Antimicrobial and antioxidant activity of proteins from Feijoa sellowiana Berg. fruit before and after in vitro gastrointestinal digestion

Abstract

In this paper we report for the first time a method for the extraction of the protein fraction from Feijoa sellowiana Berg. fruit and its electrophoretic analysis. In addition we analyzed the protein fraction for its antioxidant activity and its effectiveness against different Gram-positive and Gram-negative bacteria both as American type culture collection (ATCC) standard and clinically isolated strains. Both antimicrobial and antioxidant activity resulted stronger respect to that previously obtained for the acetonic extract from the same fruit. Further, we study both activities also on the product of in vitro gastrointestinal digestion of F. sellowiana fruit proteins. The results showed that in vitro gastrointestinal digestion increased 10 fold the antioxidant activity, while the antimicrobial activity, tested only on ATCC strains, resulted from 2 to 4 fold increased. MTT assays showed the non-toxicity of these proteins both before and after digestion.     

Antimicrobial activity and agricultural properties of bitter melon (Momordica charantia L.) grown in northern parts of Turkey: a case study for adaptation

This study was designed to determine the adaptation capability of bitter melon (Momordica charantia L.), which is widely grown in tropical and subtropical climates, in northern parts of Turkey. In this study, plant height, number of fruits, fruit length, fruit width, number of seeds and fruit weight of bitter melon grown in field conditions were determined. The antimicrobial effect of the ethanol extract of fruit and seeds against Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Salmonella typhi, Aspergillus niger and Candida albicans microorganisms was tested in vitro by the disc diffusion method. In conclusion, plant height (260 cm), number of fruits (16 per plant), number of seeds (30.2 per fruit), fruit width (3.8 cm), fruit length (10.6 cm) and fruit weight (117.28 g fruit^? 1) were determined; fruits were found to have antimicrobial activity against A. niger; oil and seeds were found to have antimicrobial activity against A. niger and E. coli.     

Antioxidant,antimicrobial and urease inhibiting activities of methanolic extracts from Cyphostemma digitatum stem and roots

Cyphostemma digitatum stem and roots extracts were investigated for antioxidant, antimicrobial, urease inhibition potential and phytochemical analysis. Phytochemical screening of the roots and stem extract revealed the presence of secondary metabolites including flavonoids, alkaloids, coumarins, saponins, terpenoids, tannins, carbohydrates/reducing sugars and phenolic compounds. The methanolic extracts of the roots displayed highest antioxidant activity (93.518%) against DPPH while the crude methanolic extract of the stem showed highest antioxidant activity (66.163%) at 100 μg/mL concentration. The methanolic extracts of both stem and roots were moderately active or even found to be less active against the selected bacterial and fungal strains (Tables S2 and S3). The roots extract (methanol) showed significant urease enzyme inhibition activity (IC₅₀ = 41.2 ± 0.66; 0.2 mg/mL) while the stem extract was found moderately active (IC₅₀ = 401.1 ± 0.58; 0.2 mg/mL) against thiourea (IC₅₀ = 21.011; 0.2 mg/mL).     

GC×GC/qMS analyses of Campomanesia guazumifolia (Cambess.) O. Berg essential oils and their antioxidant and antimicrobial activity

The present study investigated the essential oil obtained from Campomanesia guazumifolia (Cambess.) O. Berg, an aromatic plant used in Brazilian folk medicine. The chemical composition was performed by GC×GC/qMS. The antioxidant and antimicrobial activities were evaluated by DPPH and BCB and, MIC assays, respectively. Sixty-eight compounds were identified in the oil, where the major compounds were bicyclogermacrene (15%), globulol (5%) and spathulenol (5%). Sesquiterpene hydrocarbons (29 compounds) and oxygenated sesquiterpenes (20 compounds) were the most representative classes of terpenes. DPPH (IC₅₀ value 26.1 ± 0.5 μg/mL) and BCB (68.3 ± 1.5%) values indicated a significant antioxidant activity. The essential oil strongly inhibited Staphylococcus aureus (MIC 15 ± 0.1 μg/mL), Escherichia coli (MIC 25 ± 0.2 μg/mL) and Candida albicans (MIC 5 ± 0.1 μg/mL). The results give a deeper understanding of the chemical composition and report for the first time the antioxidant and antimicrobial potential of the C. guazumifolia essential oil.     

Comparative study of the chemical profiling,antioxidant and antimicrobial activities of essential oils of different parts of Thymus willdenowii Boiss & Reut

The analysis of Thymus willdenowii Boiss &; Reut essential oils (TW EOs) shows 33 components accounting for (96.3–97.7%) of all identified. The main constituents of TW EOs were thymol (35.5–47.3%), p-cymene (13.9–23.8%), γ-terpinene (8.9–20.3%). The antioxidant assays revealed that all TW EOs tested showed strong activities, the antimicrobial effect of TW EOs has been tested against isolated clinical strains of Proteus mirabilis (ATCC 35659), Escherichia coli (ATCC 25922), Candida albicans (ATCC 10231), Bacillus cereus (ATCC 10876), and Aspergillus brasilliensis (ATCC 16404). The antimicrobial test indicates that TW EOs show an inhibition effect against all the tested bacteria with a MIC of 6.9 to 27.6 μg/mL^?1. These results proving that the essential oils extracted from Thymus willdenowii Boiss &; Reut may be a new potential source of natural antimicrobial applied in pharmaceutical and food industries.     

In vitro antimicrobial activity of extracts and compounds isolated from Cladonia uncialis

Heptane (Hep), diethyl ether (Et₂O), acetone (Me₂CO) and methanolic (MeOH) extracts, as well as ( ? )-usnic acid and squamatic acid, were obtained from thallus of Cladonia uncialis (Cladoniaceae). The antimicrobial activities of these extracts, ( ? )-usnic acid and squamatic acid, were tested against reference strains: Staphylococcus aureus, Escherichia coli and Candida albicans. In addition, Me₂CO extract was analysed against 10 strains of Methicillin-resistant S. aureus (MRSA) isolated from patients. All extracts exerted antibacterial activity against the reference strain S. aureus, comparably to chloramphenicol [minimum inhibitory concentration (MIC) = 5.0 μg/mL]. The Me₂CO extract exhibited the strongest activity against S. aureus (MIC = 0.5 μg/mL), higher than ( ? )-usnic acid, whereas squamatic acid proved inactive. The Me₂CO extract showed potent antimicrobial activity against MRSA (MIC 2.5–7.5 μg/mL). Also no activity of C. uncialis extracts against E. coli and C. albicans was observed.     

Chemical composition and biological activities of Iranian Achillea wilhelmsii L. essential oil: a high effectiveness against Candida spp. and Escherichia strains

In the case of Achillea wilhelmsii, 30 compounds were identified representing 94.48% of the total oil with a yield of 0.82% w/w. The major constituents of the oil were described as α-thujene (6.11%), α-pinene (5.11%), sabinene (5.23%), p-cymene (7%), 1,8-cineole (6%), linalool (10%), camphor (8.43%), thymol (18.98%) and carvacrol (20.13%). A. wilhelmsii oil exhibited higher antibacterial and antifungal activities with a high effectiveness against Escherichia coli and Candida albicans with the lowest minimum inhibitory concentration and minimum bactericidal concentration/minimum fungicidal concentration value (2 ± 0.0–2 ± 0.0 g/mL, 1 ± 0.5–1 ± 0.5 g/mL), respectively. Results showed that A. wilhelmsii oil exhibits a higher activity in each antioxidant system with a special attention for β-carotene bleaching test (IC₅₀: 19 μg/mL) and reducing power (EC₅₀: 10 μg/mL). Antioxidant activity-guided fractionation of the oil was carried out by TLC-bioautography screening and fractionation resulted in the separation of main antioxidant compounds which were identified as thymol (65%) and carvacrol (19%). In conclusion, these results support the use of the essential oil and its main compounds for their antioxidant properties and antimicrobial activity.     

Radical scavenging and antimicrobial activities of Croton zehntneri,Pterodon emarginatus and Schinopsis brasiliensis essential oils and their major constituents: estragole,trans-anethole, β-caryophyllene and myrcene

The essential oils (EOs) from the Brazilian species Croton zehntneri, Pterodon emarginatus and Schinopsis brasiliensis were examined for their chemical constituents, and antioxidant and antimicrobial activities. The composition of EOs was determined by using gas chromatography coupled with mass spectrometry analysis, while the antioxidant activity was evaluated through the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and oxygen radical absorbance capacity (ORAC) assays. Furthermore, the antimicrobial activity was investigated against Escherichia coli and Pseudomonas aeruginosa (both Gram-negative), Staphylococcus aureus (Gram-positive) and Candida parapsilosis (fungus). The main components of C. zehntneri, P. emarginatus and S. brasiliensis were identified as estragole, trans-anethole, β-caryophyllene and myrcene. Among the EOs, P. emarginatus showed the highest antioxidant activity, with an IC₅₀ of 7.36 mg/mL and a Trolox equivalent antioxidant capacity of 3748 μmol/g determined by DPPH and ORAC assays, respectively. All EOs showed low activities against the bacterial strains tested, whereas the C. zehntneri oil and its main constituent estragole exhibited an appreciable antifungal activity against C. parapsilosis.     

Chemical composition,antimicrobial and antioxidant activities of the essential oil of Psammogetoncanescens

This study reports the chemical composition, antimicrobial activity and antioxidant properties of Psammogeton canescens essential oil (EO) and its main compounds. The EO was obtained from the aerial parts of P. canescens by hydrodistillation and analysed by using GC/MS. The main constituent was β-bisabolene (25%), followed by α-pinene (20%), apiole (15.34%), γ-terpinene (7.34%), p-cymene (5.35%), β-pinene (5.41%), camphene (5.12%), dill apiole (5%), myrcene (4.54%), colchicine (0.56), sylvestrene (0.56%), β-caryophyllene (0.45%), caryophyllene oxide (0.43%), (Z)-β-farnesene (0.32%), cembrene (0.21%), folic acid (0.21%), germacrene D (0.14) and β-sesquiphellandrene (0.13). β-Bisabolene exhibited strong antioxidant activity (14 ± 0.8 μg/mL). The EO of P. canescens was particularly active against Candida albicans and Escherichia coli, with the lowest minimum inhibitory concentration and minimum bactericidal/fungicidal concentration values. In conclusion, these results support the use of the EO and its main compounds for their antioxidant properties and antimicrobial activity.     

Phytochemical characterisation and bioprospection for antibacterial and antioxidant activities of Lippia alba Brown ex Britton & Wilson (Verbenaceae)

Ethanol extract and fractions obtained from fresh and dry aerial parts of Lippia alba were examined in order to determine their phytochemical composition, antioxidant capacity and antibacterial activities. The ethanol extracts and fractions exhibited an antioxidant effect by the DPPH assay, especially samples of fresh plant. HPLC analysis of the ethyl acetate fractions identified the presence of phenolic acids and flavonoids. The ethanol extract and fractions showed activity against reference and multidrug-resistant strains of Staphylococcus aureus and Enterococcus faecalis (MIC range 2000–250 μg/mL). The hexane and dichloromethane fractions of fresh plant showed better activity against reference strains of Escherichia coli (MIC of 250 and 125 μg/mL, respectively), but all extracts and fractions were less active against multidrug-resistant strains of all the Gram-negative species evaluated. The results showed that the extract and fractions of L alba aerial parts showed antibacterial activity, even against multidrug-resistant Gram-positive bacteria, and antioxidant effect (DPPH assay).     

Screening of medicinal plants traditionally used in Peruvian Amazon for in vitro antioxidant and anticancer potential

Plants mentioned in this study have numerous records in traditional Peruvian medicine being used in treatment of cancer and other diseases likely to be associated with oxidative stress. Amongst the eight plant species tested, only Dysphania ambrosioides exhibited combinatory antioxidant and anti-proliferative effect on a broad spectrum of cancer cells (DPPH and ORAC values = 80.6 and 687.3 μg TE/mg extract, respectively; IC₅₀ against Caco-2, HT-29 and Hep-G2 = 129.2, 69.9 and 130.6, respectively). Alkaloids and phenolic compounds might significantly contribute to anticancer/antioxidant activity of this plant. The results justify the traditional medicinal use of this plant. Our findings further suggest that D. ambrosioides might serve as a prospective material for further development of novel plant-based antioxidant and/or anti-proliferative agents. Detailed analysis of chemical composition together with toxicology assessments and in vivo antioxidant/anti-proliferative activity of this plant should be carried out in order to verify its potential practical use.     

Chemical composition,antioxidant and antimicrobial activity of the essential oil from the leaves of Macleaya cordata (Willd) R. Br.

The essential oil from the leaves of Macleaya cordata R.Br. obtained by hydrodistillation was analysed by gas chromatography/mass spectrometry. Sixty-eight compounds consisting of up to 92.53% of the essential oil were identified. Antioxidant activities of the essential oil were evaluated by using DPPH radical scavenging and β-carotene–linoleic acid assays. The essential oil showed moderate antioxidant activity. In addition, the essential oil exhibited potential antimicrobial activity against all tested microorganisms, with diameters of inhibition zones ranging from 8.7 ± 0.5 to 17.2 ± 1.2 mm and minimum inhibitory concentration values from 125 to 500 μg/mL. We selected the most sensitive bacterium Staphylococcus aureus as model to observe of the action of essential oils of M. cordata on the membrane structure by scanning electron microscopy. The treated cell membranes were damaged severely. The results presented here indicate that the essential oil of M. cordata may be potential sources of antioxidant and antimicrobial agents in the future.     

Chemical constituents,in vitro antioxidant and antimicrobial properties of ethyl acetate extract obtained from Cytisus triflorus l’Her

Abstract

The present study investigates the phenolic composition, antioxidant and antimicrobial activities of an ethyl acetate extract from C. triflorus L’Her. The phytochemical study on the aerial parts of C. triflorus belonging to the Fabaceae family led to the isolation and structural elucidation of 5-Hydroxy-7-O-glucosylflavone (P1), 5-Hydroxy-7-O-galactosylflavone (P2), 5,7-Dihydroxy-flavone (P3), 5,7,3’-Trihydroxy,4’-methoxy-flavone (P4). These compounds were identified by 1D and 2D NMR combined analysis as well as by UV.

Ethyl acetate extract of C. triflorus showed a significant and dose-dependent antioxidant activity in vitro, related to the presence of phenolics (180.33?±?12.22?µg GAE/mg) and flavonoids (16.78?± 1.54?µg QE/mg). The antimicrobial activity was evaluated in vitro against Staphylococcus aureus CECT 240 and Escherichia coli CECT 4099, by agar-diffusion method. The most active antibacterial activity was expressed by ethyl acetate extract of C. triflorus against Gram-positive bacteria S. aureus. The gathered results suggest that C. triflorus polyphenols and flavonoids are closely associated to its antioxidant and antimicrobial properties.     

Synthesis,characterization, and antibacterial evaluation of copper(II) complexes supported by phenylacetic acid derivatives,and diamine ligands

Four mixed-ligand complexes, [Cu₃(cpa)₆(pda)₁] (1) (cpa = 4-chlorophenylacetic acid, pda = 1,2-diaminopropane), [Cu₃(fpa)₆(tn)₁] (2) (fpa = 4-fluorophenylacetic acid, tn = 1,3-diaminopropane), [Cu₃(cpa)₆(en)₁] (3) (cpa = 4-chlorophenylacetic acid, en = ethylenediamine), and [Cu₃(fpa)₆(pda)₁] (4) (fpa = 4-fluorophenylacetic acid, pda = 1,2-diaminopropane), were synthesized by reacting 4-chlorophenylacetic acid or 4-fluorophenylacetic acid, the diamines, and metal salts. Their structures were determined by elemental analysis and single-crystal X-ray diffraction analysis. The antimicrobial activities for the metal complexes were evaluated against Escherichia coli, Pseudomonas putida, Bacillus subtilis, and Bacillus cereus. The antimicrobial results indicated that the four synthesized complexes displayed good inhibitory activity against E. coli and B. subtilis, and could be promising antibacterial agents.     

Synthesis and Antimicrobial Evaluation of Some New 4,5′‐Bisthiazoles

Thiazole and bisthiazole derivatives represent a prevalent scaffold in the antimicrobial drug discovery. Therefore, we have decided to synthesize some new series of 4,5′‐bisthiazoles. A total of 17 compounds were synthesized, their structural elucidation being based on elemental analysis (C,H,N,S) and spectroscopic data (MS and ¹H NMR). Their in vitro antimicrobial activities were assessed against several Gram‐positive and Gram‐negative bacteria strains and also against one fungal strain (Candida albicans) using the difusimetric method. Some of the compounds showed modest to good antibacterial activity against Gram‐negative Escherichia coli and Salmonella typhimurium and Gram‐positive Staphylococcus aureus and Bacillus cereus bacterial strains. All of the synthesized compounds showed moderate to very good antifungal activity against C. albicans.     

Modulation of antibiotic activity by the hydroalcoholic extract from leaves of Caryocar coriaceum WITTM

The aim of this study was to identify the presence of tannins, phenols and flavonoids on the hydroalcoholic extract of Caryocar coriaceum leaves (HECCL) and to determine the antioxidant and antibacterial activity of this extract. The extract was tested alone (1024–1 μg/mL) or associated (MIC/8) with several antibiotics in order to identify any antibacterial activity against multiresistant bacterial strains (Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa). The existence of tannins, total phenols (901.31 mg/g) and flavonoids (89.68 mg/g) was confirmed in the HECCL. The presence of rutin and quercetin were confirmed by Thin-layer chromatography (TLC). Using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method, the antioxidant activity of the extract (9 μg/mL) was determined. Moreover, the Minimum Inhibitory Concentration (MIC) value found for HECCL was 1024 μg/mL and the association between HECCL (MIC/8) with benzylpenicillin significantly changed its minimum inhibitory concentration from 2500 to 625 μg/mL against E. coli.     

Daphne striata Tratt. and D. mezereum L.: a study of anti-proliferative activity towards human cancer cells and antioxidant properties

In this study, we investigated for the first time the anti-proliferative and antioxidant properties of D. mezereum and D. striata. The aerial parts were extracted by maceration with n-hexane, dichloromethane, and methanol. MPLC, GC, and GC-MS were used for the phytochemical study. The anti-proliferative activity was tested against MCF-7, A549, LNCaP, ACHN, and C32 cancer human cells. The antioxidant activity was measured by employing β-carotene bleaching, ABTS, DPPH, and FRAP tests. The Relative Antioxidant Capacity Index (RACI) was applied from the perspective of statistics. D. mezereum dichloromethane extract showed a remarkable anti-proliferative with an IC₅₀ of 6.08 μg/mL against LNCaP cells. Experimental data indicate that Daphne species have interesting anti-proliferative and antioxidant properties that deserve more investigations to develop novel antineoplastic drugs.     

Effects of Fermentation and Storage on Bioactive Activities in Milks and Yoghurts

Fermentation of milk enhances its nutritional value through improved bioavailability of nutrients and production of bioactive substances which have biological functions. The goals of this research were to study the effect of fermentation and storage on antioxidant and antimicrobial activities in buffalo, goat and cow milks and yoghurts. Samples of buffalo, goat, cow milks and their yoghurts during their fermentation and storage were determined for proximate analysis and bioactive activities including antioxidant activities of DPPH, ABTS and reducing power assays, and antimicrobial activities against Staphylococcus aureus, Bacillus cereus, Salmonella typhimurium and Escherichia coli. Results showed that buffalo, cow and goat yoghurts had antioxidant activities in all assays and their activities significantly increased during their fermentation. Pasteurization did not affect the antioxidant activities. The activities of all yoghurts remained unchanged after a storage time of 21 days at 4 °C. For the antimicrobial activities, only yoghurts from buffalo, cow and goat milks had the activities, while all milks did not show any activities. However, buffalo yoghurt could inhibit only Gram positive strains (S. aureus and B. cereus), while goat and cow yoghurt inhibited all tested strains. A chemical responsible for antimicrobial activities in yoghurts was lactic acid formed by lactic acid bacteria. However, bioactive peptides produced by protein digestion during milk fermentation by lactic acid bacteria could not be ruled out for antioxidant and antimicrobial activities present. The antimicrobial activities of all yoghurts remained constant during their storage. It is concluded that all yoghurts would retain milk nutrition and bioactive functions during their storage in a refrigerator and may be served as a functional food with benefits from those activities for consumers.     

Chemical composition and in vitro anticancer,antimicrobial and antioxidant activities of essential oil and methanol extract from Rumex nervosus

Chemical composition, antioxidant, anticancer, and antimacrobial activities of essential oil obtained from leaves of Rumex nervosus has been evaluated here for the first time. GC/MS analysis reveals the presence of Palmitoleic Acid (28.35%) and Palmitic acid, (25. 37%) as their methyl ester as major components. The essential oil showed significant DPPH radical scavenging activity (94.907 ± 0.1089% and 94.003 ± 0.0749%) at concentration (100 and 80) μg/mL respectively. The oil showed promising activity against staph aureus, while showed weak activity against (Hela and 3T3) cell lines. The crude extract / fractions of R. nervosus (leaves) showed significant antioxidant activity at dose (100 and 80) μg/mL. Futhermore the crude showed significant activity against (MCF-7 and MDA-MB-231) cell lines with IC₅₀ (20.5138 ± 0.933 and 25.1728 ± 0.9176) μg/mL respectively, and chloroform fraction showed good activity against (MCF-7 and MDA-MB-231) cell lines with IC₅₀ (31.154 ± 0.965 and 42.269 ± 2.1045) μg/mL.     

Chemical composition,N-nitrosamine inhibition and antioxidant and antimicrobial properties of essential oil from Coreopsis tinctoria flowering tops

Coreopsis tinctoria flowering (CTF) tops from the Kunlun Mountains in Xinjing (north-western China) have been used for tea production for about a century. This study was to assess antioxidant, nitrite-scavenging and N-nitrosamine inhibitory and antimicrobial activities of the essential oil extracted from CTF tops. The essential oil was extracted through hydrodistillation and its chemical compositions were analysed by GC–MS. Seventy compounds of the oil were identified, representing 81.87% of total oil. The antioxidant capacities of the oil with IC₅₀ values for scavenging DPPH and ABTS were 287.66 ± 12.60 and 1.251 ± 0.127 μg mL^? 1, respectively. The nitrite-scavenging and N-nitrosamine inhibitory activities (IC₅₀) were 0.3912 ± 0.0127 and 0.6564 ± 0.036 μg mL^? 1, respectively. The oil has a certain antimicrobial capacity, but its capacity was weaker than that of penicillinG (24 μg mL^? 1). The oil showed antioxidant and antimicrobial capacities and had a stronger nitrite-scavenging and N-nitrosamine inhibitory properties.