Changes In GSH Levels Research Articles

Mitochondrial damage precedes the changes of glutathione metabolism in CdCl2 treated neuronal SH-SY5Y cells

Cadmium crosses the blood-brain barrier inducing damage to neurons. Cell impairment is predominantly linked to oxidative stress and glutathione (GSH) depletion. On the other hand, several reports have described an increase of GSH levels in neuronal cells after CdCl2 exposure. Therefore, the aim of the present report was to investigate the relation between changes in GSH levels and mitochondrial damage in neuronal cells after CdCl2 treatment. To characterize neuronal impairment after CdCl2 treatment (0–200 μM) for 1–48 h, we used the SH-SY5Y cell line. We analyzed GSH metabolism and determined mitochondrial activity using high-resolution respirometry. CdCl2 treatment induced both the decreases and increases of GSH levels in SH-SY5Y cells. GSH concentration was significantly increased in cells incubated with up to 50 μM CdCl2 but only 100 μM CdCl2 induced GSH depletion linked to increased ROS production. The overexpression of proteins involved in GSH synthesis increased in response to 50 and 100 μM CdCl2 after 6 h. Finally, strong mitochondrial impairment was detected even in 50 μM CdCl2 treated cells after 24 h. We conclude that a significant decrease in mitochondrial activity can be observed in 50 μM CdCl2 even without the occurrence of GSH depletion in SH-SY5Y cells.

MnO2-based dual channel surface plasmon resonance fiber sensor for trace glutathione and refractive index detection.

Glutathione (GSH) plays vital role in human biological systems, so its rapid and sensitive detection is necessary for health condition monitoring. In this work, a simple structure for dual channel GSH and refractive index (RI) detection is proposed. By introducing Au-MnO2 thin film coating on the fiber surface for the first time, GSH solution would lead to the dissolution of MnO2, the change in GSH levels could be monitored over a short period in channel 2. For channel 1, ITO-Ag thin film is applied for RI change detection. After optimization, the GSH detection sensitivity reached about -2.361 nm/mM in the range of 0.005-50 mM, and the RI sensitivity reached 1704.252 nm/RIU in the range of 1.331-1.3895 RIU. Channel 1 could also put into GSH detection in the high concentration scale to enlarge the sensor's range and 0.095 nm/mM of sensitivity is acquired within the range of 50-600 mM. With the presence of MnO2 film, the detection sensitivity increased 25.663 times. Neither channel interferes with the operation of the other. Proposed sensor provides stability, high selectivity and elevation in GSH detection sensitivity, which shows great potential for environmental and biological detection field and their applications.

Meso-aryltellurium-BODIPY-based fluorescence turn-on probe for selective, sensitive and fast glutathione sensing in HepG2 cells

Glutathione (GSH) as one most abundant thiol, acts as important roles in regulating cellular redox activities, and various diseases are closely related with its abnormal levels. Thus, monitoring intracellular GSH levels is essential for understanding cellular metabolism of many related diseases. In this work, we firstly reported a new fluorescence turn-on sensor, which was capable of selectively, sensitively and rapid sensing GSH over other thiols, especially cysteine and homocysteine in solutions and living cells. A meso-aryltellurium boron dipyrromethene (BODIPY) was firstly designed and synthesized, which showed silenced emission due to an efficient photoinduced electron transfer (PET) process from electron-rich Te to BODIPY, and then upon exposure to GSH, the meso-Te-C bond could be rapidly cleaved by the thiol group of GSH, thus resulting in an obvious fluorescence “turn-on” phenomenon through inhibition of the PET effect. This probe exhibited excellent selectivity and sensitivity towards GSH with a short response time of 2 min, showing a remarkable fluorescence enhancement observed at 541 nm with a large fluorescence quantum yield increase from nearly 0 to 0.73 upon excitation at 500 nm in PBS/CH3CN (9/1, v/v). The detection limit towards GSH was further calculated to be 1.7 nM by the linear fluorescence change at 541 nm in the GSH-concentration ranging from 0 to 4 μM. Furthermore, its sensing mechanism was validated by using mass spectrometry, confirming the rapid cleavage of the Te–C bond by GSH. Finally, cell imaging experiments demonstrated that this probe could successfully detect GSH in living cells, highlighting its potential for rapid and sensitive detection of intracellular GSH level changes. Therefore, a new meso-aryltellurium-BODIPY fluorescence turn-on sensor was firstly developed, which could selectively, sensitively and fast detect cellular GSH over other thiols based on the rapid cleavage of the meso Te–C bond.

An ultrasensitive GSH-specific fluorescent probe unveils celastrol-induced ccRCC ferroptosis

Glutathione (GSH) is closely related to the occurrence and development of tumors. The intracellular GSH levels are abnormally altered when tumor cells undergo programmed cell death. Therefore, real-time monitoring of the dynamic changes of intracellular GSH levels can better enable the early diagnosis of diseases and evaluate the effects of cell death-inducing drugs. In this study, a stable and highly selective fluorescent probe AR has been designed and synthesized for the fluorescence imaging and rapid detection of GSH in vitro and in vivo, as well as patient-derived tumor tissue. More importantly, the AR probe can be used to track changes in GSH levels and fluorescence imaging during the treatment of clear cell renal cell carcinoma (ccRCC) with celastrol (CeT) via inducing ferroptosis. These findings demonstrate that the developed fluorescent probe AR exhibits high selectivity and sensitivity, as well as good biocompatibility and long-term stability, which can be used to image endogenous GSH in living tumors and cells. Also, a significant decrease in GSH levels was observed by the fluorescent probe AR during the treatment of ccRCC with CeT-induced ferroptosis in vitro and in vivo. Overall, these findings will provide a novel strategy for celastrol targeting ferroptosis in the treatment of ccRCC and the application of fluorescent probes to help reveal the underlying mechanism of CeT in the treatment of ccRCC.

A dual-reaction-site and dual-channel fluorescent-on probe for selectively monitoring mitochondrial glutathione

Glutathione (GSH) is the most abundant endogenous antioxidant and serves critical cellular functions in living system. As a results, it is of great significant to disclose GSH-specific fluorescent probe to deeply understand its biological functions. In this study, we developed a dual-reaction-site and dual-channel turn-on fluorescent probe Cyan-S-Nap for GSH by installing the sensing groups of thiophenol and sulfonamide moieties into the dyes of heptamethine cyanine and naphthalimide, respectively. The probe displayed selective response to GSH by the two independent fluorescent channels in visible (λem = 492 nm) and near-infrared (λem = 810 nm) regions. The dual emissions feature endows the probe with the ability to precisely detect the concentration fluctuation of GSH. In addition, the biological utilities of Cyan-S-Nap suggested that the probe was capable of imaging mitochondrial GSH in dual channels in a synchronous and independent manner, as well as monitoring the changes of GSH levels modulated by exogenous/endogenous reactive oxygen species in living cells and zebrafish.

Glutathione in cancer progression and chemoresistance: an update

Glutathione (GSH) is one of the most important components of the cellular antioxidant system, and it is able to exert several pleiotropic functions influencing cell growth, proliferation, adaptation and death. It has been demonstrated that changes in GSH levels underlie the pathogenesis of many human diseases, including cancer. In detail, although on one hand GSH homeostasis plays a protective role from the onset of cancer, on the other, it is involved in cancer progression and in therapy resistance. In this review, after a brief report on the physiological role of GSH, we have focused the attention on its role in cancer and refractoriness to anticancer therapy giving an update on the preclinical and clinical studies relied on the compounds targeting GSH system. Based on these considerations, a deeper knowledge of GSH-dependent network can be crucial to identify new strategies for preventing and/or curing cancer.

Perfluorooctanoic acid affects mouse brain and liver tissue through oxidative stress.

The aim of this study was to investigate oxidative stress induced by perfluorooctanoic acid (PFOA) in the brain and liver tissues of Balb/c mice as well as protective effects of taurine and coenzyme Q10 (CoQ10) in both organs. For this purpose, animals were treated with PFOA (15 and 30 mg/kg) orally and their lipid peroxidation, total glutathione levels (GSH), and antioxidant enzyme activities measured and both tissues analysed for histopathological changes. Our results showed a dose-dependent decrease in body weight and increase in relative brain and liver weights, PFOA-induced lipid peroxidation and reduced glutathione peroxidase (GPx) activity in the brain tissue, and changes in GSH levels, GPx, superoxide dismutase (Cu-Zn SOD), and catalase (CAT) activities in the liver tissue. Pre-treatment with taurine or CoQ10 provided protection against PFOA-induced Cu-Zn SOD reduction in the liver tissue. Our findings evidence the depleting effect of PFOA on antioxidative systems and confirm that PFOA exerts its (neuro)toxicity through oxidative stress, but further research is needed to identify the exact toxicity mechanisms, especially in the brain.

Dual mode assay of glutathione with Tb-doped g-C3N4/MnO2 nanoconjugates as fluorescence probe and Mn as elemental target

Glutathione (GSH) plays important roles in various physiological processes, thus highly sensitive assay of GSH and timely warning of its variation at trace level in complex biological matrixes is of great significance. However, this is challenging due to the coexisting reductive biomolecules and dynamic change of GSH levels in responding to various stimuli which remain largely unexploited. Herein, we report a dual mode protocol for the assay of GSH based on nanoconjugate g-C3N4:Tb/MnO2 between MnO2 nanosheets and terbium-doped g-C3N4 (g-C3N4:Tb) nanosheets. MnO2 moiety effectively quenches the emission at 546 nm from Tb3+ in the nanoconjugate, which is restored under the reduction of MnO2 by GSH to ensure fluorescence turn-on assay of GSH. Meanwhile, the generated Mn2+ facilitates inductively coupled plasma mass spectrometry (ICP-MS) detection to endow indirect highly sensitive assay of GSH. Fluorescence mode derived a limit of detection (LOD) of 0.17 μmol L−1 within a linear range of 0.5–160 μmol L−1, while ICP-MS resulted in a superior LOD of 0.016 μmol L−1 within 0.05–160 μmol L−1. Both detection modes provide excellent selectivity to GSH. The dual mode platform was validated by GSH assay in cell lysates. It was further demonstrated by monitoring the variation of dynamic change of GSH level under CuSO4 or cisplatin induced GSH consumption.

Ionizing radiation reduces glutathione levels in the eye: A pilot study

In 2011, the International Commission on Radiological Protection recommended reducing the threshold dose and occupational equivalent dose limit for the lens of the eye. However, this recommendation was based on limited epidemiological evidence and a few assumptions. Additional epidemiological and biological studies are thus required to understand radiation cataracts and optimize radiation protection practices. Glutathione is present in large amounts in the lens and inhibits the onset and progression of cataracts. A few studies have reported changes in glutathione levels in laboratory animal lenses after irradiation, but evidence about dose rate and time dependence remains lacking. In this study, we analyzed dose rate- and time-dependent changes in whole-eye reduced glutathione (GSH) and oxidized glutathione (GSSG) levels after γ-irradiation. We found that both decreases in eye GSH levels and delays in eye GSH recovery depended on dose rate. Our results support the concept that changes in GSH levels influenced on radiation cataractogenesis, consistent with previous biological research. This study will contribute to the mechanistic understanding of radiation cataractogenesis.

Design and Development of a Non‐Enzymatic Electrochemical Biosensor for the Detection of Glutathione

AbstractGlutathione (GSH‐reduced form) is a tripeptide that plays a vital role as an antioxidant to remove xenobiotics in the human body and changes in GSH levels are a marker for the progression of various diseases. In this context, a highly sensitive non‐enzymatic electrochemical biosensor for the detection of GSH has been developed using reduced graphene oxide Manganese oxide (rGMnO) nanocomposite as the nano‐interface. Initially, graphene oxide was synthesized by Hummer's method and then thermally reduced in the presence of MnO2in a blast furnace to obtain rGMnO nanocomposite. The nanocomposite was characterized to validate its structure and morphological properties via Scanning electron microscopy (SEM), X‐ray diffraction (XRD), Raman, and X‐ray photoelectron spectroscopy (XPS). Cyclic voltammetry and amperometry studies showed that upon the addition of GSH, the Pt/rGMnO modified working electrode exhibited a linear response in the range of 1–100 μM at an input voltage of −0.62 V. The developed sensor was found to have a sensitivity of 0.3256 μA μM−1and LOD of 970 nM with a recovery of 92–104 % in real blood serum samples.

Fluorescence imaging of glutathione with aptasensor and monitoring deoxynivalenol-induced oxidative stress in living cells

Glutathione (GSH) is an important intracellular antioxidant. It is closely related to the homeostasis of the intracellular redox state which can be changed through deoxynivalenol (DON) exposure. More importantly, GSH deficiency can directly lead to apoptosis and cellular metabolic disorders mediated by intracellular redox homeostasis. Therefore, real-time monitoring of dynamic changes of GSH levels in living cells is urgently needed for the evaluation of intracellular oxidative stress. Herein, for the first time, an aptamer-based recognition composite nanoprobe (Apt-AuNCs-MoS2) was successfully constructed. The nanoprobe was employed for real-time and in situ imaging of DON-induced intracellular GSH changes and evaluation of oxidative stress status. The results indicated that the aptasensor revealed excellent specificity and high sensitivity to GSH in the solution system, and the limit of detection was as low as 35 nM. The results about DON-mediated oxidative stress indicated that the oxidative stress in living cells tends to be saturated with more than 20 ppm DON concentration. Thus, the strategy provides a novel aptasensor for the determination of GSH, offers a promising platform for fluorescence imaging of intracellular GSH in living cells, and further enriches in situ analysis of the in vitro toxicology.

The Impact of Dehydration and Hyperthermia on Circulatory Glutathione Metabolism after Exercise in the Heat with Insights into the Role of Erythrocytes.

Background: Reduced glutathione (GSH) is one of the main thiols involved in antioxidant defense. Changes in circulatory levels of GSH during exercise are associated with hyperthermia and dehydration. The mechanisms by which these alterations occur are not entirely known. We hypothesize that erythrocytes could be an important source of circulatory GSH during heat stress conditions. We performed two separate experiments to address this hypothesis. Methods: In the first experiment, we sought to investigate the impact of exercise in the heat and dehydration on erythrocyte levels of GSH. A total of 10 men performed 60 min of cycling at 60% VO2peak in the heat (38.0 ± 0.9 °C) or in a control temperate environment (23.0 ± 1.0 °C), both with and without dehydration. Relative humidity ranged from 50 to 70%. Blood samples were taken before and after exercise to measure GSH and oxidized (GSSG) glutathione. In the second experiment, erythrocytes were isolated from blood samples taken at rest and heated in vitro to determine the impact of heat on erythrocyte glutathione content. Tubes with erythrocytes were exposed to water baths at different temperatures; one tube was exposed to a water bath at 35 °C and the other tube to a water bath at 41 °C for a period of 30 min. After exposure to heat, plasma and erythrocytes were extracted for GSH and GSSG analyses. Results: Dehydration decreased circulatory GSH, regardless of ambient temperature (temperate and heat decreased 15.35% and 30.31%, respectively), resulting in an altered redox balance. Heat increased GSH levels in vitro. Conclusion: Our data suggest that dehydration decreases circulatory GSH levels regardless of environmental temperature. In addition, in vitro data suggests that erythrocytes may contribute to the release of GSH during exposure to heat stress.

Milk Intake Enhances Cerebral Antioxidant (Glutathione) Concentration in Older Adults: A Randomized Controlled Intervention Study

ObjectivesThis randomized controlled trial was to confirm the potential benefit of adequate dairy food intake to raise brain antioxidant, glutathione (GSH), in low dairy consumers through a longitudinal dietary intervention. This confirmatory study is based on our previous findings of positive correlations between brain GSH levels and dairy food consumption, particularly milk (P < 0.001), in a cross-sectional study of older adults. MethodsA total of 80 older adults with a low dairy intake (≤1.5 servings/day) were enrolled in a 3-month milk intervention study. Brain GSH levels were measured using multiple quantum chemical shift imaging at 3 T. After baseline MR scans, participants were randomized into either the intervention or control group using a random-sequence algorithm. The control group continued their usual intake of dairy ≤1.5 servings/day (<1 cup of milk/day) while the milk intervention group was provided 1% milk weekly and instructed to consume 3 cups of milk/day for three months. Dietary intake was assessed with 24-hr diet recalls, 7-day food records, and a Diet Screener Questionnaire and was analyzed using NDSR software. Brain GSH levels in each group were compared between baseline and post-intervention using paired t-tests, and longitudinal changes of GSH levels were compared between groups using two sample t-tests. ResultsAmong 80 enrolled participants (60–89 years old), 66 participants (49 intervention; 17 controls) completed the study. The milk intake of the controls was similar at baseline and the end of study timepoints (0.4 ± 0.4 cups/day for both), while that of the intervention group increased from 0.2 ± 0.3 cups/day to 3.0 ± 0.6 cups/day (P < 0.001). The intervention group showed 7.4 ± 11.7% increases in parietal GSH (P < 0.001) and 4.6 ± 8.7% increases in fronto-parietal GSH (P = 0.003) levels after intervention, while the control group showed no changes in brain GSH. The fronto-parietal GSH increase in the intervention group was greater than that of the control group (P < 0.05). ConclusionsDietary milk consumption could modulate brain GSH levels. This study demonstrates the effect of diet on brain antioxidants, which could lead to the development of new strategies in strengthening cerebral antioxidant defenses and thereby improving brain health in the aging population. Funding SourcesNational Dairy Council.

Avaliação do efeito antioxidante de cipó-mil-homens (Aristolochia triangularis Cham.) em eritrócitos de pacientes com doenças neurodegenerativas

O objetivo do estudo foi avaliar o efeito antioxidante do extrato hidroetanólico de cipó-mil-homens (Aristolochia tringularis Cham.), em testes in vitro com eritrócitos de indivíduos portadores de doença neurodegenerativa, por meio da avaliação de biomarcadores oxidativos e antioxidantes enzimáticos e não enzimáticos. Realizou-se a análise dos compostos fenólicos totais dos caules de cipó-mil-homens, provenientes da cidade de Panambi- RS. Na sequência foram realizados os testes in vitro, mediante o tratamento com diferentes concentrações do extrato da planta (0,025; 0,050; 0,100 e 0,200 mg/mL). Após, realizou-se a análise dos níveis de TBARS, CAT, GSH e GST. Na dosagem dos compostos fenólicos totais obteve-se o valor de 426mg/mL de extrato. Nas avaliações de estresse oxidativo, foi possível observar o aumento da lipoperoxidação nas concentrações de 0,050mg/mL e 0,200mg/mL, destacando-se a concentração de 0,050mg/mL, onde o dano em lipídeos foi mais expressivo. Não houve alteração significativa nos níveis de GSH em nenhuma das concentrações do extrato utilizadas no estudo. A atividade da enzima catalase mostrou-se diminuída na concentração de 0,100mg/mL. Houve a diminuição da GST nas concentrações de 0,100 e 0,200mg/mL, prejudicando assim a ação antioxidante endógena. Desta forma, o extrato hidroetanólico de cipó-mil-homens não apresentou efeito antioxidante, mas sim um efeito tóxico nessas concentrações.

Endogenous Cys-Assisted GSH@AgNCs-rGO Nanoprobe for Real-Time Monitoring of Dynamic Change in GSH Levels Regulated by Natural Drug.

Glutathione (GSH) levels are closely related to the homeostasis of redox state which directly affects human disease occurrence by regulating cell apoptosis. Hence, real-time monitoring of dynamic changes in intracellular GSH levels is urgently needed for disease early diagnosis and evaluation of therapy efficiency. In this study, an endogenous cysteine (Cys)-assisted detection system based on GSH@AgNCs and reduced graphene oxide (rGO) with high sensitivity and specificity was developed for GSH detection. Compared with GSH, GSH@AgNCs with weaker affinity and bonding force was quite easier to extrude from the rGO surface when competing against GSH, leading to the obvious change in fluorescence signal. This phenomenon was termed as "a crowding out effect". Furthermore, the presence of Cys can improve GSH assay sensitivity by enhancing the quenching efficiency of rGO on the GSH@AgNCs. In vitro assay indicated that the efficiency of fluorescence recovery was positively related with GSH concentration in the range from 0 to 10 mM. In addition, the method was employed for real-time monitoring of the dynamic changes in GSH levels regulated by natural drugs. The imaging results showed that the natural compound 3 (C3) can downregulate GSH levels in HepG2 cells, which was accompanied by reactive oxygen species (ROS) release and apoptosis induction. Finally, the method was used to monitor the change of GSH levels in serum samples with chronic hepatitis B (CHB) infection. The results demonstrated that the occurrence and development of CHB may be positively correlated with GSH levels to some extent. Overall, the above results demonstrate the potential application of this new nanosystem in anticancer natural drug screening and clinical assay regarding GSH levels.

Selectively monitoring glutathione in human serum and growth-associated living cells using gold nanoclusters

Glutathione (GSH) plays a variety of vital functions in biological systems. Growth-associated change of GSH level in cells might be critical for cell survival and monitoring of GSH in living cells are of great significance for understanding the dynamic link between GSH and some diseases. In this work, chitason micelles templated gold nanoclusters (CM-Au NCs) emitting red fluorescence were prepared with a simple and rapid method, which shows interesting phenomenon of aggregation induced emission (AIE) affected by the size of the chitosan micelles. The unique CM-Au NCs can be used to develop turn-off fluorescent probe for detecting GSH in human serum and living cells based on the reverse process of AIE of CM-Au NCs, completely different from the principle of aggregation caused quenching (ACQ) effect, which can distinguish GSH from other biothiols (cysteine and homocysteine) and quantitatively detect GSH concentration of human serum in healthy people and cancer patients with high sensitivity. The practical application of fluorescent CM-Au NCs for cellular imaging and detecting GSH level indicates ultra-trace changes of GSH levels in normal and cancer cells could be monitored at different growth stages, which reveals that the levels of GSH in cancer cells was always higher than that of normal cells. Compared with commercial GSH assay kits for detection GSH in human serum and living cells, the proposed method was verified to be accuracy and precision. The results not only reflect the changes of GSH during cell growth at different stages, but also demonstrate the feasibility of reverse process of AIE of CM-Au NCs for detection GSH. This strategy would provide a platform to understand the dynamic link between GSH and disease to clarify the disease mechanism.

Sinapic acid mitigates intracerebroventricular streptozotocin induced oxidative stress and neuro-inflammatory changes in rats

Oxidative stress and inflammatory cytokines play an important role in progression of Alzheimer’s disease (AD). Sinapic acid, a natural phenolic compound has shown neuro-protection by amelioration of oxidative stress and neuro-inflammation. Here, we evaluated the effect of sinapic acid on oxidative stress and inflammatory cytokines in intracerebroventricular streptozotocin (ICV-STZ) sporadic model of AD in rats. Male Wistar rats (260 ± 20g), were administered ICV-STZ (3 mg/kg) and sinapic acid (10 and 20 mg/kg, orally) was administered for 21 days. Morris water maze and passive avoidance paradigm test was carried out on 0 and 21st days. On 21st day rats were sacrificed, levels of MDA, GSH, TNF-α and IL-1β were estimated in cortex and hippocampus. The expression of choline acetyltransferase (ChAT) was also assessed by western blot. On day 21, STZ produced memory impairment as evidenced by increased escape latency (p < 0.001), decreased time spent in target zone in Morris water maze. Sinapic acid attenuated the increased escape latency and improved the time spent in target quadrant at 20 mg/kg on 21st day (p < 0.05). STZ induced decreased transfer latency in passive avoidance paradigm was also significantly increased. STZ induced changes in levels of GSH and MDA were significantly normalised by sinapic acid. STZ induced levels of TNF-α and IL-1β were significantly (p < 0.05) attenuated by sinapic acid 20 mg/kg. Moreover, sinapic acid ameliorated the STZ induced decreased expression of ChAT in hippocampus. The results suggest that sinapic acid improves STZ-induced cognitive impairment by ameliorating oxidative stress and neuro inflammation in cortex and hippocampus.

Non-invasive mapping of glutathione levels in mouse brains by in vivo electron paramagnetic resonance (EPR) imaging: Applied to a kindling mouse model

Glutathione (GSH) is an important antioxidant that can protect cells under oxidative stress. Thus, a non-invasive method to measure and map the distribution of GSH in live animals is needed. To image the distribution of GSH levels in specific brain regions, a new method using electron paramagnetic resonance (EPR) imaging with a nitroxide imaging probe was developed. Pixel-based mapping of brain GSH levels was successfully obtained by using the linear relationship between reduction rates for nitroxides in brains, measured by an in vivo EPR imager, and brain GSH levels, measured by an in vitro biochemical assay. The newly developed method was applied to a kindling mouse model induced with pentylenetetrazole (PTZ) to visualize changes in GSH levels in specific brain regions after seizure. The obtained map of brain GSH levels clearly indicated decreased GSH levels around the hippocampal region compared to control mice.

Real time detection of glutathionse in chemotherapy squamous-cell carcinoma cells of a fluorescent probe

Glutathione (GSH) plays a key role in protecting damage induced by radiation and chemotherapy drugs. Current methods, which quantify GSH level changes by using cellular extraction or being based on redox homeostasis results, are unable to directly measure real time GSH level in live cells. In this article, we utilized a newly designed reversible fluorescent probe to measure GSH in living cells. The image of probe 1 can reveal intracellular GSH location and GSH level changes caused by different chemotherapy drugs in squamous-cell carcinoma cells. The results show that it is the first report with probe 1 that to quantify real-time GSH level changes in the cultured chemotherapy cancer cells and different changes in GSH level that may confer chemotherapy resistance.

Effect of hesperetin derivatives on the development of selenite‑induced cataracts in rats.

Cataracts are a major cause of blindness worldwide. As anti‑cataract pharmaceutical therapies require long‑term treatment, identifying anti‑cataract compounds that are ubiquitous in the human diet, have no adverse effects and are affordable, is of paramount importance. The present study focused on hesperetin and its derived compounds, hesperetin stearic acid ester (Hes‑S) and hesperetin oleic acid ester (Hes‑O), in order to investigate their therapeutic potential to treat cataracts in a selenite animal model. Thirteen‑day‑old Sprague Dawley rats were divided into 12 groups. Animals in groups 1 and 7 were subcutaneously injected with vehicle, those in groups2and8 were administered hesperetin, those in groups3and9 received stearic acid, those in groups4and10 were injected with oleic acid, those in groups5 and11 were administered Hes‑S, and those in groups6and12 received Hes‑O (10nmol/kg body weight on days 0, 1 and 2). Animals in groups 7 to 12 were treated with sodium selenite (20µmol/kg body weight given 4h following the test compound treatment on day 0) to induce cataract. On day6, rats had less severe central opacities and lower stage cataracts than rats in the selenite treatment‑only control groups. The levels of glutathione (GSH) and ascorbic acid (AsA) in lenses with selenite‑induced cataracts declined to one‑third of that of controls, and the reduction in GSH and AsA levels was rescued following hesperetin, Hes‑S or Hes‑O treatment, with concentrations remaining to 70‑80% of that of controls. However, there were no changes in the plasma levels of GSH and AsA following treatments. Administration of either hesperetin or hesperetin‑derived compounds prevented the reduction of chaperone activity in the lens, and rats treated with Hes‑S or Hes‑O treatment had significantly greater chaperone activity than hesperetin‑treated rats. Collectively, these results suggested that hesperetin and hesperetin‑derived compounds may be novel drug compounds that have the potential to prevent or delay the onset of cataracts.