**5. Important Bioactivities**

With the growing interest towards functional materials from natural sources, fucoidans isolated from different seaweeds have been scientifically and industrially studied aiming at assessing their potential biological activities such as anti-inflammatory, immunomodulatory, antioxidant, anticoagulant, antivirus, and anticancer properties [5,12]. Besides the cellular level activities, studies also focused on non-classical studies from fucoidans such as angiogenesis, treatment of intestinal diseases (inflammatory bowel disease and gastric ulcers), treatment of metabolic syndrome, and bone health supplements [13,14]. In this Special Issue, many articles provided bioactivities and physiological functionalities of fucoidans; for example, fucoidans of Moroccan brown seaweed act as an elicitor of natural defenses in date palm roots [15] and fucoidan from *Ascophyllum nodosum* suppresses postprandial hyperglycemia by inhibiting Na+/glucose cotransporter 1 activity [16]. It is well known that fucoidans show a protective effect against apoptosis [17] and ultraviolet B-induced photodamage [18]. On the other hand, one of the important bioactivities of fucoidans is an anticancer effect. Two articles in the Special Issue published anticancer activities of fucoidan via inducing apoptosis of cancer cells [19,20]. M. E. Reyes et al. reviewed brown seaweed fucoidan in cancer, in particular introduced implications in metastasis and drug resistance [21]. Typical bioactivities of fucoidans are antibacterial and antioxidant. Fucoidans in this Special Issue exhibited antibacterial effect against *Helicobacter pylori* infection [22] and antioxidant effect against oxidative stress [23]. Fucoidans can be effective on skin. Takahashi, M. et al. [24] have studied the improvement of psoriasis by alteration of the gu<sup>t</sup> environment by oral administration of fucoidan. Furthermore, fucoidans were recently utilized to create a multilayer film with chitosan to bind fibroblast growth factor-2 for pharmaceutical-grade use [25].
