A comparative evaluation of mutagenic,antimutagenic, radical scavenging and antibacterial activities of essential oils of Pituranthos chloranthus (Coss. et Dur.)

The Salmonella typhimurium/microsome assay is a widely used bacterial genotoxicity assay to test potential carcinogens. The aim of this work was to evaluate the mutagenic and antimutagenic activities with and without the addition of an extrinsic metabolic activation system of essential oils obtained from an aerial part of Pituranthos chloranthus harvested from different stations in Tunisia. The oils showed no mutagenicity when tested with S. typhimurium strains TA98, TA100, and TA1535. On the other hand, we showed that these essential oils reduced significantly Benzo [a] pyrene (B[a] P) and sodium-azide–induced mutagenicity. The scavenging capacity of these essential oils was also estimated by evaluating the inhibition of DPPH radical. Essential oils harvested at Medenine and Gabes in November were more effective in scavenging activity. The essential oils were tested for their antimicrobial properties against five different bacteria, and were found to be weakly active, with MIC and MBC values in the range 0.6–4 and 2.2–5?mg/mL, respectively.     

Biological activities of commercial bee pollens: Antimicrobial,antimutagenic, antioxidant and anti-inflammatory

Bee pollen is considered, since memorable times, a good source of nourishing substances and energy. The present study aimed to evaluate the biological activities of eight commercial bee pollens purchased from the market. The origin of sample A was not specified in the labeling; samples B, C, D and G were from Portugal and the remaining were from Spain. The sample E presented the highest value of phenolics (32.15 ± 2.12 mg/g) and the H the lowest (18.55 ± 095 mg/g). Sample C had the highest value of flavonoids (10.14 ± 1.57 mg/g) and sample H the lowest (3.92 ± 0.68 mg/g). All the samples exhibited antimicrobial activity, being Staphylococcus aureus the most sensitive and Candida glabrata the most resistant of the microorganisms studied. All the samples exhibited antimutagenic activity, even though some samples were more effective in decreasing the number of gene conversion colonies and mutant colonies. Regarding the antioxidant activity, assessed using two methods, the more effective was sample B. The anti-inflammatory activity, assessed using the hyaluronidase enzyme, was highest in samples B and D. Pearson’s correlation coefficients between polyphenols, flavonoids, antioxidant activity and antimicrobial activity were computed. It was also performed a discriminant analysis.     

Maculosin,a non-toxic antioxidant compound isolated from Streptomyces sp. KTM18

ContextStreptomyces species are prolific sources of bioactive secondary metabolites known especially for their antimicrobial and anticancer activities.ObjectiveThis study sought to isolate and characterize antioxidant molecules biosynthesized by Streptomyces sp. KTM18. The antioxidant potential of an isolated compound and its toxicity were accessed.Materials and methodsThe compound was purified using bioassay-guided chromatography techniques. Nuclear magnetic resonance (NMR) experiments were carried out for structure elucidation. The antioxidant potential of the isolated compound was determined using DPPH free radical scavenging assay. The toxicity of the isolated compound was measured using a brine shrimp lethality (BSL) assay.ResultsEthyl acetate extract of Streptomyces sp. KTM18 showed more than 90% inhibition of DPPH free radical at 50 µg/mL of the test concentration. These data were the strongest among 13 Streptomyces isolates (KTM12–KTM24). The active molecule was isolated and characterized as maculosin (molecular formula, C₁₄H₁₆N₂O₃ as determined by the [M + H]⁺ peak at 261.1259). The DPPH free radical scavenging activity of pure maculosin was higher (IC₅₀, 2.16 ± 0.05 µg/mL) than that of commercial butylated hydroxyanisole (BHA) (IC₅₀, 4.8 ± 0.05 µg/mL). No toxicity was observed for maculosin (LD₅₀, <128 µg/mL) in brine shrimp lethality assay (BSLA) up to the compound’s antioxidant activity (IC₅₀) concentration range. The commercial standard, berberine chloride, showed toxicity in BSLA with an LD₅₀ value of 8.63 ± 0.15 µg/mL.ConclusionsMaculosin may be a leading drug candidate in various cosmetic and therapeutic applications owing to its strong antioxidant and non-toxic properties.     

天然产物抗氧化活性成分研究进展

天然产物抗氧化剂在自然界有广泛的分布,研究表明多糖、黄酮、多酚、生物碱、皂苷、维生素等天然产物均能有效清除自由基以保护机体健康。随着人们回归自然思潮的兴起及安全意识的提高,天然抗氧化剂因其高效、低毒更是倍受关注。从天然产物中寻找新的清除体内自由基的抗氧化剂已成为现代医药、保健行业发展的必然趋势。综述了天然产物抗氧化活性成分的研究进展,以期为天然产物抗氧化活性的研究和发展提供参考。     

Genotoxic and antimutagenic activities of extracts from pseudocereals in the Salmonella mutagenicity assay

Extracts of amaranth (Amaranthus L.), sorghum (Sorghumbicolor L.) and Japanese millet (Echinochloafrumentacea L.) were evaluated for mutagenicity in Salmonellatyphimurium strains TA98, TA100 and TA102. All three pseudocereal extracts were also assessed for their antimutagenic properties against the direct mutagens 2-nitrofluorene (2NF) for strain TA98, 3-(5-nitro-2-furyl)acrylic acid (5NFAA) for TA100 and H₂O₂ for TA102 strain and against the indirect mutagen aflatoxin B₁ (AFB₁). No mutagenicity was induced by any of the pseudocereal extracts when tested at concentrations as high as 50 mg/ml. All three extracts showed similar antimutagenicity against 5NFAA and no antimutagenicity against 2NF. The number of revertants induced by H₂O₂ extract was inhibited in order amaranth > Japanese milet > sorghum. All extracts were effective in the inhibition of mutagenic activity of aflatoxin B₁. The total polyphenol content as well as the amount of the flavonoids and phenolic acids as main component of polyphenolics were also determined.     

槲皮素抗氧化作用研究进展

槲皮素的多种药理活性与其抗氧化作用有关,现对近年来槲皮素抗氧化作用的研究进展作一综述。     

Phytochemical characterization and antioxidant,antibacterial and antimutagenic activities of aqueous extract from leaves of Alchornea glandulosa

Plant extracts exist as a complex matrix which serves as a source of numerous bioactive metabolites. The ultra performance liquid chromatography with diode-array detection-coupled electrospray ionization-mass spectrometry/mass spectrometry technique was used to characterize the aqueous extract from leaves of Alchornea glandulosa (EAG), a species popularly used to treat gastrointestinal problems as an antiulcer agent. Quantification of phenolic derivatives was determined using Folin–Ciocalteu and aluminum trichloride (AlCl₃) methods. In addition, antioxidant (2,2-diphenyl-1-picrylhydrazyl [DPPH^?] radical scavenging, β-carotene–linoleic acid, and lipid peroxidation), antibacterial (agar well diffusion method and minimum inhibitory concentration), antimutagenic (Ames test), and antigenotoxic (plasmid cleavage) assays were also performed on this plant extract. The ellagitannin tris-galloyl-hexahydroxydiphenic acid-glucose was identified as the predominant compound along with tannins as majority metabolites. EAG showed high antioxidant activity accompanied by moderate antibacterial activity against Staphylococcus aureus. The highest antimutagenic activity was observed for TA97 strain without metabolic activation (S9) and with metabolic activation, TA100 and TA102 were completely inhibited. In addition, EAG exhibited potential signs of antigenotoxic action. The high antioxidant and antimutagenic activity observed for EAG suggests important therapeutic uses that still need to be verified in future studies.     

Effect of ultrasonic degradation of hyaluronic acid extracted from rooster comb on antioxidant and antiglycation activities

Content: Recently, low-molecular-weight hyaluronic acid (LMWHA) has been reported to have novel features, such as free radical scavenging activities, antioxidant activities and dietary supplements.

Objective: In this study, hyaluronic acid (HA) was extracted from rooster comb and LMWHA was obtained by ultrasonic degradation in order to assess their antioxidant and antiglycation activities.

Materials and methods: Molecular weight (Mw) and the content of glucuronic acid (GlcA) were used as the index for comparison of the effect of ultrasonic treatment. The effects on the structure were determined by ultraviolet (UV) spectra and Fourier transform infrared spectra (FTIR). The antioxidant activity was determined by three analytical assays (DPPH, NO and TBARS), and the inhibitory effect against glycated-BSA was also assessed.

Results: The GlcA content of HA and LMWHA was estimated at about 48.6% and 47.3%, respectively. The results demonstrate that ultrasonic irradiation decreases the Mw (1090–181?kDa) and intrinsic viscosity (1550–473?mL/g), which indicate the cleavage of the glycosidic bonds. The FTIR and UV spectra did not significantly change before and after degradation. The IC₅₀ value of HA and LWMHA was 1.43, 0.76 and 0.36?mg/mL and 1.20, 0.89 and 0.17?mg/mL toward DPPH, NO and TBARS, respectively. Likewise LMWHA exhibited significant inhibitory effects on the AGEs formation than HA.

Discussion and conclusion: The results demonstrated that the ultrasonic irradiation did not damage and change the chemical structure of HA after degradation; furthermore, decreasing Mw and viscosity of LMWHA after degradation may enhance the antioxidant and antiglycation activity.     

Evaluation of the irritating influence of carane derivatives and their antioxidant properties in a deoxyribose degradation test

Previous studies of the propranolol monoterpene derivative (-)-4-[2-hydroxy-3-(N-isopropylamino)-propoxyimino]-cis-carane hydrochloride (KP-23) and its diastereoisomers, KP-23R and KP-23S, demonstrated different effects on the cyclic AMP generating system as well as anti-inflammatory, analgesic, antihistaminic and antioxidant activity. The present study examined the influence of KP-23 and its diastereoisomers KP-23R and KP-23S on the skin-irritating activity and the mucous membrane-irritating activity as well as their influence on a late-type contact allergy in the in vivo tests. The hydroxyl radical scavenging potential of the three analogues was evaluated using their ability to inhibit Fe(II)/H2O2-induced oxidative degradation of 2-deoxyribose (2-DR) in the in vitro tests. The results obtained indicated that the hydroxyamine carane derivative did not evoke irritative changes and did not induce a late-type contact allergy in the guinea-pig. Diastereoisomers of KP-23 exhibit antioxidant properties in a dose-dependent manner and protected against OH-radicals generated from the Fenton reaction.     

Antioxidant,mutagenic and antimutagenic activities of an aqueous extract of Limoniastrum guyonianum gall

Abstract

An aqueous extract of Limoniastrum guyonianum gall (G extract) was tested on Salmonella typhimurium to assess its mutagenic and antimutagenic effects. This extract showed no mutagenicity when tested with S. typhimurium strain TA104 either with or without exogenous metabolic activation mixture (S9), whereas our findings revealed that the aqueous gall extract induced a mutagenic effect in S. typhimurium TA1538 when tested in the presence, as well as in the absence, of S9 activation mixture at the concentration of 500?µg/mL. Thus, the same concentration produced a mutagenic effect, when incubated with S. typhimurium TA100 in the presence of metabolic activation mixture. In contrast, our results showed a weak antimutagenic potential of the same extract against sodium azide in the presence of S. typhimurium TA100 and S. typhimurium TA1538 without metabolic activation (S9), whereas, in the presence of S. typhimurium TA104, we obtained a significant inhibition percentage (76.39%) toward 3.25?µg/plate of methylmethanesulfonate. Antimutagenicity against aflatoxin B1, 4-nitro-o-phenylene-diamine and 2-aminoanthracène was significant, with an inhibition percentage of, respectively, 70.63, 99.3 and 63.37% in the presence of, respectively, S. typhimurium TA100, S. typhimurium TA1538 and S. typhimurium TA104 strains at a concentration of 250?µg/plate after metabolic activation (S9). Antioxidant capacity of the tested extract was evaluated using the enzymatic (xanthine/xanthine oxidase assay) and the nonenzymatic (2,2-diphenyl-1-picrylhydrazyl) system. G extract exhibited high antioxidant activity.     

Extraction of brown pigment from Rosa laevigata and its antioxidant activities

Context: Rosa laevigata Michx. (Rosaceae), widespread in China, contains many valuable nutrients and has long been used as food and medicine in Chinese folklore. Nowadays, due to its favorable property of coloring, the brown pigment of R. laevigata has an attractive potential as an available additive in food.

Objective: The aims of this study were to optimize the extraction process of brown pigment from R. laevigata and investigate its antioxidant activities on the basis of its abilities to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, hydroxyl radical and superoxide radical.

Materials and methods: Extraction conditions of brown pigment from R. laevigata were investigated through an orthogonal design of L₉ (3)⁴ assay. Ethanol concentration, extraction temperature, time, and ratio of material to solvent were the main factors affecting the extraction rate. Subsequently, the antioxidant activity of brown pigment was assessed using DPPH method, while hydroxyl radicals and superoxide free radicals were respectively determined by the Fenton-RhB (Rhodamine B) system and using the pyrogallol-luminol system.

Results: The optimum extraction conditions were determined: temperature 70°C, ethanol concentration was 60%, extraction time 2?h and ratio of material to solvent was 1:6. Brown pigment showed a good radical scavenging activity, and exhibited a concentration-dependent inhibition of hydroxyl radical and superoxide free radical at low concentrations. When the concentration of brown pigment was 1?mg/mL, the scavenging percentage of hydroxyl radical reached 67.33%.

Discussion and conclusion: The brown pigment of R. laevigata could potentially be used as a promising natural antioxidant in the food and pharmaceutical industries.     

飞龙掌血提取物体外抗氧化活性研究

目的研究飞龙掌血体外不同极性部位的抗氧化作用。方法采用Fenton法、DPPH自由基法、硫代巴比妥酸(TBA)法,测定飞龙掌血总提取物(TEF)、石油醚萃取相(PEF)、乙酸乙酯萃取相(EAF)、正丁醇萃取相(NBF)和剩余水相(WF)的抗氧化活性。结果 TEP、PEF、EAF、NBF和WF对羟基自由基、DPPH自由基均有较好的清除作用,且对自由基的清除效率与提取物质量浓度有一定量效关系;适当质量浓度的TEP、PEF、EAF、NBF对脂质过氧化有较强的抑制作用,高浓度WF对脂质过氧化有诱导作用。结论飞龙掌血提取物具有体外抗氧化作用,可被开发成天然的抗氧化剂。     

Antioxidant and antimutagenic activity of N-(2-carboxyethyl)chitosan

The antioxidant and antimutagenic activities of the novel carboxyethyl derivatives of chitosan with three different degrees of substitution have been assayed in vitro in the unicellular flagellate Euglena gracilis subjected to the action of genotoxic agents acridine orange and ofloxacin. It has been demonstrated that chitosan derivatives exhibit concentration-dependent protective antigenotoxic activity against both mutagens. It is suggested that different mechanisms may be involved in its protective action--antioxidant activity in case of ofloxacin-induced DNA damage, as well as possible interaction with the cell membrane that prevents acridine orange from reaching the genetic compartments and subsequent damaging DNA through intercalative binding. Direct adsorption of acridine orange on chitosan derivatives was ruled out as a possible mechanism of protection on the basis of spectrophotometric measurements. Dependence of the antimutagenic properties of the studied chitosan derivatives on the degree of substitution was reversed in experiments involving acridine orange and ofloxacin, which also indicated different mechanisms of protection involved in these two cases.     

Antimutagenic and antioxidant activity of a protein fraction from aerial parts of Urtica dioica

Abstract

Context: Urtica dioica L. (Urticaceae), stinging nettle, has been employed as a folklore remedy for a wide spectrum of ailments, including urinary disorders, prostatic hyperplasia, and liver diseases. It has been also used traditionally for cancer treatment.

Object: To evaluate the potential chemopreventive properties of a protein fraction from the aerial part of Urtica dioica (namely UDHL₃₀).

Materials and methods: UDHL₃₀ has been tested for the antimutagenic activity in bacteria (50–800?μg/plate; Ames test by the preincubation method) and for the cytotoxicity on human hepatoma HepG2 cells (0.06–2?mg/mL; 24 and 48?h incubation). Moreover, the antioxidant activity of UDHL₃₀ (0.1–1200?μg/mL; ABTS and superoxide-radical scavenger assays) was evaluated as potential protective mechanisms.

Results: UDHL₃₀ was not cytotoxic on HepG2 cells up to 2?mg/mL; conversely, it exhibited a strong antimutagenic activity against the mutagen 2-aminoanthracene (2AA) in all strains tested (maximum inhibition of 56, 78, and 61% in TA98, TA100, and WP2uvrA strains, respectively, at 800?μg/plate). In addition, a remarkable scavenging activity against ABTS radical and superoxide anion (IC₅₀ values of 19.9?±?1.0?μg/mL and 75.3?±?0.9?μg/mL, respectively) was produced.

Discussion and conclusions: UDHL₃₀ possesses antimutagenic and radical scavenging properties. Being 2AA a pro-carcinogenic agent, we hypothesize that the antimutagenicity of UDHL₃₀ can be due to the inhibition of CYP450-isoenzymes, involved in the mutagen bioactivation. The radical scavenger ability could contribute to 2AA-antimutagenicity. These data encourage further studies in order to better define the potential usefulness of UDHL₃₀ in chemoprevention.     

Synthesis and mutagenic and antimutagenic activity of substituted 2,2-dimethyltetrahydropyranopyrazolines and pyrazoles

Translated from Khimiko-farmatsevticheskii Zhurnal, Vol. 24, No. 7, pp. 35–37, July, 1990.     

Preparation and effects of 2,3-dehydrosilymarin, a promising and potent antioxidant and free radical scavenger

Objectives Silymarin or silybin has been effectively used for treating liver diseases and acute liver injury partly due to its antioxidant activity. In this study, 2,3‐dehydrosilymarin, a compound exhibiting remarkable antiradical/antioxidant activity, was prepared from silymarin for the first time. The solubility, radical scavenging capacity and liver protecting activity of 2,3‐dehydrosilymarin were studied and compared with silybin, dehydrosilybin and silymarin. Methods The structures of its main components were verified by ultra‐performance liquid chromatography/mass spectrometry (UPLC‐MS) and other spectral analysis. In addition, a rapid screening method, online high‐performance liquid chromatography/1,1‐dipheny1‐2‐picrylhydrazyl (HPLC‐DPPH) system, was developed for identifying the individual antioxidants in 2,3‐dehydrosilymarin. Key findings Both in‐vitro and in‐vivo results markedly proved that dehydrosilymarin has decent aqueous solubility and remarkable antiradical/antioxidation capacity. Moreover, 2,3‐dehydrosilybin and 2,3‐dehydrosilychristin were identified to be the two major active compounds contained in 2,3‐dehydrosilymarin. Conclusions Our results suggest that 2,3‐dehydrosilymarin may be a promising and potent alternative for inhibition of free radical and prevention of oxidation.     

Mutagenic,antimutagenic and antioxidant potency of leaf extracts from Nitraria retusa

Four extracts were prepared from the leaves of Nitraria retusa; methanol, ethyl acetate, chloroform and hexane extracts. An assay for the ability of these extracts to prevent mutations induced by various oxidants in Salmonella typhimurium TA102 and TA 104 strains was conducted. These extracts from leaf parts of N. retusa showed no mutagenicity either with or without the metabolic enzyme preparation (microsome fraction). The highest protection against methylmethanesulfonate induced mutagenicity was observed with chloroform and methanol extracts with inhibition percentages of 44.93% (at 50 μg/plate in the presence of TA102 strain) and 38% (at 10 μg/plate in the presence of TA104 strain), respectively. Whereas Hexane and chloroform extracts reduced the mutagenicity induced by 2-aminoanthracene by 83.4% (using the S. typhimurium TA104 assay system) and 65.3% (using the S. typhimurium TA 102 assay system), respectively. Antioxidant activity of N. retusa extracts was determined by the ability of each extract to protect plasmid DNA against strand scission induced by hydroxyl radicals. Chloroform extract exhibited the highest ability to protect plasmid DNA against hydroxyl radical induced DNA damages and exhibited the highest antioxidant capacity, with 0.95 mM trolox equivalent when tested by the ferric reducing/antioxidant method.     

Evaluation of the antimutagenic,antigenotoxic, and antioxidant activities of Eriobotrya japonica leaves

Abstract

Context: The leaves of Eriobotrya japonica (Thunb.) Lindl. (Rosaceae) are used in traditional medicine to treat inflammatory diseases. However, information about the antigenotoxic and antioxidant properties of its leaves remains to be elucidated.

Objective: The objective of this work was to evaluate the mutagenic/antimutagenic, genotoxic/antigenotoxic, and antioxidant potentials of aqueous and total oligomers flavonoid (TOF) extracts from E. japonica.

Materials and methods: The mutagenic/antimutagenic and genotoxic/antigenotoxic potentials of extracts (50, 250, and 500?µg/plate) were evaluated, respectively, by the Ames test with 48?h incubation and the SOS chromotest test with 2?h incubation. The antioxidant capacity of these extracts (ranging from 50 to 700?µg/mL) was tested using xanthine/xanthine oxidase and the deoxyribose assays.

Results: Eriobotrya japonica extracts showed neither mutagenic nor genotoxic effect. The highest protective effect against methyl methanesulfonate and 2-aminoanthracene was obtained in the presence of aqueous extract, with IC₅₀ values of 80 and 140?µg/plate, respectively, against S. typhimurium TA104. Moreover, this extract (500?µg/plate) was also able to reduce significantly the genotoxicity induced by nitrofurantoin and aflatoxin B1 with IC₅₀ values of 140 and 240?µg/assay, respectively. Likewise, aqueous and TOF extracts inhibited xanthine oxidase and superoxide anion formation with IC₅₀ values ranging from 45 to 95 and from 70 to 90?µg/mL, respectively. However, TOF extract is more efficient in inhibiting hydroxyl radical and chelating iron ion with IC₅₀ values of 140 and 400?µg/mL, respectively, when compared with the aqueous extract.

Conclusion: Eriobotrya japonica prevents the genotoxicity of some carcinogenic substances probably thanks to its antioxidant capacities.     

中药抗氧化作用的研究进展

综述和展望近年来国内外对中药(包括单味药、复方或其他成分)抗氧化作用的研究状况。