Bioprospecting of Microorganism-Based Industrial Molecules. Группа авторов

105]. The ulvans are widely known for the antioxidative, chelating, gelling, moisturizing, and protective properties. The antioxidant capacity of ulvan is modulated by ROS scavenging and inhibition of lipid peroxidation. Besides, ulvans are also known to suppress antiaging by enhancing the endogenous enzymatic antioxidant systems such as superoxide dismutase, catalase, and glutathione peroxidase activities owing to the abundant sulfated polysaccharides [88, 90, 104]. Moreover, the gelling property of ulvan is not significantly affected in the presence of various cations (Ca²⁺, Cu²⁺, and Zn²⁺), in the pH range of 7.5–8.0 and temperature up to 180 °C makes it a rheological suitable in cosmetic formulations [88, 91].

      4.4.4.5 Porphyran

      Porphyrans are exclusively derived from Porphyra species belonging to genus Rhodophyta. Porphyran is a sulfated polysaccharide consisting of D‐galactose, 3,6‐anhydro‐L‐galactose, 6‐O‐methyl‐D‐galactose, and L‐galactose 6‐sulfate units [151]. Porphyran demonstrates high solubility in an aqueous solvent and safe for the skin when it is formulated in cosmetic products as a solvent in liquid or emulsion form. The bio‐functional activity of porphyrans includes skin whitening, anti‐inflammatory, and moisturizing properties and hence used in topical or systemic skin cleansers, cosmetic wipes, cosmetic cotton, sanitary cotton, wet tissue, skin lotion, skin cream, ointments, gel, face pack, shaving agents, facial cleansing agents, etc. [78, 88, 93, 100].

      4.4.4.6 Carrageenan

      Carrageenan is naturally derived from the Rhodophyta genus (carrageenophytes). Carrageenan is a sulfated polysaccharide with galactose units with alternating α (1–3) and β (1–4) bonds. There are three main classes of carrageenan, kappa (κ), iota (Ι), and lambda (λ) owing to differences in the degree of sulfation. Κ‐carrageenan has one sulfate moiety per disaccharide, Ι‐carrageenan has two sulfate moieties, while λ ‐carrageenan has three. Furthermore, Ι‐carrageenan and Κ‐carrageenan are used as gelling agents, and λ ‐carrageenan are used as thickening and viscosifier agent in cosmetic application due to its unique rheological properties [130, 131]. Carrageenan is known to decrease the effect of photoaging, sunburn, wrinkles, and skin cancer induced by harmful ultraviolet‐B rays (UVB) (290–320 nm) [132]. Several studies have demonstrated significant photo‐protection properties of carrageenan against detrimental effects of UVB‐induced cell damage and ROS, suggesting its crucial role as a photo‐protective cosmetic excipient in skin lightening products [101–103].

      4.4.4.7 Agar

      Agar is commonly known as agar or agarose, and is fundamentally a combination of two polysaccharides, agaropectin, and agarose obtained from several different genus of Rhodophyta. Agarose, the chief component of agar, consists of straight‐chain polymeric units of agarobiose. Agarobiose is made up of disaccharide units of D‐galactose and 3,6‐anhydro‐L‐galactopyranose. While the agaropectin consists of β‐1,3‐linked D‐galactose units altered with sulfate and pyruvate moieties [78, 88]. As mentioned earlier, the gelling property of these polysaccharides exclusively depends on the degree of sulfation and the number of 3, 6‐anhydrogalactose molecules present.

      The distinctive property of agar to easily melt at 85 °C and solidify at 32–40 °C makes it a prominent candidate in various industrial, laboratory, cosmetic, and culinary applications. Furthermore, agar is a biocompatible and inert substance and hence can be readily formulated with various other biochemical compounds used in cosmetic products such as hand lotions, deodorants, antiaging treatment creams, facial and acne treatment, and so on [78, 82, 88, 92, 122].

      Other agarose‐derived polysaccharides (agar oligosaccharides) also have antiaging, anti‐melanogenesis, skin brightening, and ROS scavenging properties [92, 133, 134]. There are two forms of agar oligosaccharides, namely, neo‐form and agaro‐form. Neo‐form AOSs are called neoagarooligosaccharides (NAOSs) and have repeating neoagarobiose units composed of d‐galactose at the nonreducing end and 3,6‐anhydro‐L‐galactose [92].

      4.4.4.8 Alginic Acids

Alginic acids are obtained from brown seaweed, i.e. Pheaeophyta genus. Alginic acid is made up of linear polymers of α‐l‐guluronic acid and β‐d‐mannuronic acid units connected by 1 → 4 glycosidic bonds. Alginates can rapidly form hydrogels in the existence of divalent cations (Mg²⁺, Ca²⁺etc) at room temperature. Moreover, Na⁺‐alginate and Ca^2+_alginate are used in microencapsulation and immobilization of various compounds, enzymes, cells, etc. owing due to its gelling, biocompatibility, and biodegradability properties [135]. The chelating and gelling properties of alginates have widely attracted its use in cosmetic products as thickeners, emulsion stabilizers, hand jellies, ointment bases, skin lightening face packs, wound dressing for skin recovery, etc. The alginate masks are known to restore type I and type III collagen synthesis in the skin, and also helps in moisturizing by enhancing the water holding capacity of the skin. Furthermore, alginate is known to provide vital minerals and microelements to deeper dermal layers in the skin [136]. Several commercially available formulation is exploiting the benefit of alginate in the treatment of ulcers, wounds, and skin burns anti‐cellulite programs, face sculpturing, and skin regeneration therapy [136–138] (Figure 4.3).

      4.4.5 Pigments from Algae

      Algae contain three major classes of photosynthetic pigments categorized as chlorophylls, carotenoids (carotenes and xanthophylls), and phycobilins [139]. The chlorophylls and carotenes are fat‐soluble molecules and can be readily extracted by using organic solvents (acetone, methanol, or DMSO). However, the phycobilins being water‐soluble can be extracted by using polar and nonpolar solvent mixtures. Most of these pigments can counteract against the UV light exposure during growth and development of algae and are known to involve in protecting the cell against harmful oxidative ROS species [140, 141]. Hence, these pigments are used in cosmetic formulations not only to reduce the oxidation of oils, occurring due to rancidity, but also to reduce skin aging, owing due to antioxidant nature. Moreover, these pigments are a natural source of dyes and colorants, making it useful in the various cosmetic industry as the replacement against synthetic dyes (Table 4.2). The various pigments and their cosmeceutical application with respect to antiaging and skin lightening are discussed as follows.

      4.4.5.1 Phycobiliproteins

Phycobiliproteins obtained from algae and cyanobacteria are categorized into three main classes depending on absorption properties: phycoerythrins (PE, λ = 540–570 nm), phycocyanins (PC, λ = 610–620 nm), and allophycocyanins (APC, λ = 650–655 nm) [118]. PEs are of utmost interest owing to their fluorescent and antioxidant properties. These pigments are red and are known to absorb light in the green wavelength (λ = 498 and λ = 565 nm) and emit in the yellow wavelength (λ = 573 nm). In vitro, the antioxidant activity of PE is a well‐studied phenomenon in Caenorhabditis elegans, which resembles the human aging pathways, wherein PE is known to upregulate enzymes such as superoxide dismutase, catalase activities, and reduce oxidative stress damage [142]. The PC and APC are also known to express antioxidant activities and radical‐scavenging properties in several studies [97, 119, 120]. PC is involved in inducing expression of heme‐oxygenase‐1 (HO‐1), thereby reducing the UV‐B‐induced cell death in skin cells, demonstrating the photo‐protective role [121].

Figure 4.3