Metabolite profile and in vitro activities of Phagnalon saxatile (L.) Cass. relevant to treatment of Alzheimer’s disease

The present study describes for the first time the in vitro properties (inhibition of NO production and anticholinesterase) of Phagnalon saxatile (L.) Cass. (Asteraceae). The methanolic extract showed antioxidant activity that was measured by DPPH assay and β-carotene bleaching test. The same extract inhibited NO production in the murine monocytic macrophage cell line RAW 264.7. Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibition was assessed by modifications of Ellman’s method. Purification of the MeOH extract of P. saxatile allowed the isolation of phenolic compounds. Among them, the compounds that most effectively inhibited lipopolysaccharide-induced NO production were caffeic acid and methylchlorogenic acid, with IC₅₀ values of 7?μg/mL and 12?μg/mL, respectively. Luteolin and 3,5-dicaffeoylquinic acid exhibited the most promising activity against AChE with an IC₅₀ of 25.2 and 54.5?μg/mL, respectively, while caffeic acid and luteolin exhibited higher activity against BChE with an IC₅₀ of 32.2 and 37.2?μg/mL, respectively.     

Chemical composition and protective effect of oregano (Origanum heracleoticum L.) ethanolic extract on oxidative damage and on inhibition of NO in LPS-stimulated RAW 264.7 macrophages

The present study shows the chemical profile and the in vitro properties (antioxidant and inhibition of nitric oxide production) of the Origanum heracleoticum L. (Lamiaceae). The ethanolic extract of the aerial parts is characterized by terpenes and fatty acids. The extract, with high total phenol and flavonoid content, showed a significant radical-scavenging activity (IC₅₀ value of 12.8 μg/mL) using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) test and an interesting antioxidant activity with the β-carotene bleaching test (IC₅₀ values of 12.9 and 14.1 μg/mL at 30 and 60?min of incubation, respectively). The test for the inhibition of NO production, performed using the murine monocytic macrophage RAW 264.7 cell line, showed that the extract had significant activity with an IC₅₀ value of 108.5 μg/mL. The cytotoxic effect of O. heracleoticum extract in presence of lipopolysaccharide (LPS) (1 μg/mL) was evaluated but found to be negligible.     

Screening of traditional Lebanese medicinal plants as antioxidants and inhibitors of key enzymes linked to type 2 diabetes

Abstract

This study aimed to investigate the inhibitory activity of key enzymes linked to type 2 diabetes (α-amylase and α-glucosidase) and the antioxidant properties of non polar (n-hexane) extracts from Coffea arabica, Citrus lanatus, Cucumis melo, Cuminum cyminum, Cocos nucifera, Coriandrum sativum, Foeniculum vulgare, Nigella sativa, Rhus coriaria, Pimpinella anisum, Syzygium aromaticum and Sesamum indicum collected in Lebanon. Extracts were analysed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The antioxidant activity was investigated by using different in vitro methods namely 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), Ferric Reducing Ability Power (FRAP) and β-carotene bleaching tests. C. melo showed the highest α-glucosidase inhibitory activity with an IC₅₀ value of 25.55?μg/ml, followed by C. lanatus white seeds and S. indicum (IC₅₀ of 34.41 and 38.78?μg/ml, respectively). S. indicum exhibited also the highest protection of lipid peroxidation with IC₅₀ values of 0.07 and 0.06?mg/ml after 30 and 60?min of incubation, respectively.     

Antioxidant,antimicrobial activities and comparative analysis of the composition of essential oils of leaf,stem, flower and aerial part of Nepeta hindostana

Nepeta hindostana (B.Heyne ex Roth) Haines is belonging to lamiaceae family and used as a component of herbal ayurvedic formulation Abana which is useful for the treatment of Hyperlipidemia, Dyslipidemia and Hypercholesterolemia. In the present study, the essential oil from aerial parts (flower, leaves, stem and whole aerial) was collected and the major constituents of essential oils were characterized by GC-FID and GC/MS and further evaluated for their antioxidant and antimicrobial efficacy. The major components of the essential oil were sesquiterpene hydrocarbons (77.2, 80.5, 62.5, 77.8%), oxygenated sesquiterpenes (10.5, 9.2, 20.6, 9.2%) and oxygenated monoterpenes (5.3, 4.2, 2.5, 3.6%) in leaves, stem, flowers and aerial part, respectively. The major compounds in essential oils were identified as β-sesquiphellandrene, cadina-1,4-diene, α-cadinene, (E)-caryophyllene, α-humulene and β-bisabolene. At 100 μg/mL concentration, leaves essential oil showed strong 2,2-diphenyl-1-picryl-hydrazyl-hydrate free radical scavenging activity with the IC₅₀ 2.8 μg/mL and 34.0% by β-carotene bleaching assay. Furthermore, the antibacterial activity was tested against four Gram-negative and five Gram-positive pathogenic strains. The essential oil from flower showed potent activity (37.5 μg/ml) against S. aureus, S. mutans but was less active against Gram-negative bacterial strains. In anti-MRSA activity, leaves and flowers exhibited strong activity against S. aureus (SA-2071) and S. aureus (SA-4627) with lowest IC₅₀ value of 50–100 μg/mL. Overall, N. hinodostana (L.) essential oil represented a potential reservoir of molecules having potent antioxidant and antimicrobial potential.     

Echinophora tenuifolia L. inflorescences: phytochemistry and in vitro antioxidant and anti-inflammatory properties in LPS-stimulated RAW 264.7 macrophages

During the last decades, different natural compounds have been demonstrated to modulate inflammatory pathways. In this study, methanolic extract of Echinophora tenuifolia L. inflorescences was investigated for its chemical composition and in vitro antioxidant and anti-inflammatory properties. Phytochemical profile was investigated by means of high-performance thin layer chromatography (HPTLC) and gas chromatography–mass spectrometry analyses. Myristic acid and palmitic acid were found to be the major constituents. Six terpenes were identified: α-phellandrene, o-cymene, dihydroactinidiolide, neophytadiene, phytol and β-amyrin, and two phenolic compounds: carvacrol and ferulic acid. HPTLC analysis of the ethyl acetate fraction highlighted the presence of the flavonoid glycosides rutin and quercitrin. This sample showed the best diphenylpicrylhydrazyl scavenging capacity, with an IC₅₀ value equal to 40.39 μg/ml, and the strongest capacity to protect linoleic acid from peroxidation, as assessed by the β-carotene bleaching test (IC₅₀ = 16.31 μg/ml). All samples inhibited nitric oxide production in cell supernatants in a dose-dependent manner, being the two apolar fractions (n-hexane and dichloromethane) even more active than the positive control indomethacin. A relevant biological activity was observed for dichloromethane fraction (IC₅₀ value equal to 39.97 μg/ml). Obtained results indicate that this sample could be an excellent candidate for further investigations aimed at the development of new antioxidant and anti-inflammatory drugs.     

Chemical Composition and Antioxidant,Antiparasitic, Cytotoxicity and Antimicrobial Potential of the Algerian Limonium Oleifolium Mill. Essential Oil and Organic Extracts

This work aimed to investigate, for the first time, the chemical composition, antioxidant, antiparasitic, cytotoxicity, and antimicrobial activities of the aromatic plant Limonium oleifolium Mill. essential oil (EO) and organic extracts. L. oleifolium aerial parts essential oil was analyzed by GC-FID and GC-MS, and 46 constituents representing 98.25±1.12 % of the oil were identified. γ-Muurolene (10.81±0.07 %), cis-caryophyllene (7.71±0.06 %), o-cymene (7.07±0.01 %) and α-copaene (5.02±0.05 %) were the essential oil main compounds. The antioxidant activity of L. oleifolium EO and organic extracts (MeOH, CHCl₃, AcOEt, BuOH) was explored using 2,2-diphenyl-1-picrylhydrazyl (DPPH), ABTS, β-carotene/linoleic acid, cupric reducing antioxidant capacity (CUPRAC), and ferric reducing power assays. The results showed that L. oleifolium EO exhibit antioxidant capacity (IC₅₀=17.40±1.32 μg/mL for DPPH assay, IC₅₀=29.82±1.08 μg/mL for β-carotene assay, IC₅₀=25.23±1.01 μg/mL for ABTS assay, IC₅₀=9.11±0.08 μg/mL for CUPRAC assay and IC₅₀=19.41±2.06 mg/mL for reducing power assay). Additionally, the EO showed significant activity against trophozoite form of Acanthamoeba castellanii (IC₅₀=7.48±0.41 μg/mL) and promastigote form of Leishmania amazonensis (IC₅₀=19.36±1.06 μg/mL) and low cytotoxicity on murine macrophages (LC₅₀ 90.23±1.09 μg/mL), as well as good antimicrobial activity against Staphylococcus aureus, Escherichia coli, Klebsiella oxytoca, and Pseudomonas aeruginosa. These results suggest that L. oleifolium essential oil is a valuable source of bioactive compounds presenting antioxidant, antiparasitic, and antimicrobial activities. Furthermore, it is considered nontoxic.     

Antioxidant Activity of Supramolecular Water-Soluble Fullerenes Evaluated by β-Carotene Bleaching Assay

We investigated the antioxidant activity of supramolecular water-soluble fullerenes, polyvinylpyrrolidone (PVP)-entrapped C₆₀, and γ-cyclodextrin (CD)-bicapped C₆₀, based on comparable β-carotene bleaching assay. Antioxidant activity against reactive oxygen species (ROS) generated by three different methods, (i) autoxidation of linoleic acid, (ii) hydrogen peroxide promoter, and (iii) photoirradiation, was evaluated as percent of inhibition relative to a control experiment in view of the bleaching rate constant (k _obs) as well as the persistent absorbancy of β-carotene. Water-soluble fullerenes exhibit significant inhibitory effects on the oxidative discoloration of β-carotene in any system.     

Acetylcholinesterase and butyrylcholinesterase inhibitory activity of Pinus species essential oils and their constituents

This study aimed to investigate the acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity of the essential oils from Pinus nigra subsp. nigra, P. nigra var. calabrica, and P. heldreichii subsp. leucodermis. This activity is relevant to the treatment of Alzheimer’s disease (AD), since cholinesterase drugs are currently the only drugs available to treat AD. P. heldreichii subsp. leucodermis exhibited the most promising activity, with IC₅₀ values of 51.1 and 80.6?μg/mL against AChE and BChE, respectively. An interesting activity against AChE was also observed with P. nigra subsp. nigra essential oil, with an IC₅₀ value of 94.4?μg/mL. Essential oils were analyzed by GC and GC-MS with the purpose of investigating their relationships with the observed activities. Among the identified constituents, terpinolene, β-phellandrene, linalyl acetate, trans-caryophyllene, and terpinen-4-ol were tested. trans-Caryophyllene and terpinen-4-ol inhibited BChE with IC₅₀ values of 78.6 and 107.6?μg/mL, respectively. β-Phellandrene was selective against AChE (IC₅₀ value of 120.2?μg/mL).     

Chemical Profile and Antioxidant Properties of Extracts and Essential Oils from Citrus × limon (L.) Burm. cv. Femminello Comune

Citrus × limon cv. Femminello Comune (Rutaceae) from Rocca Imperiale (Italy), one of the six Protected Geographical Indication (PGI) Italian lemon crops, has been recently received renewed interest. In this work, fresh and dried peels and leaves were extracted by hydrodistillation, supercritical fluid extraction (SFE), and Soxhlet apparatus. Chemical profile was assessed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). Except for leaves extracts obtained by Soxhlet apparatus, the monoterpene hydrocarbons fraction dominated. Limonene, γ‐terpinene, and β‐pinene were the main identified compounds. The antioxidant activity was investigated using different in vitro assays namely 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH), ABTS, ferric reducing ability power (FRAP), and β‐carotene bleaching test. In DPPH test, the essential oil obtained by hydrodistillation of fresh peel exhibited the highest activity (IC₅₀ of 1.17 mg/ml). Leaves extracted by SFE showed a good activity in both DPPH and β‐carotene bleaching test with IC₅₀ values of 2.20 and 6.66 mg/ml, respectively. Monoterpene hydrocarbons fraction exhibited a positive Pearson's correlation coefficient with all antioxidant assays. Leaves, often considered waste material, should be considered from a different point because they represent a matrix of indisputable interest.     

Total phenolic and flavonoid contents and antioxidant activity of ginger (Zingiber officinale Rosc.) rhizome,callus and callus treated with some elicitors

The present study was aimed at determining total phenolic and flavonoid contents and studying the antioxidant activity of ginger (Zingiber officinale Rosc.) rhizome and callus, 6-gingerol and 6-shogaol and callus treated with elicitors. Petroleum ether (PE) and chloroform: methanol (1:1, v/v) (CM) extracts were prepared by maceration. Highest total phenolic content was obtained from the CM extract (60.34?±?0.43?mg gallic acid/g) of rhizome while callus showed lower content detected in the CM extract (33.6?±?0.07?mg gallic acid/g). Flavonoids were only detected in rhizome (CM extract 40.25?±?0.21?mg quercetin/g). Both rhizome extracts exhibited good antioxidant activity with higher activity recorded in PE extract (IC₅₀ value 8.29?±?1.73?μg/mL). Callus extracts revealed lower antioxidant activity (IC₅₀ value 1265.49?±?59.9?μg/mL obtained from CM extract). 6-gingerol and 6-shogaol displayed high antioxidant activity in both assays with IC₅₀ 4.85?+?0.58_DPPH and 5.35?±?0.33_ABTS μg/mL for the former and IC₅₀ 7.61?±?0.81_DPPH and IC₅₀ 7.05?±?0.23_ABTS μg/mL for the latter. Treatment of callus with elicitors showed significant (p?<?0.05) effects in enhancing phenolic content and related antioxidant activity. The highest significant increase in phenolic content (37% and 34%) and antioxidant activity in DPPH assay (34% and 30%) was observed in callus treated with 100?mg/L yeast extract and 50?mg/L salicylic acid respectively. Therefore, studying the effect of the elicitation of ginger cultured tissues in phenolic accumulation would be of immense importance for pharmacological, cosmetic and agronomic industries.     

Phytochemical analysis and antioxidant activity of Tamarix africana,Arthrocnemum macrostachyum and Suaeda fruticosa,three halophyte species from Algeria

Abstract

Extracts and fractions using six solvents of increasing polarities from Northwest Algeria (Tamarix africana, Arthrocnemum macrostachyum and Suaeda fruticosa) were studied for phytochemical analysis and in vitro antioxidant properties. Methanol and water fractions were found to be the more suitable solvents used for extraction of polyphenolic compounds. Aqueous leaf fraction of T. africana showed the highest content of phenolics (61.06?±?0.40?mg GAE/g DW) and condensed tannins (118.43?±?11.79?mg CE/g DW). Dichloromethane stem fraction of T. africana had the highest 2,2-diphenyl-1-picrylhydrazil radical scavenging ability (0.34?±?0.00?mg/ml). Methanol leaf fraction of the same plant exhibited the highest antioxidant power against the inhibition of β-carotene bleaching, while the maximum total antioxidant capacity was recorded in the leaf extract of S. fruticosa. Phenolic content was not influenced by the species but very affected by the extraction solvent, while antioxidant activities were not influenced by these two parameters. High-performance liquid chromatography with a diode-array detector analysis of methanol and aqueous leaf fractions of T. africana revealed the presence of six phenolic acids; chlorogenic and gallic acids were predominant and 10 flavonoid compounds among which rutin and quercetin-3-O-arabonoside were the major constituents. These findings suggest that these species may be considered as an interesting source of antioxidants.     

Antioxidant,anti‐inflammatory,and enzyme inhibitory activity of natural plant flavonoids and their synthesized derivatives

The synthesized flavonoid derivatives were examined for their antioxidant, anti‐inflammatory, xanthine oxidase (XO), urease inhibitory activity, and cytotoxicity. Except few, all the flavonoids under this study showed significant antioxidant activity (45.6%–85.5%, 32.6%–70.6%, and 24.9%–65.5% inhibition by DPPH, ferric reducing/antioxidant power, and oxygen radical absorption capacity assays) with promising TNF‐α inhibitory activity (42%–73% at 10 μM) and IL‐6 inhibitory activity (54%–81% at 10 μM) compared with that of control dexamethasone. The flavonoids luteolin, apigenin, diosmetin, chrysin, O^3?, O⁷‐dihexyl diosmetin, O^4?, O⁷‐dihexyl apigenin, and O⁷‐hexyl chrysin, showed an inhibition with IC₅₀ values (4.5‐8.1 μg/mL), more than allopurinol (8.5 μg/mL) at 5 μM against XO and showing more than 50% inhibition at a final concentration (5 mM) with an IC₅₀ value of ranging from 4.8 to 7.2 (μg/mL) in comparison with the positive control thiourea (5.8 μg/mL) for urease inhibition. Thus, the flavonoid derivatives may be considered as potential antioxidant and antigout agents.     

Polyphenol Characterization,Antioxidant and Skin Whitening Properties of Alnus cordata Stem Bark

In this study, we investigated the phenolic composition of the crude extract (MeOH 80 %) of Alnus cordata (Loisel .) Duby stem bark (ACE) and its antioxidant and skin whitening properties. RP‐LC‐DAD analysis showed a high content of hydroxycinnamic acids (47.64 %), flavanones (26.74 %) and diarylheptanoids (17.69 %). Furthermore, ACE exhibited a dose‐dependent antioxidant and free‐radical scavenging activity, expressed as half‐maximal inhibitory concentration (IC₅₀): Oxygen radical absorbance capacity (ORAC, IC₅₀ 1.78 μg mL^?1)>Trolox equivalent antioxidant capacity (TEAC, IC₅₀ 3.47 μg mL^?1)>2,2‐Diphenyl‐1‐picrylhydrazyl (DPPH, IC₅₀ 5.83 μg mL^?1)>β‐carotene bleaching (IC₅₀ 11.58 μg mL^?1)>Ferric reducing antioxidant power (FRAP, IC₅₀ 17.28 μg mL^?1). Moreover, ACE was able to inhibit in vitro tyrosinase activity (IC₅₀ 77.44 μg mL^?1), l ‐DOPA auto‐oxidation (IC₅₀ 39.58 μg mL^?1) and in an in vivo model it exhibited bleaching effects on the pigmentation of zebrafish embryos (72 h post fertilization) without affecting their development and survival. In conclusion, results show that A. cordata stem bark may be considered a potential source of agents for the treatment of skin disorders due to its bleaching properties and favorable safety profiles, associated to a good antioxidant power.     

In Vitro α-Glucosidase Inhibition and Antioxidative Potential of an Endophyte Species (Streptomyces sp. Loyola UGC) Isolated from Datura stramonium L

Endophytic actinomycetes isolated from Datura stramonium L. was evaluated for its effects against in vitro α-glucosidase inhibition, antioxidant, and free radical scavenging activities. Based on microbial cultural characteristic and 16S rRNA sequencing, it was identified as Streptomyces sp. loyola UGC. The methanolic extract of endophytic actinomycetes (MeEA) shows remarkable inhibition of α-glucosidase (IC₅₀ 730.21 ± 1.33 μg/ml), scavenging activity on 2,2-diphenyl-picrylhydrazyl (DPPH) (IC₅₀ 435.31 ± 1.79 μg/ml), hydroxyl radical (IC₅₀ 350.21 ± 1.02 μg/ml), nitric oxide scavenging (IC₅₀ 800.12 ± 1.05 μg/ml), superoxide anion radical (IC₅₀ 220.31 ± 1.47 μg/ml), as well as a high and dose-dependent reducing power. The MeEA also showed a strong suppressive effect on rat liver lipid peroxidation. Antioxidants of β-carotene linoleate model system revels significantly lower than BHA. The total phenolic content of the extract was 176 mg of catechol equivalents/gram extract. Perusal of this study indicates MeEA can be used as natural resource of α-glucosidase inhibitor and antioxidants.     

A study of Salvia fruticosa Mill subsp. thomasii (Lacaita) Brullo,Guglielmo, Pavone & Terrasi,an endemic Sage of Southern Italy

The aim of this study was to investigate the essential oil profile of Salvia thomasii (Southern Italy) and to assess the relationship of this taxonomic unit to S. fruticosa. The essential oil, obtained by hydrodistillation, was analysed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The main components are β-pinene, viridiflorol, 1,8-cineole, camphor, α-pinene and trans-caryophyllene. The oil was tested for its potential antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH), Ferric Reducing Ability Power (FRAP) and β-carotene bleaching test. Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity assays were used to screen the neuroprotective effect of the essential oil. A clear distinction of the two taxonomic units emerge by the comparison of S. thomasii and S. fruticosa s.l. essential oil composition. Considering the weak morphological differences and the clear-cut geographic separation we propose to treat the Italian unit at subspecies level as Salvia fruticosa Mill subsp. thomasii (Lacaita) Brullo, Guglielmo, Pavone & Terrasi.     

Crocus cancellatus subsp. damascenus stigmas: chemical profile,and inhibition of α-amylase, α-glucosidase and lipase,key enzymes related to type 2 diabetes and obesity

Spices are appreciated for their medicinal properties besides their use as food adjuncts to enhance the sensory quality of food. In this study, Crocus cancellatus subsp. damascenus was investigated for its antioxidant activities employing different in vitro systems. Stigma extract demonstrated a radical scavenging activity against both 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radicals with IC₅₀ values of 34.6 and 21.6?µg/mL and a good ferric reducing ability (53.9?µM Fe(II)/g). In order to clarify the potential functional properties of this spice, the carbohydrate-hydrolysing enzymes and pancreatic lipase inhibitory properties were investigated. Crocus cancellatus subsp. damascenus extract inhibited α-amylase and α-glucosidase with IC₅₀ values of 57.1 and 68.6?µg/mL, respectively. The bioactivity was discussed in terms of phytochemicals content. The obtained results may be of interest from a functional point of view or as food additive and to promote the revalorization of this species.     

Carotenoid oxidative degradation products inhibit Na+-K+-ATPase

This study investigates the biological significance of carotenoid oxidation products using inhibition of Na⁺-K⁺-ATPase activity as an index. β-Carotene was completely oxidized by hypochlorous acid and the oxidation products were analyzed by capillary gasliquid chromatography and high performance liquid chromatography. The Na⁺-K⁺-ATPase activity was assayed in the presence of these oxidized carotenoids and was rapidly and potently inhibited. This was demonstrated for a mixture of β-carotene oxidative breakdown products, β-Apo-10′-carotenal and retinal. Most of the β-carotene oxidation products were identified as aldehydic. The concentration of the oxidized carotenoid mixture that inhibited Na⁺-K⁺-ATPase activity by 50% (IC₅₀) was equivalent to 10μM non-degraded β-carotene, whereas the IC₅₀ for 4-hydroxy-2-nonenal, a major lipid peroxidation product, was 120 μM. Carotenoid oxidation products are more potent inhibitors of Na⁺-K⁺-ATPase than 4-hydroxy-2-nonenal. Enzyme activity was only partially restored with hydroxylamine and/or β-mercaptoethanol. Thus, in vitro binding of carotenoid oxidation products results in strong enzyme inhibition. These data indicate the potential toxicity of oxidative carotenoid metabolites and their activity on key enzyme regulators and signal modulators.     

Antioxidant and free radical scavenging properties of N-acetylcysteine amide (NACA) and comparison with N-acetylcysteine (NAC)

The antioxidant potential of N-acetylcysteine amide (NACA), also known as AD4, was assessed by employing different in vitro assays. These included reducing power, free radical scavenging capacities, peroxidation inhibiting activity through linoleic acid emulsion system and metal chelating capacity, as compared to NAC and three widely used antioxidants, α-tocopherol, ascorbic acid and butylated hydroxytoluene (BHT). Of the antioxidant properties that were investigated, NACA was shown to possess higher 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) radical scavenging ability and reducing power than NAC, at all the concentrations, whereas the scavenging ability of H₂O₂ differed with concentration. While NACA had greater H₂O₂ scavenging capacity at the highest concentration, NAC was better than NACA at lower concentrations. NAC and NACA had a 60% and 55% higher ability to prevent β-carotene bleaching, respectively, as compared to control. The chelating activity of NACA was more than 50% that of the metal chelating capacity of EDTA and four and nine times that of BHT and α-tocopherol, respectively. When compared to NACA and NAC; α-tocopherol had higher DPPH scavenging abilities and BHT and α-tocopherol had better β-carotene bleaching power. These findings provide evidence that the novel antioxidant, NACA, has indeed enhanced the antioxidant properties of NAC.     

Antioxidant Capacity of the Leaf Extract Obtained from Arrabidaea chica Cultivated in Southern Brazil

Arrabidaea chica leaf extract has been used by people as an anti-inflammatory and astringent agent as well as a remedy for intestinal colic, diarrhea, leucorrhea, anemia, and leukemia. A. chica is known to be a good producer of phenolics. Therefore, in the present study, we investigated its antioxidant activity. The phenolic composition of A. chica leaves was studied by liquid chromatography coupled to diode array detection (LC–DAD) and liquid chromatography coupled to electrospray ionization-tandem mass spectrometry (LC–ESI-MS/MS), and isoscutellarein, 6-hydroxyluteolin, hispidulin, scutellarein, luteolin, and apigenin were identified. The extract from leaves of A. chica was tested for antioxidant activity using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method, β-carotene bleaching test, and total reactive antioxidant potential (TRAP) method. The crude extract quenched DPPH free radicals in a dose-dependent manner, and the IC₅₀ of the extract was 13.51 µg/mL. The β-carotene bleaching test showed that the addition of the A. chica extract in different concentrations (200 and 500 µg/mL) prevented the bleaching of β-carotene at different degrees (51.2% ±3.38% and 94% ±4.61%, respectively). The TRAP test showed dose-dependent correlation between the increasing concentrations of A. chica extract (0.1, 0.5, and 1.0 µg/mL) and the TRAP values obtained by trolox (hydro-soluble vitamin E) 0.4738±0.0466, 1.981±0.1603, and 6.877±1.445 µM, respectively. The 2 main flavonoids, scutellarein and apigenin, were separated, and their antioxidant activity was found to be the same as that of the plant extract. These 2 flavonoids were quantified in the plant extract by using a validated HPLC-UV method. The results of these tests showed that the extract of A. chica had a significant antioxidant activity, which could be attributed to the presence of the mixture of flavonoids in the plant extract, with the main contribution of scutellarein and apigenin.     

Antimicrobial and cytotoxicity activities of the medicinal plant Primula macrophylla

Primula macrophylla (Primulaceae) is reported as to be useful in asthma, restlessness, insomnia and fish poisoning. Antifungal and toxic activities of crude extract, fractions and a pure isolated compound exhibited statistically significant activities. Excellent antifungal activity was found in the crude extract, benzene and ethyl acetate fractions against T. longifusis and against M. canis with different MIC values. Antileishmanial activity (IC₅₀ = 50ug/mL) was observed as compared to standard drug Amphotericin B, and cytotoxic activity (LD₅₀ = 47.919μg/mL) was also found in the chloroform fraction. While pure compound 2-phenylchromone (Flavone) isolated from the chloroform fraction showed good activity (IC₅₀ = 25μg/mL) against Leishmania and cytotoxicity (LD₅₀ = 2.0116 μg/mL) in Brine Shrimp experiments. From antileishmanial and cytotoxic activity it can be concluded that 2-phenylchromone is the major compound responsible for these activities.