Marine algae are rich in a variety of biologically and pharmacologically active
substances. They are considered as a resource that has been used by humans to some
extent [6]. Nowadays, algal biomass is a renewable source of many valuable bioactive
substances, having a wide array of applications in many industries, such as food,
chemical, agricultural, pharmaceutical, cosmetic, medical. The present work focuses
on the impact of algae on the human body. The potential use of algae and algal
extracts in medicine and cosmetic industry is discussed. Due to the antibacterial,
antiviral, antifungal, anti-inflammatory properties, algae can be used in the curing
of many types of diseases [7, 8]. These properties result from the biologically active
compounds present in the biomass of algae. The components of the algae that may
help in the treatment tumor diseases are: polyphenols [37], polysaccharides [38],
carrageenan [33–35], fucoidan [24, 30–32], fucoxanthin [25], diterpenes [27–29]
or monoterpenes [36]. Substances extracted from algae with anti-inflammatory,
antipyretic and analgesic include: fucosterol [48], porphyrins [52], lactones, phenols,
carbohydrates [40], polysaccharides [51, 53, 54], fucoidan [46], galactan [49],
fucan [45]. Fucoxanthin [64–68], fucoidan [58], triacyloglycerols [69], polyphenols
[71] or phlorotannin [63] can be used as anti-obesity agents. Overreaction of the
immune system to harmless environmental substances can be minimized by the use
of antiallergic substances, which include mainly phlorotannins [73, 77, 78] and fatty
acids [79, 80]. The components of algae, such as polysaccharides [99–101], diterpenes
[91], bromophenol [90], carbohydrates [102], fucans [96, 97], galactans [98],
carrageenan [94], fucoidan [92] or galactofucan [93] could be successfully utilized
against various types of viruses. It has been proved that algae show dermatological
and cosmetic properties: anti-inflammatory and bactericidal action (due to the
presence of zinc) [8, 9, 19, 113], increase of the flexibility of the skin (peptides and
vitamins) [13, 104, 105], improve blood circulation of the skin and thanks to the
alginic acid they treat erythema [13, 103]. They influence on of inhibition of sebum
secretion and on other problems of oily skin. Algae are used in many cosmetics to
tone up the skin, lighten stretch marks [104, 111, 112]. Compresses made of algae
slenderize and eliminate cellulite. A field of skin cosmetics called Thalassotherapy
is a form of therapy that uses marine climate, sea water, mud, algae, sand and other
substances derived from the sea as a therapeutic agents [13, 103].