Ascorbic Acid 2-glucoside Research Articles

Ascorbic acid 2-glucoside improves survival, quality, and fertility of frozen-thawed C57Bl/6J and C57Bl/6N mouse spermatozoa.

Ascorbic acid 2-glucoside (AA2G) is a stabilized form of ascorbic acid and a potent antioxidant. Ascorbic acid is present in the testes and epididymis and helps maintain the physiological integrity of reproductive organs. Its properties have been utilized to protect spermatozoa of different species from oxidative stress. Spermatozoa of C57Bl/6J and C57Bl/6N strains were frozen and analyzed, after thawing, by supplementing the capacitation medium with AA2G, both in the presence and absence of methyl-β-cyclodextrin (MBCD). The effect of treatment was evaluated by SCA System (Microptic) analyzing the velocity, vitality, morphology, and the DNA fragmentation. We also examined sperm capacitation (CTC), acrosome reaction (Coomassie Brillant Blue), and fertility (in vitro fertilization) of treated spermatozoa. AA2G improved sperm quality and fertility particularly in association with MBCD. We observed a significant increase of sperm motility, velocity, and vitality associated with an enhanced capacitation and acrosome reaction. These improvements resulted in a marked increase in in vitro fertilization success. Embryos obtained were cultured and reached normally the blastocyst stage. This study aimed to determine if AA2G could safeguard mouse spermatozoa during cryopreservation. We found a protective effect of AA2G that increased sperm survivability resulting in higher fertilization rate. This newly improved protocol shows potential for reanimating cryopreserved GEMMs stored in mouse biobanks and international repositories, such as the European Mouse Mutant Archive (EMMA). This can serve as a pivotal tool in fulfilling the 3Rs mission (replacement, reduction, and refinement), promoting ethical and humane research practices.

Single stage bi-substrate transglycosylation reaction for the synthesis of ascorbic acid 2 glucoside using immobilized α-glucosidase

Alpha glucosidases are multifunctional glycoside hydrolases with hydrolysis and transglycosylation ability. It can be utilized for the glycosidic bond synthesis or glycosylation of Ascorbic acid/Vitamin C to its stable analogue, Ascorbic acid 2 glucoside (AA2G), a compound with wide applications in cosmetics and pharma. The application of α-glucosidases for industrial scale transglycosylation is limited due to the low transglycosylation yield of free enzymes. Enzyme immobilization techniques could enable the development of efficient, reusable catalysts. Only a few glycoside hydrolases have been studied in immobilized form for transglycosylation reactions, and α-glucosidases are probably the least explored in this form. Transglycosylation activity of immobilized α-glucosidase from Aspergillus carbonarius BTCF 5 was studied for AA2G synthesis, where different immobilization techniques like calcium alginate encapsulation, adsorption on chitosan beads, covalent cross-linking on magnetic nanoparticles, and cross-linked enzyme aggregates (CLEA) were employed for the immobilization. The immobilization yield of calcium alginate encapsulated enzyme, enzyme immobilized on Fe-MNP support, enzyme immobilized on chitosan beads and as CLEA were 107%, 99%, 46% and 486%, respectively. CLEA was identified as the best immobilization technique for this bi-substrate reaction due to the high immobilization yield and activity retention (30% activity retained after 5 consecutive cycles). Enzyme immobilization increased the transglycosylation activity by 38%, yielding 118 mM AA2G against 72 mM by the free enzyme. This indicates the potential of immobilized α-glucosidase as a catalyst for synthesizing AA2G at an industrial scale.

Exploration of N6-methyladenosine modification in ascorbic acid 2-glucoside constructed stem cell sheets.

The aim of this study was to explore the mechanism of bone marrow stem cells (BMSCs) sheets constructed with different doses of Ascorbic acid 2-glucoside (AA-2G) in conjunction with N6-methyladenosine (m6A)-associated epigenetic genes analysing transcriptome sequencing data. Experimental groups of BMSCs induced by different AA-2G concentrations were set up, and the tissue structures were observed by histological staining of cell slices and scanning electron microscopy. Expression patterns of DEGs were analysed using short-time sequence expression mining software, and DEGs associated with m6A were selected for gene ontology analysis and pathway analysis. The protein-protein interaction (PPI) network of DEGs was analysed and gene functions were predicted using the search tool of the Retrieve Interacting Genes database. There were 464 up-regulated DEGs and 303 down-regulated DEGs between the control and high-dose AA-2G treatment groups, and 175 up-regulated DEGs and 37 down-regulated DEGs between the low and high-dose AA-2G treatment groups. The profile 7 exhibited a gradual increase in gene expression levels over AA-2G concentration. In contrast, profile 0 exhibited a gradual decrease in gene expression levels over AA-2G concentration. In the PPI network of m6A-related DEGs in profile 7, the cluster of metallopeptidase inhibitor 1 (Timp1), intercellular adhesion molecule 1(Icam1), insulin-like growth factor 1 (Igf1), matrix metallopeptidase 2(Mmp2), serpin family E member 1 (Serpine1), C-X-C motif chemokine ligand 2 (Cxcl2), galectin 3(Lgals3) and angiopoietin-1(Angpt1) was the top hub gene cluster. The expression of all hub genes was significantly increased after AA-2G intervention (P < 0.05), and the expression of Igf1 and Timp1 increased with increasing intervention concentration. The m6A epigenetic modifications were involved in the AA-2G-induced formation of BMSCs. Igf1, Serpine1 and Cxcl2 in DEGs were enriched for tissue repair, promotion of endothelial and epithelial proliferation and regulation of apoptosis.

Palmitoyl ascorbic acid glucoside enhanced cell survival with post irradiation treatment

Radiation exposure poses a significant threat to cellular integrity by inducing DNA damage through the generation of free radicals and reactive oxygen species. Ascorbic acid, particularly its derivative Palmitoyl Ascorbic Acid 2-Glucoside (PA2G), has demonstrated remarkable radioprotective properties. While previous research focused on its pre-irradiation application, this study explores the post-irradiation radiomitigation potential of PA2G. Our findings reveal that post-irradiation treatment with PA2G enhances cell survival and accelerates DNA repair processes, particularly the non-homologous end-joining (NHEJ) repair pathway. Notably, PA2G treatment reduces the frequency of lethal chromosomal aberrations and micronuclei formation, indicating its ability to enhance the repair of complex DNA lesions. Furthermore, PA2G is shown to play a role in potentially lethal damage repair (PLDR). These radioprotective effects are specific to NHEJ and ATM pathways, as cells deficient in these mechanisms do not benefit from PA2G treatment. This study highlights PA2G as a versatile radioprotector, both pre- and post-irradiation, with significant potential for applications in radiation therapy and protection, offering new insights into its mechanism of action. Further research is required to elucidate the precise molecular mechanisms underlying PA2G's radiomitigation effects and its potential clinical applications.

Safety evaluation of the food enzyme cyclomaltodextrin glucanotransferase from the non-genetically modified Anoxybacillus caldiproteolyticus strain TCM3-539.

The food enzyme cyclomaltodextrin glucanotransferase ((1-4)-α-d-glucan:(1-4)-α-d-glucan 4-α-d-[(1-4)-α-d-glucano]-transferase; EC 2.4.1.19) is produced with the non-genetically modified bacteria Anoxybacillus caldiproteolyticus strain TCM3-539 by Hayashibara Co., Ltd. It is free from viable cells of the production strain. The food enzyme is intended to be used for the manufacture of glucosyl hesperidin and ascorbic acid 2-glucoside. Since residual amounts of total organic solids are removed by filtration, adsorption, chromatography and crystallisation, dietary exposure estimation was considered not necessary. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and one match with a respiratory allergen was found. The Panel considered that, under the intended conditions of use, the risk of allergic reactions by dietary exposure cannot be excluded, but the likelihood is low. Based on the data provided, the Panel concluded that the food enzyme does not give rise to safety concerns under the intended conditions of use.

Activating transcription factor-2 supports the antioxidant capacity and ability of human mesenchymal stem cells to prevent asthmatic airway inflammation

Glutathione (GSH), an abundant nonprotein thiol antioxidant, participates in several biological processes and determines the functionality of stem cells. A detailed understanding of the molecular network mediating GSH dynamics is still lacking. Here, we show that activating transcription factor-2 (ATF2), a cAMP-response element binding protein (CREB), plays a crucial role in maintaining the level and activity of GSH in human mesenchymal stem cells (MSCs) by crosstalking with nuclear factor erythroid-2 like-2 (NRF2), a well-known master regulator of cellular redox homeostasis. Priming with ascorbic acid 2-glucoside (AA2G), a stable vitamin C derivative, increased the expression and activity of ATF2 in MSCs derived from human embryonic stem cells and umbilical cord. Subsequently, activated ATF2 crosstalked with the CREB1-NRF2 pathway to preserve the GSH dynamics of MSCs through the induction of genes involved in GSH synthesis (GCLC and GCLM) and redox cycling (GSR and PRDX1). Accordingly, shRNA-mediated silencing of ATF2 significantly impaired the self-renewal, migratory, proangiogenic, and anti-inflammatory capacities of MSCs, and these defects were rescued by supplementation of the cells with GSH. In addition, silencing ATF2 attenuated the ability of MSCs to alleviate airway inflammatory responses in an ovalbumin-induced mouse model of allergic asthma. Consistently, activation of ATF2 by overexpression or the AA2G-based priming procedure enhanced the core functions of MSCs, improving the in vivo therapeutic efficacy of MSCs for treating asthma. Collectively, our findings suggest that ATF2 is a novel modulator of GSH dynamics that determines the core functionality and therapeutic potency of MSCs used to treat allergic asthma.

Efficient dermal delivery of ascorbic acid 2-glucoside with photoacoustic waves.

Ascorbic acid (i.e., vitamin C) is an important antioxidant present in skin. The protective role of vitamin C against photoaging motivated numerous attempts to promote its topical delivery, with a success limited by its chemical instability and poor skin permeability. Vitamin C precursors, such as ascorbic acid 2-glucoside (AA2G), which are metabolized to vitamin C by enzymes present in the skin, solve the problem of stability but are limited by low skin permeability. We developed a 2% (w/v) gel formulation of AA2G application (viscosity 4.30 × 104 Pa.s, pH5.94) and compared its passive dermal delivery with the delivery promoted by photoacoustic waves that transiently perturb the skin barrier. Photoacoustic (PA) waves were generated by laser pulses absorbed by piezophotonic (light-to-pressure) transducers. Pig skin samples were exposed to the 2% AA2G formulation alone or combined with 5 min of PA waves. One hour later, AA2G was extracted from the skin and quantified by reverse-phase HPLC. AA2G transdermal fluxes using Franz cells with 760 μm thick pig skin samples were also measured. Photoacoustic waves transiently enhanced skin permeability and increased dermal delivery of AA2G. AA2G was released from the formulation nearly quantitatively (92.6 ± 6.2%) in 24h, showing a non-Fickian behaviour controlled by diffusion and swelling. AA2G dermal delivery with exposure for 5 min to PA waves was compared with passive delivery to pig skin. PA waves increased the delivery of AA2G to the skin by a factor of 15-fold with respect to passive delivery, as measured from skin extracts after 1 h of contact of the formulation with the skin. Five minutes of exposure to PA waves is a safe and effective method to deliver large quantities of AA2G to the skin.

Ascorbic acid 2-glucoside preconditioning enhances the ability of bone marrow mesenchymal stem cells in promoting wound healing

BackgroundNowadays, wound is associated with a complicated repairing process and still represents a significant biomedical burden worldwide. Bone marrow mesenchymal stem cells (BMSCs) possess multidirectional differentiation potential and secretory function, emerging as potential cellular candidates in treating wounds. Ascorbic acid 2-glucoside (AA2G) is a well-known antioxidant and its function in BMSC-promoting wound healing is worth exploring.MethodsThe in vitro cell proliferation, migration, and angiogenesis of BMSCs and AA2G-treated BMSCs were detected by flow cytometry, EDU staining, scratch assay, transwell assay, and immunofluorescence (IF). Besides, the collagen formation effect of AA2G-treated BMSCs conditioned medium (CM) on NIH-3T3 cells was evaluated by hydroxyproline, qRT-PCR and IF staining detection. Next, in the wound healing mouse model, the histological evaluation of wound tissue in PBS, BMSCs, and AA2G-treated BMSCs group were further investigated. Lastly, western blot and ELISA were used to detect the expression levels of 5-hmc, TET2 and VEGF protein, and PI3K/AKT pathway activation in BMSCs treated with or without AA2G.ResultsThe in vitro results indicated that AA2G-treated BMSCs exhibited stronger proliferation and improved the angiogenesis ability of vascular endothelial cells. In addition, the AA2G-treated BMSCs CM enhanced migration and collagen formation of NIH-3T3 cells. In vivo, the AA2G-treated BMSCs group had a faster wound healing rate and a higher degree of vascularization in the new wound, compared with the PBS and BMSCs group. Moreover, AA2G preconditioning might enhance the demethylation process of BMSCs by regulating TET2 and up-regulating VEGF expression by activating the PI3K/AKT pathway.ConclusionsAA2G-treated BMSCs promoted wound healing by promoting angiogenesis and collagen deposition, thereby providing a feasible strategy to reinforce the biofunctionability of BMSCs in treating wounds.

Ascorbic acid-2 glucoside mitigates intestinal damage during pelvic radiotherapy in a rat bladder tumor model

Purpose Ascorbic acid is a strong antioxidant and has potent radioprotective effects on radiation injuries. Ascorbic acid 2-glucoside (AA2G) is a stabilized derivative of ascorbic acid and rapidly hydrolyzed into ascorbic acid and glucose. Since there is the possibility that AA2G treatment interferes with the antitumor activity of radiotherapy, we investigated the effect of AA2G treatment during radiotherapy on acute radiation enteritis and antitumor activity of radiotherapy in rats. Materials and methods AY-27 rat bladder tumor cells were used to induce bladder tumors in rats. Two weeks after inoculation rats received fractionated pelvic radiotherapy in eight fractions for 4 weeks totaling 40 Gy. During radiotherapy, one group of rats received per os AA2G (ascorbic acid: 250 mg/kg/day) and its bolus engulfment (ascorbic acid: 250 mg/kg) 8 h before each X-irradiation fraction. Seven days after the last X-irradiation, we studied histology, DNA double strand break (DSB) damage (by 53BP1 foci staining), and the M1/M2 macrophage response by immunohistochemistry of paraffin-fixed bladder and intestinal tissues. Results AA2G treatment reduced the intestinal damage (shortening of villi) but did not reduce antitumor effectiveness of radiotherapy against bladder tumors. Like the controls, AA2G-treated rats showed no residual tumor lesions in the bladder after X-irradiation. Both AA2G-treated and control groups showed similar persistent DSB damage (53BP1 foci) both in bladders and ilea seven days after radiotherapy. Radiotherapy tended to reduce CD163+ M2 macrophages, which are considered as an anti-inflammatory subtype favoring tissue repair, in the bladders. X-irradiation also reduced the occurrence of M2 macrophages in the ilea. AA2G treatment significantly increased CD163+/CD68+ macrophage ratio in the ilea of rats after pelvic irradiation in comparison to the sham irradiated control rats. AA2G treatment increased, albeit not significantly, the CD163+/CD68+ macrophage ratio in the irradiated bladders relative to the control irradiated rats. On the other hand, bladders and ilea of the irradiated rats with and without AA2G treatment showed similar frequencies of CD68+ macrophages. Conclusions AA2G treatment mitigated radiation-induced intestinal damage without reducing antitumor activity after fractionated pelvic radiotherapy against bladder tumors in rats. The beneficial effect of AA2G treatment seems to promote a restoration of the M2 answer as well as tissue remodeling and wound healing. Similar residual DNA damage in bladders and ilea seven days post-irradiation is consistent with tumor control in both groups.

Ascorbic acid 2-glucoside: An ascorbic acid pro-drug with longer-term antioxidant efficacy in skin.

Deleterious effects of pollutants and ultraviolet radiation on the skin can be attenuated using formulations containing antioxidants. However, these have disadvantages, including chemical instability, photodegradation, poor bioavailability or biological activity. Here, two commercial formulations were evaluated: one optimized to stabilize and deliver ascorbic acid (AA) at 15% and the other containing a glucoside form of AA, namely ascorbic acid 2-glucoside (AA2G), at 1.8% and at a physiological pH. We compared the skin delivery, antioxidative effects and chemical stability of AA2G with AA in their respective formulations. Skin delivery was measured using fresh viable human skin explants, and oxidative stress was measured using a human reconstructed epidermal (RHE) model according to levels of malondialdehyde (MDA), superoxide dismutase (SOD) and catalase. Ascorbic acid 2-glucoside was completely metabolized to AA by the skin before entering the receptor compartment. The skin contained parent and AA, indicating a reserve of AA2G was present for further metabolism. For AA2G and AA, maximum flux of AA-equivalents was at 12h, with continued absorption over 24h. The absolute amount in µg was higher in the skin after application of AA than after application of AA2G. This may suggest a greater antioxidative effect; however, according to all three measurements of oxidative stress, the protective effect of AA and AA2G was similar. Unlike AA, AA2G was chemically stable under storage conditions. A lower concentration of AA2G is as effective as the active metabolite, AA, in terms of antioxidant effects. AA2G was chemically stable and can be applied at a lower concentration than AA, thus avoiding the need for an acidic formulation with a pH below 3.5.

Cytotoxicity and genotoxicity of blue LED light and protective effects of AA2G in mammalian cells and associated DNA repair deficient cell lines

Light emitting diode (LED) devices emit narrow bands of the blue, green, and red light spectrum rather than the continuous spectrum emitted from sunlight and fluorescent light bulbs. LED devices have become considerably common in society, and the fluence of blue light from LED devices is more intense than other light sources. Previous studies presented that the blue light spectrum may harness potentially inimical genotoxicity. Therefore, the aim of this study was to investigate this potential cytotoxicity and genotoxicity, as well as identify the mechanism of the cellular effects induced by blue LED light exposure in mammalian cell lines with their DNA repair deficient mutants. Our results demonstrated that blue LED light induced both oxidative stress to cells and cytotoxic and genotoxic effects including reduction of clonogenicity, cell cycle arrest, induction of sister chromatid exchanges, endoreduplicated chromosomes, and increased frequency of HPRT locus mutations. In DNA repair deficient cells, particularly those involving double strand break repair deficiency, cells presented hypersensitivity to blue LED light exposure. Blue LED light also induced chromosome aberrations more in DNA repair deficient cells than wild type cells. The cytotoxicity of blue LED light was reduced by an effective antioxidant, ascorbic acid 2-glucoside, which can suppress blue LED light induced oxidative stress. These results indicated that prolonged, high intensity exposure to blue LED light induces genotoxic stress to cells, and oxidative stress induced by blue LED light is targeting DNA to induce these biological effects.

Discovering and efficiently promoting the extracellular secretory expression of Thermobacillus sp. ZCTH02-B1 sucrose phosphorylase in Escherichia coli

Sucrose phosphorylase (SPase, EC2.4.1.7) is a promising transglycosylation biocatalyst used for producing glycosylated compounds that are widely used in the food, cosmetics, and pharmaceutical industries. In this study, a recombinant SPase from the Thermobacillus sp. ZCTH02-B1 (rTSPase), which was previously reported to have high thermostability and the catalytic ability to synthesize ascorbic acid 2-glucoside, was attempted to be extracellularly expressed in Escherichia coli BL21(DE3) by fusion of endogenous osmotically-inducible protein Y. Unexpectedly, the rTSPase itself was produced outside the cells with an underestimated performance, although no typical signal peptide was predicted. Further N- and C-terminal truncation experiments revealed that both termini of rTSPase have an important role in protein folding and enzymatic activity, while its secretion was N-terminus associated. Extracellular protein concentration and rTSPase activity achieved 1.8 mg/mL and 6.2 U/mL after induction of 36 h in a 5-L fermenter. High-level extracellular rTSPase production could also be obtained from E. coli within 24 h by inducing overexpression of D, D-carboxypeptidase for cell lysis.

An aqueous approach to functionalize waterlogged archaeological wood followed by improved surface-initiated ARGET ATRP for maintaining dimensional stability

A previous study on consolidation of waterlogged archaeological wood (WAW) via surface initiated ARGET ATRP of the cell walls has shown its potential of maintaining the dimensional stability. But the defects lie in the unsuitable initiator immobilization methods and polymerization conditions, which impedes its application. Therefore, we are proposing a novel functionalization method for initiator immobilization in water or water/ethanol solution and an improved thermo-initiated ARGET ATRP system. First, mercaptoethylamine (MEA) was used to functionalize WAW with amino groups in water under circumneutral conditions. Then, quinone-based initiators reacted with those amino groups realizing its immobilization. Finally, by using less active reductants such as ascorbic acid 2-glucoside and glucose, monomer, catalyst, and reductant were able to permeate into the WAW samples at room temperature and polymerization was initiated by heating to 60 °C (for ascorbic acid 2-glucoside) or 80 °C (for glucose). Both satisfying uniformity and dimensional stability (77.0–85.1% ASE) can be achieved through the described approach. Moreover, the described functionalization methods may also provide reference for WAW consolidation material designs and applications in other lignocellulosic materials in the future.

Preparation and characterization of triamterene complex with ascorbic acid derivatives

The purpose of this study was to prepare solid dispersions of triamterene (TRT) with ascorbic acid (AA) or ascorbic acid 2 glucoside (AA2G) and to evaluate their physical properties. Solid dispersions were prepared by dissolving each sample in an organic solvent and evaporation (EVP). Powder X-ray diffraction (PXRD) revealed a halo pattern for EVP1 (AA/TRT = 1/1) and EVP2 (AA2G/TRT = 1/1). In differential scanning calorimetry (DSC), endothermic peaks due to the melting of TRT and AA disappeared for EVP1 (AA/TRT = 1/1), and the melting peaks of TRT and AA2G disappeared for EVP2 (AA2G/TRT = 1/1). Fourier transform infrared (FT-IR) spectroscopy revealed broadened peaks for EVP1 (AA/TRT = 1/1) and EVP2 (AA2G/TRT = 1/1) due to the hydroxyl groups (-OH) of AA and the amino groups (-NH2) of TRT and also revealed a peak shift due to the pteridine skeleton (C = N) of TRT. In near-infrared absorption (NIR) spectroscopy, peaks due to the hydroxyl groups (-OH) of AA and AA2G were found for EVP1 (AA/TRT = 1/1) and EVP2 (AA2G/TRT = 1/1), respectively. A peak due to the amino groups (-NH2) was evident. This suggested the formation of an evaporation, in which TRT interacted with AA or AA2G. In the dissolution test, the dissolved fraction of TRT alone after 3 min was 30%, whereas the fractions were enhanced to approximately 90% for EVP1 (AA/TRT = 1/1) and EVP2 (AA2G/TRT= 1/1). Results confirmed that dissolution properties were improved as a result of complex formation. The above findings indicated improvement the dissolution properties of TRT.

Clinical efficacy of dissolvable microneedles armed with anti-melanogenic compounds to counter hyperpigmentation.

Hyperpigmentation is a complex physiological process associated with alterations of skin color due to melanin overproduction and distribution. Both intrinsic and extrinsic factors influence discoloration with the involvement of multiple pathways in cooperative manners. Restoring natural skin color requires a multi-targeted approach. Latest advances in anti-melanogenic compounds and microneedle delivery system have presented opportunities for tackling hyperpigmentationsuccessfully. This work was aimed at assessing the dermal tolerability and efficacy of hyaluronic acid-based microneedle patches loaded with anti-melanogenic actives for improvements of skin discoloration. The test products consist of hyaluronic acid with niacinamide, ascorbic acid 2-glucoside, tranexamic acid, resveratrol, 4-n-butyl-resorcinol, and Halidrys siliquosa extract. In a monocentric 12weeks clinical trial, the HA-MNs patches were applied to the affected areas of the faces on subjects with hyperpigmented skin. The color properties of the skin were analyzed spectrophotometrically. The products were tolerated remarkably; none of the subjects informed any primary or cumulative skin responses. Evaluation of color related measurable skin properties provided insight into the general effectiveness: The individual topology measurements showed 51.4% noticeable improvements in hyperpigmented zones, which were also in good agreement with the personal impressions of the subjects determined by questionnaires before and after the treatments. The concentrated blends of actives in microneedle patches act in a multi-targeted manner, and they could be worked in a complementary fashion for the improvement of skin color and appearance. The study has established the overall convenience of the HA-MNs with the formulation of anti-melogenic compounds against skin discoloration.

776 Optimized Vitamin C prodrug for controlled release and antioxidant activity

Vitamin C (vitC) plays key roles in many biological processes and it is a powerful anti-oxidant which protect the skin against UV exposure. Nevertheless, vitC is unstable under oxidative conditions. A pro-vitamin C, Ascorbic acid 2-glucoside (AA2G) was developed to stabilize vitC. The purpose of the study was to assess skin delivery, metabolism and antioxidant effect of AA2G compared to two concurrent products with 5% of encapsulated vitC or with 15% of free vitC. Skin delivery and metabolism studies were performed on human skin explants by UHPLC/UV. For anti-oxidative protection, three parameters were evaluated by measuring superoxide dismutase, catalase following UV exposure and malondialdehyde by GC/MS. We demonstrated prodrug concept with a good stability of AA2G and release of vitC. A better bioavailability was observed with prodrug compare to encapsulated vitC and equivalent to free vitC. A reservoir effect of AA2G in the SC was also observed which allows a controlled release of vitC according to the needs of the skin. These results are in accordance with a better anti-oxidant activity of the prodrug compare to the encapsulated vitC and equivalent to the free vitC with a lower percentage in the formulation 1,8% of prodrug versus 15% of free vitC.

Oral ascorbic acid 2-glucoside prevents coordination disorder induced via laser-induced shock waves in rat brain.

Oxidative stress is considered to be involved in the pathogenesis of primary blast-related traumatic brain injury (bTBI). We evaluated the effects of ascorbic acid 2-glucoside (AA2G), a well-known antioxidant, to control oxidative stress in rat brain exposed to laser-induced shock waves (LISWs). The design consisted of a controlled animal study using male 10-week-old Sprague-Dawley rats. The study was conducted at the University research laboratory. Low-impulse (54 Pa•s) LISWs were transcranially applied to rat brain. Rats were randomized to control group (anesthesia and head shaving, n = 10), LISW group (anesthesia, head shaving and LISW application, n = 10) or LISW + post AA2G group (AA2G administration after LISW application, n = 10) in the first study. In another study, rats were randomized to control group (n = 10), LISW group (n = 10) or LISW + pre and post AA2G group (AA2G administration before and after LISW application, n = 10). The measured outcomes were as follows: (i) motor function assessed by accelerating rotarod test; (ii) levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG), an oxidative stress marker; (iii) ascorbic acid in each group of rats. Ascorbic acid levels were significantly decreased and 8-OHdG levels were significantly increased in the cerebellum of the LISW group. Motor coordination disorder was also observed in the group. Prophylactic AA2G administration significantly increased the ascorbic acid levels, reduced oxidative stress and mitigated the motor dysfunction. In contrast, the effects of therapeutic AA2G administration alone were limited. The results suggest that the prophylactic administration of ascorbic acid can reduce shock wave-related oxidative stress and prevented motor dysfunction in rats.

Ascorbic Acid 2-Glucoside Pretreatment Protects Cells from Ionizing Radiation, UVC, and Short Wavelength of UVB.

Ascorbic acid 2-glucoside (AA2G), glucosylated ascorbic acid (AA), has superior properties for bioavailability and stability compared to AA. Although AA2G has shown radioprotective properties similar to AA, effects for UV light, especially UVC and UVB, are not studied. AA2G was tested for cytotoxicity and protective effects against ionizing radiation, UVC, and broadband and narrowband UVB in Chinese hamster ovary (CHO) cells and compared to AA and dimethyl sulfoxide (DMSO). Pretreatment with DMSO, AA, and AA2G showed comparative protective effects in CHO wild type and radiosensitive xrs5 cells for cell death against ionizing radiation with reducing the number of radiation-induced DNA damages. Pretreatment with AA and AA2G protected CHO wild type and UV sensitive UV135 cells from UVC and broadband UV, but not from narrowband UVB. DMSO showed no protective effects against tested UV. The UV filtration effects of AA and AA2G were analyzed with a spectrometer and spectroradiometer. AA and AA2G blocked UVC and reduced short wavelengths of UVB, but had no effect on wavelengths above 300 nm. These results suggest that AA2G protects cells from radiation by acting as a radical scavenger to reduce initial DNA damage, as well as protecting cells from certain UVB wavelengths by filtration.

PH affects the hormesis profiles of personal care product components on luminescence of the bacteria Vibrio qinghaiensis sp. -Q67

Hormesis describes a specific phenomenon in a biphasic concentration-response curve: low concentrations stimulate a response, while high concentrations suppress it. Hormesis could be influenced by several environmental factors, e.g. pH. In this study, the concentration-response/bioluminescence inhibition profiles (CRPs) of six components in personal care products to Vibrio qinghaiensis sp.-Q67 were measured at five different pH levels. When the exposure lasted for 0.25 h, CRPs of the six components at various pH levels were S-shaped, except ascorbic acid 2-glucoside (AA2G) at pH 10.5. When it lasted for 12 h, the CRPs were J-shaped, except AA2G at pH 6.5, 7.5, and 9.5. To rationally explain these changes in hormesis expressed by J-shaped CRP, four characteristic parameters, the minimum effect (Emin) and its corresponding concentration (ECmin), the median effective concentration (EC50), and the zero effect concentration point (ZEP, where the effect is 0 and the concentration is ZEP), were used to quantify the J-shaped CRP. The results indicated that these parameters vary with pH. Additionally, ZEP showed an excellent linear relationship with EC10 (R2 = 0.9994) at all pH levels, indicating that EC10 could replace the no-observed effective concentration (NOEC) in ecological risk assessment. Furthermore, to elucidate the possible mechanism of hormesis, the binding of the components to the luciferase receptors was analyzed using molecular docking technology. The results showed that the components displaying hormesis bind more easily to the α subunit of luciferase than to the β subunit.

Ascorbic Acid 2-Glucoside Stably Promotes the Primitiveness of Embryonic and Mesenchymal Stem Cells Through Ten-Eleven Translocation- and cAMP-Responsive Element-Binding Protein-1-Dependent Mechanisms.

Aims: The naive or primitive states of stem cells (SCs) residing in specific niches are unstable and difficult to preserve in vitro. Vitamin C (VitC), in addition to suppressing oxygen radicals, exerts pleiotropic effects to preserve the core functions of SCs. However, this compound is labile and readily oxidized, resulting in cellular toxicity and preventing its reliable application in this context. We found that a VitC derivative, ascorbic acid 2-glucoside (AA2G), stably maintains the naive pluripotency of murine embryonic SCs (mESCs) and the primitiveness of human mesenchymal SCs (hMSCs) without cellular toxicity. Results: The beneficial effects of AA2G and related molecular mechanisms were evaluated in mESCs, induced pluripotent-SCs (iPSCs), and hMSCs. AA2G was stable in aqueous solution and barely induced cellular toxicity in cultured SCs, unlike VitC. AA2G supplementation recapitulated the well-known effects of VitC, including induction of ten-eleven translocation-dependent DNA demethylation in mESCs and suppression of p53 during generation of murine iPSCs. Furthermore, supplementation of hMSCs with AA2G improved therapeutic outcomes in an asthma mouse model by promoting their self-renewal, engraftment, and anti-inflammatory properties. Particularly, activation of the cAMP-responsive element-binding protein-1 (CREB1) pathway contributed to the ability of AA2G to maintain naive pluripotency of mESCs and functionality of hMSCs. Innovation and Conclusion: Given its long-lasting effects and low cellular toxicity, AA2G supplementation is useful to support the naive pluripotency of mESCs and the primitiveness of hMSCs, affecting their developmental potency and therapeutic efficacy. Furthermore, we demonstrate the significance of the CREB1 pathway in the mechanism of action of AA2G.