Generation Of Oxidative Radicals Research Articles

Tailoring the selective generation of oxidative organic radicals for toxic-by-product-free water decontamination

Peracetic acid (PAA) is emerging as a versatile agent for generating long-lived and selectively oxidative organic radicals (R-O•). Currently, the conventional transition metal-based activation strategies still suffer from metal ion leaching, undesirable by-products formation, and uncontrolled reactive species production. To address these challenges, we present a method employing BiOI with a unique electron structure as a PAA activator, thereby predominantly generating CH3C(O)O• radicals. The specificity of CH3C(O)O• generation ensured the superior performance of the BiOI/PAA system across a wide pH range (2.0 to 11.0), even in the presence of complex interfering substances such as humic acids, chloride ions, bicarbonate ions, and real-world water matrices. Unlike conventional catalytic oxidative methods, the BiOI/PAA system degrades sulfonamides without producing any toxic by-products. Our findings demonstrate the advantages of CH3C(O)O• in water decontamination and pave the way for the development of eco-friendly water decontaminations based on organic peroxides.

Antidiabetic effectiveness of Phyllanthus niruri bioactive compounds via targeting DPP-IV.

Phyllanthus niruri Linn. (Euphorbiaceae) is a small herb and is categorised as one of the rich medicinal plants throughout the world. This study aimed to evaluate the P. niruri L. whole plant extract (PNE) for secondary metabolite assay (total phenolic and terpenoid content) followed by the potential antioxidant activity (ABTS diammonium salt radical assay, DPPH· activity, superoxide anion (O2-) radicals' assay, and nitric oxide (NO) radical generation) and antidiabetic activity in vivo and in vitro in streptozotocin (STZ) induced albino mice. PNE showed good scavenging activity with a value of 286.45 ± 6.55 mg TE/g and 194.54 ± 4.64 mg TE/g in ABTS and DPPH assays respectively. In the superoxide anion assay, the PNE caused a dose-dependent inhibition at the lowest IC25 value of 0.17 ± 0.00 mg/mL compared to ascorbic acid (IC25 of 0.25 ± 0.02 mg/mL). The scavenging ability of PNE against nitric oxide showed an IC25 of 1.13 ± 0.04 mg/mL compared to ascorbic acid (IC25 4.78 ± 0.09 mg/mL). Unlike diabetic control mice, the PNE-treated diabetic mice presented significant amelioration of glycaemia and lipid dysmetabolism. Phytochemicals like Astragalin, Gallocatechin, Ellagic acid, Gallic acid, Brevifolin carboxylic acid, Phyllnirurin, and Hypophyllanthin showed significant docking score (> -4) of inhibitory potential with DPP-IV protein. Results indicated that PNE phytochemicals could be a promising antidiabetic agent by targeting DPP-IV.

Effects of pH on the triplet state dissolved organic matter induced free available chlorine decay and radical formation

Triplet state dissolved organic matter (3DOM*) plays a significant role in inducing oxidant decay and radical generation in light-based advanced oxidation processes. However, the effects of pH still need investigation. This work quantitatively analyzed the pH-dependent free available chlorine (FAC) decay and radical formation (i.e., HO• and Cl•) induced by 3DOM* or triplet state photosensitizer (3PS*). Upon UV irradiation at 254 nm, the decay rate of FAC by 3DOM* or 3PS* was the highest at neutral pH, while those by dark reaction of DOM and the direct photolysis of FAC were the highest at acidic conditions. This is attributed to the variation of FAC species, 3DOM* or 3PS* formation, and the reaction rate constants of FAC with 3DOM* or 3PS* at pH 5.0–10.0. 3DOM* and 3PS* formed increasingly with pH varying from 5.0 to 10.0, while their reactivity with FAC decreased due to the speciation from HOCl to OCl–. Radical formation (i.e., HO• and Cl•) from FAC reaction with 3DOM* or 3PS* occurred at all the testing pH range (5.0–10.0). This work highlighted the pH-dependent role of 3DOM* in oxidant decay and radical formation in treating DOM containing waters through oxidant photolysis. Environmental implicationsTriplet state dissolved organic matter (3DOM*) plays a significant role in inducing oxidant decay and radical generation in light-based AOPs. This study revealed the effects of pH in 3DOM* induced free available chlorine (FAC) decay and radical formation (i.e., HO• and Cl•). With DOM at 3 mgC L−1, FAC decayed fastest under neutral conditions and radical formation (i.e., HO• and Cl•) was enhanced at 5.0–10.0 due to 3DOM* reaction with FAC. These results highlighted the pH-dependent role of 3DOM* in oxidant transformation and radical formation in treating DOM containing waters by AOPs based on oxidant photolysis.

The regulation of Lewis acid/basic sites in NaFe bimetal MOXs for the controllable photocatalytic degradation of electron-rich/deficient VOCs

The performance of metal-organic xerogels (MOXs) in the photocatalytic oxidative degradation (PCO) of volatile organic compounds (VOCs) relies on their Lewis acid-base interaction and the generation of oxidative radicals. Herein, by engineering the local charge imbalance of carboxyl ligands through synthesizing NaFe bimetal MOXs, the Lewis acidity of MIL-100(Fe) MOX was well tuned for the adsorption-degradation of electron-rich (aromatic hydrocarbons) and electron-deficient (aldehydes) VOCs. Benefiting from the implanted Lewis basic sites, NaFe-MOXs showed increased adsorption-PCO capacity for single acetaldehyde, while Fe-MOX with abundant Lewis acid sites could capture and degrade more o-xylene. The Lewis basic sites promoted the mineralization of single o-xylene and acetaldehyde by altering their interactions with the photocatalysts and improving the generation of oxidative radicals, which extended the lifetime of photocatalysts. By regulating the Lewis acid/basic sites within MOXs, this work provides an effective way for optimizing photocatalysts to enable the photocatalytic degradation of both electron-rich/deficient VOCs.

Generation of oxidative radicals by advanced oxidation processes (AOPs) in wastewater treatment: a mechanistic, environmental and economic review

Generation of oxidative radicals by advanced oxidation processes (AOPs) in wastewater treatment: a mechanistic, environmental and economic review

Quasi-In Situ Synthesis of Ag NPs@m-MIL-100(Fe) for the Enhanced Photocatalytic Elimination of Flowing Xylenes

The implantation of metal nanoparticles (MNPs) into metal-organic framework (MOF) hosts is a promising means to prepare high-performance photocatalysts for the degradation of gas pollutants. However, the uniform encapsulation of MNPs in MOFs is still challenging. Herein, a facile "quasi-in situ" encapsulation method is proposed by utilizing the spatial confinement effect of the colloidal network formed during the synthesis of the MIL-100(Fe) monolith [noted as m-MIL-100(Fe)]. Highly dispersed Ag NPs with an average diameter of ∼2 nm are encapsulated in the MIL-100(Fe) monolith to form a unique "watermelon-seed" structure, which ensures the large contact area between the two components and protects Ag NPs from being oxidized. The fast charge transfer between m-MIL-100(Fe) and Ag NPs enables the spatial separation of electron-hole pairs and promotes the generation of oxidative radicals. Compared with pristine m-MIL-100(Fe), the 0.2 wt % Ag@m-MIL-100(Fe) composite shows obviously enhanced photodegradation efficiencies for flowing o-xylene under both xenon (∼97%) and visible light (∼80.0%) with high stability. This work not only provides a promising Ag@m-MIL-100(Fe) material for eliminating air pollutants but also gives a versatile means for the design and synthesis of nanoparticles@MOFs composites with desired performance.

A novel approach to interpret quasi-collimated beam results to support design and scale-up of vacuum UV based AOPs

UV-C at 254 nm and vacuum UV (VUV) at 185 nm are the two major emission lines of a low-pressure mercury lamp. Upon absorption of VUV photons, water molecules and selected inorganic anions generate hydroxyl (HO.) and other redox radicals, both capable of degrading organic micropollutants (OMPs), thereby offering the opportunity to reduce H2O2 and energy consumption in UV-based advanced oxidation process (AOP). To be successfully scaled-up, the dual-wavelength VUV+UV/H2O2 AOP requires laboratory-scale experiments to establish design criteria. The figures of merit typically used for reporting and interpreting quasi-collimated beam results for UV-based AOPs (time, dose, absorbed energy and EEO) are insufficient and inaccurate when employed for dual-wavelength AOP such as the VUV+UV/H2O2 AOP, and do not support system scale-up. In this study, we introduce a novel figure of merit, useful absorbed energy (uAE), defined as fraction of absorbed energy that results in the generation of oxidative radicals. Here, results of quasi-collimated beam VUV+UV/H2O2 AOP experiments on four different water matrices are used to introduce 2D plots that employ both uAEUV and uAEVUV as a novel method to represent laboratory-scale experiments of VUV+UV/H2O2 AOP and demonstrate how the 2D plots sufficiently support scale-up of the AOP.

High selective conversion of fructose to lactic acid by photocatalytic reforming of BiOBr/Znx@SnO2-n in alkaline condition

Herein, a novel p-n type BiOBr/Znx@SnO2-n photocatalyst was designed by using BiOBr coupling with large specific surface area Zn doped SnO2 through a facile in situ approach. The composite possesses proper redox potential as well as high efficiency interfacial charge transfer capability. Coupling BiOBr with Zn doped SnO2 is proved efficiency to form a facile bandgap regulation mechanism and could adjust the absorption capacity of visible light, thus enhances the photocatalytic performance effectively. The photocatalyst exhibits high efficiency in photo-reforming of fructose to lactic acid under alkaline conditions, achieving a maximum yield of 79.6% and still achieving a lactic acid yield of 70.7% even after five cycles of recycling. Possible pathways of the lactic acid production were proposed based on the generation of active oxidative radicals and the products detected during the reaction. Therefore, this work provides an effective approach for biomass conversion through rational photocatalyst design.

Oxidative potential and hydroxyl radical generation capacity of ambient PM2.5 over a high-altitude site in northeastern Himalaya: Role of long-range transport

This study investigates the dithiothreitol (DTT)-based oxidative potential (OP) and corresponding hydroxyl radical (•OH) generations capacity of PM2.5 (particulate matter with aerodynamic diameter ≤ 2.5 μm) over a high-altitude site, Shillong (25.7 °N, 91.9 °E; 1064 m above mean sea level), located in the northeastern Himalaya. Measured OP and •OH are reported in two units: per m3 of filtered air (OPV and OHV) or per unit mass of PM2.5 in μg (OPM and OHM). Based on the characteristic ratios of chemical species in different sources, PM2.5 were classified into three source categories: Biomass Burning (BB) (N = 10), Secondary Organic Aerosols (SOA) (N = 12), and Mixed (N = 12). Consistently higher OP and •OH generation per m3 of air (OPV: 6.2 ± 1.0 (average ± SD, 1σ) nmol DTT min−1 m−3, and OHV: 1.2 ± 0.31 nmol •OH m−3) in all BB-dominated PM2.5 samples indicate relatively hazardous exposure dose from BB emissions among all sources. Characteristic OC/EC, WSOC/OC, and nss-K+/EC ratios evoked that SOA from biogenic precursors was a significant source for the observed OP and •OH in SOA-categorized samples. Distinctly different chemical composition of PM2.5 over Shillong (about 55% composed of organic matter) makes it relatively more (2–4 times) intrinsically redox-active compare to a reported study over another high-altitude site in a semi-arid region of India. Despite ∼1.7 times lower PM2.5 mass over Shillong (characterized by more aged PM2.5) compare to Patiala (30.3°N, 76.4°E; 250m amsl, a semi-urban city, characterized by fresher PM2.5 from mixed sources), the observed OPV over Shillong was about 1.2 times higher, and the OPM was about 2 times higher. It is attributed to the effect of atmospheric processing on particle's redox-activity. While examining the relationship of OPV and OHV with chemical species, it was observed that •OH generation capacity was more influenced by WSOC species' origin (primary or secondary) compare to DTT consumption. Such an observation restricts the practicality of particle-induced OP to be considered as the only metric for aerosol particle toxicity, and suggests also to consider simultaneous measurements of •OH generations. For the BB-dominated category, OC-normalized OP (OPOC) was correlated strongly with the fractions of N-containing water-soluble organic aerosols (i.e., a fraction of WSON and a fraction of familyCHO1N). Corresponding OC/EC, nss-K+/EC and nss-SO42−/EC ratios hint that coal combustion, in addition to BB, could be a significant source of redox-active WSON species in these samples. Such studies are important for identifying redox-active aerosol species and developing appropriate mitigation policies for healthy air.

Vitamin C and its therapeutic potential in the management of COVID19.

COVID19 has emerged as one of the worst pandemics in the history of mankind. Several vaccines have been approved by different government agencies worldwide, but data on their efficacy and safety are limited, and distribution remains a massive challenge. As per WHO, personal immunity is vital for protection against COVID19. Earlier, Vitamin C-mediated pathways have been shown to play critical role in boosting immunity attributed to its antioxidant properties. Recently, the involvement of such pathways in protection against COVID19 has been suggested. The controlled doses of Vitamin C administered through intravenous (IV) injections are being studied for determining its role in the prognosis of COVID19. In this article, we have discussed the potential role of Vitamin C in the management in COVID19 patients and presented recent clinical trials data. Additionally, we have elaborated the possibility of administering Vitamin C through inhalers in order to achieve local high concentration and the challenges of such approach.

Trigonal Bipyramidal Rhodium(I) Methyl and Phenyl Complexes: Precursors of Oxidative Methyl and Phenyl Radical Generation

The new complexes [Rh(Me)(trop3P)] (2) and [Rh(Ph)(trop3P)] (3) (trop = 5H-dibenzo[a,d]cyclohepten-5-yl) were synthesised by addition of organolithium reagents (MeLi and PhLi) to the parent pentacoordinated chloride complex [RhCl(trop3P)]. The compounds have a trigonal bipyramidal structure with olefin-only ligands in the equatorial position and the methyl or phenyl substituent in the axial position. Oxidation of complexes 2 and 3 leads to the liberation of methyl and phenyl radicals, which were indirectly detected by reaction with common spin trapping reagents.

Hierarchical porous zeolitic imidazolate frameworks (ZIF-8) and ZnO@N-doped carbon for selective adsorption and photocatalytic degradation of organic pollutants.

Removing organic contaminants such as dyes from water is essential to purify wastewater. Herein, zeolitic imidazolate framework-8 (ZIF-8) and ZnO@N-doped C are reported as effective adsorbents and photocatalysts for the adsorption and degradation of organic dyes. The materials showed effective and selective adsorption toward anionic dyes such as methyl blue (MeB) dye in the presence of fluorescein (FLU) dye. The adsorption capacities of ZnO@N-doped C for MeB and FLU dyes are 900 mg g−1 and 100 mg g−1, respectively. According to UV-Vis diffuse reflectance spectroscopy (DRS) data, ZnO@N-doped C has a lower bandgap (2.07 eV) than ZIF-8 (4.34 eV) and ZnO (3.12 eV). Thus, ZnO@N-doped C serves as an effective photocatalyst for the degradation of both dyes under UV exposure. The degradation efficiency capacity of the dye (50 mg L−1) is >90% using 200 mg L−1 of the photocatalyst. The mechanism of adsorption and photocatalysis is investigated. The photodegradation pathway of the dye involved the generation of oxidative hydroxy radicals (OH˙), which can degrade the dyes. The degradation products of FLU were recorded using mass spectrometry.

On-site generation of reactive oxidative radicals from dithionite treated oxic soil slurry

ABSTRACT Whereas dithionite has been extensively used as a reducing agent in soil and sediment remediation, here, we demonstrate that it can be used as a potential source of oxidizing radical in oxic soils with potential application in organic pollutant remediation. Benzoic acid was used as a probe compound and the generation of its oxidative product para-hydroxybenzoic acid (p-HBA) was detected to quantify the production of oxidative radicals (ROS). By increasing the dithionite concentration from 2.5–10 Mm, the accumulated P-HBA concentration in 120 min increased from 15.0–27 µM. Whereas, above 10 mM, the p-HBA concentration decreased due to radical scavenging. Increasing soil dosage from 2.5–15 g/100 mL the accumulated p-HBA amount increased from 22.8–33.7 µM. Temperature 25–35 oC and pH 6.2–7.5 were favoured for p-HBA generation. Furthermore, we investigated the roles of different active intermediates in the reaction system and proposed the mechanism behind the ROS genearation. This study suggested that dithionite can be used as an active reagent for advanced oxidation remediation in oxic soil medium.

Strengthened photocatalytic removal of bisphenol a by robust 3D hierarchical n-p heterojunctions Bi4O5Br2-MnO2via boosting oxidative radicals generation

Design and creation of photocatalytic systems with favorable microstructural and morphological merits are quite crucial to heighten removal of environmental hormones. For such purpose, in the current study n-type Bi4O5Br2 and p-type MnO2 were specially selected to construct three-dimensional (3D) hierarchical composites Bi4O5Br2-MnO2 (MB) via a facile one-pot procedure. Through thorough and systematical analyses, the existence of both expected components was confirmed in composites and these heterojunction MB composites showed significantly improved photocatalytic degradation of bisphenol A (BPA) under visible light. Particularly, the best candidate 0.5 MB owned the largest Kapp value 11.03 × 10−3 min−1 that was about 3.89 and 1.81 times those of bare Bi4O5Br2 and mechanical mixture 0.5 MB, which primarily attributed to strengthened visible-light absorption, effective integration of favorable morphologies, proper chemical composition, and efficient spatial separation of induced charge carriers through n-p heterojunction domains and thus boosted generation of oxidative radicals in a Z-Scheme model. In addition, other parameters possibly influenced photocatalytic degradation performance such as catalyst dosages, initial concentrations of BPA, pH values, and involvement of inorganic anions were also explored. Moreover, some intermediates were detected by GC-MS analysis to provide a plausible degradation path of these robust 3D hierarchical heterojunctions with satisfactory reusability and structural stability.

Simultaneously Enhanced Activity and Selectivity for C(sp3)\u2013H Bond Oxidation Under Visible Light by Nitrogen Doping

Selective oxidation of saturated C(sp3)–H bonds in hydrocarbon to target chemicals under mild conditions remains a significant but challenging task because of the chemical inertness and high dissociation energy of C(sp3)–H bonds. Semiconductor photocatalysis can induce the generation of holes and oxidative radicals, offering an alternative way toward selective oxidation of hydrocarbons under ambient conditions. Herein, we constructed N-doped TiO2 nanotubes (N-TNTs) that exhibited remarkable activity and selectivity for toluene oxidation under visible light, delivering the conversion of toluene and selectivity of benzaldehyde of 32% and > 99%, respectively. Further mechanistic studies demonstrated that the incorporation of nitrogen induced the generation of N-doping level above the O 2p valance band, directly contributing to the visible-light response of TiO2. Furthermore, hydroxyl radicals generated by photogenerated holes at the orbit of O 2p were found to be unselective for the oxidation of toluene, affording both benzaldehyde and benzoic acid. The incorporation of nitrogen was able to inhibit the generation of hydroxyl radicals, terminating the formation of benzoic acid.

Isolation and neuronal apoptosis inhibitory property of bacoside-A3 via downregulation of β-amyloid induced inflammatory response.

Alzheimer's disease is one of the neurodegenerative disorders caused by neuronal degeneration and apoptosis in brain. Bacoside A and B isolated from the Bacopa monniera plant are responsible for cognitive effects. These compounds repair damaged neurons by promoting activity of kinases, synaptic activity restoration, and improvement of nerve transmission. The present study explored the effect of bacoside-A3 on β-amyloid-induced reduction of U87MG cell viability, generation of oxidative radicals, and activation of nuclear factor-κB. The U87MG cells were stimulated with β-amyloid (10 μM) after 24 h of bacoside-A3 pretreatment or without pretreatment to induce characteristics of Alzheimer disease in vitro. Sulforhodamine B (SRB) assay was used to count viable cells and ELISA kit for analysis of PGE2 secretion. The pretreatment with bacoside-A3 prevented β-amyloid-mediated suppression of U87MG cell proliferation. Pretreatment of U87MG cells with bacoside-A3 prior to β-amyloid stimulation suppressed generation of ROS in a concentration-based manner. The β-amyloid-mediated formation of iNOS in U87MG cells was suppressed by bacoside-A3 in a dose-based manner. The β-amyloid-mediated PGE2 secretion was suppressed by bacoside-A3 pretreatment in U87MG cells in the dose-based manner. The overexpression of COX-2 by β-amyloid stimulation was suppressed in bacoside-A pretreated cells in the dose-based manner. The bacoside-A3 pretreatment prevented nuclear translocation of NF-κB in U87MG cells in the dose-based manner. In summary, bacoside-A3 prevented β-amyloid-mediated suppression of U87MG cell viability, inhibited generation of oxidative radicals, PGE2, and synthesis of iNOS. Therefore, bacoside-A3 has therapeutic potential for Alzheimer disease and further in vivo studies need to be performed.

Advances in Nanomaterial‐based Water Treatment Approaches for Photocatalytic Degradation of Water Pollutants

AbstractDemand of pure drinking water is increasing day by day in line with both a growing population and global industrialization. Studies in the past few decades on the application of advanced oxidation processes (AOP) for the treatment of wastewater containing perilous organic pollutants, are promising when compared to conventional water treatment methods. In case of AOP, generation of powerful oxidant radicals (.OH, HOO.) is crucial for the purpose of degradation. Several processes for the in‐situ generation of such highly reactive oxidants have been discussed. This Review highlights the literature reports on the degradation of various organic pollutants (dyes, pharmaceuticals, pesticides, herbicides, insecticides) by means of photocatalysis. A number of scientific investigations have been performed, which elucidate suitable properties (band gap energy, carrier transport, crystallinity etc.) for the deliberate design of efficient photocatalysts. The oxidation rates and degradation efficiency of photocatalysts are governed by some basic parameters, like organic pollutant concentration, photocatalyst concentration, pH, reaction temperature, light intensity, irradiation time, inorganic ions, oxidants, and these are also discussed. Titania and titania based materials have many attractive properties (nontoxicity, less costly, advanced optical properties, high stability) towards photo degradation process. Several studies have been reported investigating the intermediates produced during degradation process as well as the final degraded product, which might be toxic and/or hazardous to the human as well as to the environment. This review assimilates elaborate study on the mechanism of photocatalytic degradation of various organic pollutants.

Comparative Study of the Oxidative Degradation of Different 4-Aminobenzene Sulfonamides in Aqueous Solution by Sulfite Activation in the Presence of Fe(0), Fe(II), Fe(III) or Fe(VI)

This study is focused on advanced oxidation technologies (AOTs) using the combined effect of Fe(0–VI)/sulfite systems, that produce mainly SO4•− radicals, to remove different 4-aminobenzene sulfonamides (SAs), namely sulfamethazine, sulfadiazine, sulfamethizole, from aqueous solutions. Results obtained showed that neither sulfite nor iron alone is able to degrade SAs; however, the combined effect depends on the oxidation state of iron species whose effectiveness to activate sulfite to promote the degradation of SAs increased following this order: Fe(III) < Fe(II) < Fe(0) < Fe(VI). Using Fe(VI)/sulfite, the complete removal of SAs was obtained in 5 min largely surpassing the effectiveness of the other three systems. The sulfonamides’ removal percentage was markedly influenced by sulfite concentration and dissolved oxygen, which improved the generation of oxidant radicals. Response surface methodology was applied, and a quadratic polynomial model was obtained, which allowed us to determine the percentage of SAs degradation as a function of both the iron species and sulfite concentrations. The study of the influence of the water matrix on these AOTs revealed an inhibition of SAs’ removal percentage when using ground water. This is probably due to the presence of different anions, such as HCO3−, Cl−, and SO42− in relatively high concentrations. According to the byproducts identified, the proposed degradation pathways include hydroxylation, SO2 extrusion, and different bond-cleavage processes. Cytotoxicity of degradation byproducts, using MTS assay with HEK 293 and J774 cell lines for the first time, did not show an inhibition in cell proliferation, sustaining the safety of the process.

The effects of abamectin on oxidative stress and gene expression in rat liver and brain tissues: Modulation by sesame oil and ascorbic acid

The present work was designed to assess the modulatory effects of sesame oil (SO) and ascorbic acid (AA) on abamectin (ABM)-induced oxidative stress and altered gene expression of hepatic cytochrome P450 2E1 (CYP-2E1), p38 MAPK, and caspase-3 and cerebral P-glycoprotein (Abcb1a receptor). Male rats were distributed into five groups (6 rats/group), receiving distilled water, ABM 2 mg/kg bwt 1/5 LD50 orally for 5 days, ABM + AA 100 mg/kg bwt orally, ABM + SO 5 ml/kg bwt orally, or ABM + SO + AA at the aforementioned doses. Nineteen compounds were identified in the SO sample by GC–MS analysis, including tetradecane,2,6,10-trimethyl, octadecane, 1-hexadecanol,2-methyl, and octadecane,6-methyl. Abamectin significantly upregulated the hepatic CYP-2E1 expression with excess generation of oxidative radicals, as evident by the significant depletion of reduced glutathione and elevation of malondialdehyde concentration (p ≤ 0.05) in rat liver and brain tissues. Further, ABM significantly increased TNF-α concentration, the expression of caspase-3 and p38 MAPK in the liver, as well as p-glycoprotein and GABA-A receptor in the brain. These results were in line with the observed histopathological changes. Sesame oil and/or AA supplementation alleviated ABM-induced cell damage by modulating all tested parameters. In conclusion, ABM induces oxidative stress and increases the expression of CYP-2E1, caspase-3, and p38 MAPK in the liver, as well as P-gp and GABA-A receptor in the brain. These effects could be ameliorated by SO and AA, alone and in combination, probably due to their anti-oxidant, anti-apoptotic, and gene-regulating activities.

Non‐Fenton‐Type Hydroxyl Radical Generation and Photothermal Effect by Mitochondria‐Targeted WSSe/MnO2 Nanocomposite Loaded with Isoniazid for Synergistic Anticancer Treatment

AbstractHere, in terms of the highly reactive oxidative hydroxyl radical (•OH) generation ability of isoniazid (INH) catalyzed by Mn2+ ion and the photothermal effect of WSSe nanoflakes, a WSSe/MnO2‐INH nanocomposite for synergistic anticancer treatment is developed. Advanced INH‐induced •OH formation ability is systemically demonstrated in the presence of manganese and relevant non‐Fenton‐type mechanism, and good photothermal conversion efficiency of the WSSe/MnO2 nanocomposite. After modifying with mitochondria‐targeted triphenylphosphonium bromide (TPP) moieties and camouflaging with cancer cells membrane (WSSe/MnO2‐INH‐TPP@CM), it confers a sequential cell‐to‐mitochondria targeting ability. In vivo X‐ray computed tomography and magnetic resonance tumor imaging capability of the nanocomposite are also revealed. The mitochondria‐targeted oxidative damage and photothermal therapy by WSSe/MnO2‐INH‐TPP@CM results in excellent anticancer treatment efficacy both in vitro and in vivo. This is the first exploration of the possibility of non‐Fenton‐type •OH formation for anticancer treatment, which opens new opportunities for ROS‐based and combined cancer treatment strategies.