In vitro antioxidant activity of extracts of Sybaris liquorice roots from Southern Italy

The antioxidant properties of extracts of Sybaris liquorice roots have been assessed using 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity assay. The extracts, obtained by Soxhlet extraction (Et(2)O, AcOEt, MeOH and BuOH) of the yellow (inner part) and brown (cortex) root powders ensuing from decortication of the raw dry roots, followed by separation and powderisation, were analysed for their scavenging activity by evaluating the colourimetric decrease in the absorbance of DPPH. The highest antioxidant activity (98.39?±?0.56%) was observed in the case of the Et(2)O extract of the brown powder, at a concentration of 3.33?mg?mL(-1). Moreover, the total phenolic content of the extracts was determined using the Folin-Ciocalteu reagent and expressed as milligram gallic acid equivalent per gram of dry extract. Our results show that the Et(2)O extract of the liquorice root cortex could be used as an attractive natural source of antioxidant additives for food, cosmetic or pharmaceutical applications.     

In vitro cytotoxic and antiviral activities of Ficus carica latex extracts

The latex of fig fruit (Ficus carica) is used in traditional medicine for the treatment of skin infections such as warts and also diseases of possible viral origin. Five extracts (methanolic, hexanic, ethyl acetate, hexane-ethyl acetate (v/v) and chloroformic) of this species were investigated in?vitro for their antiviral potential activity against herpes simplex type 1 (HSV-1), echovirus type 11 (ECV-11) and adenovirus (ADV). To evaluate the capacity of the extracts to inhibit the replication of viruses, the following assays were performed: adsorption and penetration, intracellular inhibition and virucidal activity. Observation of cytopathic effects was used to determine the antiviral action. The hexanic and hexane-ethyl acetate (v/v) extracts inhibited multiplication of viruses by tested techniques at concentrations of 78 μg mL(-1). These two extracts were possible candidates as herbal medicines for herpes virus, echovirus and adenovirus infectious diseases. All extracts had no cytotoxic effect on Vero cells at all tested concentrations.     

In vitro antioxidant and radical scavenging of Guinean kinkeliba leaf (Combretum micranthum G. Don) extracts

The antioxidant properties of the water and ethanol leaf extracts of kinkeliba (Combretum micranthum) were investigated, including scavenging of the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical (IC?? values: 8.02?±?0.34 for the ethanol extract [KE] and 9.1?±?0.28 for the water extract [KW]), the 2,2'-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical (IC(50) values: 7.4?±?0.14 for KE and 11.8?±?0.01 for KW) and the hydroxyl radical (58.1% for KE and 61.1% for KW). The ferric thiocyanate method, reducing power, metal chelating activity, an assay of protein oxidation and the β-carotene-linoleic bleaching assay were also used. Butylated hydroxytoluene and ascorbic acid were used as the reference antioxidant compounds. At 20 mg mL?1 concentration, KW and KE provided 36.8% and 75.1% inhibition of lipid peroxidation of linoleic acid emulsion, respectively. The IC?? values of the ethanol extract in ABTS and DPPH tests were significantly lower than those from the water extract. Furthermore, crude polyphenols were extracted from kinkeliba leaf with 90% ethanol solution using a water bath treatment and then purified by a macroporous resin, AB-8. The polyphenols from kinkeliba leaf were subjected to analyses by RP-HPLC and ESI-MS. The dominant polyphenols in kinkeliba leaf were identified as gallic acid, rutin trihydrate, (+)-catechin and benzoic acid.     

Chemical composition of essential oil and in vitro antioxidant activities of the essential oil and methanol extracts of Eucalyptus loxophleba

This study was designed to examine the chemical composition of the essential oil and the antioxidant activity of the essential oil and methanol extracts of Eucalyptus loxophleba Benth. subsp. The chemical composition of the essential oil of the leaves of E. loxophleba was analysed by GC and GC/MS. The main constituents of the oil were found to be 1,8-cineole (39.4%), methyl amyl acetate (19.8%) and aromadendrene (10%). Antioxidant activities of the samples were determined by two different test systems namely DPPH and β-carotene/linoleic acid. In the DPPH system, the highest radical-scavenging activity was shown by the polar subfraction of the methanol extract (15.2?±?1.7?μg?mL?1). Also, in the second case, the inhibition capacity (%) of the polar subfraction (94.1?±?1.3) was found to be stronger. In addition, the amounts of total phenol components in the polar subfraction (273.0?±?2.6?μg?mg?1) and nonpolar subfraction (146.3?±?2.5?μg?mg?1) were determined.     

In vitro antioxidant and inhibitory activity of water decoctions of carob tree (Ceratonia siliqua L.) on cholinesterases, α-amylase and α-glucosidase

This work reports the in vitro inhibitory activity of water decoctions of leaves, germ flour, pulp, locust bean gum and stem bark of carob tree on α-amylase, α-glucosidase, acetylcholinesterase and butyrylcholinesterase. The antioxidant activity and the chemical characterisation of the extracts made by spectrophotometric assays and by high-performance liquid chromatography are also reported. Leaves and stem bark decoctions strongly inhibited all the enzymes tested, had significant antioxidant activity and the highest total phenolics content. The major compounds were identified as gallic acid in the leaves and gentisic acid in the stem bark.     

In vitro antioxidant activities of the methanol extract and its different solvent fractions obtained from the fruit pericarp of Terminalia bellerica

Terminalia bellerica has been used as a traditional medicine in a variety of ailments including anaemia, asthma, cancer, inflammation, rheumatism and hypertension. In this study, the free radical scavenging and antioxidant activities of methanol extract (ME) and its different solvent fractions (namely hexane (HE), ethyl acetate (EA), butanol (BL) and water (WA)) of the T. bellerica fruit pericarp were evaluated and compared with standard antioxidant compounds like gallic acid (GA), catechin and ascorbic acid. Among the different fractions tested, the EA fraction exhibited higher antioxidant and radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH), superoxide and hydroxyl radicals than the other fractions, which may be attributed to its higher phenolic and flavonoid content, since a linear relation was observed between the phenolic content and the antioxidant parameters. The HPTLC analysis of the EA fraction revealed that it mainly contains GA and ferulic acid (FA) as major phenolics, and the higher antioxidant activities of EA fraction may be due to the presence of these compounds.     

In vitro antibacterial activity of medicinal plant extracts against Escherichia coli strains from human clinical specimens and interactions with antimicrobial drugs

The biological properties of medicinal plants have been documented worldwide for many centuries. We aimed to evaluate interactions between crude extracts from Psidium guajava, Zingiber officinale, Cymbopogon citratus, Caryophyllus aromaticus, Mikania glomerata and Allium sativum samples and antimicrobial drugs against Escherichia coli strains. The susceptibility test performed was disc diffusion, and crude extracts were diluted (%v/v) into Müller-Hinton agar (MHA) at one quarter of the minimal inhibitory concentration for 90% (MIC(90%)) of E. coli strains found previously. Synergistic interactions were observed between C. citratus and polymyxin, and A. sativum extracts and gentamicin. The crude A. sativum extract was the only one that did not show any antagonism with the antimicrobial drugs. The results thus showed the potential use of these medicinal plants against E. coli strains, although antagonism with antimicrobial drugs is a negative aspect in the combined therapy of infectious diseases caused by E. coli.     

In vitro evaluation of the schistosomicidal potential of Eremanthus erythropappus (DC) McLeisch (Asteraceae) extracts

Eremanthus erythropappus (DC) McLeisch, a plant popularly known as Candeia (Asteraceae), has high therapeutic potential. In this study, the in?vitro schistosomicidal potentials of the ethanolic, dichloromethane and hexane extract of branches were evaluated. Couples of worms obtained from the infected mice were cultured in RPMI supplemented with foetal bovine serum and antibiotics. Four pairs of adult worms were exposed to increasing concentrations of each extract and examined by light microscope. The extracts at 100 and 200?μg?mL(-1) had schistosomicidal activity, as demonstrated by the analysis of several aspects such as tegument darkening, absence of motility, incapacity of adhesion in culture plate and absence of egg in culture medium. At 50 and 75?μg?mL(-1), the dichloromethane and hexane extracts were highly effective. The results suggest that these extracts could be useful in the development of new schistosomicidal drugs.     

Anti-allergic effect of the flavonoid myricitrin from Myrica rubra leaf extracts in vitro and in vivo

Flavonoids are ingested by the general population as anti-oxidant and anti-inflammatory agents. In this study, we investigated the effects of myricitrin, a flavonoid rich in Myrica rubra leaf, upon anti-inflammatory action. Myrica rubra leaf extracts inhibited pro-inflammatory TNFα production in a macrophage cell line, Raw264.7 cells. We observed that the serum IgE levels in the leaf extract-treated DO11.10, a mouse allergy model, were down-regulated. HPLC was performed to demonstrate that M. rubra leaf extracts contain a large amount of myricitrin. We observed an inhibitory effect of HPLC-purified myricitrin on TNFα production in Raw264.7 cells. Thus, myricitrin may be of potential interest in the management of inflammatory conditions.     

In vitro activity of plant extracts and alkaloids against clinical isolates of extended-spectrum β-lactamase (ESBL)-producing strains

The antibacterial activity of 80% ethanol extracts of 10 medicinal plants collected in Yunnan (Southwest China), was tested against clinical isolates of extended-spectrum β-lactamase (ESBL)-producing strains. Their MIC values ranged between 1.56-12.50 mg/mL. The most active plant extract was Chelidonium majus L. (MIC = 1.56 mg/mL). Two potent isoquinoline alkaloids, 8-hydroxydihydrosanguinarine and 8-hydroxydihydrochelerythrine, were identified as the major active principles through bioassay-guided fractionation and identification of the active ethyl acetate fraction from C. majus, with minimum MIC/MBC values of 15.63/62.50 mg/mL.     

In vitro antiperoxidative, free radical scavenging and xanthine oxidase inhibitory potentials of ethyl acetate fraction of Saraca ashoka flowers

Saraca ashoka is a widely used medicinal herb claimed to cure many diseases. This study investigated the antiperoxidative, free radical scavenging and xanthine oxidase (XO) inhibitory potential of the ethyl acetate fraction of S. ashoka flowers (SAF) and compared it with standard compounds like gallic acid, ascorbic acid, butylated hydroxyl toluene and allopurinol. The ethyl acetate fraction of SAF exhibited free radical scavenging activity against the 1,1-diphenyl-2-picrylhydrazyl radical and superoxide radical, along with hydroxyl radical scavenging activity. Lipid peroxidation inhibitory potential of SAF was studied using a linoleic acid emulsion system, which shows significant antioxidant potential. SAF also demonstrated significant XO (key enzyme linked to inflammation) inhibitory activity, which revealed its therapeutic potential as an antioxidant and XO inhibitor. HPLC profiling of the ethyl acetate fraction of SAF revealed that it contains ellagic acid as a major compound and thus the beneficial effects of this fraction may be due to the presence of this compound.     

New water-soluble forms of α-tocopherol: preparation and study of antioxidant activity in vitro

Water-soluble forms of α-tocopherol (vitamin E) possessing antioxidant activity in vitro were obtained by encapsulating in N-vinylpyrrolidone with triethylene glycol dimethacrylate polymer particles and were characterized by various physicochemical methods. Quantum-chemical modeling of a structure of α-tocopherol with the copolymer moiety and its theoretical absorption spectra modeling were carried out.     

Neat synthesis and antioxidant activity of α-aminophosphonates

A simple, efficient, and environmentally benign method for a three-component reaction of an amine, an aldehyde and diethyl phosphite catalyzed by Amberlyst-15 has been developed to afford α-amino phosphonates in high yields and short reaction times under solvent-free reaction conditions using microwave irradiation. The major advantages of the present method are inexpensive, ecofriendly and reusable catalyst and also studied their antioxidant activity of synthesized compounds.     

In vivo antioxidant activity of Pinus koraiensis nut oil obtained by optimised supercritical carbon dioxide extraction

In this study, an orthogonal array design OA? (3?) was employed to optimise the conditions of supercritical carbon dioxide (SC-CO?) extraction of Pinus koraiensis nut oil. The effects of pressure, temperature and extraction time on the oil yield were investigated. Next, the fatty acid composition of the oil was examined by gas chromatography-mass spectrometry (GC-MS). The in vivo antioxidant activity of the oil was determined by estimating the superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), total antioxidant capacity (T-AOC) and the content of malondialdehyde (MDA) in rats fed with a high-fat diet. The results showed that extraction pressure and time were the main variables that influenced the oil yields. The optimal conditions with which to obtain highest yield of oil were determined to be 5760.83?psi, 50°C and 3.0?h (extraction yield was 458.5?g?kg?1); nine compounds, constituting about 99.98% of the total oil, were identified. The most abundant polyunsaturated fatty acids identified in the oil, linoleic acid and α-linolenic acid, constituted 41.79% and 15.62% of the oil, respectively. Moreover, the results on their antioxidant activities showed that the oil could improve the activities of SOD, GSH-Px and T-AOC, and reduce the content of MDA significantly, in the serum. These results indicate that P. koraiensis nut oil obtained by SC-CO? extraction had excellent antioxidant activities.     

Synthesis and antioxidant activity of phenolic derivatives ofα-santonin

Phenolic derivatives of-santonin have been synthesized and their antioxidant effect has been studied.Institute of Phytochemistry, National Academy of Sciences of the Republic of Kazakhstan, Karaganda. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 247–249, March–April, 1997.     

Characteristics of sodium alginate membranes for the pervaporation dehydration of ethanol–water and isopropanol–water mixtures

Alginate membranes for the pervaporation dehydration of ethanol–water and isopropanol–water mixtures were prepared and tested. The sodium alginate membrane was water soluble and mechanically weak but it showed promising performance for the pervaporation dehydration. To control the water solubility the sodium alginate membrane was crosslinked ionically using various divalent and trivalent ions. Among them the alginate membrane crosslinked with Ca²⁺ ion showed the highest pervaporation performance in terms of the flux and separation factors.     

Influence of ethanol and ultrasound on drying,bioactive compounds,and antioxidant activity of strawberries (Fragaria × ananassa)

This study aimed to evaluate the use of ethanol (ET) and ultrasound (US) in convective drying of strawberry slices, as well as the effect on physicochemical, bioactive, and antioxidant parameters. For this, strawberry slices with a thickness of 0.005 m were pretreated with ET (in different volume fractions), US, and a combination of both. Drying kinetics were performed for control strawberry slices (without ET and US) and pretreated with 50% ethanol (ET50), 50% ethanol and ultrasonic (ET50US), 100% ethanol (ET100), and 100% ethanol and ultrasonic (ET100US) at a temperature of 60 °C. Empirical and diffusive models were fitted to the experimental data to describe the drying kinetics, and the fresh and dried slices were analyzed according to the parameters of water activity (aw), water content, total phenolic compounds (TPC), total anthocyanins (ATS), vitamin C and antioxidant activity (AA) (ABTS?+, DPPH?, and FRAP). The use of the ET100US combination provided an increase in the moisture transport process, higher drying rate, shorter process time (570 min), and reduction of a_w to a safe value (a_w <0.5), however, it sharply degraded the TPC, ATS, and AA. The ET50US pre-treatment even with a drying time of 690 min was the most efficient, since the values of TPC, ATS, and vitamin C suffered smaller reductions, where the AA varied in only 10.32%, 13.78% and 6.54% for the methods ABTS?+, DPPH?, and FRAP, respectively when compared to fresh strawberry. In this sense, it can be stated that the pre-treatment with 50% ethanol and ultrasound (ET50US) showed less reduction in the degradation of bioactive and antioxidant properties, and in the minimization of drying time for strawberry slices.     

In vitro antitumor activity of titanocene alanine complex and its interaction with nucleic acids

Titanocene alanine complex, Cp2Ti(O2CCH(CH3)NH3+Cl-)2, has been found to have in vitro antitumor activity against Ehrlich ascites tumor cells. Study of the interaction between Cp2Ti(O2CCH(CH3)NH+Cl-)2 and DNA by UV-VIS spectra, fluorescence spectra, agarose gel elec-trophoresis reveals that Cp2Ti(O2CCH(CH3)NH3 Cl-)2 forms a stable compound with DNA in molar ratio 1:1 and reduces the migration rate of ccc-DNA band and oc-DNA band. However, unlike cis-platin, the complex does not induce nicking of DNA even after a long incubation at a high ratio of the complex to DNA. The results suggest that titanocene-based antitumor agents have different mechanism of action from cisplatin-like antitumor agents.