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Fulltext Factors influencing pulse oximetry as compared to functional arterial saturation in multi-ethnic Singapore

Lee KH, Hui KP, Tan WC, Lim TK

Singapore Med J, 1993 Oct;34(5):385-7.
PMID: 8153680

Noninvasive oximetry provides continuous monitoring of arterial oxygen saturation and hence, early detection of hypoxia. This has proved to be a useful adjunct to patients' safety, and is considered indispensable in certain settings. However, errors may be present in the pulse oximeter estimation (SpO2) of arterial oxygen saturation (SaO2), which may be due to various parameters. We have studied a multi-ethnic population where the skin pigmentation is different, and also under different conditions comparing SpO2 with SaO2. Our results showed that SpO2 estimation of SaO2 amongst the three racial groups (Chinese, Malays, and Indians) varied significantly (ANOVA, p < 0.05). The over-estimation was more pronounced by hypoxic conditions and jaundice. Haemoglobin and systolic blood pressure did not affect the difference between SpO2 and SaO2.

Matched MeSH terms: Oxygen/blood*
Responses of phytoplankton community to eutrophication in Semerak Lagoon (Malaysia)

Er HH, Lee LK, Lim ZF, Teng ST, Leaw CP, Lim PT

Environ Sci Pollut Res Int, 2018 Aug;25(23):22944-22962.
PMID: 29858995 DOI: 10.1007/s11356-018-2389-0

Effects of aquaculture activities on the environmental parameters and phytoplankton community structure were investigated in a semi-enclosed lagoon located at Semerak River, Malaysia. Elevated concentrations of phosphate and ammonia were observed at the aquaculture area and the inner lagoon. Relatively low dissolved oxygen, high total chlorophyll a, and high phytoplankton abundances but low species richness were recorded. Chaetoceros, Pseudo-nitzschia brasiliana, Blixaea quinquecornis, and Skeletonema blooms were observed, and some were associated with anoxia condition. Eutrophication level assessed by UNTRIX suggests that the water quality in the lagoon is deteriorating. Dissolved inorganic phosphorus and nitrogen at the impacted area were 15 and 12 times higher than the reference sites, respectively. Such trophic status indices could provide a useful guideline for optimal aquaculture management plan to reduce the environmental impact caused by aquaculture.

Matched MeSH terms: Oxygen/analysis
Performance of ANFIS versus MLP-NN dissolved oxygen prediction models in water quality monitoring

Najah A, El-Shafie A, Karim OA, El-Shafie AH

Environ Sci Pollut Res Int, 2014 Feb;21(3):1658-1670.
PMID: 23949111 DOI: 10.1007/s11356-013-2048-4

We discuss the accuracy and performance of the adaptive neuro-fuzzy inference system (ANFIS) in training and prediction of dissolved oxygen (DO) concentrations. The model was used to analyze historical data generated through continuous monitoring of water quality parameters at several stations on the Johor River to predict DO concentrations. Four water quality parameters were selected for ANFIS modeling, including temperature, pH, nitrate (NO3) concentration, and ammoniacal nitrogen concentration (NH3-NL). Sensitivity analysis was performed to evaluate the effects of the input parameters. The inputs with the greatest effect were those related to oxygen content (NO3) or oxygen demand (NH3-NL). Temperature was the parameter with the least effect, whereas pH provided the lowest contribution to the proposed model. To evaluate the performance of the model, three statistical indices were used: the coefficient of determination (R (2)), the mean absolute prediction error, and the correlation coefficient. The performance of the ANFIS model was compared with an artificial neural network model. The ANFIS model was capable of providing greater accuracy, particularly in the case of extreme events.

Matched MeSH terms: Oxygen/analysis*
Investigating effect of proton-exchange membrane on new air-cathode single-chamber microbial fuel cell configuration for bioenergy recovery from Azorubine dye degradation

Kardi SN, Ibrahim N, Rashid NAA, Darzi GN

Environ Sci Pollut Res Int, 2019 Jul;26(21):21201-21215.
PMID: 31115820 DOI: 10.1007/s11356-019-05204-z

One of the biggest challenges of using single-chamber microbial fuel cells (MFCs) that utilize proton-exchange membrane (PEM) air cathode for bioenergy recovery from recalcitrant organic compounds present in wastewater is mainly attributed to their high internal resistance in the anodic chamber of the single microbial fuel cell (MFC) configurations. The high internal resistance is due to the small surface area of the anode and cathode electrodes following membrane biofouling and pH splitting conditions as well as substrate and oxygen crossover through the membrane pores by diffusion. To address this issue, the fabrication of new PEM air-cathode single-chamber MFC configuration was investigated with inner channel flow open assembled with double PEM air cathodes (two oxygen reduction activity zones) coupled with spiral-anode MFC (2MA-CsS-AMFC). The effect of various proton-exchange membranes (PEMs), including Nafion 117 (N-117), Nafion 115 (N-115), and Nafion 212 (N-212) with respective thicknesses of 183, 127, and 50.08 μ, was separately incorporated into carbon cloth as PEM air-cathode electrode to evaluate their influences on the performance of the 2MA-CsS-AMFC configuration operated in fed-batch mode, while Azorubine dye was selected as the recalcitrant organic compound. The fed-batch test results showed that the 2MA-CsS-AMFC configuration with PEM N-115 operated at Azorubine dye concentration of 300 mg L-1 produced the highest power density of 1022.5 mW m-2 and open-circuit voltage (OCV) of 1.20 V coupled with enhanced dye removal (4.77 mg L h-1) compared to 2MA-CsS-AMFCs with PEMs N-117 and N-212 and those in previously published data. Interestingly, PEM 115 showed remarkable reduction in biofouling and pH splitting. Apart from that, mass transfer coefficient of PEM N-117 was the most permeable to oxygen (KO = 1.72 × 10-4 cm s-1) and PEM N-212 was the most permeable membrane to Azorubine (KA = 7.52 × 10-8 cm s-1), while PEM N-115 was the least permeable to both oxygen (KO = 1.54 × 10-4) and Azorubine (KA = 7.70 × 10-10). The results demonstrated that the 2MA-CsS-AMFC could be promising configuration for bioenergy recovery from wastewater treatment under various PEMs, while application of PEM N-115 produced the best performance compared to PEMs N-212 and N-117 and those in previous studies of membrane/membrane-less air-cathode single-chamber MFCs that consumed dye wastewater.

Matched MeSH terms: Oxygen/chemistry
Three-dimensional Au-MnO2 nanostructure as an agent of synergistic cancer therapy: chemo-/photodynamic and photothermal approaches

Sugito SFA, Wibrianto A, Chang JY, Fahmi MZ, Khairunisa SQ, Sakti SCW, et al.

Dalton Trans, 2024 Jul 09;53(27):11368-11379.
PMID: 38896134 DOI: 10.1039/d4dt01123f

The design of multimodal cancer therapy was focused on reaching an efficient process and minimizing harmful effects on patients. In the present study, the Au-MnO2 nanostructures have been successfully constructed and produced as novel multipurpose photosensitive agents simultaneously for photodynamic therapy (PDT), photothermal therapy (PTT), and chemodynamic therapy (CDT). The prepared AuNPs were conjugated with MnO2 NPs by its participation in the thermal decomposition process of KMnO4 confirmed by X-ray diffraction (XRD), transmission electron microscopy (TEM), and Fourier transform infrared (FTIR) spectroscopy (FT-IR). The 16.5 nm Au-MnO2 nanostructure exhibited an absorbance at 438 nm, which is beneficial for application in light induction therapy due to the NIR band, as well as its properties of generating reactive oxygen species (ROS) associated with the 808 nm laser light for PDT. The photothermal transduction efficiency was calculated and compared with that of the non-irradiated nanostructure, in which it was found that the 808 nm laser induced a high efficiency of 83%, 41.5%, and 37.5% for PDT, PTT, and CDT, respectively. The results of DPBF and TMB assays showed that the efficiency of PDT and PTT was higher than that of CDT. The nanostructure also confirmed the time-dependent peroxidase properties at different H2O2, TMB, and H2TMB concentrations, promising good potency in applying nanomedicine in clinical cancer therapy.

Matched MeSH terms: Reactive Oxygen Species/metabolism
Aspergillus niger as an efficient biological agent for separator sludge remediation: two-level factorial design for optimal fermentation

Thegarathah P, Jewaratnam J, Simarani K, Elgharbawy AAM

PeerJ, 2024;12:e17151.
PMID: 39026538 DOI: 10.7717/peerj.17151

BACKGROUND: The booming palm oil industry is in line with the growing population worldwide and surge in demand. This leads to a massive generation of palm oil mill effluent (POME). POME is composed of sterilizer condensate (SC), separator sludge (SS), and hydro-cyclone wastewater (HCW). Comparatively, SS exhibits the highest organic content, resulting in various environmental impacts. However, past studies mainly focused on treating the final effluent. Therefore, this pioneering research investigated the optimization of pollutant removal in SS via different aspects of bioremediation, including experimental conditions, treatment efficiencies, mechanisms, and degradation pathways.
METHODS: A two-level factorial design was employed to optimize the removal of chemical oxygen demand (COD) and turbidity using Aspergillus niger. Bioremediation of SS was performed through submerged fermentation (SmF) under several independent variables, including temperature (20-40 °C), agitation speed (100-200 RPM), fermentation duration (72-240 h), and initial sample concentration (20-100%). The characteristics of the treated SS were then compared to that of raw sludge.
RESULTS: Optimal COD and turbidity removal were achieved at 37 °C 100 RPM, 156 h, and 100% sludge. The analysis of variance (ANOVA) revealed a significant effect of selective individual and interacting variables (p oxygen demand (BOD), oil and grease (OG), color, and carbon content. In short, this study demonstrated the effectiveness of A. niger in treating SS through the application of a two-level factorial design.

Matched MeSH terms: Biological Oxygen Demand Analysis*
Fulltext Timosaponin AIII promotes non-small-cell lung cancer ferroptosis through targeting and facilitating HSP90 mediated GPX4 ubiquitination and degradation

Zhou C, Yu T, Zhu R, Lu J, Ouyang X, Zhang Z, et al.

Int J Biol Sci, 2023;19(5):1471-1489.
PMID: 37056925 DOI: 10.7150/ijbs.77979

Timosaponin AIII (Tim-AIII), a steroid saponin, exhibits strong anticancer activity in a variety of cancers, especially breast cancer and liver cancer. However, the underlying mechanism of the effects of Tim-AIII-mediated anti-lung cancer effects remain obscure. In this study, we showed that Tim-AIII suppressed cell proliferation and migration, induced G2/M phase arrest and ultimately triggered cell death of non-small cell lung cancer (NSCLC) cell lines accompanied by the release of reactive oxygen species (ROS) and iron accumulation, malondialdehyde (MDA) production, and glutathione (GSH) depletion. Interestingly, we found that Tim-AIII-mediated cell death was reversed by ferroptosis inhibitor ferrostatin-1 (Fer-1). Meanwhile, the heat shock protein 90 (HSP90) was predicted and verified as the direct binding target of Tim-AIII by SwissTargetPrediction (STP) and surface plasmon resonance (SPR) assay. Further study showed that Tim-AIII promoted HSP90 expression and Tim-AIII induced cell death was blocked by the HSP90 inhibitor tanespimycin, indicating that HSP90 was the main target of Tim-AIII to further trigger intracellular events. Mechanical analysis revealed that the Tim-AIII-HSP90 complex further targeted and degraded glutathione peroxidase 4 (GPX4), and promoted the ubiquitination of GPX4, as shown by an immunoprecipitation, degradation and in vitro ubiquitination assay. In addition, Tim-AIII inhibited cell proliferation, induced cell death, led to ROS and iron accumulation, MDA production, GSH depletion, as well as GPX4 ubiquitination and degradation, were markedly abrogated when HSP90 was knockdown by HSP90-shRNA transfection. Importantly, Tim-AIII also showed a strong capacity of preventing tumor growth by promoting ferroptosis in a subcutaneous xenograft tumor model, whether C57BL/6J or BALB/c-nu/nu nude mice. Together, HSP90 was identified as a new target of Tim-AIII. Tim-AIII, by binding and forming a complex with HSP90, further targeted and degraded GPX4, ultimately induced ferroptosis in NSCLC. These findings provided solid evidence that Tim-AIII can serve as a potential candidate for NSCLC treatment.

Matched MeSH terms: Reactive Oxygen Species/metabolism
Fulltext Protecting mechanism of Swietenia macrophylla ethanol extract nanoparticle on streptozotocin induced renal damage in rat

Kurnijasanti R, Wardani G, Mustafa MR, Sudjarwo SA

Open Vet J, 2023 Dec;13(12):1623-1630.
PMID: 38292712 DOI: 10.5455/OVJ.2023.v13.i12.12

BACKGROUND: Hyperglycemia increases reactive oxygen species (ROS), which contributes to diabetic complications such as kidney cell damage. Antioxidant administration could inhibit ROS and kidney cell damage commonly seen in hyperglycemia.
AIM: We want to demonstrate that the antioxidant properties of Swietenia macrophylla ethanol extract nanoparticles can prevent kidney cell damage brought on by streptozotocin (STZ) in the current investigation.
METHODS: This study employs high-energy ball milling to produce nanoparticles from S. macrophylla extract. Additionally, dynamic light scattering (DLS) is utilized to characterize the nanoparticle sizes of the S. macrophylla ethanol extract. Five groups, each consisting of 8 rats, were formed from 40 rats. Control rats received distilled water, the diabetic rats were administered STZ injections, while S. macrophylla rats were given S. macrophylla extract nanoparticles orally and STZ injection. After the trial, blood from a rat was drawn intracardially to check the levels of blood urea nitrogen (BUN) and creatinine. The levels of superoxide dismutase (SOD), glutathione peroxidase (GPx), and malondialdehyde (MDA) were then assessed in kidney tissue samples. Histological alterations were evaluated in kidney section samples.
RESULTS: A DLS analysis estimated the size of the S. macrophylla ethanol extract nanoparticles to be about 91.50 ± 23.06 nm. BUN and creatinine levels were significantly raised after STZ treatment. STZ significantly decreased SOD and GPx levels in kidney tissue while raising MDA levels (p < 0.05). Swietenia macrophylla ethanol extract nanoparticle caused the decreased levels of BUN and creatinine in blood to normal levels (p < 0.05), indicating that S. macrophylla ethanol extract prevented the STZ-induced kidney cell damage. Additionally, S. macrophylla nanoparticles significantly raise GPx and SOD levels in kidney tissue while lowering MDA levels (p < 0.05). These actions are thought to have prevented kidney histological alterations (degeneration and necrosis) in diabetic rats.
CONCLUSION: According to these results, the anti-oxidative stress properties of S. macrophylla nanoparticles make them potentially effective nephroprotective therapies for STZ-induced kidney cell damage.

Matched MeSH terms: Reactive Oxygen Species/pharmacology
Fulltext Reactive oxygen species and male reproductive hormones

Darbandi M, Darbandi S, Agarwal A, Sengupta P, Durairajanayagam D, Henkel R, et al.

Reprod Biol Endocrinol, 2018 Sep 11;16(1):87.
PMID: 30205828 DOI: 10.1186/s12958-018-0406-2

Reports of the increasing incidence of male infertility paired with decreasing semen quality have triggered studies on the effects of lifestyle and environmental factors on the male reproductive potential. There are numerous exogenous and endogenous factors that are able to induce excessive production of reactive oxygen species (ROS) beyond that of cellular antioxidant capacity, thus causing oxidative stress. In turn, oxidative stress negatively affects male reproductive functions and may induce infertility either directly or indirectly by affecting the hypothalamus-pituitary-gonadal (HPG) axis and/or disrupting its crosstalk with other hormonal axes. This review discusses the important exogenous and endogenous factors leading to the generation of ROS in different parts of the male reproductive tract. It also highlights the negative impact of oxidative stress on the regulation and cross-talk between the reproductive hormones. It further describes the mechanism of ROS-induced derangement of male reproductive hormonal profiles that could ultimately lead to male infertility. An understanding of the disruptive effects of ROS on male reproductive hormones would encourage further investigations directed towards the prevention of ROS-mediated hormonal imbalances, which in turn could help in the management of male infertility.

Matched MeSH terms: Reactive Oxygen Species/metabolism*
Regulation of hippo signaling mediated apoptosis by Rauvolfia tetraphylla in triple-negative breast cancer

Balavaishnavi B, Kamaraj M, Nithya TG, Santhosh P, GokilaLakshmi S, Shaik MR

Med Oncol, 2024 Mar 29;41(5):103.
PMID: 38553593 DOI: 10.1007/s12032-024-02341-5

Rauvolfia tetraphylla is an essential medicinal plant that has been widely used in traditional medicine for various disease treatments. However, the tumor suppressor activity of R. tetraphylla and its phytocompounds were not explored against triple-negative breast cancer. The current research investigated the impact of R. tetraphylla methanolic extract (RTE) and its isolated compounds Ajmaline (RTC1) and Reserpine (RTC2) on triple-negative breast cancer cell line (MDA-MB-231) focusing on anti-proliferative effects. Our study imparts that RTE and RTC2 showed promising cytotoxic effects compared to RTC1. So further experiments have proceeded with RTE and RTC2, to evaluate its proliferation, migration, and apoptotic effect. The result shows around 80% of cells were observed in the G0/G1 phase in cell cycle analysis indicating the cell cycle inhibition and duel staining clearly showed the apoptotic effect. The migration of cells after the scratch was 60.45% observed in control and 90% in treated cells showing the inhibition of migration. ROS distribution was intense compared to control indicating the increased ROS stress in treated cells. Both RTE and RTC2-treated cells showed the potential to suppress proliferation and induce apoptotic change by upregulating BAX and MST-1 and suppressing Bcl2, LATS-1, and YAP, proving that deregulation of YAP resulting in the blockage of TEAD-YAP complex and inhibit proliferation. Therefore, R. tetraphylla extract and its isolated compounds were demonstrated to find its ability to act against MDA-MB-231 and these findings will help adjudicate it as a therapeutic drug against experimental triple-negative breast cancer.

Matched MeSH terms: Reactive Oxygen Species/metabolism
RUNX1/ETO regulates reactive oxygen species (ROS) levels in t(8,21) acute myeloid leukaemia via FLT3 and RAC1

Azlan A, Khor KZ, Rajasegaran Y, Rosli AA, Said MSM, Yusoff NM, et al.

Med Oncol, 2023 Jun 21;40(7):208.
PMID: 37341821 DOI: 10.1007/s12032-023-02075-w

Reactive oxygen species (ROS) homeostasis is crucial for leukaemogenesisand deregulation would hamper leukaemic progression. Although the regulatory effects of RUNX1/ETO has been extensively studied, its underlying molecular mechanims in ROS production in t(8,21) AML is yet to be fully elucidated. Here, we report that RUNX1/ETO could directly control FLT3 by occupying several DNA elements on FLT3 locus. The possible hijacking mechanism by RUNX1/ETO over FLT3 mediated ROS modulation in AML t(8;21) was made apparent when suppression of RUNX1/ETO led to decrement in ROS levels and the direct oxidative marker FOXO3 but not in FLT3 and RAC1 suppressed t(8,21) AML cell line Furthermore, nuclear import of RUNX1/ETO was aberrated following RUNX1/ETO and RAC1 suppression suggesting association in ROS control. A different picture was depicted in non t(8;21) cells where suppression of RAC1 and FLT3 led to decreased levels of FOXO3a and ROS. Results alltogether indicate a possible dysregulation of ROS levels by RUNX1/ETO in t(8,21) AML.

Matched MeSH terms: Reactive Oxygen Species/metabolism
Peroxisome proliferator-activated receptor agonist (pioglitazone) with exogenous adiponectin ameliorates arterial stiffness and oxidative stress in diabetic Wistar Kyoto rats

Afzal S, Sattar MA, Johns EJ, Eseyin OA

Eur J Pharmacol, 2021 Sep 15;907:174218.
PMID: 34111396 DOI: 10.1016/j.ejphar.2021.174218

Oxidative stress causes hypoadiponectemia and reactive oxygen species production. This study investigates the pathophysiological role and potential effects of adiponectin with partial and full peroxisome proliferator-activated receptor-gamma agonists on modulation of metabolic dysregulation and oxidative stress in diabetic model of Wistar Kyoto rats (WKY). Forty two male WKY rats were randomized equally into 7 groups (n = 6), Group I serve as control, group II as WKY diabetic control, groups III, IV and V treated with irbesartan (30 mg/kg), pioglitazone (10 mg/kg) and adiponectin (2.5 μg/kg), groups VI and VII were co-treated as: irbesartan + adiponectin, pioglitazone + adiponectin, respectively. Streptozotocin @ 40 mg/kg was administered intraperitoneally to induce diabetes. Plasma adiponectin, metabolic indices, pulse wave velocity, oxidative stress and antioxidant enzymatic activities were measured. Streptozotocin induced WKYs expressed hyperglycaemia, hypertriglyceridemia, hypercholesterolemia, hypoadiponectemia, increased arterial stiffness and decreased antioxidant enzymatic levels (P<0.05). Treatment with adiponectin or pioglitazone alone showed improvements in metabolic indices, antioxidant enzymes, and abrogated arterial stiffness, attenuated generation of reactive oxygen species and dyslipidaemic effects of streptozotocin better as compared to irbesartan sets of treatment (all P<0.05). Co-treatment of adiponectin with pioglitazone significantly amplified the improvement in plasma triglycerides, adiponectin concentration, pulse wave velocity and antioxidant enzymatic activities indicating synergistic effects of adiponectin with full PPAR-γ agonist.

Matched MeSH terms: Reactive Oxygen Species/metabolism
Fulltext Novel indole Schiff base β-diiminato compound as an anti-cancer agent against triple-negative breast cancer: In vitro anticancer activity evaluation and in vivo acute toxicity study

Farghadani R, Lim HY, Abdulla MA, Rajarajeswaran J

Bioorg Chem, 2024 Nov;152:107730.
PMID: 39216194 DOI: 10.1016/j.bioorg.2024.107730

Breast cancer is the most prevalent cancer among women globally, with triple-negative breast cancer (TNBC) associated with poor prognosis and low five-year survival rates. Schiff base compounds, known for their extensive pharmacological activities, have garnered significant attention in cancer drug research. This study aimed to evaluate the anticancer potential of a novel β-diiminato compound and elucidate its mechanism of action. The compound's effect on cell viability was assessed using MTT assays in breast cancer cell lines including MCF-7 and MDA-MB-231. Cytotoxic effects were further analyzed using trypan blue exclusion and lactate dehydrogenase (LDH) release assays. In order to assess the mechanism of inhibitory activity and mode of cell death induced by this compound, flow cytometry of cell cycle distribution and apoptosis analysis were carried out. Apoptosis incidence was initially assessed through cell and nuclear morphological changes (Hoechst 33342/Propidium iodide (PI) staining) and further confirmed by Annexin V/PI staining and flow cytometry analysis. In addition, the effect of this compound on the disruption of mitochondrial membrane potential (MMP) and generation of the reactive oxygen species (ROS) was determined using the JC-1 indicator and DCFDA dye, respectively. The results demonstrated that the 24 h treatment with β-diiminato compound significantly suppressed the viability of MDA-MB-231 and MCF-7 cancer cells in a dose-dependent manner with the IC50 value of 2.41 ± 0.29 and 3.51 ± 0.14, respectively. The cytotoxic effect of the compound was further confirmed with a dose-dependent increase in the number of dead cells and enhanced LDH level in the culture medium. This compound exerted its anti-proliferative effect by G2/M phase cell growth arrest in MDA-MB-231 breast cancer cells and induced apoptosis-mediated cell death, which involved characteristic changes in cell and nuclear morphology, phosphatidylserine externalization, mitochondrial membrane depolarization, and increased ROS level. Neither hepatotoxicity nor nephrotoxicity was detected in the biochemical and histopathological analysis confirming the safety characterization of this compound usage. Therefore, the results significantly confirmed the potential anticancer activity of a novel β-diiminato compound, as evidenced by the induction of cell cycle arrest and apoptosis, which might be driven by the ROS‑mediated mitochondrial death pathway. This compound can be a promising candidate for future anticancer drug design and TNBC treatment, and further preclinical and clinical studies are warranted.

Matched MeSH terms: Reactive Oxygen Species/metabolism
Medicinal Tiger Milk Mushroom Lignosus rhinocerus TM02® (Agaricomycetes) Sclerotia Supplementation Mitigates Hypertension and Alleviates Vascular Dysfunction Partly through Oxidative Stress Modulation in Spontaneously Hypertensive Rats

Wong YE, Razif MFM, Ng ST, Tan CS, Fung SY, Murugan DD

Int J Med Mushrooms, 2024;26(11):27-40.
PMID: 39241161 DOI: 10.1615/IntJMedMushrooms.2024055061

Hypertension is a risk factor for cardiovascular diseases such as coronary artery disease, heart failure, and stroke. Lignosus rhinocerus (Cooke) Ryvarden (also known as tiger milk mushroom), has been reported to exhibit a range of pharmacological effects, such as anti-inflammatory, anti-proliferative, antioxidative, immunomodulatory and anti-asthmatic activities. Thus far, there is limited research that has explored its ability to mediate vascular effects in vivo. Therefore, this study investigated the antihypertensive and vascular protective effects of L. rhinocerus TM02® sclerotia supplementation in spontaneously hypertensive rats (SHR). Wistar Kyoto (WKY) rats served as a normotensive control group. SHR were orally administered with L. rhinocerus TM02® sclerotia (100 mg/kg and 300 mg/kg, respectively) for 8 weeks, and blood pressure was monitored every 2 weeks. Vascular function was evaluated using an organ bath (aorta) and wire myograph (renal artery) at the treatment endpoint. The levels of reactive oxygen species (ROS) and nitric oxide (NO) in the aorta and renal artery were evaluated using dihydroethidium (DHE) and difluoro fluorescein acetate (DAF-FM) fluorescence assays, respectively. Total plasma nitrate/nitrite and tumor necrosis factor alpha (TNF-α) levels were evaluated via colorimetric assays. In vivo treatment with L. rhinocerus TM02® sclerotia significantly attenuated the increase in systolic blood pressure (SBP). It also alleviated vascular dysfunction and decreased elevated ROS in the aorta and renal arteries of the treated SHRs. Moreover, L. rhinocerus TM02® sclerotia attenuated plasma TNF-α level but increased total plasma nitrate/nitrite, albeit slightly, coupled with significantly increased NO at the vascular level. Collectively, the present study demonstrated that L. rhinocerus TM02® sclerotia supplementation exerted blood pressure lowering effects, partly attributed to improvements in vascular function via reduction in vascular oxidative stress.

Matched MeSH terms: Reactive Oxygen Species/metabolism
Fulltext Haematococcus pluvialis as a Potential Source of Astaxanthin with Diverse Applications in Industrial Sectors: Current Research and Future Directions

Oslan SNH, Tan JS, Oslan SN, Matanjun P, Mokhtar RAM, Shapawi R, et al.

Molecules, 2021 Oct 27;26(21).
PMID: 34770879 DOI: 10.3390/molecules26216470

Haematococcus pluvialis, a green microalga, appears to be a rich source of valuable bioactive compounds, such as astaxanthin, carotenoids, proteins, lutein, and fatty acids (FAs). Astaxanthin has a variety of health benefits and is used in the nutraceutical and pharmaceutical industries. Astaxanthin, for example, preserves the redox state and functional integrity of mitochondria and shows advantages despite a low dietary intake. Because of its antioxidant capacity, astaxanthin has recently piqued the interest of researchers due to its potential pharmacological effects, which include anti-diabetic, anti-inflammatory, and antioxidant activities, as well as neuro-, cardiovascular-, ocular, and skin-protective properties. Astaxanthin is a popular nutritional ingredient and a significant component in animal and aquaculture feed. Extensive studies over the last two decades have established the mechanism by which persistent oxidative stress leads to chronic inflammation, which then mediates the majority of serious diseases. This mini-review provides an overview of contemporary research that makes use of the astaxanthin pigment. This mini-review provides insight into the potential of H. pluvialis as a potent antioxidant in the industry, as well as the broad range of applications for astaxanthin molecules as a potent antioxidant in the industrial sector.

Matched MeSH terms: Reactive Oxygen Species/metabolism
Fulltext Hell's Gate globin I: an acid and thermostable bacterial hemoglobin resembling mammalian neuroglobin

Teh AH, Saito JA, Baharuddin A, Tuckerman JR, Newhouse JS, Kanbe M, et al.

FEBS Lett, 2011 Oct 20;585(20):3250-8.
PMID: 21925500 DOI: 10.1016/j.febslet.2011.09.002

Hell's Gate globin I (HGbI), a heme-containing protein structurally homologous to mammalian neuroglobins, has been identified from an acidophilic and thermophilic obligate methanotroph, Methylacidiphilum infernorum. HGbI has very high affinity for O(2) and shows barely detectable autoxidation in the pH range of 5.2-8.6 and temperature range of 25-50°C. Examination of the heme pocket by X-ray crystallography and molecular dynamics showed that conformational movements of Tyr29(B10) and Gln50(E7), as well as structural flexibility of the GH loop and H-helix, may play a role in modulating its ligand binding behavior. Bacterial HGbI's unique resistance to the sort of extreme acidity that would extract heme from any other hemoglobin makes it an ideal candidate for comparative structure-function studies of the expanding globin superfamily.

Matched MeSH terms: Oxygen/chemistry
Fulltext Centella asiatica (L.) Urban. Attenuates Cell Damage in Hydrogen Peroxide-Induced Oxidative Stress in Transgenic Murine Embryonic Stem Cell Line-Derived Neural-Like Cells: A Preliminary Study for Potential Treatment of Alzheimer's Disease

Mansor NI, Ling KH, Rosli R, Hassan Z, Adenan MI, Nordin N

J Alzheimers Dis, 2023;94(s1):S21-S44.
PMID: 37334592 DOI: 10.3233/JAD-221233

BACKGROUND: Centella asiatica (L.) (C. asiatica) is commonly known in South East and South East Asia communities for its nutritional and medicinal benefits. Besides being traditionally used to enhance memory and accelerate wound healing, its phytochemicals have been extensively documented for their neuroprotective, neuroregenerative, and antioxidant properties.
OBJECTIVE: The present study aims to investigate the effects of a standardized raw extract of C. asiatica (RECA) on hydrogen peroxide (H2O2)-induced oxidative stress and apoptotic death in neural-like cells derived from mouse embryonic stem (ES) cell line.
METHODS: A transgenic mouse ES cell (46C) was differentiated into neural-like cells using 4-/4+ protocol with addition of all-trans retinoic acid. These cells were then exposed to H2O2 for 24 h. The effects of RECA on H2O2-induced neural-like cells were assessed through cell viability, apoptosis, and reactive oxygen species (ROS) assays, as well as neurite length measurement. The gene expression levels of neuronal-specific and antioxidant markers were assessed by RT-qPCR analysis.
RESULTS: Pre-treatment with H2O2 for 24 hours, in a dose-dependent manner, damaged neural-like cells as marked by a decrease in cell viability, substantial increase in intracellular ROS accumulation, and increase in apoptotic rate compared to untreated cells. These cells were used to treat with RECA. Treatment with RECA for 48 h remarkably restored cell survival and promoted neurite outgrowth in the H2O2- damaged neurons by increasing cell viability and decreasing ROS activity. RT-qPCR analysis revealed that RECA upregulated the level of antioxidant genes such as thioredoxin-1 (Trx-1) and heme oxygenase-1 (HO-1) of treated cells, as well as the expression level of neuronal-specific markers such as Tuj1 and MAP2 genes, suggesting their contribution in neuritogenic effect.
CONCLUSION: Our findings indicate that RECA promotes neuroregenerative effects and exhibits antioxidant properties, suggesting a valuable synergistic activity of its phytochemical constituents, thus, making the extract a promising candidate in preventing or treating oxidative stress-associated Alzheimer's disease.

Matched MeSH terms: Reactive Oxygen Species/metabolism
Fulltext Metabolic and genetic screening of electromagnetic hypersensitive subjects as a feasible tool for diagnostics and intervention

De Luca C, Thai JC, Raskovic D, Cesareo E, Caccamo D, Trukhanov A, et al.

Mediators Inflamm, 2014;2014:924184.
PMID: 24812443 DOI: 10.1155/2014/924184

Growing numbers of "electromagnetic hypersensitive" (EHS) people worldwide self-report severely disabling, multiorgan, non-specific symptoms when exposed to low-dose electromagnetic radiations, often associated with symptoms of multiple chemical sensitivity (MCS) and/or other environmental "sensitivity-related illnesses" (SRI). This cluster of chronic inflammatory disorders still lacks validated pathogenetic mechanism, diagnostic biomarkers, and management guidelines. We hypothesized that SRI, not being merely psychogenic, may share organic determinants of impaired detoxification of common physic-chemical stressors. Based on our previous MCS studies, we tested a panel of 12 metabolic blood redox-related parameters and of selected drug-metabolizing-enzyme gene polymorphisms, on 153 EHS, 147 MCS, and 132 control Italians, confirming MCS altered (P < 0.05-0.0001) glutathione-(GSH), GSH-peroxidase/S-transferase, and catalase erythrocyte activities. We first described comparable-though milder-metabolic pro-oxidant/proinflammatory alterations in EHS with distinctively increased plasma coenzyme-Q10 oxidation ratio. Severe depletion of erythrocyte membrane polyunsaturated fatty acids with increased ω 6/ ω 3 ratio was confirmed in MCS, but not in EHS. We also identified significantly (P = 0.003) altered distribution-versus-control of the CYP2C19∗1/∗2 SNP variants in EHS, and a 9.7-fold increased risk (OR: 95% C.I. = 1.3-74.5) of developing EHS for the haplotype (null)GSTT1 + (null)GSTM1 variants. Altogether, results on MCS and EHS strengthen our proposal to adopt this blood metabolic/genetic biomarkers' panel as suitable diagnostic tool for SRI.

Matched MeSH terms: Reactive Oxygen Species/metabolism
Fulltext Electroacupuncture ameliorates chronic unpredictable mild stress-induced depression-like behavior and cognitive impairment through suppressing oxidative stress and neuroinflammation in rats

Tong T, Hao C, Shen J, Liu S, Yan S, Aslam MS, et al.

Brain Res Bull, 2024 Jan;206:110838.
PMID: 38123022 DOI: 10.1016/j.brainresbull.2023.110838

BACKGROUND: Depression is associated with lowered mood, anxiety, anhedonia, cognitive impairments, and even suicidal tendencies in severe cases. Yet few studies have directed acupuncture's mechanism toward enhancing axonal repair correlated with synaptic plasticity and anti-inflammatory effects related to oxidative stress in the hippocampus.
METHODS: Male Sprague-Dawley (SD) rats were randomly divided into control group (CON), chronic unpredictable mild stress (CUMS) group, CUMS + electroacupuncture group (EA), and CUMS + fluoxetine group (FLX) (n = 10/group). Rats were given a 28-day treatment at the Shangxing (GV23) and Fengfu (GV16) acupoints with electroacupuncture or fluoxetine (2.1 mg/kg).
RESULTS: Rats exposed to CUMS induced depression-like behaviors and spatial learning-memory impairment, changed the ionized calcium binding adaptor molecule 1 (IBA-1), Vglut1, myelin basic protein (MBP), and postsynaptic density protein 95 (PSD95) level of hippocampal, increased the Nod-like receptor protein 3 (NLRP3), atypical squamous cell (ASC), Caspase level and hippocampal reactive oxygen species (ROS), and prompted the activation of Epha4-mediated signaling and an inflammatory response. Conversely, electroacupuncture administration reduced these changes and prevented depression-like behaviors and cognitive impairment. Electroacupuncture also promoted hippocampal expression of Sirtuin1(SIRT1), Nuclear factor erythroid 2-like (Nrf2), Heme oxygenase-1 (HO-1); reduced the expression of interleukin-1β (IL-1β), interleukin-18 (IL-18), and tumor necrosis factor-alpha (TNF-α); and prevented neural damage, particularly the synaptic myelin sheath, and neuroinflammation by regulating Eph receptor A4 (EphA4) in the hippocampal.
CONCLUSION: These results indicate that electroacupuncture prevents depression-like behaviors with cognitive impairment and synaptic and neuronal damage, probably by reducing EphA4, which mediates ROS hyperfunction and the inflammatory response.

Matched MeSH terms: Reactive Oxygen Species/metabolism
Oxygen demand, nitrogen and copper removal by free-water-surface and subsurface-flow constructed wetlands under tropical conditions

Lim PE, Wong TF, Lim DV

Environ Int, 2001 May;26(5-6):425-31.
PMID: 11392762

This study was conducted to: (1) assess the role of wetland vegetation in the removal of oxygen demand and nitrogen under tropical conditions, (2) estimate the uptake of nitrogen and copper by wetland plants and (3) investigate the speciation of Cu in wetland media among four operationally defined host fractions, namely exchangeable, carbonate, reducible and organically bound. Four laboratory-scale wetland units, two free-water-surface (FWS) and two subsurface-flow (SF) with one of each planted with cattails (Typha augustifolia), were fed with primary-treated sewage and operated at nominal retention times of 0.6-7 days. The influent and effluent BOD/COD and nitrogen concentrations were monitored to assess the performance of the wetland units for various mass loading rates. At the end of the study, all cattail plants were harvested and analyzed for total Kjeldahl nitrogen (TKN). Four other wetland units, which were identical to the first four, were fed with domestic wastewater spiked with copper in increasing concentrations. Copper speciation patterns in the sand layer were determined at the end of the study. The results showed that wetland vegetation did not play an important role in oxygen demand removal but were capable of removing about 22% and 26% of the nitrogen input in the FWS and SF wetland units, respectively. Mass balance analysis indicated that less than 1% of copper introduced was taken up by the cattails. Copper speciation patterns in the sand media showed that the exchangeable fraction contributed 30-57% and 63-80% of the nonresidual copper in the planted and unplanted FWS wetlands, respectively. For SF units, the percentages were 52-62% and 59-67%, respectively. This indicates that large amount of copper in the media were potentially remobilizable.

Matched MeSH terms: Oxygen/metabolism*

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