Carotene Bleaching Test Research Articles

Evaluation of the Antioxidant and Anti-inflammatory Activity of the Anacyclus Valentinus L. Essential Oil and its Oxygenated Fraction.

Synthetic antioxidants and anti-inflammatories are widely used by the food and pharmaceutical industries. Like any synthetic product, these are toxic and represent a significant health risk. The objective of this study was to determine the chemical composition of Anacyclus valentinus essential oil and its oxygenated fraction, as well as their in-vitro antioxidant and anti-inflammatory properties. The essential oil was hydrodistilled using a Clevenger-type device and the oxygenated fraction was obtained by column chromatography using diethyl ether. The essential oil and its oxygenated fraction were analysed by GC and GC/MS. The antioxidant activities were performed using three different methods Radical scavenging activity (DPPH), β-carotene bleaching test, and the Ferric-Reducing Antioxidant Power (FRAP), using BHT as a positive control. The activity of antiinflammatory of essential oil and its oxygenated fraction was assessed by the protein denaturation method using the diclofenac sodium as a positive control. The essential oil of Anacyclus valentinus was represented mainly by oxygenated sesquiterpene compounds (37.7%), hydrocarbon sesquiterpenes (14.7%), oxygenated monoterpenes (18.4%) and non-terpenic compounds (15.6%). The oxygenated fraction was composed mainly of oxygenated sesquiterpenes (40.6%), oxygenated monoterpenes (38.5%), and non-terpene compounds (19.4%). Essential oil and oxygenated fraction showed antioxidant activity. The most potent activity was observed by the oxygenated fraction in the DPPH (IC50 = 8.2 mL/L) and β - carotene bleaching (IC50 = 5.6 mL/L) tests. While the essential oil of A. valentinus showed very good anti-inflammatory activity with an IC50 of 0.3 g/L higher than that of diclofenac (IC50= 0.53 g/L). The results showed that the essential oil and the oxygenated fraction of A. valentinus are rich in sesquiterpene compounds and possess interesting antioxidant and anti-inflammatory properties. However, other studies are necessary to be able to offer these extracts to the pharmaceutical and food industries.

Green synthesis of silver nanoparticles using Helianthemum lippii extracts (Hl-NPs): Characterization, antioxidant and antibacterial activities, and study of interaction with DNA

This study's objective was to formulate silver nanoparticles by reducing the extraction of Helianthemum lippii. We looked into how AgNPs attach to deoxyribonucleic acid using cyclic voltammetry and spectroscopy (UV-Vis) techniques. The DPPH, Reduction Power (RP), and -Carotene Bleaching (BCB) tests have also been used to assess antioxidant activity. The effectiveness of AgNPs against six bacterial strains was also tested. Biosynthesized AgNPs were characterized using UV-Visible and FTIR Spectroscopy, powder-XRD, and EDX technics. The UV-vis spectra at 428 nm validated the outcomes of the synthesized AgNPs. The results of SEM, EDX and powder-XRD, examination showed that AgNPs were the crystallite cubic, high purity with size ranged from 4.81 to 12.84 nm. Additionally, the produced AgNPs' FTIR spectra revealed the presence of phytoconstituents that served as capping agents. Also, the experimental findings showed that AgNPs had a strong propensity for binding to DNA through electrostatic interactions, which is supported by binding energy values. Additionally, it was demonstrated that biosynthesized AgNPs had high antioxidant activity (IC50 values for the DPPH, RP, and BCB assays were 3.16 ± 0.02µg/mL,1.73 ± 0.01µg/mL, and 1.99 ± 0.04, respectively). Additionally, results indicated an efficient antibacterial action of AgNPs with the MIC range from 0.04 to 0.18 mg/mL against six bacterial strains. To conclude, the current study opens avenues that make them candidates for therapy against many cancer disorders. Additionally, they may be used as treatment for other illnesses brought on by oxidative stress and bacteria.

Cytotoxic, antioxidant and antimicrobial activities of Nerium oleander collected in Morocco

Objective: To investigate the cytotoxic, antioxidant and antibacterial activities of ethanolic and aqueous crude extracts of Nerium oleander (N. oleander) leaves. Methods: Cytotoxic activities were evaluated by WST-1 bioassay on two human cancer cell lines, namely human colon adenocarcinoma cell line HT-29 and human breast cancer cell line MDA-MB-231. The antioxidant property of N. oleander extracts was assessed by DPPH scavenging and β -carotene bleaching tests. The agar disc diffusion method was used for the determination of antimicrobial activity against different strains. Results: Using cell viability indices, the WST-1 test revealed that both extracts reduced cell viability in both cell lines. Our results also showed that aqueous extract was more active than ethanolic extract, with IC50 values of (1.67±0.22) μg/mL and (2.36±0.44) μg/mL on MDA-MB-231 cells, and (2.89±0.35) μg/mL and (5.09±0.52) μg/mL on HT29 cells, respectively. The study of the antioxidant activity showed that N. oleander extracts had a considerable scavenging capacity and exerted a significant preventive effect against the oxidation of β -carotene by the peroxide radicals. However, the antibacterial test showed that both ethanolic and aqueous extracts of N. oleander had a moderate antibacterial effect limited only to Gram-positive bacteria. Conclusions: Our results shows that N. oleander aqueous and ethanolic extracts have significant cytotoxic activities against tumor cell lines and possesses a strong antioxidant capacity, suggesting the presence of active compounds in N. oleander leaves that could be a potential source of phytochemicals with high medicinal value to be used in cancer treatment and prevention.

Phenolic profile and antioxidant properties of dried buckwheat leaf and flower extracts

Due to a high content of rutin (2-10%), dried buckwheat leaf and flower (DBLF) formulations were shown to be efficient in the treatment of vascular diseases. In order to find a cost effective way for the extraction of antioxidants, the effects of ethanol/water ratio and temperature on the extraction efficiency of phenolic compounds and the mechanisms of antioxidant action of the extracts were tested. Extraction with ethanol/water mixture (80:20, v/v) for 24 h at room temperature, after the mixture was just brought to boil was demonstrated to be an efficient and cheap way for obtaining a high yield of rutin (49.94?0.623 mg/g DBLF). The most abundant phenolic compounds in DBLF extracts were rutin and chlorogenic acid. Flavonoids, especially rutin, were shown to be the most responsible for the antioxidant activity in all investigated lipid model systems, acting as free radical scavengers, electron-donating substances and chelators of iron ions. In ?-carotene bleaching tests, the extracts with the highest activity were as efficient as BHT (butylated hydroxytoluole). Regarding the results of antihemolytic and Schaal oven tests, the extracts demonstrated remarkable ability to inhibit the oxidative destruction of erythrocytes and to prolong the beginning of the oxidation process in sunflower oil.

Biological and chemo-diverse characterization of Amazonian (Ecuador) Citrus petitgrains

S ix Ama z onian petitgrains samples from C. nobilis Lour. , C. aurantium L. , C. limon L. and mixture of Citrus spp. (Rutaceae), named CN, CA, CL1, CL2, C1 and C2, were chemically characterized by GC-MS and 13 C NMR and evaluated for antioxidant acitivity ( DPPH and b -carotene bleaching tests), for antimicrobial properties ( disk diffusion method) and for antifungal capacity ( agar vapour assay) . CN, C1, C2 samples evidenced the most interesting results: CN ( g -terpinene/linalool chemotype: 14.3%/41.6%, with a considerable amount of thymol: 9.0% ), and C1 (linalool, 18.3%; sabinene, 11.6%; thymol, 5.5%), showed relevant antioxidant activity with both DPPH (IC 50 =3.52 and 5.48 mg/ml, respectively) and b -carotene ( IC 50 =0.387and 0.491 mg/ml, respectively). A ntibacterial properties of CN and C1 against P. mirabilis (MIC=0.61 mg/ml for both) and B. subtilis (MIC=0.61 and 0.44 mg/ml, respectively) were most probably due to thymol . C2 (geranial: 34.7%, neral: 33.1%) evidenced a valuable bioactivity against Candida albicans (MIC=0.44 mg/ml). The 50% growth inhibition (IC 50 ) of the dermatophytes T. mentagrophytes and N. cajetani was reached with amounts of C1, C2 and CN less than 4 m l/plate . Bioactivity of Amazonian Citrus spp. CN, C1 and C2 essential oils suggests their potential use as food preservatives or additives in cosmeceuticals as preventive against dermatophytic fungal infections .

In Vitro Antioxidant Activity of Extracts and Coumarins from the Stem Bark of Mammea africana Sabine

The present study aimed at evaluating the in vitro antioxidant activity (AOA) of the aqueous and methylene chloride/methanol (CH2Cl2-MeOH) extracts of Mammea africana and isolating the active principle(s). The AOA of the aqueous and CH2Cl2-MeOH extracts (3-1000 µg/ml) as well as compounds isolated (1-300 µg/ml) through bio-guided fractionation of the CH2Cl2-MeOH extract was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH), nitric oxide (NO) production and beta carotene bleaching tests. The aqueous and CH2Cl2-MeOH extracts exhibited a concentration dependent antiradical activity on DPPH with respective EC50 of 2.00 and 5.24 µg/ml. The purification of the CH2Cl2-MeOH extract yielded two coumarins: 4-phenylcoumarins (1) and 4-n-propylcoumarins (2) that exhibited potent radical scavenging activity with EC50 of 7.61 and 22.92 µg/ml, respectively. Plant extracts, fractions and compounds tested substantially increase NO production at high concentrations and exerted a protective effect against the oxidation of beta carotene at all the concentrations used; with a 400% inhibition obtained with the CH2Cl2 fraction at the concentration of 300µg/ml. The above results demonstrate that aqueous and CH2Cl2-MeOH M. africana possess potent AOA and could improve cardiovascular diseases where an increase in NO bioavailability is required. Compounds 1 and 2 are at least partially responsible for these activities.

Free radical scavenging activity of Pterogyne nitens Tul . (Fabaceae)

As part of our ongoing research on antioxidant agents from Brazilian flora, twenty extracts and fractions obtained from Pterogyne nitens Tulasne (Fabaceae) were screened for free radical scavenging activity by using ABTS [2,2’-azinobis(3-ethylenebenzothiazoline-6-sulfonic acid)] and DPPH (2,2-diphenyl-1-picrylhydrazyl-hydrate) radicals colorimetric assay and
-carotene bleaching test. The strongest activity was found in ethyl acetate fraction from the stem barks, exhibiting IC50 values (in ig/ml) of 2.10 ± 0.1 and 10.2 ± 0.3 on ABTS•+ and DPPH•, respectively. Additionally, chromatographic fractionation of stem barks yielding myricetin, quercitrin and mirycetrin, three flavonols with remarkable antioxidant activity.

Evaluation of the antioxidant activity of the essential oil of Zataria multiflora in rat

Zataria multiflora Boiss. is an endemic plant to Iran which has been used traditionally in food, especially in yoghurt as a flavouring agent, stimulant, condiment, carminative and for treatment of pre-mature labor pains and rupture. The extracts of aerial parts of Z. multiflora showed anti-inflammatory effects against acute and chronic inflammations in mice and rats .Our in vitro studies have confirmed the antioxidant activity of the essential oil. In the present work, we wish to report the In vivo antioxidant potential of the essential oil of the plant in rat. Antioxidant activity was measured by inhibition of 1,1 diphenyl-2-picrylhydrazyl(DPPH) radical and beta carotene bleaching test in serum of treated rats. Rats received the essential oil of Z. multiflora at doses of 100, 150 and 200 µl/kg daily by intragastric intubation for 10 consecutive days. The obtained results showed significant antioxidant activity in the DPPH test at all studied doses in comparing to control. This activity was in all doses compareable to that of BHT. No mortality was reported in the tested doses. The results here confirm in vivo antioxidant activity of the essential oil of Z. multiflora. Further studies in details are needed to find if this plant has any toxicity in comparing to BHT on vital organs like liver or kidney.

Antioxidant and antimicrobial activities of extract and essential oil of korarima (Aframomum corrorima (Braun) P.C.M. Jansen)

The antioxidant potential of extracts and essential oils of korarima (Aframomum corrorima (Braun) P.C.M. Jansen) were investigated, as well as total phenolics, total ascorbic acid (TAA), condensed tannins (CT) and antifungal potential. Antioxidant capacities of seeds and pods as assayed in methanol extracts, and of essential oils were at moderate levels.The antioxidant activity of seeds (29.59 imol/g dry weight (DW)) was significantly higher than that of pods (14.23 imol/g DW) by FRAP (Ferric Reducing Ability of Plasma) assay. Also the antiradical power of seeds (9.26 imol/g DW) was higher than of pods (3.08 imol/g DW) in the DPPH (1,1-diphenyl-2-picrylhydrazyl) test. Similarly, the antioxidant activity of seeds was higher than of pods in the
-carotene bleaching test. A lower 50% effective concentration (EC50) was achieved with seeds (42.10 mg/mL) as compared to pods (120.50 mg/mL), while EC50 of pod oils (11.9 mg/mL) was lower than seed oils (59.2 mg/mL). The total phenolic content in seeds (3.98 mg/g DW) was significantly higher than in pods (1.32 mg/g DW), while TAA content was significantly lower in seeds (3.49 mg/100 g DW) than in pods (6.25 mg/100 g DW). Differences in CT were non-significant. Antifungal tests exhibited that the extracts from seed were more effective than the control. Based on the present study the consumption of korarima as a spice may be used as source of antioxidants.

Antibacterial and antioxidant activities of Origanum compactum essential oil

In the present study, essential oil of Origanum compactum was analysed and its chemical composition was identified by gas chromatography coupled to mass spectrometry (GC-MS). Among thirty two assayed constituents, carvacrol (30.53%), thymol (27.50%) and its precursor g-terpinene (18.20%) were found to be the major components. The oil was investigated for its in vitro antibacterial activity against a panel of standard reference strains using well diffusion and broth dilution methods. In solid medium, the oil was found to be remarkably active against all tested strains except Pseudomonas which showed resistance. In liquid medium the Minimum Inhibitory Concentrations (MICs) and Minimum Bactericidal Concentration (MBCs) ranged from 0.0078 to 0.25% (v/v). The antioxidant activity was investigated by three different methods; 1,1-diphenyl-2-picryl-hydrasyl (DPPH) radical scavenging assay,
-carotene bleaching test and reducing power. The results of this study revealed evidence that the essential oil of O. compactum possesses a good antioxidant effect with all assays; the antioxidant activity is dependent on the oil concentration and can be attributed to the phenolic compounds present in the oil.

Volatile components, antioxidant and antibacterial activities of Dacryodes buettneri H. J. Lam. essential oil from Gabon

The water-distilled oil obtained from resin of Dacryodes buettneri H.J.Lam, Burseraceae from Gabon was examined by GC and GC/MS. The analysis led to the identification of 28 components. The essential oil is characterized by a high proportion of terpinen-4-ol (27.33%) along with p-cymene (19%), �-pinene (13.23%), sabinene (4.40%) and isoascaridol (4%). The in vitro antioxidant activity was investigated with two methods: 2,2-diphenylpicrylhydrasyl radical (DPPH) scavenging assay and �-carotene bleaching test. Butylated hydroxytoluene (BHT) was employed as positive control. The essential oil showed antioxidant and DPPH radical scavenging activities, and it displayed the inhibition of lipid peroxidation. The essential oil was tested against twelve strains of bacteria using a broth microdilution method. D. buettneri essential oil exhibited antibacterial activity against almost microorganisms tested; however it was unable to inhibit growth of Streptococcus pyogenes.

English

The antioxidant activity of the essential oil was investigated using 2,2-diphenylpicrylhydrazyl (DPPH) radical scavenging assay and the β-carotene bleaching test. Butylated hydroxytoluene (BHT) was employed as a positive control. The essential oil showed antioxidant and DPPH radical scavenging activities, and it displayed the inhibition of lipid peroxidation. The antibacterial and antifungal activities of the essential oil of Canarium schweinfurthii from Centrafrican Republic were also evaluated against twelve strains of bacteria and three strains of fungi using agar diffusion and broth microdilution methods. The essential oil showed antimicrobial activity against almost the strains studied. The results suggest that C. schweinfurthii essential oil could be a natural antimicrobial and antioxidant agent.   Key words: Canarium schweinfurthii, Burceraceae, essential oil, antimicrobial, antioxidant.

Simple and rapid carotene bleaching tests for the detection of lipoxygenase isozymes in soybean seeds.

New techniques using the carotene bleaching activity of. Iipoxygenase were developed for the detection of soybean seed lipoxygenases, L-1, L-2, and L-3 isozymes, respectively. The carotene bleaching tests for the three isozymes were performed as follows : (Test I for L-3) the seed extract was incubated with linoleic acid and carotene at pH 6.8. When the seed extract contained L-3, carotene was bleached in a few minutes at 20°C. In the absence of L-3 carotene bleaching was not observed ; (Test II far L-2) the seed extract was incubated with arachidonic acid and carotene at pH 6.8. After incubation for 3 minutes at 20°C, methanol was added into the mixture to stop the bleaching reaction. Since L-2 is much more active than L-1 and L-3 towards arachidonic acid at pH 6. 8, the lack of L-2 significantly decreased the level of the carotene bleaching activity. The presence or absence of L-2 in the F2 seeds from Suzuyutaka (Lx2/Lx2) x P186023 (lx2/lx2) soybeans was accurately determined by the application of Test II ; (Test III for L-1) the seed extract was preincubated with linoleic acid and carotene at pH 9. 0. After preincubation for 60 seconds at 20°C, the mixture. was adjusted to pH 6.8. When the seed extract did not contain L-1, carotene bleaching was observed within thirty minutes at 20°C. The levels of the carotene bleaching activity in the three tests were determined visually or by measurements in a spectrophotometer at 452 nm within 60 minutes. Since the L-3 isozyme is indispensable for the carotene bleaching activity, seed extracts from soybeans la.cking L-3 do not cooxidize carotene. Therefore, in order to determine the presence or absence of L-2 or L-1 in the seeds lacking L-3, seed extracts from the soybeans lacking L-2 and L-1 in addition to the seed extracts to be examined were added to 60mpensate the lack of L-3 isozyme into the reaction mixture, respectively. The other procedures were the same as those applied in Tests II and III, respectively. These tests which are simple, rapid, and accurate, require only a few mg of seed sample.

Enzymic oxidation of carotene and linoleate by alfalfa: Properties of active fractions

An aqueous Triton X-100 extract, prepared from alfalfa leaves, was fractionated on carboxymethylcellulose into four fractions designated A–D. Fractions B and C, which contained the bulk of the carotene-bleaching and linoleate-oxidizing activity, resembled soyben lipoxygenase in several respects. The most striking among these were the high specific activities with regard to the formation of conjugated dienes and oxygen absorption by linoleate; the inability to oxidize oleate; and the insensitivity to cyanide. Fraction C, like lipoxygenase, exhibited the absorption spectrum of a pure protein devoid of a prosthetic chromophore, whereas the spectrum of fraction B hinted at some contamination with a heme protein. Fraction A resembled peroxidase in its high specific peroxidase and indoleacetic acid oxidase activities, coupled with weak linoleate oxidizing and carotene-bleaching activities. Like peroxidase, fraction A was able to effect some bleaching of carotene in the presence of oleate and also in the absence of polyunsaturated fatty acids, with a characteristic rapid decline in activity. Additional points of resemblance of fraction A with peroxidase were its sensitivity to cyanide and ascorbic acid and its pH optimum in the carotene-bleaching test. Finally, fraction A could be separated on carboxymethylcellulose into two subfractions, which exhibited heme protein absorption spectra with typical redox shifts. Fraction D was only weakly active. It exhibited some of the properties of heme proteins, but no clear picture as to its nature could be obtained by the tests used.