Optimization of Flavonoid Extraction from Xanthoceras sorbifolia Bunge Flowers,and the Antioxidant and Antibacterial Capacity of the Extract

In the present work, the extraction process of total flavonoids (TFs) from X. sorbifolia flowers by ultrasound-assisted extraction was optimized under the response surface methodology (RSM) on the basis of single-factor experiments. The optimal extraction conditions were as follows: ethanol concentration of 80%, solid–liquid ratio of 1:37 (g/mL), temperature of 84 °C, and extraction time of 1 h. Under the optimized conditions, the extraction yield of the TFs was 3.956 ± 0.04%. The radical scavenging capacities of TFs against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) were much greater than that of rutin. The results of antibacterial experiments indicated that the TFs displayed strong inhibitory activities on E. coli, S. aureus and Bacillus subtilis. Therefore, X. sorbifolia flowers can be used as a novel source of natural flavonoids, and the TFs have potential applications as natural antioxidants or antibacterial agents in the food and pharmaceutical industries.     

New natural barrigenol-like triterpenoid isolated from the husks of Xanthoceras sorbifolia Bunge

The Xanthoceras sorbifolia Bunge husks were known for their abundant triterpenoids resource, which contributed to many bioactivities, such as antitumor, antiinflammatory and neuroprotection. The present study has led to the purification of a new triterpenoid saponin, 21β-O-acetyl-xanthohuskiside A (1), together with six known barrigenol derivatives (2–7), whose structures were authenticated on the basis of NMR, HR-MS, IR spectrum and acid hydrolysis experiment. Compound 7 showed more noteworthy cytotoxicity towards three human tumour cell lines (HCT-116, HepG-2 and U87-MG) than other compounds.     

Structure elucidation and complete NMR spectral assignments of two new oleanane‐type pentacyclic triterpenoid saponins from the husks of Xanthoceras sorbifolia Bunge

Two new saponins were isolated from husks of Xanthoceras sorbifolia Bunge and their structures were elucidated as 3‐O‐[β‐D‐galactopyranosyl(1→2)]‐α‐L‐arabinofuranosyl(1→3)‐β‐D‐methyl glucuronic acid‐21‐O‐(3,4‐diangeloyl)‐α‐L‐rhamnose‐3β, 16α, 21β, 22α, 28β‐pentahydroxyl‐22‐acetoxy‐olean‐12‐ene(1) and 3‐O‐[β‐D‐galactopyranosyl(1→2)]‐α‐L‐arabinofuranosyl(1→3)‐β‐D‐methyl glucuronic acid‐21,22‐O‐diangeloyl‐3β,15α,16α,21β,22α,28β‐hexahydroxyl‐olean‐12‐ene(2) on the basis of 1D and 2D NMR (including ¹H, ¹³C‐NMR, ¹H? ¹H COSY, HSQC, HMBC and DEPT), ESI‐MS spectrometry and chemical methods. Copyright © 2009 John Wiley & Sons, Ltd.     

Pharmacokinetic study of the major chemical constituents in Xanthoceras sorbifolia wood after oral administration of methanol extract,wood powder,and single constituents

The wood powder and extract of Xanthoceras sorbifolia are used to treat rheumatism, gout, and other diseases in Mongolian medicine. Information on the pharmacokinetic differences between various forms of the herb drug is needed. Eight Xanthoceras constituents were examined simultaneously in rat plasma by ultra liquid chromatography-triple quadrupole mass spectrometry. In vitro experiments were performed to determine the influence of digestive juices on the pharmacokinetic profiles. Epicatechin and dihydromyricetin had higher AUC values in rats that were gavaged with X. sorbifolia extract versus the pure compounds. The AUC value of epicatechin in rats that were gavaged with X. sorbifolia wood powder was higher than that with the methanol extract. The nonextractable epicatechin polymer in the wood powder could be degraded to epicatechin by gastric juice, consequently elevating the epicatechin levels in blood.     

Physicochemical,Antioxidant and Anticancer Characteristics of Seed Oil from Three Chenopodium quinoa Genotypes

Chenopodium quinoa Willd. is recognized to be an excellent nutrient with high nutritional content. However, few genotypes of quinoa were analyzed, so we found a knowledge gap in the comparison of quinoa seeds of different genotypes. This study aims to compare the physicochemical, antioxidant, and anticancer properties of seed oil from three C. quinoa genotypes. Seeds of three genotypes (white, red, and black) were extracted with hexane and compared in this study. The oil yields of these quinoa seeds were 5.68–6.19% which contained predominantly polyunsaturated fatty acids (82.78–85.52%). The total tocopherol content ranged from 117.29 to 156.67 mg/kg and mainly consisted of γ-tocopherol. Total phytosterols in the three oils ranged from 9.4 to 12.2 g/kg. Black quinoa seed oil had the highest phytosterols followed by red and white quinoas. The chemical profile of quinoa seed oils paralleled by their antioxidant and anticancer activities in vitro was positively correlated with the seed coat color. Black quinoa seed oil had the best antioxidant and anti-proliferation effect on HCT 116 cells by the induction of apoptosis in a dose-dependent manner, which may play more significant roles in the chemoprevention of cancer and other diseases related to oxidative stress as a source of functional foods.     

Effects of Enzymatic Pretreatment of Seeds on the Physicochemical Properties,Bioactive Compounds,and Antioxidant Activity of Pomegranate Seed Oil

Enzymatic pretreatment of seeds is a novel approach that enhances the health benefits of the extracted oil. The study investigated the influence of the enzymatic pretreatment of seeds on the quality of oil from different pomegranate cultivars. The quality of the ultrasound-assisted (and ethanol-extracted) oil was studied, with respect to the refractive index (RI), yellowness index (YI), conjugated dienes (K232), peroxide value (PV) ρ-anisidine value (AV), total oxidation value (TOTOX), total carotenoid content (TCC), total phenolic compounds (TPC), fatty acid composition, phytosterol composition, ferric reducing antioxidant power (FRAP), and 2.2-diphenyl-1-picryl hydrazyl (DPPH) radical scavenging capacity. The seeds of three different pomegranate cultivars (‘Wonderful’, ‘Herskawitz’, and ‘Acco’) were digested with an equal mixture of Pectinex Ultra SPL, Flavourzyme 100 L, and cellulase crude enzymes, at a concentration, pH, temperature, and time of 1.7%, 4.5, 40 °C, and 5 h, respectively. Enzymatic pretreatment of PS increased oil yield, PV, TPC, TCC, and DPPH radical scavenging capacity, but decreased the YI. The levels of K232, AV and TOTOX, fatty acids, phytosterols, RI, and FRAP, were not significantly affected by enzymatic pretreatment of PS. Principal component analysis (PCA) established that oil extracted from the ‘Acco’ seed after enzymatic pretreatment had higher yield, TPC, TCC, and DPPH radical scavenging capacity. Therefore, enzyme-pretreated ‘Acco’ pomegranate fruit seed is a source of quality seed oil with excellent antioxidant properties.     

Extraction,Physicochemical Properties,Anti-Aging,and Antioxidant Activities of Polysaccharides from Industrial Hemp Residues

A large amount of hemp polysaccharides remain in industrial hemp residues (IHR) after cannabidiol extraction, resulting in the waste of resources. Therefore, the systematic study of hemp polysaccharides is beneficial to the development of IHR in the future. In this study, the extraction of industrial hemp residues polysaccharide (IHRPs) was optimized by single-factor experiment and orthogonal experimental design. The optimum heating extraction conditions were extraction temperature 98 °C, solid–liquid ratio 1:10, extraction time 1 h, number of successive extractions 2, and pH at 4. The extraction ratio and the polysaccharide content were 20.12 ± 0.55% and 12.35 ± 0.26% at the conditions, respectively. Besides, the best alcohol precipitation conditions were pumping with 2 L/h, stirring continuously, and ice-water bath for 4 h. The crude IHRPs was further purified by column chromatography and the polysaccharide/protein contents of purified IHRPs were 34.44% and 1.61%. IHRPs was mainly made up of ten monosaccharides and some non-sugar components including organic acids, flavonoids, steroids, and glycoside. The FT-IR demonstrated the polysaccharide skeleton of IHRPs. Moreover, the DPPH and ABTS scavenging rate of IHRPs were 76.00% and 99.05% at the concentrations of 1 mg/mL. IHRPs could promote the epidermal cells proliferation and healing of cell scratches. Meanwhile, IHRPs could promoted the expression of anti-aging-related genes. Overall, IHRPs could be a desirable natural source of antioxidants and anti-aging products in many aspects.     

The Effect of Oil Components and Homogenization Conditions on the Physicochemical Properties of Zedoary Turmeric Oil Submicron Emulsions

Zedoary turmeric oil submicron emulsions were studied. The effects of the oil phase as a mixture (ternary) on the emulsion droplet size were investigated by means of the simplex lattice design. By optimizing the homogenization process and using only 1.2% soya lecithin, emulsions with 20% oil phase consisting of zedoary turmeric oil–MCT–soybean oil ratio of 0.5:0.25:0.25 with particle sizes in the range of 132–148 nm and moderate viscosity (3.6–4.0 mPa · s) could be prepared. These emulsions showed good stability over 6 months. This study showed the dominating influence of composition of the oil phase as well as the importance of the homogenizing conditions on processing and stability of the zedoary turmeric oil submicron emulsions.     

Microwave-Assisted Extraction of Curcuma longa L. Oil: Optimization,Chemical Structure and Composition,Antioxidant Activity and Comparison with Conventional Soxhlet Extraction

Curcuma root (Curcuma longa L.) is a very important plant in gastronomy and medicine for its unique antiseptic, anti-inflammatory, antimicrobial and antioxidant properties. Conventional methods for the extraction of curcuma oil require long extraction times and high temperatures that can degrade the active substances. Therefore, the objectives of the present study were: (i) first, to optimize the extraction yield of curcuma oil by applying a Box-Behnken experimental design using surface response methodology to the microwave-assisted extraction (MAE) technique (the independent variables studied were reaction time (10–30 min), microwave power (150–200 W) and curcuma powder/ethanol ratio (1:5–1:20; w/v); and, (ii) second, to assess the total phenolic content (TPC) and their antioxidant activity of the oil (at the optimum conditions point) and compare with the conventional Soxhlet technique. The optimum conditions for the MAE were found to be 29.99 min, 160 W and 1:20 w/v to obtain an optimum yield of 10.32%. Interestingly, the oil extracted by microwave-assisted extraction showed higher TPC and better antioxidant properties than the oil extracted with conventional Soxhlet technique. Thus, it was demonstrated that the method applied for extraction influences the final properties of the extracted Curcuma longa L. oil.     

Optimized Green Extraction of Polyphenols from Cassia javanica L. Petals for Their Application in Sunflower Oil: Anticancer and Antioxidant Properties

The total phenolic content (TPC) from Cassia javanica L. petals were extracted using ethanolic solvent extraction at concentrations ranging from 0 to 90% and an SCF-CO₂ co-solvent at various pressures. Ultrasound-assisted extraction parameters were optimized using response surface methodology (RSM). Antioxidant and anticancer properties of total phenols were assessed. An SCF-CO₂ co-solvent extract was nano-encapsulated and applied to sunflower oil without the addition of an antioxidant. The results indicated that the best treatment for retaining TPC and total flavonoids content (TFC) was SCF-CO₂ co-solvent followed by the ultrasound and ethanolic extraction procedures. Additionally, the best antioxidant activity by β-carotene/linoleic acid and DPPH free radical-scavenging test systems was observed by SCF-CO₂ co-solvent then ultrasound and ethanolic extraction methods. SCF-CO₂ co-solvent recorded the highest inhibition % for PC3 (76.20%) and MCF7 (98.70%) and the lowest IC₅₀ value for PC3 (145 µ/mL) and MCF7 (96 µ/mL). It was discovered that fortifying sunflower oil with SCF-CO₂ co-solvent nanoparticles had a beneficial effect on free fatty acids and peroxide levels. The SCF-CO₂ method was finally found to be superior and could be used in large-scale processing.     

Contribution to the Evaluation of Physicochemical Properties,Total Phenolic Content,Antioxidant Potential,and Antimicrobial Activity of Vinegar Commercialized in Morocco

Vinegar is a natural product widely used in food and traditional medicine thanks to its physicochemical properties and its richness in bioactive molecules. However, its direct use by consumers can have complications and undesirable effects. Therefore, this study contributes to investigating the physicochemical and biological properties of eleven vinegars marketed in Morocco. Determination of pH, acetic acid, conductivity, total soluble solids and alcohol content in vinegar was carried out. The polyphenols (TP), flavonoids (TF), and condensed tannins (CT) content was determined, and their antioxidant activities were evaluated using 2,2-diphenyl-1-picryl Hydrazyl (DPPH), Ferric Reducing Antioxidant Power (FRAP) and Phosphomolybdenum Reduction Assay (TAC). Then, the antimicrobial activity was studied against four pathogenic bacteria and two fungal strains, using the disk diffusion and the microdilution method. This study showed a wide range of acetic acid values from 0.65 ± 0.29 to 5.15 ± 0.20%. The high value of TP, TF, and CT in our samples V10, V9, and V4 was 655.00 ± 22.2 µgGAE/mL, 244.53 ± 11.32 µgQE/mL and 84.63 ± 1.00 µgTAE/mL, respectively. The tested strains showed variable sensitivities to the different samples with inhibition zones ranging from 6.33 ± 2.08 to 34.33 ± 0.58 mm. The lowest minimum inhibition concentrations were recorded against Staphylococcus aureus ATCC29213 ranging from 1.95 to 7.81 µL/mL. While Aspergillus niger ATCC16404 showed resistance against all of the analyzed samples. In general, vinegar commercialized in Morocco presents a variable range of products with variable properties. Indeed, must take into account this diversity when using it. A future study is needed to identify the phytochemical composition that will further the comprehension of this variability and contribute to its valorization.     

海豹油成分及其脂肪酸的色谱分析

本文用高压液相色谱对海豹油的主要组分进行定性、定量分析；利用气相色谱-质谱联用仪定性分析了海豹油脂中的脂肪酸部分，并以硬脂酸为内标，用气相色谱方法对海豹油脂肪酸各组分进行了定量分析，分析结果表明海豹油中油脂部分占92％，烯醛类气味物质占6％；海豹油脂中不饱和脂肪酸占脂肪酸总量的82％以上，而且富含γ-亚麻酸。为开发海豹油，从海豹油中分离除去其中气味物质-烯醛类方法的选择提供了依据。     

Effects of Extraction Methods on the Bioactivities and Nutritional Value of Virginia and Valencia-Type Peanut Oil

This study aimed to evaluate the effects of peanut varieties cultivated in Morocco (Virginia and Valencia) and extraction methods (cold press, CP; Soxhlet, Sox and maceration, and Mac) on the fatty acid profile, phytosterol, and tocopherol contents, quality characteristics, and antioxidant potential of peanut seed oil. The DPPH method was used to determine the antioxidant activity of the oils. The results revealed that fatty acid content was slightly affected by the extraction technique. However, the CP method was shown to be an excellent approach for extracting oil with desirable quality features compared to the Sox and Mac methods. Furthermore, the peanut oil extracted via CP carried a higher amount of bioactive compounds and exhibited remarkable antioxidant activities. The findings also revealed higher oleic acid levels from the Virginia oil, ranging from 56.46% to 56.99%. Besides, a higher total phytosterol and tocopherol content and DPPH scavenging capacity were obtained from the Valencia oil. Analyzing the study, it can be inferred that extraction method and variety both affect the composition of the peanut oil’s bioactive compounds and antioxidant activity. This information is relevant for extracting peanut oil with a greater level of compounds of industrial interest.     

The Comparison of Physicochemical Parameters,Antioxidant Activity and Proteins for the Raw Local Polish Honeys and Imported Honey Blends

Many imported honeys distributed on the Polish market compete with local products mainly by lower price, which can correspond to lower quality and widespread adulteration. The aim of the study was to compare honey samples (11 imported honey blends and 5 local honeys) based on their antioxidant activity (measured by DPPH, FRAP, and total phenolic content), protein profile obtained by native PAGE, soluble protein content, diastase, and acid phosphatase activities identified by zymography. These indicators were correlated with standard quality parameters (water, HMF, pH, free acidity, and electrical conductivity). It was found that raw local Polish honeys show higher antioxidant and enzymatic activity, as well as being more abundant in soluble protein. With the use of principal component analysis (PCA) and stepwise linear discriminant analysis (LDA) protein content and diastase number were found to be significant (p < 0.05) among all tested parameters to differentiate imported honey from raw local honeys.     

Effects of Sonication and Thermal Pasteurization on the Nutritional,Antioxidant, and Microbial Properties of Noni Juice

Sonication is recognized as a potential food processing method to improve the functional properties of fruit juice. This study evaluated the effects of different sonication durations (20, 40, and 60 min) and thermal pasteurization on the nutritional, antioxidant, and microbial properties of noni juice. Fresh noni juice served as the control. The main organic acids detected were malic (57.54–89.31 mg/100 mL) and ascorbic (17.15–31.55 mg/100 mL) acids. Compared with the fresh sample, the concentrations of these compounds were significantly improved (p < 0.05) in the 60 min sonicated sample but reduced (p < 0.05) in the pasteurized sample. Moreover, sonication for 60 min resulted in increments of scopoletin, rutin, and vanillic acid compared to the fresh sample. The antioxidant activity of the juice sample was improved in the sample sonicated for 60 min. Irrespective of juice processing method, the level of microbial counts in noni juice was within the satisfactory level over the 8 weeks of refrigerated (4 °C) storage. This study highlights the feasibility of using ultrasound processing to enhance the quality of noni juice on the industrial scale.     

Integrated strategy based on high‐resolution mass spectrometry coupled with multiple data mining techniques for the metabolic profiling of Xanthoceras sorbifolia Bunge husks in rat plasma,urine, and feces

An integrated strategy based on high‐resolution mass spectrometry coupled with multiple data mining techniques was developed to screen the metabolites in rat biological fluids after the oral administration of Xanthoceras sorbifolia Bunge husks. Mass defect filtering, product ion filtering, and neutral loss filtering were applied to detect metabolites from the complex matrix. As a result, 55 metabolites were tentatively identified, among which 45 barrigenol‐type triterpenoid metabolites were detected in the feces, and six flavonoids and four coumarins metabolites were in the urine. Moreover, eight prototype constituents in plasma, 36 in urine and 23 in feces were also discovered. Due to the poor bioavailability of barrigenol type triterpenoids, most of them were metabolized by intestinal flora. Phase I metabolic reactions such as deglycosylation, oxidation, demethylation, dehydrogenation, and internal hydrolysis were supposed to be their principal metabolic pathways. Coumarins were found in all the biosamples, whereas flavonoids were mainly in the urine. Unlike the saponins, they were mainly metabolized through phase II metabolic reactions like glucuronidation and sulfonation, which made them eliminated more easily by urine. This work suggested the metabolic profile of X. sorbifolia husks for the first time, which will be very valuable for its further development.     

HRGC/FID and HRGC/MSD Analysis of the Secondary Metabolites Obtained by Different Extraction Methods from Lepechinia schiedeana,and in Vitro Evaluation of Its Antioxidant Activity

Steam distillation (SD), simultaneous distillation-solvent extraction (SDE), microwave-assisted solvent extraction (MWE), and supercritical (CO₂) extraction (SFE) were used to isolate secondary metabolites from Lepechinia schiedeana. The various extracts were analyzed by capillary gas-chromatography, on poly (dimethylsiloxane) (DB-1) and poly(ethyleneglycol) (INNOWAX), 60 m columns, using FID or MSD (EI, 70 eV). Kováts indexes, mass spectra, or standard compounds were employed for compound identification. 43, 61, 67, and 79 compounds at concentrations above 0.01% were detected in the SD, SDE, MWE, and SFE extracts, respectively. Ledol, C₁₅H₂₆O, was the major constituent (20.04–36.87%) in all extracts. Oxygenated sesquiterpenes (24.36–43.14%), C₁₀H₁₆, monoterpenes (27.70–39.87%), and C₁₅H₂₄, sesquiterpenes (10.04–22.22%) were the main groups of compounds present in SD, SDE, MWE, and SFE extracts. Heavy hydrocarbons (C_n > 15), diterpenoids, and phytosterols were found only in MWE and SFE extracts. The antioxidant activity of Lepechinia schiedeana was measured by the HRGC quantification of the volatile carbonyl compounds, final products of lipoxidation, released in a model lipid system (sunflower oil) by the effect of the Fenton reagent. The concentration of volatile carbonyl compounds decreased by 65% when lipid oxidation was induced in the presence of macerated Lepechinia plant. The protection of polyunsaturated acids in sunflower oil was also studied by measuring their concentrations after heating of the oil (180°C, 2 h) with and without macerated Lepechinia plant.     

Chemical Constituents of the Essential Oil from Ecuadorian Endemic Species Croton ferrugineus and Its Antimicrobial,Antioxidant and α-Glucosidase Inhibitory Activity

Croton ferrugineus Kunth is an endemic species of Ecuador used in traditional medicine both for wound healing and as an antiseptic. In this study, fresh Croton ferrugineus leaves were collected and subjected to hydrodistillation for extraction of the essential oil. The chemical composition of the essential oil was determined by gas chromatography equipped with a flame ionization detector and gas chromatography coupled to a mass spectrometer using a non-polar and a polar chromatographic column. The antibacterial activity was assayed against three Gram-positive bacteria, one Gram-negative bacterium and one dermatophyte fungus. The radical scavenging properties of the essential oil was evaluated by means of DPPH and ABTS assays. The chemical analysis allowed us to identify thirty-five compounds representing more than 99.95% of the total composition. Aliphatic sesquiterpene hydrocarbon trans-caryophyllene was the main constituent with 20.47 ± 1.25%. Other main compounds were myrcene (11.47 ± 1.56%), β-phellandrene (10.55 ± 0.02%), germacrene D (7.60 ± 0.60%), and α-humulene (5.49 ± 0.38%). The essential oil from Croton ferrugineus presented moderate activity against Candida albicans (ATCC 10231) with an MIC of 1000 μg/mL, a scavenging capacity SC₅₀ of 901 ± 20 µg/mL with the ABTS method, and very strong antiglucosidase activity with an IC₅₀ of 146 ± 20 µg/mL.     

Performance of Thyme Oil@Na-Montmorillonite and Thyme Oil@Organo-Modified Montmorillonite Nanostructures on the Development of Melt-Extruded Poly-L-lactic Acid Antioxidant Active Packaging Films

Today, the use of natural biodegradable materials in the production processes is more and more adopted by industry to achieve cyclic economy targets and to improve environmental and human health indexes. Active packaging is the latest trend for food preservation. In this work, nanostructures were prepared by incorporation of thyme oil with natural natrium-montmorillonite and organo-montmorillonite with two different techniques, direct impregnation and the green evaporation–adsorption process. Such nanostructures were mixed with poly-L-lactic-acid for the first time via an extrusion molding process to develop a new packaging film. Comparisons of morphological, mechanical, and other basic properties for food packaging were carried out via XRD, FTIR, TG, SEM/EDS, oxygen and water vapor permeation, and antimicrobial and antioxidant activity for the first time. Results showed that poly-L-lactic-acid could be modified with clays and essential oils to produce improved active packaging films. The final product exhibits food odor prevention characteristics and shelf-life extension capabilities, and it could be used for active packaging. The films based on OrgMt clay seems to be more promising, while the thyme oil addition improves their behavior as active packaging. The PLLA/3%TO@OrgMt and PLLA/5%TO@OrgMt films were qualified between the tested samples as the most promising materials for this purpose.     

Effects of NAC and Gallic Acid on the Proliferation Inhibition and Induced Death of Lung Cancer Cells with Different Antioxidant Capacities

N-acetylcysteine (NAC) is a recognized antioxidant in culture studies and treatments for oxidative stress-related diseases, but in some cases, NAC is a pro-oxidant. To study the effect of NAC on cell proliferation in the presence or absence of ROS stress, we used the stable ROS generator gallic acid (GA) to treat CL1-0 lung cancer cell models with different antioxidant activities. Different antioxidant activities were achieved through the ectopic expression of different PERP-428 single nucleotide polymorphisms. GA increased ROS levels in CL1-0/PERP-428C cells and caused cell death but had no effect on CL1-0/PERP-428G cells within 24 h. We found that 0.1 mM NAC eliminated GA-induced growth inhibition, but 0.5 mM NAC enhanced GA-induced CL1-0/PERP-428C cell death. However, in the absence of GA, NAC exceeding 2 mM inhibited the growth of CL1-0/PERP-428G cells more significantly than that of CL1-0/PERP-428C cells. Without GA, NAC has an antioxidant effect. Under GA-induced ROS stress, NAC may have pro-oxidant effects. Each cell type has a unique range of ROS levels for survival. The levels of ROS in the cell determines the sensitivity of the cell to an antioxidant or pro-oxidant. Cells with different antioxidant capacities were used to show that the intracellular ROS level affects NAC function and provides valuable information for the adjuvant clinical application of NAC.