Project Description
The skin, as the largest organ of the human body, not only bears the responsibility of resisting the invasion of external pathogens but also plays a crucial role in maintaining fluid balance within the body and regulating body temperature, serving as a robust barrier against external pressures and injuries [1]. However, the skin faces a dual threat from both internal and external factors: intrinsic aging occurs naturally over time, while extrinsic aging is closely related to air pollution, ultraviolet radiation, and pathogenic microorganisms [2]. Among these factors, reactive oxygen species (ROS) act as key players in the process of external damage and aging [3].
The skin itself has an antioxidant system that can eliminate ROS and maintain a balance of antioxidants. However, as time goes by and exposure to ultraviolet rays, the efficiency of this system decreases, leading to the accumulation of free radicals in the body, causing cellular damage [3]. The accumulation of free radicals is considered an important reason for the decline in physiological functions and skin aging. The increase in ROS not only accelerates the aging process of skin cells but also destroys collagen in skin tissue, leading to sagging and the formation of wrinkles [4]. Therefore, effectively clearing excess ROS in the skin has become an indispensable part of anti-aging strategies [5].
Under conditions of skin damage, a moderate amount of ROS is necessary for defending against infections and promoting healing. However, when the amount of ROS gets out of control, it can trigger a series of chain reactions, causing oxidative damage to cells and tissues, which is extremely detrimental to the survival and healing process of cells [1]. Therefore, it is particularly important to develop technologies and materials that can control ROS levels and reduce their harmful effects.
Antioxidants play a key role in capturing and neutralizing free radicals, delaying or stopping the oxidation process of chemical substances. The importance of antioxidants in maintaining skin health and delaying skin aging should not be overlooked [6]. Therefore, intake of exogenous antioxidants can help supplement the body’s defense mechanisms, neutralize free radicals, reduce oxidative stress, and thereby protect the skin from damage.
Schematic diagram of antioxidation and skin damage repair (Zhu X etal., Processes 2023)
Our Solution
It has been reported that neoagarose oligosaccharides (NAOS) can act as antioxidants by inhibiting the production of excessive free radicals in vitro [7]. The preparation of NAOS can be achieved through three primary methods: chemical (acid degradation) [7], physical [8], and enzymatic [9]. The enzymatic preparation of NAOSs is preferred over the chemical and physical methods due to its numerous advantages, including milder reaction conditions, strong substrate specificity, higher yield, and reduced byproducts [10].
In our experiment, we aimed to produce an endo-type β-agarase using engineered strains of Escherichia coli and then hydrolyze agarose using this β-agarase to obtain the antioxidant NAOS.
References
[1] Zhu X; Yuan W, Li Z, et al. Progress of Research on Antioxidants and Carriers for Skin Wound Repair. Processes 2023, 11, 2069.
[2] Shin S H, Lee Y, H, Rho N K, et al. Skin aging from mechanisms to interventions: focusing on dermal aging[J]. Front Physiol, 2023, 14: 1195272.
[3] Gu Y, Han J, Jiang C, et al. Biomarkers, oxidative stress and autophagy in skin aging. Ageing Res. Rev., 2020, 59, 101036.
[4] He X, Wan F, Su W H, et al. Research Progress on Skin Aging and Active Ingredients[J].Molecules, 2023, 28: undefined.
[5] Lephart E D. Skin aging and oxidative stress: Equol’s anti-aging effects via biochemical and molecular mechanisms. Ageing Res. Rev. 2016, 31, 36–54.
[6] Flieger J, Flieger W, Baj J, et al. Antioxidants: Classification, Natural Sources, Activity/Capacity Measurements, and Usefulness for the Synthesis of Nanoparticles. Materials 2021, 14, 4135.
[7] Ducatti D R B, Colodi F G, Gonçalves A G, et al. Production of agaro- and carra-oligosaccharides by partial acid hydrolysis of galactans[J]. Revista Brasileira de Farmacognosia, 2011, 21(2):296-304.
[8] Lin X, Chen J, Xiao G, et al. Extraction, molecular weight distribution, and antioxidant activity of oligosaccharides from longan (Dimocarpus Longan Lour.) pulp[J]. Food ence & Biotechnology, 2016, 25(3): 701-706.
[9] Kang O L, Ghani M, Hassan O, et al. Novel agaro-oligosaccharide production through enzymatic hydrolysis: Physicochemical properties and antioxidant activities[J]. Food Hydrocolloids, 2014, 42: 304-308.
[10] Zhang Y H, Song X N, Lin Y, et al. Antioxidant capacity and prebiotic effects of Gracilaria neoagaro oligosaccharides prepared by agarase hydrolysis[J]. International Journal of Biological Macromolecules, 2019, 137.