# Therapeutic Potential of Seaweed-Derived Bioactive Compounds for Cardiovascular Disease Treatment
## 4 Seaweed-Derived Peptides with Therapeutic Potential against CVD  
As the importance of marine organisms as sources of novel bioactive substances is growing, marine bioactive peptides have received much attention recently. Bioactive peptides are usually 2\(-\)20 amino acid residues [123]. Depending on the amino acid sequence, they may be involved in various biological functions such as antioxidant, anti-cancer, opioid agonists or antagonists, immunomodulatory, anti-thrombotic, anti-atherosclerotic, and antimicrobial activities, in addition to nutrient utilization [123]. A pepsin-hydrolyzed peptide (VECYGPNNRPQF) from _Chlorella vulgaris_ protein waste possessed potent antioxidant activity against various free radicals and exhibited gastrointestinal enzyme resistance. Still, no cytotoxicity was observed in human lung fibroblast cell lines (WI-38) [124]. The antitumor polypeptide Y2 was obtained from the trypsin digest of _Spirulina platensis_ proteins [125]. [PERSON] et al. found that enzymatic hydrolysates from a phycobili protein byproduct of _Porphyna columbina_ exhibited immunosuppressive effects on rat splenocytes by enhancing IL-10 production and inhibiting the production of TNF-\(\alpha\) and IFN-\(\gamma\)[126]. Several bioactive peptides have been identified from _Undaria pimantifida_ (_U. pimantifida_) and _Palmaria palmate_ (_P. palmate_), which exerted an anti-hypertensive effect in vitro by showing potent ACE inhibition activity and a significant reduction in blood pressure observed in an oral feeding rat model [127; 128; 129; 130; 131]. In particular, bioactive peptides derived from various seaweeds (brown seaweed 10, red seaweed 10, and green seaweed 10) have antihypertensive effects through ACE inhibition (Table 3). One mg/kg BW of Leu-Trp, Val-Tyr, Ile-Tyr, Phe-Tyr, and Ile-Tyr from _U. pimantifida_ decreased the systolic blood pressure in spontaneously hypertensive rats (SHRs) [127]. Furthermore, [PERSON] et al. reported that both single administration and repeated oral administration of synthetic dipeptides (Tyr-His, Lys-Tyr, Phe-Tyr, and Ile-Tyr) from _U. pimantifida_ significantly decreased the blood pressure in spontaneously hypertensive rats (SHRs) [129]. The \(\alpha\) and \(\beta\) subunits of phycoerythrin (a major light-harvesting protein pigment of red seaweed) from _P. palmate_ showed ACE inhibition activity [130]. Ile-Leu-Ala-Pro, Leu-Leu-Ala-Pro, and Met-Ala-Gly-Val-Asp-His-Ile purified from _P. palmate_ inhibited DPP-IV, a novel biomarker of ischemic cardiovascular disease, and had insulinotropic potency [131; 132]. Ile-Pro and Ala-Phe-Leu isolated from _Chlorophyta U. rigida_ exhibited ACE inhibition activity. [PERSON] et al. [25] demonstrated significant systolic blood pressure reduction in hypertensive rats following 10 mg/kg body weight of Val-Glu-Gly-Tyr administered orally. _Gracilariopsis lemaneiformis_ inhibited ACE-I with IC\({}_{50}\) values of 9.64. 23.94, and 474.36 \(\upmu\)M for the peptides FQIN [M(O)] CILR, TGAPCR, and Gln-Val-Glu-Tyr, respectively [133; 134]. The administration of 10 mg/kg of FQIN [M(O)] CILR and TGAPCR had antihypertensive effects in spontaneously hypertensive rats [133]. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Source** & **Target Disease/Mechanism** & **Biactive Component** & **Model** & **Biological Effect** & **Reference** \\ \hline \multirow{4}{*}{ \begin{tabular}{c} _Undria_ \\ _primantifgals_ \\ \end{tabular}