Free Radicals in Little Cigar Mainstream Smoke and the Potential Influence of Flavoring Chemicals on Free Radical Production.

Implementation of the Tobacco Control Act in 2009 banned characterizing flavors in cigarettes (except menthol and tobacco), but substitution has occurred by the continued availability of alternative flavored products (i.e., flavored little cigars). Little is known about how flavorants in noncigarette tobacco products impact human health. Thus, we investigated the impact of flavorants on free radical production in the mainstream smoke of little cigars. Gas- and particulate-phase free radical yields in mainstream smoke generated from 12 commercial little cigar brands and research little cigars and cigarettes were measured via electron paramagnetic resonance spectroscopy using the International Organization of Standardization (ISO) smoking protocol. Flavorants were extracted from unsmoked little cigars and analyzed by gas chromatography-mass spectroscopy. Gas- and particulate-phase radical yields from little cigars ranged from 13.5 to 97.6 and 0.453-1.175 nmol/unit, respectively. Comparatively, research cigarettes yielded an average of 4.9 nmol gas-phase radicals/unit and 0.292 nmol particulate-phase radicals/unit. From the products, 66 flavorants were identified, with each brand containing 4-24 individual flavorants. The free radical content was strongly correlated with the number of flavorants present in each cigar (r = 0.74, p = 0.01), indicating that highly flavored little cigars may produce higher levels of toxic free radicals. The presence of the flavorant ethyl methylphenylglycidate (strawberry) was associated with >2-fold higher levels of GP radicals (p = 0.001). Our results show that free radical delivery from little cigars is greater than that from research cigarettes and provide empirical evidence for the harmfulness of flavored tobacco products. Additionally, it demonstrates that flavorants present in combustible tobacco products can influence the levels of free radicals produced. Therefore, future tobacco product standards should consider little cigars.

Quantification of Free Radicals from Vaping Electronic Cigarettes Containing Nicotine Salt Solutions with Different Organic Acid Types and Concentrations.

Electronic (e-) cigarette formulations containing nicotine salts from a range of organic acid conjugates and pH values have dominated the commercial market. The acids in the nicotine salt formulations may alter the redox environment in e-cigarettes, impacting free radical formation in e-cigarette aerosol. Here, the generation of aerosol mass and free radicals from a fourth-generation e-cigarette device was evaluated at 2 wt % nicotine salts (pH 7, 30:70 mixture propylene glycol to vegetable glycerin) across eight organic acids used in e-liquids: benzoic acid (BA), salicylic acid (SLA), lactic acid (LA), levulinic acid (LVA), succinic acid (SA), malic acid (MA), tartaric acid (TA), and citric acid (CA). Furthermore, 2 wt % BA nicotine salts were studied at the following nicotine to acid ratios: 1:2 (pH 4), 1:1 (pH 7), and 2:1 (pH 8), in comparison with freebase nicotine (pH 10). Radical yields were quantified by spin-trapping and electron paramagnetic resonance (EPR) spectroscopy. The EPR spectra of free radicals in the nicotine salt aerosol matched those generated from the Fenton reaction, which are primarily hydroxyl (OH) radicals and other reactive oxygen species (ROS). Although the aerosol mass formation was not significantly different for most of the tested nicotine salts and acid concentrations, notable ROS yields were observed only from BA, CA, and TA under the study conditions. The e-liquids with SLA, LA, LVA, SA, and MA produced less ROS than the 2 wt % freebase nicotine e-liquid, suggesting that organic acids may play dual roles in the production and scavenging of ROS. For BA nicotine salts, it was found that the ROS yield increased with a higher acid concentration (or a lower nicotine to acid ratio). The observation that BA nicotine salts produce the highest ROS yield in aerosol generated from a fourth-generation vape device, which increases with acid concentration, has important implications for ROS-mediated health outcomes that may be relevant to consumers, manufacturers, and regulatory agencies.

Acerola (Malpighia emarginata) Anti-Inflammatory Activity-A Review.

The manuscript provides an overview of recent scientific reports on the properties and range of health-promoting effects of acerola (Malpighia emarginata DC) fruits and leaves. Acerola is a natural raw material that, in its unprocessed form, is known to be a rich source of vitamin C and polyphenolic compounds. For this reason, the consumption of acerola may provide a number of health-promoting benefits, particularly related to its strong anti-free radical effects. The review discusses anti-inflammatory and anticancer effects of acerola fruit and leaves as well as its therapeutic effects on selected physiological processes in the human system. Their biochemical mechanisms are also explained. Recommendations for the consumption of acerola in the prevention of inflammatory and free radical diseases are presented. The part of the article devoted to anticancer effects of acerola describes the possibilities of using the edible parts of this raw material to obtain products and preparations of potential use in cancer prevention and therapy.

Optimization of ultrasound-aided extraction of bioactive ingredients from Vitis vinifera seeds using RSM and ANFIS modeling with machine learning algorithm.

Plant materials are a rich source of polyphenolic compounds with interesting health-beneficial effects. The present study aimed to determine the optimized condition for maximum extraction of polyphenols from grape seeds through RSM (response surface methodology), ANFIS (adaptive neuro-fuzzy inference system), and machine learning (ML) algorithm models. Effect of five independent variables and their ranges, particle size (X1: 0.5-1 mm), methanol concentration (X2: 60-70% in distilled water), ultrasound exposure time (X3: 18-28 min), temperature (X4: 35-45 °C), and ultrasound intensity (X5: 65-75 W cm-2) at five levels (- 2, - 1, 0, + 1, and + 2) concerning dependent variables, total phenolic content (y1; TPC), total flavonoid content (y2; TFC), 2, 2-diphenyl-1-picrylhydrazyl free radicals scavenging (y3; %DPPH*sc), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) free radicals scavenging (y4; %ABTS*sc) and Ferric ion reducing antioxidant potential (y5; FRAP) were selected. The optimized condition was observed at X1 = 0.155 mm, X2 = 65% methanol in water, X3 = 23 min ultrasound exposure time, X4 = 40 °C, and X5 = 70 W cm-2 ultrasound intensity. Under this situation, the optimal yields of TPC, TFC, and antioxidant scavenging potential were achieved to be 670.32 mg GAE/g, 451.45 mg RE/g, 81.23% DPPH*sc, 77.39% ABTS*sc and 71.55 µg mol (Fe(II))/g FRAP. This optimal condition yielded equal experimental and expected values. A well-fitted quadratic model was recommended. Furthermore, the validated extraction parameters were optimized and compared using the ANFIS and random forest regressor-ML algorithm. Gas chromatography-mass spectroscopy (GC-MS) and liquid chromatography-mass spectroscopy (LC-MS) analyses were performed to find the existence of the bioactive compounds in the optimized extract.

Cemtirestat dimerization in liposomes and erythrocytes exposed to peroxyl radicals was reverted by thiol-disulfide exchange with GSH.

In the model system of DOPC (1,2-dioleoyl-sn-glycero-3-phosphocholine) liposomes exposed to peroxyl radicals generated by the azoinitiator AAPH, cemtirestat (CMTI-SH) inhibited lipid peroxidation more efficiently than the natural antioxidant glutathione. In the concentrations 100 to 500 µM, both CMTI-SH and GSH induced distinct lag phases in the initial stages of lipid peroxidation yet GSH produced consistently shorter induction periods (about twice) than equimolar CMTI-SH. Moreover, concentration dependence of lipid peroxidation inhibition measured at the 80th minute, revealed about three times higher IC50 value for GSH compared to CMTI-SH. When the incubations prolonged till 180 min no further absorbance changes at 270 and 302 nm, respectively, occurred. After addition of the reducing agent tris(2-carboxyethyl)phosphine, the absorbance peak at 270 nm shifted back to 302 nm. These findings pointed to the presence of reducible CMTI-SH disulfide whose definite structure was confirmed by proving identity of TLC retention and spectral data with those of the synthesized CMTI disulfide. When CMTI-SH and GSH were present simultaneously in the liposomal incubations, the mixing effect on the induction period was synergistic rather than additive. This was explained by ability of GSH to reduce CMTI disulfide which was proved in separate experiments with an authentic CMTI disulfide prepared synthetically. This finding was also demonstrated by experiment with CMTI-disulfide to protect the erythrocytes against oxidative damage induced by peroxyl radicals. To conclude, CMTI-SH scavenges reactive oxygen species yielding CMTI disulfide while GSH maintains CMTI-SH in the reduced state. This finding was also demonstrated by experiment with CMTI-disulfide to protect the erythrocytes against oxidative damage induced by peroxyl radicals. CMTI-SH would thus represent the first line of the cellular defense against peroxyl radical mediated oxidative stress.

Cemtirestat inhibited lipid peroxidation more efficiently than GSHCemtirestat disulfide was proved as the main oxidation productCemtirestat disulfide protected erythrocytes against oxidative damageCemtirestat disulfide was readily reduced by GSHMechanism of thiol-disulfide exchange reaction was suggested.

Variation in antioxidant capacity, antioxidant activity and mineral composition during flower development of oil-bearing rose (Rosa damascena Mill.).

Oil-bearing rose is an economically important rose species with a wide range of uses such as cosmetics, perfumery, food and health, but the changes in antioxidant capacity and antioxidant activity during flower development are not well understood. The antioxidant content and free radical scavenging properties of oil-bearing rose flowers are used in the cosmetic industry to modulate skin damage, and in the food industry as a source of antioxidants and sweeteners. The present investigation was carried out to explore the antioxidant capacity, antioxidant enzyme activity, and the composition and distribution of minerals in petals of oil-bearing rose at five flower development stages. The total antioxidant capacity of petals was determined using CUPRAC, DPPH, FRAP, FIC and ABTS methods. The antioxidant capacity of petals decreased during the flower development, suggesting that flowers in stage I and II are valuable sources of antioxidants. CUPRAC, DPPH, FRAP, FIC and ABTS scavenging activity of the petals at various developmental stages are strongly and positively correlated with each other. The activity of the antioxidant enzymes; superoxide dismutase, catalase, glutathione reductase, ascorbate peroxidase was highest at the bud stage (stage I), whereas the fully opened flowers (stage V) exhibited the lowest activity in oil-bearing rose petals. During the development of flower, malondialdehyde (MDA) content increased significantly from stage I to stage III and decreased at stage IV. Here we detected the contents of 15 elements in petals, some of them, especially calcium, magnesium, potassium and phosphorus showed significant changes during rose flowering. Generally, the highest mineral content was observed in stage I while the lowest content observed in stage V of flower development. These results showed a close link between flower development, antioxidant capacity, enzymatic antioxidant activity and mineral content, with stage I exhibiting the best antioxidant activity, mineral content and free radical scavenging potential. This work will serve as a baseline for understanding the possible roles of antioxidant capacity, antioxidant enzymes, mineral content and their interactions in the regulation of flower development.

Outdoor Health Risk of Atmospheric Particulate Matter at Night in Xi'an, Northwestern China.

The deterioration of air quality via anthropogenic activities during the night period has been deemed a serious concern among the scientific community. Thereby, we explored the outdoor particulate matter (PM) concentration and the contributions from various sources during the day and night in winter and spring 2021 in a megacity, northwestern China. The results revealed that the changes in chemical compositions of PM and sources (motor vehicles, industrial emissions, coal combustion) at night lead to substantial PM toxicity, oxidative potential (OP), and OP/PM per unit mass, indicating high oxidative toxicity and exposure risk at nighttime. Furthermore, higher environmentally persistent free radical (EPFR) concentration and its significant correlation with OP were observed, suggesting that EPFRs cause reactive oxygen species (ROS) formation. Moreover, the noncarcinogenic and carcinogenic risks were systematically explained and spatialized to children and adults, highlighting intensified hotspots to epidemiological researchers. This better understanding of day-night-based PM formation pathways and their hazardous impact will assist to guide measures to diminish the toxicity of PM and reduce the disease led by air pollution.

Influence of Tobacco Variety and Curing on Free Radical Production in Cigarette Smoke.

INTRODUCTION: Cigarette smoke contains highly reactive free radicals thought to play an important role in tobacco smoke-induced harm. Previously, large variations in free radical and toxicant output have been observed in commercial cigarettes. These variations are likely because of cigarette design features (paper, filter, and additives), tobacco variety (burley, bright, oriental, etc.), and tobacco curing methods (air, sun, flue, and fire). Previous reports show that tobacco varieties and curing methods influence the production of tobacco smoke constituents like the tobacco-specific carcinogen nicotine-derived nitrosamine ketone (NNK). AIMS AND METHODS: We evaluated free radical, nicotine, and NNK production in cigarette smoke from cigarettes produced with 15 different types of tobacco. Gas-phase free radicals were captured by spin trapping with N-tert-butyl-α-phenylnitrone and particulate-phase radicals were captured on a Cambridge Filter pad (CFP). Both types of radicals were analyzed using electron paramagnetic resonance spectroscopy. Nicotine and NNK were extracted from the CFP and analyzed by gas chromatography flame ionization detection and liquid chromatography-mass spectrometry, respectively. RESULTS: Gas-phase radicals varied nearly 8-fold among tobacco types with Saint James Perique tobacco producing the highest levels (42 ±â€…7 nmol/g) and Canadian Virginia tobacco-producing the lowest levels (5 ±â€…2 nmol/g). Nicotine and NNK levels in smoke varied 14-fold and 192-fold, respectively, by type. Gas-phase free radicals were highly correlated with NNK levels (r = 0.92, p < .0001) and appeared to be most impacted by tobacco curing method. CONCLUSIONS: Altogether, these data suggest that tobacco types used in cigarette production may serve as a target for regulation to reduce harm from cigarette smoking. IMPLICATIONS: Variations in cigarette free radical and NNK levels vary based on the tobacco variety and curing method. Reducing the ratio of high-producing free radical and NNK tobacco types offer a potential tool for regulators and producers looking to reduce toxicant output from cigarettes.

Detection and characterization of free oxygen radicals induced protein adduct formation in differentiating macrophages.

Reactive oxygen species play a key role in cellular homeostasis and redox signaling at physiological levels, where excessive production affects the function and integrity of macromolecules, specifically proteins. Therefore, it is important to define radical-mediated proteotoxic stress in macrophages and identify target protein to prevent tissue dysfunction. A well employed, THP-1 cell line was utilized as in vitro model to study immune response and herein we employ immuno-spin trapping technique to investigate radical-mediated protein oxidation in macrophages. Hydroxyl radical formation along macrophage differentiation was confirmed by electron paramagnetic resonance along with confocal laser scanning microscopy using hydroxyphenyl fluorescein. Lipid peroxidation product, malondialdehyde, generated under experimental conditions as detected using swallow-tailed perylene derivative fluorescence observed by confocal laser scanning microscopy and high-performance liquid chromatography, respectively. The results obtained from this study warrant further corroboration and study of specific proteins involved in the macrophage activation and their role in inflammations.

Iridoids Isolation from a Phytochemical Study of the Medicinal Plant Teucrium parviflorum Collected in Iraqi Kurdistan.

Herbal medicines are still widely practiced in Kurdistan Region-Iraq, especially by people living in villages on mountainous regions. Among plants belonging to the genus Teucrium (family Lamiaceae), which are commonly employed in the Kurdish traditional medicine, we have analyzed, for the first time, the methanol and aqueous methanol extracts of T. parviflorum aerial parts. The plant is mainly used by Kurds to treat jaundice, liver disorders and stomachache. We aimed to determine the phytochemical profile of the extracts and the structures of the main components, so to provide a scientific rationale for the ancient use of the plant in the ethno-pharmacological field. TLC analysis of the two extracts on silica gel and reversed phase TLC plates, using different visualization systems, indicated similar contents and the presence of phenolics, flavonoids, terpenoids and sugars. The chlorophyll-free extracts exhibited weak/no antimicrobial activities against a panel of bacteria (MICs = 800-1600 µg/mL) and fungal strains (MICs ≥ 5 mg/mL). At the concentration of 600 µg/mL, the methanol extract showed moderate antiproliferative effects against A549 and MCF-7 cancer cell lines in the MTS assay. Moreover, both extracts exhibited a significant dose-dependent free radical scavenging action against the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical (EC50 = 62.11 and 44.25 µg/mL, respectively). In a phytochemical study, a high phenolic content (77.08 and 81.47 mg GAE/g dry extract, respectively) was found in both extracts by the Folin-Ciocalteu assay. Medium pressure liquid chromatographic (MPLC) separation of the methanol extract on a reversed phase cartridge eluted with a gradient of MeOH in H2O, afforded two bioactive iridoid glucosides, harpagide (1) and 8-O-acetylharpagide (2). The structures of 1 and 2 were established by spectral data, chemical reactions, and comparison with the literature. Interestingly, significant amounts of hepatotoxic furano neo-clerodane diterpenoids, commonly occurring in Teucrium species, were not detected in the extract. The wide range of biological activities reported in the literature for compounds 1 and 2 and the significant antiradical effects of the extracts give scientific support to the traditional use in Iraqi Kurdistan of T. parviflorum aerial parts for the preparation of herbal remedies.

Antimicrobial, antioxidant, antiviral activity, and gas chromatographic analysis of Varanus griseus oil extracts.

There is an urgent need to develop natural antimicrobials for the control of rapidly mutating drug-resistant bacteria and poultry viruses. Five extracts were prepared using diethyl ether, ethyl acetate, methanol, 1-butanol and n-hexane from abdominal fats of Varanus griseus locally known as Indian desert monitor. Antibacterial, antioxidant and antiviral activities from oil extracts were done through disc diffusion method, stable 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay and in ovo antiviral assay, respectively. The gas chromatography mass spectrometry (GC-MS) analyses were used to determine principal active compounds and chemical profile of each oil extract. n-Hexane extract showed clear zones of inhibition (ZOI) against Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae (12 ± 0.5 mm, 9 ± 0.5 mm, and 9 ± 0.5 mm) while diethyl ether extract exhibited significant antibacterial activity (11 ± 0.5 mm) against Proteus vulgaris only. In case of drug-resistant strains, methanol extract was active (6 ± 0.5 mm) against Staphylococcus aureus, whereas n-hexane extract has shown ZOI 11 ± 0.5 mm against P. aeruginosa. Range of percentage scavenging activity of V. griseus oil extracts from DPPH free radical assay was 34.9-70.7%. For antiviral potential, growth of new castle disease virus (NDV) was effectively inhibited by all five extracts (HA titer = 0-4). The highest antiviral activity against avian influenza virus (H9N2) was observed from methanol, diethyl ether and 1-Butanol oil extracts with HA titers of 2, 2 and 0, respectively. Methanol, diethyl ether, 1-butanol and n-hexane oil extracts produced best hemagglutination assay (HA) titer values (0, 0, 4 and 0) against infectious bronchitis virus (IBV). Ethyl acetate and 1-Butanol extract exhibited good antiviral potential against infectious bursal disease virus (IBDV) with indirect hemagglutination assay (IHA) titers of 8 and 4, respectively. Main classes of identified compounds through gas chromatography were aldehydes, fatty acids, phenols and esters. GC-MS identified 11 bioactive compounds in V. griseus oil extracts. It is summarized that V. griseus oil has strong antioxidant activity and good antimicrobial potential because of its bioactive compounds.

Nutrient composition of Chenopodium formosanum Koidz. bran: Fractionation and bioactivity of its soluble active polysaccharides.

Background: Chenopodium formosanum Koidz. Amaranthaceae-also known as Djulis or red quinoa (RQ)-is a cereal plant indigenous to Taiwan, known for its high nutrient value. However, its bran is considered a waste product and the nutrient value has never been analyzed. Methods: In this study, we examined the proximate composition of RQ bran, specifically its soluble polysaccharide fractions. Results: RQ bran exhibited high contents of protein (16.56%), ash (7.10%), carbohydrate (60.45%), total polyphenolics (1.85%), betaxanthin (9.91 mg/100 g of RQ bran), and indicaxanthin (7.27 mg/100 g of RQ bran). Specifically, it was rich in polyunsaturated fatty acids (PUFAs; 39.24%)-with an n-6/n-3 and PUFA/saturated fatty acid (SFA) ratio of 18.137 and 0.743, respectively. Four soluble polysaccharide fractions were also obtained: CF-1, CF-2, CF-3, and CF-4, with yields of 3.90%, 6.74%, 22.28%, and 0.06%, respectively, and molecular weights of 32.54, 24.93, 72.39, and 55.45 kDa, respectively. CF-1, CF-2, CF-3, and CF-4 had respectively 15.67%, 42.41%, 5.44%, and 14.52% peptide moiety content and 38.92%, 50.70%, 93.76%, and 19.80% carbohydrate moiety. In CF-2, the glucose content was 95.86 mol% and that of leucine was 16.23%, implicating the presence of a typical leucinoglucan. All four polysaccharide fractions lacked glutamic acid and hydroxyproline. The IC50 of CF-1, CF-2, and CF-3 was respectively 12.05, 3.98, and 14.5 mg/mL for DPPH free radical-scavenging ability; 5.77, 4.10, and 7.03 mg/mL for hydrogen peroxide-scavenging capability; 0.26, 0.05, and 0.19 mg/mL for O2 - free radical-scavenging capability; and 100.41, 28.12, and 29.73 mg/mL for Fe2+ chelation. Conclusion: Our results indicated that RQ bran has a large amount of nutrient compounds, and a cost-efficient process for their extraction is needed. Their biomedical application as nutraceuticals also warrants further investigation.

(-)-5-O-(3-O-ß-d-Glucopyranosylcaffeoyl)-quinic acid from the fruits of Lycium barbarum L. var. auranticarpum K. F. Ching: Purification, identification and in vitro bioactivities.

Chlorogenic acids are important phenolics in the fruits of wolfberry, but little attention has been paid on their glucosylated forms. In the present study, a glucosylated form of chlorogenic acid was isolated from the fruits of Lycium barbarum L. var. auranticarpum K. F. Ching (also called yellow wolfberry) and identified to be (-)-5-O-(3-O-ß-d-glucopyranosylcaffeoyl)-quinic acid (5-CQA-3'ßG) by high resolution mass spectrometry and nuclear magnetic resonance spectrometry. The content of 5-CQA-3'ßG in the dried fruit was determined as 0.0293 ± 0.0015% by HPLC. In addition, 5-CQA-3'ßG showed a good scavenging capacity for 2,2'-azino-bis-(3-ethylben-zothiazoline-6-sulphonate) free radicals but had a relatively low reducing power and scavenging capacity for 2,2-diphenyl-1-picrylhydrazyl free radical. Moreover, the secretion of nitric oxide, tumor necrosis factor-α and interleukin-6 as well as related mRNA expression were reduced in lipopolysaccharide-stimulated RAW264.7 macrophage cells treated with 5-CQA-3'ßG. This is the first report describing purification, identification and bioactivity of glucosylated CQA from yellow wolfberry.

Mitochondria-targeted accumulation of oxygen-irrelevant free radicals for enhanced synergistic low-temperature photothermal and thermodynamic therapy.

BACKGROUND: Although lower temperature (< 45 °C) photothermal therapy (LPTT) have attracted enormous attention in cancer therapy, the therapeutic effect is still unsatisfying when applying LPTT alone. Therefore, combining with other therapies is urgently needed to improve the therapeutic effect of LPTT. Recently reported oxygen-irrelevant free radicals based thermodynamic therapy (TDT) exhibit promising potential for hypoxic tumor treatment. However, overexpression of glutathione (GSH) in cancer cells would potently scavenge the free radicals before their arrival to the specific site and dramatically diminish the therapeutic efficacy. METHODS AND RESULTS: In this work, a core-shell nanoplatform with an appropriate size composed of arginine-glycine-aspartate (RGD) functioned polydopamine (PDA) as a shell and a triphenylphosphonium (TPP) modified hollow mesoporous manganese dioxide (H-mMnO2) as a core was designed and fabricated for the first time. This nanostructure endows a size-controllable hollow cavity mMnO2 and thickness-tunable PDA layers, which effectively prevented the pre-matured release of encapsulated azo initiator 2,2'-azobis[2-(2-imidazolin-2-yl) propane] dihydrochloride (AIBI) and revealed pH/NIR dual-responsive release performance. With the mitochondria-targeting ability of TPP, the smart nanocomposites (AIBI@H-mMnO2-TPP@PDA-RGD, AHTPR) could efficiently induce mitochondrial associated apoptosis in cancer cells at relatively low temperatures (< 45 °C) via selectively releasing oxygen-irrelevant free radicals in mitochondria and facilitating the depletion of intracellular GSH, exhibiting the advantages of mitochondria-targeted LPTT/TDT. More importantly, remarkable inhibition of tumor growth was observed in a subcutaneous xenograft model of osteosarcoma (OS) with negligible side effects. CONCLUSIONS: The synergistic therapy efficacy was confirmed by effectively inducing cancer cell death in vitro and completely eradicating the tumors in vivo. Additionally, the excellent biosafety and biocompatibility of the nanoplatforms were confirmed both in vitro and in vivo. Taken together, the current study provides a novel paradigm toward oxygen-independent free-radical-based cancer therapy, especially for the treatment of hypoxic solid tumors.

Application of Artificial Neural Network Based on Traditional Detection and GC-MS in Prediction of Free Radicals in Thermal Oxidation of Vegetable Oil.

In this study, electron paramagnetic resonance (EPR) and gas chromatography-mass spectrometry (GC-MS) techniques were applied to reveal the variation of lipid free radicals and oxidized volatile products of four oils in the thermal process. The EPR results showed the signal intensities of linseed oil (LO) were the highest, followed by sunflower oil (SO), rapeseed oil (RO), and palm oil (PO). Moreover, the signal intensities of the four oils increased with heating time. GC-MS results showed that (E)-2-decenal, (E,E)-2,4-decadienal, and 2-undecenal were the main volatile compounds of oxidized oil. Besides, the oxidized PO and LO contained the highest and lowest contents of volatiles, respectively. According to the oil characteristics, an artificial neural network (ANN) intelligent evaluation model of free radicals was established. The coefficients of determination (R2) of ANN models were more than 0.97, and the difference between the true and predicted values was small, which indicated that oil profiles combined with chemometrics can accurately predict the free radical of thermal oxidized oil.

Formation of Environmentally Persistent Free Radicals during Thermochemical Processes and their Correlations with Unintentional Persistent Organic Pollutants.

Attention is increasingly being paid to environmentally persistent free radicals (EPFRs), which are organic pollutants with the activities of free radicals and stabilities of organic pollutants. EPFRs readily form during thermal processes through the decomposition of organic precursors such as phenols, halogenated phenols, and quinone-type molecules, which are also important precursors of toxic unintentionally produced persistent organic pollutants (UPOPs). We have found that EPFRs are important intermediates for UPOP formation during thermal-related processes. However, interest in EPFRs is currently mostly focused on the toxicities and formation mechanisms of EPFRs themselves. Little information is available on the important roles EPFRs play in toxic UPOP formation during thermal processes. Here, we review the mechanisms involved in EPFR formation and transformation into UPOPs during thermal processes. The review is focused on typical EPFRs, including cyclopentadiene, phenoxy, and semiquinone radicals. The reaction temperature, metal species present, and oxygen concentration strongly affect EPFR and UPOP formation during thermal-related processes. Gaps in current knowledge and future directions for research into EPFR and UPOP formation, transformation, and control are presented. Understanding the relationships between EPFRs and UPOPs will allow synergistic control strategies to be developed for thermal-related industrial sources of EPFRs and UPOPs.

Peptide Vectors Carry Pyrene to Cell Organelles Allowing Real-Time Quantification of Free Radicals in Mitochondria by Time-Resolved Fluorescence Microscopy.

Real-time quantification of reactive nitrogen and oxygen species (ROS) in cells is of paramount importance as they are essential for cellular functions. Their excessive formation contributes to the dysfunction of cells and organisms, ultimately leading to cell death. As ROS are mostly produced in the mitochondria, we have synthesized a fluorescent probe able to reach this organelle to detect and quantify, in real time, the variation of ROS by time-resolved microfluorimetry. The new probes are based on the long fluorescence lifetime of pyrene butyric acid (PBA). Two PBA isomers, attached at their 1- or 2-positions to a peptide vector to target mitochondria, were compared and were shown to allow the measurement of free radical species and oxygen, but not non-radical species such as H2 O2 .

Free Radical and Nicotine Yields in Mainstream Smoke of Chinese Marketed Cigarettes: Variation with Smoking Regimens and Cigarette Brands.

Free radicals and nicotine are components of cigarette smoke that are thought to contribute to the development of smoking-induced diseases. China has the largest number of smokers in the world, yet little is known about the yields of tobacco smoke constituents in different Chinese brands of cigarettes. In this study, gas-phase and particulate-phase free radicals as well as nicotine yields were quantified in mainstream cigarette smoke from five popular Chinese brands and two research cigarettes (3R4F and 1R6F). Mainstream smoke was generated under International Organization of Standardization (ISO) and Canadian Intense (CI) smoking regimens using a linear smoking machine. Levels of free radicals and nicotine were measured by electron paramagnetic resonance spectroscopy (EPR) and gas chromatography with flame-ionization detection, respectively. Under the ISO puffing regimen, Chinese brand cigarettes produced an average of 3.0 ± 1.2 nmol/cig gas-phase radicals, 118 ± 44.7 pmol/cig particulate-phase radicals, and 0.6 ± 0.2 mg/cig nicotine. Under the CI puffing regimen, Chinese brand cigarettes produced an average of 5.6 ± 1.2 nmol/cig gas-phase radicals, 282 ± 92.1 pmol/cig particulate-phase radicals, and 2.1 ± 0.4 mg/cig nicotine. Overall, both gas- and particulate-phase free radicals were substantially lower compared to the research cigarettes under both regimens, whereas no significant differences were observed for nicotine levels. When Chinese brands were compared, the highest free radical and nicotine yields were found in "LL" and "BS" brands, while lowest levels were found in "YY". These results suggested that the lower radical delivery by Chinese cigarettes compared to United States reference cigarettes may be associated with reductions in oxidant-related harm.

Free Radical Production and Characterization of Heat-Not-Burn Cigarettes in Comparison to Conventional and Electronic Cigarettes.

With conventional cigarettes, the burning cone reaches temperatures of >900 °C, resulting in the production of numerous toxicants and significant levels of highly reactive free radicals. In attempts to eliminate combustion while still delivering nicotine and flavorings, a newer alternative tobacco product has emerged known as "heat-not-burn" (HnB). These products heat tobacco to temperatures of 250-350 °C depending on the device allowing for the volatilization of nicotine and flavorants while potentially limiting the production of combustion-related toxicants. To better understand how the designs of these new products compare to conventional cigarettes and different styles of electronic cigarettes (e-cigs), we measured and partially characterized their production of free radicals. Smoke or aerosols were trapped by a spin trap phenyl-N-tert-butylnitrone (PBN) and analyzed for free radicals using electron paramagnetic resonance (EPR). Free radical polarity was assessed by passing the aerosol or smoke through either a polar or nonpolar trap prior to being spin trapped with PBN. Particulate-phase radicals were detected only for conventional cigarettes. Gas-phase free radicals were detected in smoke/aerosol from all products with levels for HnB (IQOS, Glo) (12 pmol/puff) being similar to e-cigs (Juul, SREC, box mod e-cig) and hybrid devices (Ploom) (5-40 pmol/puff) but 50-fold lower than conventional cigarettes (1R6F). Gas phase radicals differed in polarity with HnB products and conventional cigarettes producing more polar radicals compared to those produced from e-cigs. Free radical production should be considered in evaluating the toxicological profile of nicotine delivery products and identification of the radicals is of paramount importance.

Method for Structural Determination of Lipid-Derived Radicals.

Diversified oxidized-lipid molecules are responsible for inflammation and cell death, including ferroptosis. Lipid radicals are the source of these oxidized lipids, which are the initial key molecules in the lipid peroxidation chain reaction. However, owing to their extremely high reactivity and short half-life, an established detection technique is not available. Here, we propose a high-performance liquid chromatography fluorometry and high-resolution tandem mass spectrometry system combined with a fluorescent probe as a structural analysis method for lipid-derived radicals. We detected 132 lipid-derived radicals, including 111 new species, from five polyunsaturated fatty acids. In addition, a database was constructed for which the initial fatty acid could be determined using the radical structure. Further, 12 endogenous lipid-derived radicals were identified in carcinogen-induced liver cancer mouse models. Therefore, this method and its corresponding database will provide novel insights into mechanisms underlying the lipid peroxidation, including the associated inflammation and ferroptosis.