Quantification Of Phenolic Compounds Research Articles

Comparative study of antidiabetic activity of Cajanus cajan and Tamarindus indica in alloxan-induced diabetic mice with a reference to in vitro antioxidant activity.

Background:Oxidative stress not only develops complications in diabetic (type 1 and type 2) but also contributes to beta cell destruction in type 2 diabetes in insulin resistance hyperglycemia. Glucose control plays an important role in the pro-oxidant/antioxidant balance. Some antidiabetic agents may by themselves have antioxidant properties independently of their role on glucose control.Objective:The present investigation draws a comparison of the protective antioxidant activity, total phenol content and the antihyperglycemic activity of the methanolic extract of Cajanus cajan root (MCC) and Tamarindus indica seeds (MTI).Materials and Methods:Antidiabetic potentials of the plant extracts were evaluated in alloxan-induced diabetic Swiss albino mice. The plant extracts at the doses of 200 and 400 mg/kg body weight was orally administered for glucose tolerance test during 1-hour study and hypoglycemic effect during 5-day study period in comparison with reference drug Metformin HCl (50 mg/kg). In vitro antioxidant potential of MCC and MTI was investigated by using 1, 1- diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity at 517 nm. Total phenolic content, total antioxidant capacity and reducing power activity was also assayed.Results:There was a significant decrease in fasting serum glucose level (P < 0.001), reduction in blood glucose level (P < 0.001) in 5-days study, observed in the alloxan-induced diabetic mice. The reduction efficacy of blood glucose level of both the extracts is proportional to their dose but MCC is more potent than MTI. Antioxidant study and quantification of phenolic compound of both the extracts revealed that they have high antioxidant capacity.Conclusion:These studies showed that MCC and MTI have both hypoglycemic and antioxidant potential but MCC is more potent than MTI. The present study suggests that both MCC and MTI could be used in managing oxidative stress.

Effects of γ-radiation on microbial load and antioxidant proprieties in black tea irradiated with different water activities

The aim of this paper is to study the effect of gamma radiation on black tea irradiated with different water activities. The black tea samples had their Aw adjusted to three values (0.92, 0.65, and 0.18) and were irradiated in 60Co source at doses of 0, 1.0, 1.5, 2.0, 2.5, 5.0, 7.5, and 10.0kGy. The methods used were: microbiology, total phenolic compounds quantification, antioxidant activity by ORAC, and quantification of the main antioxidants. It was observed that the greater the amount of free water present in the samples, lower was the dose to achieve microbiological control. Regardless the water activity used, there was no difference in content of the phenolic compounds and at the mainly theaflavins, as well in the antioxidant activity at doses up to 5.0kGy.

HPLC–DAD–ESI–MS Analysis of Phenolic Compounds During Ripening in Exocarp and Mesocarp of Tomato Fruit

Identification of phenolic compounds was done by means of liquid chromatography (HPLC) coupled to mass spectrometry (MS) using the electrospray ionization interface (ESI). Quantification of phenolic compounds was carried out by using HPLC with diode array detector (DAD) in exocarp and mesocarp of tomato fruit at 6 different ripeness stages (mature-green, breakers, turning, pink, light-red, and red). Several phenolic compounds were identified including chlorogenic acid, caffeic acid, p-coumaric acid, ferulic acid, and rutin and some combined phenolic acids were tentatively identified, mainly glycosides, such as caffeoyl hexose I, caffeoyl hexose II, caffeoylquinic acid isomer, dicaffeoylquinic acid, p-coumaroyl hexose I, p-coumaroyl hexose II, feruloyl hexose I, feruloyl hexose II, siringyl hexose, and caffeoyl deoxyhexose hexose. Fruit exocarp had higher quantities of total soluble phenolics (TSP) compared to mesocarp. During ripening, TSP increased in both exocarp and mesocarp, mainly in exocarp. While rutin increased, chlorogenic acid decreased in both tissues: exocarp and mesocarp.

Seasonal changes in phenolic compounds and in the biological activities of Baccharis dentata (Vell.) G.M. Barroso

Baccharis, a large genus of Asteraceae, has been extensively studied because of the medicinal properties of its species. The present study determined the seasonal variation of the levels of total phenolic compounds and flavonoids of Baccharis dentata, and determined the antioxidant and bactericidal potential of the plant extracts. Aerial parts of B. dentata were harvested during the seasons of 1 year. Samples of 0.1g dry mass (DM) were extracted with aqueous methanol (80%; v/v), and used for quantification of phenolic compounds, quercetin-derived flavonoids and antioxidant activity (DPPH). Caffeic acid and the flavonoids rutin, quercetin, apigenin and kaempferol were quantified in methanolic extracts (0.5g DM) by HPLC. The micro-dilution method was applied for the determination of the minimal inhibitory concentration (MIC) of selected bacteria strains. Concentrations of total phenolic compounds and flavonoids showed significant seasonal variation, and the antioxidant potential of extracts was related to the concentration of these compounds. Highest antioxidant activity was detected in the extracts from summer and winter plants. Concentrations of quercetin, kaempferol and apigenin were markedly higher in spring and summer plants when compared to the other seasons. This result may be related to the antibacterial activity of n-butanolic and aqueous fractions against Staphylococcus aureus. This is the first report on seasonal changes of secondary compounds and biological activities on B. dentata and might be useful to prospection of novel molecules with antioxidant and antimicrobial properties.

Quantificação de compostos fenólicos e ácido ascórbico em frutos e polpas congeladas de acerola, caju, goiaba e morango

O crescente interesse da população pela promoção da saúde vem despertando a atenção dos consumidores por alimentos ricos em antioxidantes, combinado com a praticidade do consumo de sucos de frutos processados. O presente trabalho objetivou quantificar e avaliar a capacidade antioxidante de compostos fenólicos e ácido ascórbico em frutas in natura e polpas congeladas. As frutas in natura e polpas congeladas obtidas na região de Lavras - MG foram submetidas à quantificação de compostos fenólicos e ácido ascórbico e os respectivos extratos acetônico-etanólico e acetônico-metanólico. Foram determinadas suas atividades antioxidantes pelos métodos radicalares DPPH e ABTS. O extrato acetônico-metanólico foi mais efetivo para extrair os compostos antioxidantes das amostras. Apenas as polpas congeladas de acerola apresentaram uma redução do teor de compostos fenólicos em relação ao fruto. Para o teor de ácido ascórbico, houve uma redução nas polpas congeladas de acerola e goiaba. As amostras de acerola apresentaram os maiores teores de compostos fenólicos, ácido ascórbico e atividade antioxidante em relação aos demais frutos analisados.

Simultaneous characterization and quantification of phenolic compounds in Thymus x citriodorus using a validated HPLC–UV and ESI–MS combined method

Thymus x citriodorus is a Lamiaceae plant extensively cultivated in the Mediterranean region and used for centuries in culinary and in traditional medicine. The present work describes the detailed phenolic composition of T. x citriodorus for the first time, by means of HPLC–DAD, ESI–MS and MSn and nuclear magnetic resonance (NMR) analyses. The ethanolic extract of T. x citriodorus was analyzed by reversed phase HPLC. The method of analysis was also validated concerning its linearity, instrumental and method precision (for repeatability, immediate precision and intermediate precision) and accuracy (absolute recovery study). The technique was combined with electrospray mass spectrometry in order to identify the phenolic compounds and the structure of the main phenolics was also confirmed by NMR analysis. The in-house validated HPLC–DAD method showed good linearity for the tested reference compounds as well as satisfactory repeatability and immediate precision values, for both instrument and method. Furthermore, the satisfactory results of intermediate precision analysis and recovery assays indicated that the chromatographic method could be used to quantify the main phenolic compounds of T. x citriodorus with adequate precision and accuracy. The extract was rich in rosmarinic acid (10.4±0.6mg/g extract) that is a widespread phenolic acid in Thymus plants, but also in luteolin-7-O-α-glucuronide (12±2mg/g extract), that was herein reported in Thymus for the first time. Other novel compounds comprised one eriodictyol dihexoside with O-glycosidic linkages, two eriodictyol-O-monohexosides, one quercetagetin dimethyl ether-O-hexoside, one naringenin-O-hexoside and chrysoeriol-7-β-O-glucoside. Having in mind the health-promoting properties reported in literature for some of the main polyphenols found in T. x citriodorus, we suggest that this plant has a high potential for being used as a functional food.

Comparison of Two Methods, UHPLC-UV and UHPLC-MS/MS, for the Quantification of Polyphenols in Cider Apple Juices

The aim of this study was to develop faster and more efficient phenotyping methods for in-depth genetic studies on cider apple progeny. The UHPLC chromatographic system was chosen to separate polyphenolic compounds, and quantifications were then simultaneously performed with a UV-PDA detector and an ESI-triple quadrupole mass analyzer (SRM mode). Both quantification methods were validated for 15 major compounds using two apple juice samples, on the basis of linearity, limits of detection and quantification, recovery and precision tests. The comparison between UV and SRM quantifications in 120 different samples of a cider apple progeny showed an excellent correlation for major compounds quantified with both methods. However, an overestimation was revealed for five compounds with the UV detector and the mass analyzer. Co-elution and matrix effects are discussed to explain this phenomenon. SRM methods should therefore be considered with restrictions in some cases for quantification measurements when several phenolic compounds are simultaneously quantified in complex matrices such as apple juices. For both methods, analyses were carried out over short periods of time while maintaining a high quality for the simultaneous quantification of phenolic compounds in apple juice. Each method is relevant for more in-depth genetic studies of the polyphenol content of apple juice.

Characterization and quantification of phenolic compounds and antioxidant properties of Salvia species growing in different habitats

Few literature data are available on the antioxidants of Salvia verbenaca, Salvia aegyptiaca and Salvia argentea. Such lack of information prevents exploitation of these potential pool of compounds with strong antioxidant activity. So, in the present study, phenolic contents and compositions and antioxidant activities of methanolic extracts of four Salvia species, growing in various habitats, were determined. The total phenolic contents estimated spectrophotometrically ranged from (67.67–72.02mgGAE/gDW) for S. argentea extracts to (112.93–161.37mgGAE/gDW) for Salvia officinalis samples. The HPLC analysis detected the presence of several phenolic acids, particularly the caffeic acid derivatives along with flavonoids and phenolic diterpenes. Rosmarinic acid was found to be the most abundant compound in all analyzed extracts and showed its highest values in S. officinalis samples (13,680.22–18,378.00μg/gDW). Varying degrees of antioxidant and radical-scavenging efficacity of different sage extracts were illustrated. S. officinalis methanolic extracts had the strongest antioxidant capacity as evaluated by DPPH (10.08–3.37μg/mL), ABTS (644.85–766.30μMTE/mg) and FRAP (178.65–197.33mMFe(II)/mg) assays. Significant correlations between total phenolics, the most representative phenolic compounds, particularly rosmarinic acid and the antioxidant assays were verified. Variations of total phenolic contents and compositions and antioxidant activities between Salvia samples grown at different regions were significant. Salvias aerial part extracts could be valuable as an effective and safe source of functional food materials such as natural antioxidants.

English

&nbsp; Earthworm paste (EP) has many therapeutic properties such as antioxidant, anti-inflammatory, anticancer and antibacterial activities. Antioxidant properties of the earthworm paste extract may attribute to high phenolic compounds. This study involved quantification of phenolic compounds and evaluation of the antioxidant activity of earthworm paste (EP) from&nbsp;Lumbricus rubellus&nbsp;(red worm) and&nbsp;Eudrilus eugeniae&nbsp;(African night crawler).&nbsp;Three types of solvents were used: 75% methanol, 80% methanol and 80% ethanol. Total phenolic compounds were quantified spectrophotometrically using Folin-Ciocalteu reagent. The antioxidant activity of earthworms paste was evaluated using DPPH (1,1-diphenyl-1-2-picrylhydrazl) method. The extraction of phenolics with 80% ethanol in both species yielded the highest amount of phenolics, 220.6 mg/L, in the African night crawler extract and 247.00 mg/L in the red worm extract. Extraction with 80% methanol yielded 217.00 mg/L of phenolics in the African night crawler extract and 228.00 mg/L in the red worm extract. Extraction with 75% methanol yielded higher amounts in red worm (237.00 mg/L) than in African night crawler (207.00 mg/L). EP of the African night crawler yielded a greater amount of phenolic compounds than the red worm. DPPH assay showed that the inhibition activity of African night crawler (95.23%) was significantly higher than that of the red worm extract (38.26%) in 80% methanol, whereas, in 80% ethanol, the inhibition activity of African night crawler (48.13%) was not significantly different from that of the red worm extract (47.73%). Inhibition of antioxidant activity of African night crawler extract in 75% methanol (48.13%) was higher than that of the red worm extract (47.93%). The study showed that earthworm paste has notable amounts of phenolic compounds that have significant antioxidant activity. &nbsp; Key words:&nbsp;Earthworm paste (EP), phenolic compounds, antioxidants.

Development and Validation Method for Simultaneous Quantification of Phenolic Compounds in Natural Extracts and Nanosystems

Sage and savoury (Salvia sp. and Satureja montana, respectively) are plants used in traditional medicine. The quality control of their herbal formulations is of paramount concern to guarantee the expected biological activity of their anti-oxidant compounds. To establish a simple and effective high-performance liquid chromatographic (HPLC) method to evaluate simultaneously quercetin and rosmarinic acid, in a pure form, in natural extracts (sage and savoury), and encapsulated into chitosan nanoparticles. Chromatography was performed on an RP C18 -column, in a gradient mode with a mobile phase comprising methanol:formic acid:water 92.5:2.5:5 (v/v) at a flow rate of 0.75 mL/min and at wavelength of 280 nm. The method was specific, linear in the range of 0.05-1 mg/mL (R(2) = 1.00), precise at the intraday and interday levels, accurate (recovery rate 90.5 ± 0.6%), and robust to changes in equipment conditions. The method established was effective for quercetin and rosmarinic acid characterisation in natural extracts and in chitosan nanoparticles, allowing the loading capacity determination, the association efficiency as well as the in vitro release.

Characterisation of Phenolic Compounds in South African Plum Fruits (Prunus salicina Lindl.) using HPLC Coupled with Diode-Array, Fluorescence, Mass Spectrometry and On-Line Antioxidant Detection

Phenolic compounds are abundant secondary metabolites in plums, with potential health benefits believed to be due to their antioxidant activity, amongst others. Phenolic characterisation of South African Prunus salicina Lindl. plums is necessary to fully evaluate their potential health benefits. An HPLC method using diode-array detection (DAD) for quantification of phenolic compounds was improved and fluorescence detection (FLD) was added for quantification of flavan-3-ols. Validation of the HPLC-DAD-FLD method showed its suitability for quantification of 18 phenolic compounds, including flavan-3-ols using FLD, and phenolic acids, anthocyanins and flavonols using DAD. The method was suitable for characterisation of the phenolic composition of 11 South African plum cultivars and selections, including various types with yellow and red skin and flesh. The method was used in conjunction with mass spectrometry (MS) to identify 24 phenolic compounds. Neochlorogenic acid and cyanidin-3-O-glucoside were the major compounds in most of the plums, while cyanidin-3-O-glucoside was absent in Sun Breeze plums with yellow skin and flesh. Post-column on-line coupling of the ABTS•+ scavenging assay with HPLC-DAD enabled qualitative evaluation of the relative contribution of individual phenolic compounds to the antioxidant activity. The flavan-3-ols, neochlorogenic acid and cyanidin-3-O-glucoside displayed the largest antioxidant response peaks.

Development and validation studies for determination of phenylpropanoid‐substituted flavan‐3‐ols in semipurified extract of Trichilia catigua by high‐performance liquid chromatography with photodiode array detection

The phenolic compounds are the main phytochemical constituents of the bark of Trichilia catigua and are commonly used for medicinal purposes. An HPLC method for the simultaneous quantification of phenolic compounds (procyanidin B2 (PB2), epicatechin (EPC), chinchonains Ia, Ib, IIa, IIb, catechin, and chrologenic acid) in T. catigua extract was developed and validated. A suitable chromatographic system was selected, which uses a gradient elution with methanol/ACN (75:25), and water both with 0.05% TFA, as mobile phase, column Luna, 280 nm, and flow 0.4 mL/min. Validation of the analytical method was based on the parameters: linearity, precision, LODs and LOQs, accuracy, robustness, and stability. The method showed linearity for PB2 and EPC, in the range 10-120 μg/mL with good correlation coefficients (>0.996). For precision, the repeatability ranged from 1.89 to 3.23%, and the values for accuracy for PB2 and EPC were 95 and 89%, respectively. The LODs and LOQs for PB2 were 1.36 and 4.12 μg/mL, and for EPC were 2.18 and 6.61 μg/mL, respectively. The method was robust under the conditions employed. The proposed method could be employed for quality assessment of T. catigua, as well as pharmaceutical products.

HPLC-DAD-ESI/MS Identification and Quantification of Phenolic Compounds in Ilex paraguariensis Beverages and On-Line Evaluation of Individual Antioxidant Activity

“Chimarrão” and “tererê” are maté (dried, toasted and milled Ilex paraguariensis leaves and stemlets) beverages widely consumed in South America. This paper describes the application of HPLC-DAD-ESI/MS method for the identification and quantification of caffeoylquinic acids (CQA), flavonol glycosides and purine alkaloids in these beverages. The beverage samples were prepared from commercial lots of maté from Southern Brazil. The caffeoylquinic acids, 4,5-diCQA, 3-CQA, 5-CQA, and 4-CQA were the major compounds, having 238–289, 153–242, 183–263, and 123–188 μg/mL, respectively, for chimarrão and 206–265, 122–218, 164–209, 103–169 μg/mL, respectively, for tererê. Caffeine also had high amounts while glycosides of quercetin and kaempferol were found at much lower levels. The individual antioxidant activity was also determined by an on-line system that measured their ABTS•+ radical scavenging activity, showing that the antioxidant capacity was not proportional to the concentrations of the phenolic compounds. 3-CQA, quercetina-3-O-ramnosylglucoside, and quercetina-3-O-glucoside were the major contributors to the antioxidant capacity, although the quercetin glycosides had concentrations less than 10 times that of 3-CQA.

Techniques for analysis of plant phenolic compounds.

Phenolic compounds are well-known phytochemicals found in all plants. They consist of simple phenols, benzoic and cinnamic acid, coumarins, tannins, lignins, lignans and flavonoids. Substantial developments in research focused on the extraction, identification and quantification of phenolic compounds as medicinal and/or dietary molecules have occurred over the last 25 years. Organic solvent extraction is the main method used to extract phenolics. Chemical procedures are used to detect the presence of total phenolics, while spectrophotometric and chromatographic techniques are utilized to identify and quantify individual phenolic compounds. This review addresses the application of different methodologies utilized in the analysis of phenolic compounds in plant-based products, including recent technical developments in the quantification of phenolics.

Comparison of methods for the processing of voltammetric electronic tongues data

We are making a numerical comparison of various preprocessing strategies for dealing with data from voltammetric electronic tongues in order to reduce the high dimensionality of the response matrices. Different modelling tools are presented and briefly described. We then compare combinations of four preprocessing strategies (principal component analysis, fast Fourier transform, discrete wavelet transform, voltammogram-windowed slicing integral) with four modelling alternatives (principal component regression, partial least squares regression, multi-way partial least squares regression, artificial neural networks) by employing data from a voltammetric bioelectronic tongue, an array formed by enzyme-modified biosensors and applied to the discrimination and quantification of phenolic compounds.

In vitro and in vivo antioxidant properties of Tunisian carob ( Ceratonia siliqua L.)

The present study aims at the quantification of phenolic compounds of Tunisian carob (Ceratonia siliqua L.) pods and the study of their in vitro and in vivo antioxidant activities in different extraction solvents. In this respect, we used 50 rats divided into five groups: Control and Carob-treated groups (100, 200, 600 and 1000 mg/kg, b.w.). Our results showed that the carob polar extracts are richer in total polyphenols, total flavonoids and condensed tannins than the nonpolar extracts with quantitative variation of phenolic compounds between seeds and pulp. In vitro, the determination of antioxidant capacity by 2,2'-azino-bis[3-ethylbenzthiazoline-6-sulphonic acid] (ABTS) method showed that carob extracts present high antioxidant potency in a solvent-compartment-dependent way compared to Trolox, an antioxidant reference molecule. In vivo, the subacute treatment within 7 days with aqueous extract of carob pods (AECP) decreased significantly and doses dependently the cerebral and myocardial lipid peroxidation as well as the level of hydrogen peroxide (H2O2) in kidney, liver and brain but not in heart. These data suggest that carob fruit presents an in vitro an in vivo antioxidant effects and might be proposed as a food additive to protect against oxidative stress damage. Key words: Carob, phenolic compounds, antioxidant properties, rat.

Ethanolic Extract of Polish Propolis: Chemical Composition and TRAIL-R2 Death Receptor Targeting Apoptotic Activity against Prostate Cancer Cells

Propolis possesses chemopreventive properties through direct anticancer and indirect immunomodulatory activities. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) plays a significant role in immunosurveillance and defense against cancer cells. TRAIL triggers apoptosis upon binding to TRAIL-R1 (DR4) and TRAIL-R2 (DR5) death receptors expressed on cancer cell surface. The activation of TRAIL apoptotic signaling is considered an attractive option for cancer prevention. However, as more tumor cells are reported to be resistant to TRAIL-mediated death, it is important to develop new strategies to overcome this resistance. The aim of this study was to investigate the chemical composition and proapoptotic mechanism of ethanolic extract of Polish propolis (EEP-P) against cancer cells. The identification and quantification of phenolic compounds in propolis extract were performed using HPLC-DAD and UPLC-Q-TOF-MS methods. TRAIL-resistant LNCaP prostate cancer cells were treated with EEP-P and TRAIL. Cytotoxicity was measured by MTT and LDH assays. Apoptosis was detected using annexin V-FITC staining by flow cytometry and fluorescence microscopy. Death receptors expression was analyzed using flow cytometry. Pinobanksin, chrysin, methoxyflavanone, p-coumaric acid, ferulic acid and caffeic acid were the main phenolics found in EEP-P. Propolis sensitized LNCaP cells through upregulation of TRAIL-R2. These results suggest that EEP-P supports TRAIL-mediated immunochemoprevention in prostate cancer cells.

Utilization of Prune Juice or Puree as a Laxative for Constipation Pregnant Rats Induced Iron Intake during Pregnancy and the Impact on Newborns

Iron supplementation during pregnancy causes constipation in pregnant women and newborn babies; especially on high doses. Prune juice and prune puree were tested to avoid the constipation in pregnant women and newborn babies. Phenolic compounds, vitamin C and sugar alcohols of prune juice and prune puree were determined. Forty two pregnant female rats fed a basal diet for 6 weeks. At the 10th day of pregnancy they were divided randomly into 7 groups. Group 1, was the negative control (N. control). Rats from group 2 to group 4 fed on basal diet and received 1mg Fe2+/kg b.w. Group 3 and group 4 administered 0.5 ml prune juice and prune puree twice daily, respectively. Moreover, rats from group 5 to group 7 fed on basal diet and received 2.5 mg Fe2+ /kg b.w. Group 6 and group 7 administered 0.5 ml prune juice and prune puree twice daily, respectively. Group 2 and 5 were considered positive control 1 and 2, respectively. The mothers rats were received Fe2+ (ferrous fumarate dosage form) daily until parturition; however, they were administrated prune juice and prune puree until weaning at the end of experiment (42 days). The mothers of rats and puppies were killed at the end of breast feeding. The results of HPLC-UV detector indicated that quantification of phenolic compounds, vitamin C, sorbitol and xylitol in prune puree were higher than prune juice. Concerning the results of biological experiment, it could be noticed that Fe2+ (ferrous fumarate form) significantly decreased the pellet number, weight, and % moisture of feces in pregnancy, lactating, in male and female infant rats. Moreover, gastrointestinal movements were significantly reduced in rats administrated with 1 or 2.5mg Fe2+/Kg b.w represented in the G2 and G5 compared to the negative control (G1). Moreover, prune juice and prune puree utilization improved the tested parameters for pregnancy, lactating and infant rats whether they were male or female. The results clearly showed that prune juice or puree can prevent or treat constipation via normalizing the bowel movement resulting from Fe2+administration in pregnant rats and their puppies (newborn and infant).

Phenolic Compounds from Diluted Acid Hydrolysates of Olive Stones: Effect of Overliming

Annually, important quantities of olive residue are produced and may be the source of ecological damages. Like agricultural residues, which are abundant, renewable, low cost raw materials, olive stones are mainly subjected to biotechnological or chemical modifications in order to be transformed into valuable products (biofuels, biofertilizers, animal feed and chemical feed-stock). In aim to valorize olive stones, we are trying to identify the presence of different phenolic compounds in their dilute-acid hydrolysate (DAH). Phenolic compounds (PC) are considered as toxic material for fermentation process, therefore, their behavior are studied under overliming treatment with distinct pH levels (10 and 12), temperature (25 and 60°C) and detoxification time (15,30 and 60 min). Identification and quantification of phenolic compounds were performed by two chromatographic methods: Gas Chromatography mass spectrometry (GC-MS) and High-Performance Liquid Chromatography (HPLC). A liquid-liquid microextraction procedure is used in conjunction with silylation prior to the analysis of the compounds by GC-MS. Derivatives of benzoic acid, cinnamic acid, simple phenols, and aldehydes were identified. For all treatments combinations, pH 12 was more effective in reducing the total amount of phenolic compounds. Treatment of the hydrolysate with alkali at pH 12, 60°C and 60 min resulted in up to 29% decrease in the concentration of total phenolic compounds. Tyrosol, which was the main phenolic compound decreased by 73% under the same treatment. Chromatographic methods contributed to an accurate quantification and better understanding of the behavior of each PC, solely.

Chemical Composition and Anti-Inflammatory Effect of Ethanolic Extract of Brazilian Green Propolis on Activated J774A.1 Macrophages

The aim of this study was to investigate the chemical composition and anti-inflammatory effect of ethanolic extract of Brazilian green propolis (EEP-B) on LPS + IFN-γ or PMA stimulated J774A.1 macrophages. The identification and quantification of phenolic compounds in green propolis extract were performed using HPLC-DAD and UPLC-Q-TOF-MS methods. The cell viability was evaluated by MTT and LDH assays. The radical scavenging ability was determined using DPPH• and ABTS•+. ROS and RNS generation was analyzed by chemiluminescence. NO concentration was detected by the Griess reaction. The release of various cytokines by activated J774A.1 cells was measured in the culture supernatants using a multiplex bead array system based on xMAP technology. Artepillin C, kaempferide, and their derivatives were the main phenolics found in green propolis. At the tested concentrations, the EEP-B did not decrease the cell viability and did not cause the cytotoxicity. EEP-B exerted strong antioxidant activity and significantly inhibited the production of ROS, RNS, NO, cytokine IL-1α, IL-1β, IL-4, IL-6, IL-12p40, IL-13, TNF-α, G-CSF, GM-CSF, MCP-1, MIP-1α, MIP-1β, and RANTES in stimulated J774A.1 macrophages. Our findings provide new insights for understanding the anti-inflammatory mechanism of action of Brazilian green propolis extract and support its application in complementary and alternative medicine.