistant cells with IC50 3.64–13.3 \(\mu\)M and IC\({}_{50}\) 5.95 to 12.9 \(\mu\)M respectively \\ \hline _Stypopodium fabelliforme_ & Flabellinol (**38**), flabellinone (**39**) & Cytotoxicity against NCI-H460 cells (IC\({}_{50}\) 9 \(\mu\)M and 14 \(\mu\)M, respectively) \\ \hline _Tonia atomaria_ & Atomarianone B (**41**) & Cytotoxic activity against two lung cancer cell lines (NSCLC-N6 and A549) \\ \hline _Plocamium sutrii_ & Monoterpenes (**44–49**) & Cytotoxic effects toward esophageal cancer cell lines (WHCO1) with an IC\({}_{50}\) value in the range 6.6–15.1 \(\mu\)M \\ \hline _Stypopodium fabelliforme_ & 14-keto-stypodi diacetate (**50**) & Cytotoxic effects on the prostate cancer cell line (DU-145) with IC\({}_{50}\) of 24 \(\mu\)M \\ \hline _Landsburgia quereifolia_ & Deoxylapachol (**51**) & Cytotoxicity to P-388 leukemia cells \\ \hline _Perithalia capillaries_ & Bis-prenylated quinone & Antiproliferative effects toward HL-60 cells (IC\({}_{50}\) 0.34 uM) \\ \hline _sargassum siliquaststrum_ & Sargachromanol E (**52**) & Growth inhibitory effects against HL-60 cells via caspase-3 dependent apoptosis induction \\ \hline _Cystoseira crinita_ & Tetraprenyltoluquinols (**53**) and (**54**) & Inhibiting growth of on HMO2, HepG2, and MCF7 cancer cell lines \\ \hline _Laurencia tristicta_ & Cholest-5-en-3b-,7a-diol (**55**) & Cytotoxic effects against the tested cancer cell lines A549, BGC823, Bel 7402, HCT-8, and HeLa with IC\({}_{50}\) values of 16.8 \(\mu\)M, 5.1 \(\mu\)M, 0.5 \(\mu\)M, 0.3 \(\mu\)M, respectively \\ \hline _Cystoseira myrica_ & 3-Keto-22-epi-28-nor-cathasterone (**56**), cholest-4-ene-3,6-dione (**57**) & Antiproliferative effects to HepG2 and HCT116 cancer cells \\ \hline _Pelvetica siliquosa, Cystoseira feniculaca, Sargassum angustiifolium_ & Fucosterol (**58**) & Cytotoxic effects against various types of cancer cell lines, including HT-29 colon cancer cells, breast cancer, promyelocytic leukemia, lung cancer, and cervical cancer \\ \hline \end{tabular}
\end{table} 
Table 1: Cont. ginate (2), fucoidan (3), and their derivatives. Some species of brown seaweed also contain a small amount of porphyrin (4) [15] and alginic acid (5) derivatives that exhibit anticancer potential and can be utilized as a drug delivery system. Meanwhile, some species of red seaweeds contain carrageenanan (6), which contains sulfated polysaccharides, and are used as stabilizers, gelling agents, binders, and additives in the food and pharmaceutical industries [16]. Seaweed polysaccharides possess similar repeating units of carbohydrates with different sulfation and molecular weights. The composition of sulfated polysaccharides and their biological activities are related to different isolation techniques and habituating areas [17].