Protective Properties of NovelS-Acyl-Glutathione Thioesters Against Ultraviolet-induced Oxidative Stress

Fucoidan/UVC Combined Treatment Exerts Preferential Antiproliferation in Oral Cancer Cells but Not Normal Cells

Combined treatment is a promising anticancer strategy for improving antiproliferation compared with a single treatment but is limited by adverse side effects on normal cells. Fucoidan (FN), a brown-algae-derived polysaccharide safe food ingredient, exhibits preferential function for antiproliferation to oral cancer but not normal cells. Utilizing the preferential antiproliferation, the impacts of FN in regulating ultraviolet C (UVC) irradiation were assessed in oral cancer cells. A combined treatment (UVC/FN) reduced cell viability of oral cancer cells (Ca9-22 and CAL 27) more than single treatments (FN or UVC), i.e., 53.7%/54.6% vs. 71.2%/91.6%, and 89.2%/79.4%, respectively, while the cell viability of UVC/FN treating on non-malignant oral (S–G) was higher than oral cancer cells, ranging from 106.0 to 108.5%. Mechanistically, UVC/FN preferentially generated higher subG1 accumulation and apoptosis-related inductions (annexin V, caspases 3, 8, and 9) in oral cancer cells than single treatments. UVC/FN preferentially generated higher oxidative stress than single treatments, as evidenced by flow cytometry-detecting reactive oxygen species, mitochondrial superoxide, and glutathione. Moreover, UVC/FN preferentially caused more DNA damage (γH2AX and 8-hydroxy-2’-deoxyguanosine) in oral cancer cells than in single treatments. N-acetylcysteine pretreatment validated the oxidative stress effects in these UVC/FN-induced changes. Taken together, FN effectively enhances UVC-triggered antiproliferation to oral cancer cells. UVC/FN provides a promising potential for preferential and synergistic antiproliferation in antioral cancer therapy.

Sunscreens and Cosmetic Formulations Containing Ascorbyl Tetraisopalmitate and Rice Peptides for the Improvement of Skin Photoaging: A Double-blind, Randomized Placebo-controlled Clinical Study

Photoprotective formulations containing substances with antioxidant properties in combination have been used as a strategy for the improvement of photoaged skin conditions. However, there is a lack of studies evaluating the clinical efficacy of these substances in young women with signs of photoaging. Thus, the objective of the present study was to evaluate the clinical efficacy of sunscreens and cosmetic formulations containing ascorbyl tetraisopalmitate and rice peptides for the improvement of skin photoaging in young women. A double-blind, randomized placebo-controlled clinical efficacy study was conducted on 60 female subjects aged 20-30 years with skin changes related to photoaging and without photoprotective habits. The hydrolipidic layer conditions and structural and morphological characteristics of the skin were evaluated by biophysical and skin imaging techniques. The results showed that the daily use of the formulations under study improved the skin conditions by increasing skin hydration and dermis echogenicity. In addition, the application of the active substances reduced skin hyperpigmentation and increased epidermal cell renewal. In summary, the present study showed the importance of daily application of sunscreens and formulations with antioxidant properties for the prevention and attenuation of skin changes related to photoaging in young women.

Efficacy and safety of S-acyl glutathione 2% cream vs. placebo against UVB-induced erythema: a randomized, double-blinded clinical trial

BACKGROUND

Reactive oxygen species have a major role in the UV-induced short- and long-term damage, thus the exogenous supplementation of antioxidant molecules may allow better skin protection. Despite glutathione has pivotal properties in the complex cytoplasmic antioxidant system, its supplementation is hampered by limited transmembrane absorption. Modification of glutathione pharmacokinetic properties via acetylation with long-chain polyunsaturated fatty acid may improve its passage through phospholipidic membranes.

METHODS

This was a single center randomized double-blinded clinical trial, versus placebo, cross-sectional pairwise at time 0. The participants were 10 healthy volunteers with skin phototypes II or III and age ≥18 years interested in performing minimal erythema dose (MED) evaluation performed by photoallergology unit of Division of Dermatology at P. Palagi Hospital, in Florence. Each volunteer underwent UVB phototesting, treating four different areas with increasing UVB doses in four different conditions. One arm was treated as standard procedure (naïve arm), one applying linolenic-glutathione conjugate (Lin-GSH) cream 2% before irradiation (pre-Lin-GSH arm), one with placebo (placebo arm) and one applying Lin-GSH cream 2% (SoloSale Srl, Florence, Italy) after irradiation (post-Lin-GSH arm). The main endpoint was to evaluate efficacy of Lin-GSH cream 2% before UVB irradiation compared with placebo. A secondary endpoint was the evaluation of the same cream applied after irradiation compared to no treatment. Another secondary objective is the evaluation of safety in both conditions. Mean MED was evaluated at distinct conditions. Safety was evaluated reporting all grade 3-4 adverse events up to 30 days after treatment. All volunteers were treated in all four experimental conditions. The pre-Lin-GSH and placebo arms were applied in a double-blind condition for each volunteer. Neither the volunteer nor the investigator executing MED evaluation knew which arm was given Lin-GSH and which one placebo.

RESULTS

Ten volunteers among 12 recruited for the study were correctly randomized and completed all study evaluations. Recruitment went from April 1st, 2016 to May 1st, 2016, up to adequate population number. Mean MED in pre-Lin-GSH arm was superior to mean MED in placebo arm (135±5.53 mJ/cm2 vs. 105±7.64 mJ/cm2, P=0.0003). No difference was observed among mean MED in post-Lin-GSH and naïve arms. No grade 3-4 adverse events were reported.

CONCLUSIONS

Lin-GSH 2% cream seems a safe and effective in producing a significant increase in MED compared with placebo thanks to its antioxidant properties.

Reduction of bacteria and human immunodeficiency virus Type 1 infectivity of platelet suspension in plasma using xenon flash-pulse light in a bench-scale trial

BACKGROUND

Current pathogen reduction systems for platelet concentrates (PCs) require addition of chemical compounds and/or reduction of plasma content in PCs. We have investigated a new method using xenon (Xe) flash-pulse light without additional compounds or plasma replacement.

STUDY DESIGN AND METHODS

An aliquot of apheresis platelets (PLTs) in plasma inoculated with bacteria or human immunodeficiency virus Type 1 (HIV-1) was irradiated with Xe flash-pulse light (Xe flash phototreatment). Bacterial growth was monitored up to 6 days of storage, whereas HIV-1 infectivity was assayed just after treatment. Pairs of Xe flash-phototreated and untreated PCs were examined for PLT lesion during the storage period.

RESULTS

Under the current conditions, a low titer (1.8 colony-forming units [CFUs]/mL) of Staphylococcus aureus did not proliferate during the 6-day storage period, but grew in some cases at high-titer (24.0 CFUs/mL) inoculation. HIV-1 infectivity was reduced by 1.8 log. PLT recovery of the treated PCs was lower than untreated ones. An increase of mean PLT volume and glucose consumption, together with a decrease of hypotonic shock response and pH, were enhanced by the treatment. CD62P- and PAC-1-positive PLTs increased after the treatment, indicating the induction of PLT activation. Among biologic response modifiers, soluble CD40 ligand was significantly increased in the treated PCs on Day 6.

CONCLUSIONS

Xe flash phototreatment could prevent bacterial proliferation and reduce HIV-1 infectivity in 100% plasma PCs without any additional compounds, but enhanced PLT storage lesions. Further improvement is required to increase the potency of pathogen inactivation with reducing PLT damage.

S-linolenoyl glutathione intake extends life-span and stress resistance via Sir-2.1 upregulation in Caenorhabditis elegans

Oxidative stress has a prominent role in life-span regulation of living organisms. One of the endogenous free radical scavenger systems is associated with glutathione (GSH), the most abundant nonprotein thiol in mammalian cells, acting as a major reducing agent and in antioxidant defense by maintaining a tight control over redox status. We have recently designed a series of novel S-acyl-GSH derivatives capable of preventing amyloid oxidative stress and cholinergic dysfunction in Alzheimer disease models, upon an increase in GSH intake. In this study we show that the longevity of the wild-type N2 Caenorhabditis elegans strain was significantly enhanced by dietary supplementation with linolenoyl-SG (lin-SG) thioester with respect to the ethyl ester of GSH, linolenic acid, or vitamin E. RNA interference analysis and activity inhibition assay indicate that life-span extension was mediated by the upregulation of Sir-2.1, a NAD-dependent histone deacetylase ortholog of mammalian SIRT1. In particular, lin-SG-mediated overexpression of Sir-2.1 appears to be related to the Daf-16 (FoxO) pathway. Moreover, the lin-SG derivative protects N2 worms from the paralysis and oxidative stress induced by Aβ/H2O2 exposure. Overall, our findings put forward lin-SG thioester as an antioxidant supplement triggering sirtuin upregulation, thus opening new future perspectives for healthy aging or delayed onset of oxidative-related diseases.

TDP-43 inclusion bodies formed in bacteria are structurally amorphous, non-amyloid and inherently toxic to neuroblastoma cells

Accumulation of ubiquitin-positive, tau- and α-synuclein-negative intracellular inclusions of TDP-43 in the central nervous system represents the major hallmark correlated to amyotrophic lateral sclerosis and frontotemporal lobar degeneration with ubiquitin-positive inclusions. Such inclusions have variably been described as amorphous aggregates or more structured deposits having an amyloid structure. Following the observations that bacterial inclusion bodies generally consist of amyloid aggregates, we have overexpressed full-length TDP-43 and C-terminal TDP-43 in E. coli, purified the resulting full-length and C-terminal TDP-43 containing inclusion bodies (FL and Ct TDP-43 IBs) and subjected them to biophysical analyses to assess their structure/morphology. We show that both FL and Ct TDP-43 aggregates contained in the bacterial IBs do not bind amyloid dyes such as thioflavin T and Congo red, possess a disordered secondary structure, as inferred using circular dichroism and infrared spectroscopies, and are susceptible to proteinase K digestion, thus possessing none of the hallmarks for amyloid. Moreover, atomic force microscopy revealed an irregular structure for both types of TDP-43 IBs and confirmed the absence of amyloid-like species after proteinase K treatment. Cell biology experiments showed that FL TDP-43 IBs were able to impair the viability of cultured neuroblastoma cells when added to their extracellular medium and, more markedly, when transfected into their cytosol, where they are at least in part ubiquitinated and phosphorylated. These data reveal an inherently high propensity of TDP-43 to form amorphous aggregates, which possess, however, an inherently high ability to cause cell dysfunction. This indicates that a gain of toxic function caused by TDP-43 deposits is effective in TDP-43 pathologies, in addition to possible loss of function mechanisms originating from the cellular mistrafficking of the protein.

A bioactive probe for glutathione-dependent antioxidant capacity in breast cancer patients: implications in measuring biological effects of arsenic compounds

INTRODUCTION

Glutathione, a major cellular non-protein thiol (NPSH), serves a central role in repairing damage induced by cancer drugs, pollutants and radiation and in the detoxification of several cancer chemotherapeutic drugs and toxins. Current methods measure glutathione levels only, which require cellular extraction, rather than the glutathione recycling dependent antioxidant activity in intact cells. Here, we present a novel method using a bioactive probe of the oxidative pentose phosphate cycle, termed the OxPhos™ test, to quantify glutathione recycling dependent antioxidant activity in whole blood and intact human and rodent cells without the need for the isolation and cytoplasm extraction of cells.

METHODS

OxPhos™ test kit (Rockland Immunochemicals, USA), which uses hydroxyethyldisulfide (HEDS) as a probe for the oxidative pentose phosphate cycle, was used in these studies. The results with OxPhos™ test kit in human blood and intact cells were compared with total thiol and high pressure liquid chromatography/electrochemical detection of HEDS metabolism.

RESULTS

The OxPhos™ test measured glutathione-dependent antioxidant activity both in intact human and rodent cells and breast cancer patient's blood with a better correlation coefficient and biological variability than the thiol assay. Additionally, human blood and mammalian cells treated with various arsenicals showed a concentration-dependent decrease in activity.

DISCUSSION

The results demonstrate the application of this test for measuring the antioxidant capacity of blood and the effects of environmental pollutants/toxins. It opens up new avenues for an easy and reliable assessment of glutathione-dependent antioxidant capacity in various diseases such as stroke, blood borne diseases, infection, cardiovascular disease and other oxidative stress related diseases and as a prognostic indicator of chemotherapy response and toxicity. The use of this approach in pharmacology/toxicology including screening drugs that improve the glutathione-dependent antioxidant capacity and not just the glutathione level is clinically relevant since mammalian cells require glutathione dependent pathways for antioxidant activity.

Novel vitamin D compounds and skin cancer prevention

As skin cancer is one of the most costly health issues in many countries, particularly in Australia, the possibility that vitamin D compounds might contribute to prevention of this disease is becoming increasingly more attractive to researchers and health communities. In this article, important epidemiologic, mechanistic and experimental data supporting the chemopreventive potential of several vitamin D-related compounds are explored. Evidence of photoprotection by the active hormone, 1α,25dihydroxyvitamin D3, as well as a derivative of an over-irradiation product, lumisterol, a fluorinated analog and bufalin, a potential vitamin D-like compound, are provided. The aim of this article is to understand how vitamin D compounds contribute to UV adaptation and potentially, skin cancer prevention.