*1.2.1 Biological activity of edible seaweeds*

There two categories of algae as macro-algae (macroscopic) and micro-algae (microscopic) [10, 24]. Although algeas are great source and producers of vitamins, *Major Natural Vegetation in Coastal and Marine Wetlands: Edible Seaweeds DOI: http://dx.doi.org/10.5772/intechopen.88303*


### **Table 1.**

*Plant Communities and Their Environment*

increasingly important, the world seaweed production in 2000, including wild and

*laciniata*/*Porphyra umbilicalis*), Gim (*Pyropia*, *Porphyra*) and Nori (*Porphyra*) [23]. Common edible Green algaes are Chlorella (*Chlorella* sp.), Gutweed (*Ulva intestinalis*), Sea grapes or *green caviar* (*Caulerpa lentillifera*), Sea lettuce (*Ulva* spp.) [23].

There two categories of algae as macro-algae (macroscopic) and micro-algae (microscopic) [10, 24]. Although algeas are great source and producers of vitamins,

As it was mentioned above, seaweeds are categorized into three classes of Rhodophyta (red), Phaeophyta (brown) and Chlorophyta (green) marine macroalgae. Some reported common edible Brown algae (Phaeophycae) are divided as Kelp, Fucales and Ectocarpales, given in **Table 1** [23]. Common edible Red algae (Rhodophyta) are Carola (*Callophyllis* spp.), Carrageen moss (*Mastocarpus stellatus*), Dulse (*Palmaria palmata*), *Eucheuma* (*Eucheuma spinosum* and *Eucheuma cottonii*), Gelidiella (*Gelidiella acerosa*), Ogonori (*Gracilaria*), Grapestone *Mastocarpus* 

*papillatus*, *Hypnea*, Irish moss (*Chondrus crispus*), Laverbread (*Porphyra* 

softened, has reached about 10 million tons [21, 22].

*1.2.1 Biological activity of edible seaweeds*

**194**

**Figure 3.**

**Figure 2.**

*Some species of red seaweeds [13].*

*Some species of green seaweeds [13].*

*The list of the common edible Brown algae types (Kelps, Fucales and Ectocarpales).*

minerals and proteins and fatty acids but not great efforts have been allocated on the research of these plant like organisms [10, 25, 26]. Seaweeds are considered as source of soluble dietary fibers, proteins, minerals, vitamins, antioxidants, phytochemicals, and polyunsaturated fatty acids, with low caloric value. These nutrient factors are directly influenced by external environmental factors such as geographic location, temperature and season [27, 28]. Although their main application is gelling agent, thickened and stabilizers in food industries but currently studies are focused on medicinal usage and their anticancer, diabetes, inflammation, obesity and other ailments treatments [27].

Edible seaweeds are fundamental part of the cuisine for people living by the seas in areas such as Asia, Hawaii, South America and Africa, as well as marine products obtained from the sea, which are the source of protein from the sea, and in recent years a focus of interest in Europe and America due to the increasing interest in healthy nutrition. Edible seaweeds are a very good source of vitamins such as A, B1, B2, B6, B12, niacin and C and also rich in iodine, potassium, iron, magnesium and calcium. They are nutritious as a component in food [4, 13, 21, 22, 29–32].

In addition to being source of food, seaweeds have antibacterial, antiviral and antifungal properties [2, 33]. In ancient researches, there are tracks of seaweed applications specially in 2500 years old Chinese literature [34, 35]. For instance, Japanese were using seaweed as one of the main ingredients in recipe for Nori in addition to raw fish and sticky rice. It is also well known in Europe and North America that seaweeds have therapeutic powers in treatment of tuberculosis, arthritis, colds and influenza. Very early discovery in 1990s, marine bacteria, invertebrates and algae were used in bioactive compounds [34, 36]. Major milestone in pharmaceutical industries during 1980–1995 was research on seaweed [34, 37]. The discoveries showed that many types of seaweed have anti-inflammatory and anti-microbial agents. These agents are able to be used in treatment of wounds, burns and rashes and some evidences have suggested the algae have been used in treatment of breast cancer in ancient Egypt [38, 39].

Seaweeds are known to contain strong natural anti-oxidants, since algae contain a lot of secondary metabolites such as tocopherol, carotenoids, polyphenols, flavonoids, tannins, lignans, and mycosporine-like amino acids (MAA), vitamin C, and glutathione [40].

The studies have shown that seaweeds possess anticancer agents and there are hopes they can be effective in treatment of tumors and leukemia [34]. As the efforts have continued, scientists successfully isolated chemical compounds from brown seaweed with anticancer and antitumor activities [38, 39]. It has been reported that fucoidan from *U. pinnatifida* shows very good anti-cancer activity against human lung cancer cell line which is known A549 cell line [41].

Some studies in last decades show that fucoxanthin and fucoxanthinol from *U. pinnatifida* shows also anti-obesity activity. As obesity is known a serious health issue and has cost significant economic problem, that edible seaweeds possess anti-obesity activity, is very notable because; it is well known that obesity cost to some chronic diseases, such as liver steatosis, cardiovascular disease, osteoarthritis, type 2 diabetes, and some types of cancer. Alongside having antiobesity activity, some reports show that fucoxanthin and fucoxanthinol from *U. pinnatifida* possesses anti-diabetic activity [41]. Therefore, it can be considered that anti-obesitity activity and anti-diabetic activity are related each other. It is expected that if seaweeds have anti-obesity activity, they can able to show antidiabetic activity.
