Surface Active Agents and Their Health-Promoting Properties: Molecules of Multifunctional Significance

Abstract

Surface active agents (SAAs) are molecules with the capacity to adsorb to solid surfaces and/or fluid interfaces, a property that allows them to act as multifunctional ingredients (e.g., wetting and dispersion agents, emulsifiers, foaming and anti-foaming agents, lubricants, etc.) in a widerange of the consumer products of various industrial sectors (e.g., pharmaceuticals, cosmetics, personal care, detergents, food, etc.). Given their widespread utilization, there is a continuously growing interest to explore their role in consumer products (relevant to promoting human health) and how such information can be utilized in order to synthesize better chemical derivatives. In this review article, weaimed to provide updated information on synthetic and biological (biosurfactants) SAAs and their health-promoting properties (e.g., anti-microbial, anti-oxidant, anti-viral, anti-inflammatory, anti-cancer and anti-aging) in an attempt to better define some of the underlying mechanism(s) by which they exert such properties.

Keywords: anti-aging; anti-cancer; anti-inflammatory; anti-microbial; anti-oxidant; anti-viral; health promotion; surface active agents; surfactants.

Figure 1

Representative structures of synthetic and biosurfactants. (i) Anionic synthetic surface-active agent (SAA) sodium dodecyl sulphate (SDS); (ii) cationic synthetic SAA cetyltrimethyl ammonium bromide (CTAB); (iii) non-ionic synthetic SAA Tween 20 (polyoxyethylene sorbitan monolaurate) (Tween 40 = monopalmitate; Tween 60 = monostearate; Tween 80 = monooleate, the sum of alkyl chains a, b, c and d is 20 for all Tweens); (iv) Monorhamnolipid R1 with two C10 alkanoate chains; (v) Dirhamnolipid R2 with two C10 alkanoate chains; (vi) Acetylated lactonic sophorolipid; (vii) Acetylated acidic sophorolipid; (viii) Mannositylerithritol lipid (the length of the alkyl chains, n, can be between 6 and 10). For mannosityl erithritol lipid (MEL), A, R₁ and R₂ are acetyl groups; MEL B, R₁ = acetyl, R₂ = H; MEL C, R₁ = H, R₂ = acetyl.

Figure 2

Anti-inflammatory activity of SAAs. Synthetic and biosurfactants exert potent anti-inflammatory effects by manipulating crucial cell signaling events. Specifically, S-DMPG treatments were shown to inhibit TLR-4 signaling, while a synthetic mixture comprised of recombinant surfactant protein (rSP)-C, palmitoyl phosphatidyl glycerol, and dipalmitoyl phosphatidyl choline (DPPC) exerted anti-inflammatory actions by reducing inflammasome signaling. Furthermore, CHF5633, SLS, Venticute and S-SF treatments significantly decreased the production of inflammatory mediators via unknown mechanisms. Synthetic mixture*: synthetic surfactant composed of recombinant surfactant protein (rSP)-C, palmitoyl phosphatidyl glycerol, and dipalmitoyl phosphatidyl choline (DPPC); SLS**: SP-CL16(6-28) and synthetic phospholipid mixture; S-SF mixture***: synthetic surfactant comprised of dipalmitoyl phosphohatidyl choline (DPPC), hexadecanol and tyloxapol. Abbreviations: G-T: synthetic galactose-taurine sodium; S-DMPG: synthetic-dimyristyl phosphatidyl glycerol; P2X7: P2X purinoceptor 7;nAchR: nicotinic acetylcholine receptor; TLR: Toll-like receptor; IL: interleukin; IL-1R: interleukin-1 receptor; MyD88: myeloid differentiation primary response 88; TRIF: toll/interleukin-1 receptor-like protein (TIR)-domain-containing adaptor-inducing interferon-β; ΤRAM: TRIF-related adaptor molecule; IRAK: IL-1 receptor associated kinase; TRAF: tumor necrosis factor receptor-associated factor; TAB1/2: tumor growth factor-β (TGF-β)-activated kinase 1; TAK: TGF-β activated kinase 1; IKK: IκΒ kinase; MKK: mitogen activated protein (MAP) kinase; NF-κΒ: nuclear factor κΒ; ΕRK: extracellular signal activated kinase; JNK: c-Jun N-terminal kinase; AP-1: activator protein-1.

Figure 3

Anti-cancer activity of the synthetic SAs. Synthetic surfactants demonstrate significant anti-cancer activity through the activation of both intrinsic (BCL, Edelfosine, NP-40) and extrinsic apoptotic pathways (BCL, Edelfosine), unfolded protein response-mediated cell death (Edelfosine) and the suppression of the MAPK/ERK and Akt/PI3K signaling pathways (Edelfosine). Additionally, the synthetic SAAs Edelfosine was shown to inhibit the migration of cancer cells by suppressing the small conductance calcium-activated potassium channel 3 (SK3) activity. Abbreviations: RTK: receptor tyrosine kinase; PI3K: phosphatidylinositol-3-Kinase; MAPK: mitogen-activated protein kinase; ERK: extracellular signal-regulated kinase; MEK: MAPK/ERK kinase; PIP₂: phosphatidylinositol 4,5-bisphosphate; PIP₃: phosphatidylinositol (3,4,5)-trisphosphate; NF-kB: nuclear factor kappa-light-chain-enhancer of activated B cells; FOXO3a: forkhead box O3a; GSK3β: glycogen synthase kinase 3 beta; UPR-mediated cell death: unfolded protein response-mediated cell death; BiP: binding immunoglobulin protein; PERK:protein kinase R-like endoplasmic reticulum kinase; eIF2a: eukaryotic translation initiation factor 2a; ATF4: activating transcription factor 4; CHOP: CCAAT-enhancer-binding protein homologous protein; PARP: poly (ADP-ribose) polymerase; Bid: BH3-interacting domain death agonist; tBid: truncated Bid; Bcl-2: B-cell lymphoma 2; BCL-XL: B-cell lymphoma-extra-large; BAX: BCL2 associated X; BAK: BCL2-antagonist/killer; ROS: reactive oxygen species; Smac/DIABLO: second mitochondria-derived activator of caspase/direct inhibitor of apoptosis-binding protein with low pI; IAPs: inhibitors of apoptosis proteins; Apaf-1: apoptotic protease activating factor 1; SK3: small conductance calcium-activated potassium channel 3 (SK3); Orai1: ORAI calcium release-activated calcium modulator 1.