Phenols and antioxidant activity of hydro-alcoholic extracts of propolis from Algarve,South of Portugal

Propolis is a natural honeybee product known to be beneficial for human health, with a complex chemical composition, highly dependent on the collection site. The objective of the present research was to evaluate phenols and antioxidant activity of propolis samples collected in three main areas of Algarve, South of Portugal. Water revealed to be less effective for extracting phenolic compounds from propolis than the methanol and water/ethanol. The last two were good extraction solvents of phenols. Nevertheless water/ethanol was the solvent chosen because it was able to extract phenols in considerable amounts being less toxic than methanol.     

Comparison of total phenols content and antioxidant potential of peel extracts of local and imported lemons samples

The design of this study was to investigate and compare the total phenols content and antioxidant activity of various crude extracts of lemon peels collected from local farmers and imported one from the local supermarket. Investigation of the total phenol content and antioxidant activity of various polarity peel extracts were performed by modifying Folin-Ciocalteu reagent (FCR) and 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) bioassay. The maximum total phenol content in locally grown lemon was found in methanol extract and the minimum was obtained in butanol extract. However, the maximum concentration of total phenol content in imported lemon was also found in the methanol crude extract and the minimum was found in chloroform extract. The high antioxidant activity among the six prepared extracts of local lemon peels was found in the ethyl acetate extract and the lowest was found in chloroform extract. Similar antioxidant activity result was found in the imported lemon collected from the supermarket. Our results show that both lemon peels have the considerable concentration of total phenols content and antioxidant activity, respectively. The lemon peels are cheap and available globally and may find extensive use in medicine, food and perfume industries as vital sources of natural antioxidants.     

Total phenols, antioxidant potential and antimicrobial activity of walnut (Juglans regia L.) green husks

The total phenols content and antioxidant and antimicrobial activities were studied in walnut (Juglans regia L.) green husks aqueous extracts of five different cultivars (Franquette, Mayette, Marbot, Mellanaise and Parisienne). Total phenols content was determined by colorimetric assay and their amount ranged from 32.61 mg/g of GAE (cv. Mellanaise) to 74.08 mg/g of GAE t (cv. Franquette). The antioxidant capacity of aqueous extracts was assessed through reducing power assay, scavenging effects on DPPH (2,2-diphenyl-1-picrylhydrazyl) radicals and beta-carotene linoleate model system. A concentration-dependent antioxidative capacity was verified in reducing power and DPPH assays, with EC50 values lower than 1 mg/mL for all the tested extracts. The antimicrobial capacity was screened against Gram positive and Gram negative bacteria, and fungi. All the extracts inhibited the growth of Gram positive bacteria, being Staphylococcus aureus the most susceptible one with MIC of 0.1 mg/mL for all the extracts. The results obtained indicate that walnut green husks may become important in the obtainment of a noticeable source of compounds with health protective potential and antimicrobial activity.     

Correlations between polyphenolic composition and antioxidant activity of Venetian propolis

Four propolis samples have been picked up in the Venetian region, from different orography and habitative density areas with the purpose to: (i) evaluate propolis’ antioxidant activity, measured by inhibition of lipid peroxidation; (ii) determine the polyphenolic components – flavonoids and caffeic acid derivatives – which give antioxidant activity to propolis; (iii) verify the potential correlations between antioxidant activity, polyphenolic content, that has been determined by Folin–Ciocalteu, enzymatic, DPPH quenching, TEAC-like assays, and spectroscopic characteristics of propolis and (iv) correlate chemical structure and antioxidant efficacy of each of the major components. The possible localization of the lipophylic components of propolis into the phospholipidic bilayer by thermal analysis (DSC) and spin label EPR techniques has also been investigated.     

Antioxidant activities, metal contents, total phenolics and flavonoids of seven Morchella species

Seven Morchella species were analyzed for their antioxidant activities in different test systems namely β-carotene/linoleic acid, DPPH, reducing power, chelating effect and scavenging effect (%) on the stable ABTS⁺, in addition to their heavy metals, total phenolic and flavonoid contents. In β-carotene/linoleic acid system, the most active mushrooms were M. esculenta var. umbrina and M. angusticeps. In the case of DPPH, methanol extract of M. conica showed high antioxidant activity. The reducing power of the methanol extracts of mushrooms increased with concentration. Chelating capacity of the extracts was also increased with the concentration. On the other hand, in 40 μg ml⁻¹ concentration, methanol extract of M. conica, exhibited the highest radical scavenging activity (78.66 ± 2.07%) when reacted with the ABTS⁺ radical. Amounts of seven elements (Cu, Mn, Co, Zn, Fe, Ca, and Mg) and five heavy metals (Ni, Pb, Cd, Cr, and Al) were also determined in all species. M. conica was found to have the highest phenolic content among the samples. Flavonoid content of M. rotunda was also found superior (0.59 ± 0.01 μg QEs/mg extract).     

Antioxidant and antimicrobial effects of phenolic compounds extracts of Northeast Portugal honey

Phenolic compounds of dark and clear honeys from Trás-os-Montes of Portugal were extracted with Amberlite XAD-2 and evaluated for their antioxidant and antimicrobial activities. The antioxidant effect was studied using the in vitro test capacity of scavenge the 2,2-diphenyl-1-picryhydrazyl (DPPH) free radical and of reducing power of iron (III)/ferricyanide complex. The antimicrobial activity was screened using three Gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus, Staphylococcus lentus) and three Gram-negative bacteria (Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli). The results obtained from the partial identification of honey phenolic compounds by high-performance liquid chromatography with a diode array detector showed that p-hydroxibenzoic acid, cinnamic acid, naringenin, pinocembrin and chrysin are the phenolic compounds present in most of the samples analyzed. Antioxidant potential was dependent of honey extract concentration and the results showed that dark honey phenolic compounds had higher activity than the obtained from clear honey. In the biological assays, results showed that S. aureus were the most sensitive microrganisms and B. subtilis, S. lentus, K. pneumoniae and E. coli were each moderately sensitive to the antimicrobial activity of honey extracts. Nevertheless, no antimicrobial activity was observed in the test with P. aeruginosa.     

Comparative study of different Portuguese samples of propolis: Pollinic,sensorial, physicochemical,microbiological characterization and antibacterial activity

The aim of this work was to study four propolis samples from Trás-os-Montes region of Portugal. The propolis samples’ color was different, which pollen analysis showed to be due to different botanical sources: Populus sp., Pinus sp., Quercus sp. and Castanea sativa. The data from physicochemical analysis (moisture, soluble and insoluble solids content, pH, conductivity, ash content, wax, total phenolics and flavonoids content) was treated using multivariate statistical tools as cluster heat map, principal components analysis and linear discriminant analysis with the purpose of classifying the sample accordingly to the botanical/geographical origin. The discriminant analysis was applied with stepwise to select the variables that most contribute to sample identification accordingly to pollinic profile. The cross-validation technique was applied, using the leave-one-out procedure, which showed good prediction capabilities of the samples. Microbiologically, the commercial quality was satisfactory, since the samples didn’t contain deterioration or pathogenic microorganisms. All the samples studied presented antimicrobial activity against Methicillin-resistant Staphylococcus aureus, in a dose dependent way. The antimicrobial activity was strictly related to the physicochemical composition. This work will allow connecting a particular chemical propolis type to a specific type of biological activity, what is essential for the use in therapeutic applications.     

Antioxidant and antimicrobial properties of Teucrium arduini L. (Lamiaceae) flower and leaf infusions (Teucrium arduini L. antioxidant capacity)

Antioxidant and antimicrobial activities, as well as total phenol (TP, Folin–Ciocalteu method) and phenolic acid (UPLC–MS/MS) contents of leaf and flower infusions of Teucrium arduini L. from six different mountainous localities in Croatia (U?ka, Vošac, Sveti Jure, Snje?nica, Vaganac, Šušanj) were analysed in this study. Antioxidant capacity was evaluated using the ferric reducing/antioxidant power (FRAP) assay, as well as 2,2-diphenyl-1-picrylhydrazyl (DPPH), and 2,2′-azinobis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical scavenging assays. The antioxidant potency composite index (ACI), giving equal weight to all three methods used to quantify antioxidant capacity, was the highest for the sample from Vošac (96.7) among flower infusions, while maximum ACI (100) was determined for the infusion from U?ka among leaf infusions. Strong positive correlation was found between the total phenols and ACI for leaf (r = 0.953) and flower (r = 0.977) infusions. Our results point to significantly (p < 0.05) different TP content between leaf and flower infusions, as well as across localities. Leaf infusions of T. arduini from Šušanj exhibited marked antibacterial activity against Staphylococcus aureus, while none of the tested infusions exhibited antimicrobial activity against gram-negative bacterial species, or the tested fungal species.     

New p-Substituted Salicylaldehyde Phenylhydrazone Derivatives: Synthesis,Characterization, and Antioxidant Activities

A series of new p-nitrophenylhydrazone derivatives 3a–f were synthesized, characterized, and investigated for their antioxidant activities. These compounds have been synthesized by refluxing (p-nitrophenyl)hydrazine with 4-sub-stituted salicylaldehydes. The structures of the compounds were established by IR, ¹H- and ¹³C-NMR, and MS data. The antioxidant activities (free radical-scavenging activity, reducing power, metal chelating activity, and total anti-oxidant activity) of the hydrazone compounds were evaluated. All of the compounds exhibited significant activities, while compound 3a, with the shortest chain, showed the highest antioxidant activity in all of the tests.     

Honeybee-collected pollen from five Portuguese Natural Parks: Palynological origin, phenolic content, antioxidant properties and antimicrobial activity

The aim of this study was to determine the palynological origin, phenolic content, antioxidant and antimicrobial properties of pollen from five Portuguese Natural-Parks [Parque Nacional Peneda Gerês (PNPG); Parque Natural do Montesinho (PNM); Parque Natural do Alvão (PNA); Parque Natural da Serra da Estrela (PNSE) and Parque Natural do Douro Internacional (PNDI)]. Eight families were found in the mixture of bee pollen: Rosaceae, Cistaceae, Boraginaceae, Asteraceae, Fagaceae, Ericaeae, Myrtaceae and Fabaceae. The phenolic compounds content, determined by the Folin-Ciocalteu method, varied between 10.5 and 16.8 mg of gallic acid equivalents/g of extract (mg GAE/g) found in bee pollen from PNM and PNDI, respectively. The free radical scavenging measured showed the highest effective extract - PNM with EC₅₀ 2.16, followed by PND with 2.24 mg/mL. In the β-carotene bleaching assay the same behaviour as in the DPPH method was verified. We also verified that the presence of pollen differentially affected the growth of bacteria Gram-positive, Gram-negative and yeasts under study, depending this on the microorganism and the pollen used. This is an important study since, as far we know, it is the first time that Portuguese bee pollen from Natural Parks was studied, and their characterization can increase their economic value.     

Chemical characterization of Iraqi propolis samples and assessing their antioxidant potentials

Propolis samples, collected from different geographical locations in Iraq (Baghdad, Dahuk, Mosul and Salah ad-Din), were analyzed and assessed for their anti-oxidant activity. Concentrations of phenolic compounds (flavonoids, phenolic acids and their esters) in propolis were estimated using high performance liquid chromatography coupled to electrospray mass spectrometry. Thirty-eight different compounds were identified and 33 of them were polyphenols. Other compounds were tentatively identified as clerodane diterpenoids, and one was considered unknown. Semi-quantitative measurements showed that phenolic acids and their esters were the predominant constituents in propolis extracts, followed by flavones and flavonols, and then flavanones and dihydroflavonols. Propolis samples were further spectrophotometrically characterized using the Folin-Ciocalteu reagent for the determination of total phenolic compounds. The free radical scavenging activities of propolis samples were also evaluated by using the 2,2-diphenyl-1-picrylhydrazyl assay. The results revealed that propolis extracts exhibited strong free radical scavenging activity.     

Antimicrobial activity,phenolic profile and role in the inflammation of propolis

Nowadays a great amount of information regarding chemical and biological aspects of bee products is available in the literature, but few data on its therapeutic uses are found. The aim of this study was to evaluate the phenolic profile, the in vitro antimicrobial activity and effect in the hyaluronidase enzyme (widely related with the inflammation process) of propolis harvested in Portugal. The efficacy of three extracts (hydro-alcoholic, methanolic and aqueous) was also compared. It was chosen the hydro-alcoholic extract, because this was the most effective for extracting phenolic compounds. The antimicrobial activity was accessed in Gram-positive and Gram-negative bacteria and yeasts, isolated from different biological fluids and the results were then compared with the obtained for reference microorganisms. The propolis from Bragança was the one that possessed the highest polyphenols’ content. The sample from Beja showed the less significant inhibition of the hyaluronidase enzyme. Concerning the antimicrobial activity, Candida albicans was the most resistant and Staphylococcus aureus the most sensitive. The reference microorganisms were more sensitive than the ones isolated from biological fluids.     

Antioxidant activity and total phenolic content of ethanolic extract of Caesalpinia bonducella seeds

The aim of this study was to assess the in vitro potential of ethanolic extract of Caesalpinia bonducella seeds as a natural antioxidant. The DPPH activity of the extract (20, 40, 50, 100 and 200 μg/ml) was increased in a dose dependent manner, which was found in the range of 38.93–74.77% as compared to ascorbic acid (64.26–82.58%). The IC₅₀ values of ethanolic extract and ascorbic acid in DPPH radical scavenging assay were obtained to be 74.73 and 26.68 μg/ml, respectively. The ethanolic extract was also found to scavenge the superoxide generated by EDTA/NBT system. Measurement of total phenolic content of the ethanolic extract of C. bonducella was achieved using Folin–Ciocalteau reagent containing 62.50 mg/g of phenolic content, which was found significantly higher when compared to reference standard gallic acid. The ethanolic extract also inhibited the hydroxyl radical, nitric oxide, superoxide anions with IC₅₀ values of 109.85, 102.65 and 89.84 μg/ml, respectively. However, the IC₅₀ values for the standard ascorbic acid were noted to be 70.79, 65.98 and 36.68 μg/ml respectively. The results obtained in this study clearly indicate that C. bonducella has a significant potential to use as a natural antioxidant agent.     

虎奶菇菌核总三萜提取工艺优化及抗氧化活性研究

目的优化虎奶菇菌核总三萜提取工艺,研究其醇提物的体外抗氧化活性。方法以乙醇浓度、提取温度、提取时间和料液比为考察因素,以总三萜提取率为评价指标,采用L 9(3^4)正交试验表优选虎奶菇菌核总三萜提取工艺;采用紫外可见分光光度法检测虎奶菇醇提物的总三萜含量和体外抗氧化活性。结果虎奶菇菌核总三萜最佳提取工艺参数为:乙醇浓度95%、提取时间2h、提取温度90℃、料液比1∶15(g·mL^-1),提取率为(2.29±0.06)mg·g^-1。菌核醇提物表现出较强的OH自由基和良好的DPPH自由基清除活性,而对ABTS自由基的清除能力相对较弱,相应的半数抑制浓度(IC 50)分别为(0.425±0.01)、(3.25±0.05)和(18.35±2.32)mg·mL^-1。结论该提取工艺稳定可行,适合虎奶菇菌核总三萜的提取。虎奶菇菌核醇提物具有良好的体外抗氧化活性。     

超高效液相色谱串联四极杆飞行时间质谱联合网络药理学及分子对接技术分析蜂胶总黄酮治疗牙周炎的作用机制

目的 系统描述蜂胶总黄酮(TFP)中主要化学成分，探讨蜂胶总黄酮治疗牙周炎的作用机制。方法 采用超高效液相色谱串联四极杆飞行时间质谱(UPLC-Q-TOF/MS)明确TFP的化学成分。利用PubChem与Swiss target prediction数据库获取TFP作用靶点，通过在线人类孟德尔遗传数据库(OMIM)和GeneCards数据库筛选牙周炎相关靶点，并通过Venny 2.1平台获取TFP与牙周炎交集靶点。采用Cytoscape 3.7.2软件与STRING数据库分别构建“成分-靶点”网络图和交集靶点互作网络图，并利用DAVID数据库对交集靶点进行GO功能及KEGG通路富集分析。利用Autodock vina1.1.2软件对筛选的TFP潜在药效成分与核心靶点进行分子对接。体外建立LPS诱导的人牙周膜干细胞(hPDLSCs)炎症损伤模型，并验证TFP的抗炎活性。结果从TFP中共鉴定出13个黄酮类成分。共获得90个TFP与牙周炎交集靶点，其中RAC-α丝氨酸/苏氨酸蛋白激酶(AKT1)、前列腺素内过氧化物合酶(PTGS2)、表皮生长因子受体(EGFR)等为TFP治疗牙周炎的核心靶点...     

Anti-inflammatory,Antioxidant and Antimicrobial Effects of Artemisinin Extracts from Artemisia annua L.

The anti-inflammatory, antioxidant, and antimicrobial properties of artemisinin derived from water, methanol, ethanol, or acetone extracts of Artemisia annua L. were evaluated. All 4 artemisinin-containing extracts had anti-inflammatory effects. Of these, the acetone extract had the greatest inhibitory effect on lipopolysaccharide-induced nitric oxide (NO), prostaglandin E₂ (PGE₂), and proinflammatory cytokine (IL-1β , IL-6, and IL-10) production. Antioxidant activity evaluations revealed that the ethanol extract had the highest free radical scavenging activity, (91.0±3.2%), similar to α-tocopherol (99.9%). The extracts had antimicrobial activity against the periodontopathic microorganisms Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum subsp. animalis, Fusobacterium nucleatum subsp. polymorphum, and Prevotella intermedia. This study shows that Artemisia annua L. extracts contain anti-inflammatory, antioxidant, and antimicrobial substances and should be considered for use in pharmaceutical products for the treatment of dental diseases.     

岗松总黄酮抗氧化及抗炎作用研究

目的:研究岗松总黄酮体内抗氧化和抗炎作用.方法:小鼠灌胃岗松总黄酮9 d后,测定血清 SOD、MAD、GSH-Px水平以探讨岗松总黄酮的体内抗氧化作用;通过测定岗松总黄酮对二甲苯致小鼠耳肿胀抑制率的影响,研究岗松总黄酮的抗炎作用.结果:岗松总黄酮80 mg·kg-1组可显著提高小鼠SOD、GSH-Px活力,明显降低MAD含量(P＜0.05);而且能显著抑制二甲苯致小鼠耳的肿胀(P＜0.05).结论:岗松总黄酮具有较好的抗氧化和抗炎作用.     

In vivo antioxidant activity of total flavonoids from indocalamus leaves in aging mice caused by D-galactose

Objective: The aim of this thesis is to explore antioxidant activity of total flavonoids extracted from indocalamus leaves. Method: Aging mice model was established by D-galactose induction. Three groups of mice were treated with total flavonoids extracted from indocalamus leaves at doses of 20, 40 and 80 mg/kg d bw respectively. The antioxidant status in the aging mice was measured by determining the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT) and total anti-oxidant capability (T-AOC) in the serum and liver and malondialdehyde (MDA) content in the serum, liver and brain. Results: Compared with control group, extracts of indocalamus leaves significantly enhanced activities of SOD, GSH-Px, CAT in the serum and liver, and decreased MDA content in the serum, liver and brain at the tested doses. Conclusion: Total flavonoids extracted from indocalamus leaves demonstrated the potent antioxidant activity.     

Polyphenol profile by UHPLC-MS/MS,anti-glycation,antioxidant and cytotoxic activities of several samples of propolis from the northeastern semi-arid region of Brazil

Context: Propolis has promising biological activities. Propolis samples from the Northeast of Bahia, Brazil – sample A from Ribeira do Pombal and B, from Tucano – were investigated, with new information regarding their biological activities.

Objective: This paper describes the chemical profile, antioxidant, anti-glycation and cytotoxic activities of these propolis samples.

Material and methods: Ethanol extracts of these propolis samples (EEP) and their fractions were analyzed to determine total phenolic content (TPC); antioxidant capacity through DPPH^?, FRAP and lipid peroxidation; anti-glycation activity, by an in vitro glucose (10?mg/mL) bovine serum albumine (1?mg/mL) assay, during 7?d; cytotoxic activity on cancer (SF295, HCT-116, OVCAR-8, MDA-MB435, MX-1, MCF7, HL60, JURKAT, MOLT-4, K562, PC3, DU145) and normal cell lines (V79) at 0.04–25?μg/mL concentrations, for 72?h. The determination of primary phenols by ultra high-pressure liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) and volatile organic compounds content by gas chromatography-mass spectrometry (GC-MS) were also performed.

Results: The EEP polar fractions exhibited up to 90% protection against lipid peroxidation. The IC₅₀ value for anti-glycation activity of EEP was between 16.5 and 19.2?μg/mL, close to aminoguanidine (IC₅₀?=?7.7?μg/mL). The use of UHPLC-MS/MS and GC-MS allowed the identification of 12 bioactive phenols in the EEP and 24 volatile compounds, all already reported.

Conclusions: The samples present good antioxidant/anti-glycation/cytotoxic activities and a plethora of biologically active compounds. These results suggest a potential role of propolis in targeting ageing and diseases associated with oxidative and carbonylic stress, aggregating value to them.     

Antioxidant, cytotoxic activities, and structure-activity relationship of gallic acid-based indole derivatives

A new series of gallic hydrazones containing an indole moiety was synthesized through the reaction of gallic hydrazide and different indole carboxaldehydes. Their antioxidant activities were determined on DPPH radical scavenging and inhibition of lipid peroxidation. The in-vitro cytotoxic activities of the compounds were evaluated against HCT-116 (human colon cancer cell line) and MCF-7 (estrogen-dependent human breast cancer cell line) by the MTT method. An attempt to correlate the biological results with their structural characteristics has been done. A limited positive structure activity relationship was found between cytotoxic and antioxidant activities.