Optimised method for the analysis of phenolic compounds from caper (Capparis spinosa L.) berries and monitoring of their changes during fermentation

Bioaccessibility of phenolic compounds and antioxidant activity in raw and pickled capers

Capers are excellent sources of phenolic compounds, which possess antioxidant activity and a variety of health benefits. Capers are often not eaten fresh due to their bitterness, instead, they are usually brined and eaten as pickles. For phenolics to display beneficial effects, they should be bioaccessible. This research aimed to investigate the bioaccessibility values of phenolics in raw and pickled capers. Before and after in vitro digestion, total phenolic content (TPC), total flavonoid content (TFC), ABTS, DPPH, and FRAP antioxidant activities and individual phenolics were determined in raw (RC) and pickled capers (PC). TPC, TFC, and antioxidant activity of capers were not affected by pickling. The bioaccessibility of TPC in RC and PC was 77.8% and 72.9%, respectively. In vitro digestion decreased ABTS, DPPH, and FRAP antioxidant activity values in RC and PC significantly (p < 0.05). Rutin (quercetin-3-O-rutinoside) and kaempferol-3-O-rutinoside were found to be the main phenolic compounds before and after in vitro digestion in all caper samples. After in vitro digestion, rutin content decreased, while kaempferol-3-O-rutinoside content in capers was stable. The results suggest that capers are really good sources of bioaccessible phenolics.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-023-05824-x.

A randomized, placebo-controlled trial evaluating the safety of excessive administration of kaempferol aglycone

Kaempferol (KMP) is an important flavonoid in many fruits and vegetables. Preclinical studies on KMP have reported its pharmacological effects, including antimicrobial, antioxidant, anti-inflammatory, antitumor, antidiabetic, myocardial protective, and neuroprotective effects. Additionally, some epidemiological studies have revealed a negative association between the consumption of KMP-containing foods and the risk of developing several disorders, such as cancer and cardiovascular diseases. Thus, although a large body of literature has demonstrated the benefits of KMP supplementation, there are no reports of clinical trials evaluating the safety of KMP aglycone administration or KMP aglycone-rich food consumption. The purpose of this study was to evaluate the safety of a high dose of KMP aglycone by administrating KMP aglycone-containing supplements to healthy adults. This study had a randomized, double-blind, placebo-controlled design and a 4-week duration. Participants were randomly allocated to the KMP (n = 24) or placebo (n = 24) group. For 4 weeks, the KMP group received a capsule containing 50-mg KMP daily, a dose approximately five times higher than the estimated human dietary intake. The placebo group received a capsule containing cornstarch-based powder daily. The general toxicity parameters were evaluated by examining the characteristics of the participants, hematological and blood biochemical parameters, general urinalysis, qualitative urine tests, and adverse events. No clinical changes were observed in anthropometric and blood pressure measurements or blood and urine parameters in the KMP group compared to those in the placebo group. Furthermore, no adverse events owing to KMP aglycone administration occurred. The study results revealed that the consumption of 50-mg KMP aglycone daily for 4 weeks is safe in healthy adults.

Quality variation and biosynthesis of anti-inflammatory compounds for Capparis spinosa based on the metabolome and transcriptome analysis

Introduction

Capparis spinosa L. fruits as edible and medicinal plant, has anti-inflammatory activities. The different morphological characteristics of C. spinosa fruits from Ili, Turpan, and Karamay may affect their anti-inflammatory components and functions.

Methods

The anti-inflammatory activity of C. spinosa fruit was assessed using an LPS-induced inflammatory cell model. Furthermore, the differences in anti-inflammatory compounds were analyzed by metabolome and RNA-seq. Additionally, the anti-inflammatory mechanism was elucidated using network pharmacology.

Results

In the study, we found that the 95% ethanol extracts (CSE) obtained from the three kinds of fruits showed remarkable anti-inflammatory effects both in vivo and in vitro. However, the CSE derived from Ili fruits significantly reduced CD86 levels on DCs. As a result of metabolomic analysis, the metabolic profiles of Ili fruits differed significantly from those of the other two habitats, which were consistent with transcriptome analysis. A total of 15 compounds exhibiting anti-inflammatory activity were subjected to screening, revealing a greater accumulation of flavonoids in the Turpan and Karamay districts. Notably, phenolic compounds were identified as the principal anti-inflammatory components in C. spinosa.

Conclusion

There were significant differences in the morphology, metabolites, transcriptional levels, and anti-inflammatory activity of C. spinosa from the three districts.

Capparis spinosa L. as a potential source of nutrition and its health benefits in foods: A comprehensive review of its phytochemistry, bioactivities, safety, and application

Capparis spinosa L. (C. spinosa) is an edible plant with health-promoting benefits. C. spinosa possesses various biological activities, including antioxidant, antidiabetic, anticancer, hepatoprotective, neuroprotective, anti-inflammatory, anti-arthritic, antibacterial, and insecticidal effects. The active compounds associated with these effects mainly include flavonoids, phenolic acids, alkaloids, volatile oils, fatty acids, and polysaccharides. Moreover, C. spinosa has considerable nutritional value. Apart from being a food condiment, it belongs to a class of functional ingredients that act as preservatives and antioxidants in food products. C. spinosa has also shown good potential applications in novel food packaging materials. In this article, in addition to systematically reviewing the botanical characteristics, traditional edible uses, phytochemical composition, bioactivities and safety of C. spinosa, we highlight for the first time its potential applications in the foods. The findings will provide critical information for the future development of C. spinosa into a multifunctional food product with essential roles in health benefits.

Edible Insects an Alternative Nutritional Source of Bioactive Compounds: A Review

Edible insects have the potential to become one of the major future foods. In fact, they can be considered cheap, highly nutritious, and healthy food sources. International agencies, such as the Food and Agriculture Organization (FAO), have focused their attention on the consumption of edible insects, in particular, regarding their nutritional value and possible biological, toxicological, and allergenic risks, wishing the development of analytical methods to verify the authenticity, quality, and safety of insect-based products. Edible insects are rich in proteins, fats, fiber, vitamins, and minerals but also seem to contain large amounts of polyphenols able to have a key role in specific bioactivities. Therefore, this review is an overview of the potential of edible insects as a source of bioactive compounds, such as polyphenols, that can be a function of diet but also related to insect chemical defense. Currently, insect phenolic compounds have mostly been assayed for their antioxidant bioactivity; however, they also exert other activities, such as anti-inflammatory and anticancer activity, antityrosinase, antigenotoxic, and pancreatic lipase inhibitory activities.

Potential Functional Snacks: Date Fruit Bars Supplemented by Different Species of Lactobacillus spp

The influence of the addition of four different potential probiotic strains, Lactiplantibacillus plantarum subsp. plantarum (L. plantarum), Lactobacillus delbruekii subsp. bulgaricus (L. bulgaricus), Lactobacillus acidophilus (L. acidophilus) and Lactinocaseibacillus rhamnosus (L. rhamnosus), in date fruit-based products was investigated in order to evaluate the possibility of producing a functional snack. All bacterial strains tested were able to grow in date fruit palp, reaching probiotic concentrations ranging from 3.1 × 10⁹ to 4.9 × 10⁹ colony-forming units after 48 h of fermentation, and the pH was reduced to 3.5–3.7 or below. The viability of inoculated probiotic bacteria after 4 weeks of storage at 4 °C was slightly reduced. Some biochemical features of the fermented snacks, such as the total phenolic content (TPC), antioxidant activity and detailed polyphenolic profile, were also evaluated. After fermentation, changes in the polyphenol profile in terms of increased free phenolic compounds and related activity were observed. These results may be attributed to the enzymatic activity of Lactobacillus spp. in catalyzing both the release of bioactive components from the food matrix and the remodeling of polyphenolic composition in favor of more bioaccessible molecules. These positive effects were more evident when the snack were fermented with L. rhamnosus. Our results suggest the use of lactic acid fermentation as an approach to enhance the nutritional value of functional foods, resulting in the enhancement of their health-promoting potential.

LC-DAD-ESI-MS/MS-based assessment of the bioactive compounds in fresh and fermented caper (Capparis spinosa) buds and berries

The main objective of this study was to compare bioactive compounds and other important quality parameters of fresh and fermented caper buds and berries. Fresh samples were fermented using dry-salted and brined techniques. The higher phenolic content was determined in the fresh (1843.71 mg/100 g DW) and fermented buds (1198.54-1539.49 mg/100 g DW) rather than the berries (29.72-40.75 mg/100 g DW). Quercetin-3-O-rutinoside, kaempferol-3-O-rutinoside, and quercetin-O-galloly-O-hexoside were the principal phenolic components in fresh and fermented buds while quercetin-3-O-rutinoside in fresh and fermented berries. The amounts of isorhamnetin, quercetin, and kaempferol increased in fermented buds and berries compared to fresh samples. Similarly, antioxidant capacity of buds was found to be markedly higher than berries. As for sugar compounds, it was found that fructose in buds (1.56-3.23 g/100 g DW) and glucose in berries (1.96-6.38 g/100 g DW) had the highest amount. When total phenolics and antioxidant properties were evaluated, it was observed that they were better preserved in the dry-salted samples than the brined samples.

The influence of fermentation and bud sizes on antioxidant activity and bioactive compounds of three different size buds of Capparis ovata Desf. var. canescens plant

The impact of fermentation and bud size on the antioxidant activity, total phenolic content (TPC), and bioactive compounds of caper buds were investigated. The results showed significant differences in the bioactive properties depending on bud sizes and fermentation process. Antioxidant activity values of fresh caper buds were ranged between 69.61% (bid size) and 72.78% (small size), whereas the values of fermented ones varied between 12.50% (big size) and 39.09% (small size). TPC of fresh caper buds were found in the range of 357.81 mg GAE/100 g (medium size) and 372.22 mg GAE/100 g (small size), while those of fermented buds were ranged from 167.53 mg GAE/100 g (medium) to 246.01 mg GAE/100 g (small). Apigenin-7-glucoside, (+)-catechin, 1,2-dihydroxybenzene, and 3,4-dihydroxybenzoic, syringic, and gallic acids were the major phenolic compounds in both fresh and fermented caper buds. Overall, this study clearly demonstrated that both fermentation process and bud size significantly affected the antioxidant activity, TPC, and phenolic compounds of caper buds.

Polyphenol Compounds and Biological Activity of Caper (Capparis spinosa L.) Flowers Buds

The aim of the study was to analyze potential health-promoting components of caper flower buds (Capparis spinosa L.) at six stages of development in two cultivars. Polyphenol compounds (flavonols, hydroxycinnamic acids, flavan-3-ols) were identified by Liquid Chromatography- quadrupole Time-of-Flight -Mass Spectrofotometer/Mass Spectrofotometer (LC-qTOF-MS/MS) and quantified by Ultra Performance Liquid Chromatography-Photodiode Array-Fluorescence Detector (UPLC-PDA-FL). Moreover, antioxidant properties (ABTS+•, FRAP, and ORAC), anti-diabetic potential (α-amylase and α-glucosidase), and anti-aging activity (acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE)) of the buds were examined. Total phenolic compounds in the investigated caper varied from 10,720 to 3256 mg/100 g dry weight (DW), and depended on a genotype and growing stage of caper flowers. Among six different growing stages, the one named 'nonpareilles' was characterized by significantly higher content of polyphenols than the remaining five stages. The flavonols in caper flowers represented a mixture of different glycosylated quercetin, kaempferol, myricetin, and isorhamnetin derivatives, accounting for 38%-67%, 15%-36%, 4%-7%, and 0.8%-3%, respectively, of total flavonols,. Their contents strongly depended on the growth stage. 'Nonpareilles' and 'surfines' were richer in flavonols than 'fines' and 'gruesas'. Of the six investigated growth stages, 'nonpareilles' accumulated the greatest amounts of bioactive compounds that correlated with antioxidant and anti-diabetic properties, and were more potent BuChE than AChE inhibitors.

Screening of lactic starter from Tunisian fermented vegetables and application for the improvement of caper (Capparis spinosa) fermentation through an experimental factorial design

Purpose

This study aims at designing a lactic starter for caper fermentation isolated from Tunisian fermented vegetables to improve the process and produce consistent and high-quality product.

Methods

In this study, the lactic starter was isolated by exploring the lactic acid bacteria (LAB) of Tunisian artisanal fermented vegetables. Identification was carried out by partial 16S rRNA gene sequencing. Screening was based on salt tolerance and antagonistic activities against Escherichia coli ATCC 10536 and Enterococcus faecalis ATCC 10541. Caper fermentation was optimized through a full factorial experimental design (23), by exploring three factors: starter inoculum size, NaCl concentration, and acetate content. Differences in pH values, Total aerobic mesophilic bacteria and LAB counts between the beginning and end of fermentation are selected as responses and corresponding regression coefficients were calculated.

Results

The lactic microbiota is mainly represented by Lactobacillus plantarum group. Based on salt tolerance and antimicrobial activity, the strain Lactobacillus plantarum F3 was selected as starter for caper fermentation. The effect of NaCl concentration, acetate content, and inoculum size on acidity, total aerobic mesophilic bacteria count, and LAB count after 1 week and 1 month of caper fermentation was studied. Depending on the fermentation time, either 1 week or 1 month, the initial conditions should comprise 0% acetate, 108 CFU/mL inoculum, and 5% NaCl for 1 week against 5% acetate, 107 CFU/mL inoculum, and 10% NaCl for 1 month lasting caper fermentation. A protocol for caper fermentation was set up ensuring hygienic quality and LAB viability.

Conclusion

Lb. plantarum F3 was selected as lactic starter for caper fermentation, and initial fermentation conditions were optimized through a full factorial design. This work has shown loss in LAB viability after 1 week of fermentation. Based on results obtained, an optimized fermentation protocol was set up. This protocol ensures LAB survival and high hygienic quality of the product.

Characterization of Aroma-Active Compounds, Phenolics, and Antioxidant Properties in Fresh and Fermented Capers (Capparis spinosa) by GC-MS-Olfactometry and LC-DAD-ESI-MS/MS

Caper (Capparis spinosa) is an important food ingredient whose fresh parts, particularly the flower buds, are consumed as a starter with olives, cheese, and nuts, or are used as a component in other foods. It is one of the most popular species of aromatic plants grown in the Mediterranean zone. Fermentation makes the caper edible and affects the overall aroma as well as sensory and nutritional characteristics. This study aimed to evaluate the changes in aroma, aroma-active, and phenolic compounds of caper as affected by fermentation. Purge and trap method was used for the extraction of the aroma compounds, while gas chromatography-mass spectrometry olfactometry and Liquid chromatography coupled to diode array detection and electrospray ionization tandem mass spectrometry (LC-DAD-ESI-MS/MS) were employed for the detection of aroma-active compounds and phenolics, respectively. The results showed that the total amount of aroma compounds decreased drastically (62,616 to 21,471 µg/kg) in fermented sample. Twelve and 10 aroma-active compounds were detected in fresh and fermented caper buds, respectively, for the first time by the application of aroma extract dilution analysis. Among these compounds, methyl isothiocyanate (flavor dilution [FD] factor = 512) in fresh caper and acetic acid (FD factor = 128) in the fermented caper had the highest FD factor. With regard to the phenolic compounds, a total of 16 components were identified in fresh and fermented capers. As observed in aroma compounds, the total phenolic concentration decreased as a result of fermentation. Two phenolic compounds being kaempferol-3-O-glucosyl-rhamnosyl-glucoside and isorhamnetin hexoside were newly identified in caper. PRACTICAL APPLICATIONS: Capparis spinosa is one of the most popular sources of different secondary metabolites of interest to consumers. The results of the present study showed that the fermentation process of the capers is highly influential on the neutral composition of the sample. The total concentrations of aroma and phenolic compounds were reduced by 66% and 78%, respectively, in response to fermentation process.

Nutraceutical Value of Pantelleria Capers (Capparis spinosa L.)

Unopened flower buds of Capparis spinosa L. (capers), generally used in the Mediterranean area as food flavoring, are known to be a good source of bioactive compounds. The aim of this work was to evaluate the nutraceutical value of salt-fermented capers collected from different areas of Pantelleria Island (Italy), testing their methylglyoxal and glyoxal trapping capacity and antioxidant activity by 2,2-diphenyl-1-picryl hydrazyl (DPPH), [2,2-azinobis(3-ethylben- zothiazoline-6-sulfonic acid)] diammonium salt (ABTS), and oxygen radical absorbance capacity (ORAC) assays. Hydrophilic extracts were also characterized by high-performance liquid chromatography-electrospray ionization/mass spectrometry. Among 24 detected compounds, several flavonol derivatives and glucosinolates were identified. The levels of kaempferol and quercetin derivatives varied considerably among the five accessions considered (6.46 to 267.93 and 22.39 to 367.14 mg kaempferol and quercetin equivalent /g fresh weight, respectively), with kaempferol derivatives more representative than quercetin ones. Person's coefficient indicated a high correlation between total phenolic content and anti-DPPH radical capacity (R² = 0.665), as well as between total flavonoid content and antioxidant capacity (by ORAC assay; R² = 0.888) and between total flavonoid content and glyoxal and methylglyoxal trapping capacity (R² = 0.918). Results indicate that capers from Pantelleria Island represent a rich source of bioactive compounds with potential nutraceutical relevance. PRACTICAL APPLICATION: The findings of this study highlight the health benefits of Pantelleria capers consumption due to their composition in antioxidants and their biological properties (antiradical and alpha-dicarbonyls trapping) correlated with the development of a high number of chronic-degenerative diseases. These results are also important for the agricultural and commercial sectors involved in the production of capers from Pantelleria, which received the Protected Geographical Indications recognition.

Approaches to improve the growth of the starter lactic acid bacterium OM13 during the early stages of green Spanish-style table olive production

The present research aimed at determining the optimal conditions for the lactic acid fermentation of green Spanish-style table olives. The work is a follow-up, and focuses on the performance of the commercial starter strain Lactobacillus pentosus OM13 by applying an acclimatization step and the addition of nutrients, and concentrations of lactic acid that were previously investigated. The acclimatization of the cells warranted the dominance of the starter culture even at an inoculation level of 2 Log cycles lower than that commonly used in standard fermentation. A significant effect was found in terms of acidification kinetics within the first week of fermentation, with the highest decrease in pH, at ~2.5 units, which occurred in the trial and after inoculation with 106 CFU/mL of starter after acclimatation (EO3) that showed values similar to control C obtained with Lactobacillus pentosus OM13 at a concentration of 107 CFU/mL. After day 3, further decreases in pH of up to 4.30 were observed until day 30, and then these values remained almost constant until the end of process (day 190) when lower pH values were reached for trial EO3 and control C. The results of microbiological dynamics, the changes in VOCs and finally the effect of the processes on the sensory analysis of the fermented product were investigated by multivariate analysis. The acclimatization process and the initial inoculation level influenced the bacterial microflora, aromatic compounds and organoleptic characteristics of the final product. Finally, the trials C, EO2 and EO3 showed higher values (60-80%) of preferences and satisfaction compared to other experimental productions.

Modified Sample Preparation Approach for the Determination of the Phenolic and Humic-Like Substances in Natural Organic Materials By the Folin Ciocalteu Method

A novel modification of the sample preparation procedure for the Folin-Ciocalteu colorimetric assay for the determination of total phenolic compounds in natural solid and semisolid organic materials (e.g., foods, organic solid waste, soils, plant tissues, agricultural residues, manure) is proposed. In this method, the sample is prepared by adding sodium sulfate as a solid diluting agent before homogenization. The method allows for the determination of total phenols (TP) in samples with high solids contents, and it provides good accuracy and reproducibility. Additionally, this method permits analyses of significant amounts of sample, which reduces problems related to heterogeneity. We applied this method to phenols-rich lignocellulosic and humic-like solids and semisolid samples, including rice straw (RS), peat-rich soil (PS), and food waste (FW). The TP concentrations measured with the solid dilution (SD) preparation were substantially higher (increases of 41.4%, 15.5%, and 59.4% in RS, PS and FW, respectively) than those obtained with the traditional method (solids suspended in water). These results showed that the traditional method underestimates the phenolic contents in the studied solids.

Capparis spinosa L. in A Systematic Review: A Xerophilous Species of Multi Values and Promising Potentialities for Agrosystems under the Threat of Global Warming

Caper (Capparis spinosa L.) is a xerophytic shrub with a remarkable adaptability to harsh environments. This plant species is of great interest for its medicinal/pharmacological properties and its culinary uses. Its phytochemical importance relies on many bioactive components present in different organs and its cultivation can be of considerable economic value. Moreover, taxonomic identification of C. spinosa L. has been difficult due to its wide heterogeneity, and many authors fell into confusion due to the scarcity of genetic studies. The present review summarizes information concerning C. spinosa L. including agronomic performance, botanical description, taxonomical approaches, traditional pharmacological uses, phytochemical evaluation and genetic studies. This knowledge represents an important tool for further research studies and agronomic development on this indigenous species with respect to the emerging climatic change in the Eastern Mediterranean countries. Indeed, this world region is particularly under the threat of global warming and it appears necessary to rethink agricultural systems to adapt them to current and futures challenging environmental conditions. Capparis spinosa L. could be a part of this approach. So, this review presents a state of the art considering caper as a potential interesting crop under arid or semi-arid regions (such as Eastern Mediterranean countries) within the climate change context. The aim is to raise awareness in the scientific community (geneticists, physiologists, ecophysiologists, agronomists, …) about the caper strengths and interest to the development of this shrub as a crop.

Metabolomic study of wild and cultivated caper (Capparis spinosa L.) from different areas of Sardinia and their comparative evaluation

Capparis spinosa L. (Capparidaceae), also known as caper, is widely known for its very aromatic flower buds (capers),that are largely employed as a flavouring in cooking. Capparis species are regarded as a potential source of important bioactive compounds, in fact, due to their botanical relationship with Brassica species; they contain glucosinolates, secondary plant metabolites, that have been studied for their potential anticarcinogenic properties. In addition, the presence of other numerous beneficial compounds such as polyphenols, alkaloids, lipids, vitamins and minerals have been reported. The aim of this study was to individuate and determinate the principal bioactive compounds occurring in different part (leaves, buds and flowers) of wild and cultivated C. spinosa collected from different area of Sardinia (Italy). Ultra-high performance liquid chromatography-triple quadrupole/linear ion trap tandem mass spectrometry methods were used for identification and simultaneous determination of 27 bioactive molecules. Analysis of different samples revealed qualitative and quantitative differences in the content of flavonoids, glucosinolates, anthocyanins and phenolic acids. In particular, glucocapparin resulted the most abundant with values ranging from 112 to 364 mg/100 g Fresh Weight (FW); followed by rutin with highest value of 126 mg/100 g FW, 4-hydroxyglucobrassicin with highest value of 42 mg/100 g FW and isorhamnetin 3-O-rutinoside with highest value of 24 mg/100 g FW. Based on this metabolomic targeted approach, quantitative results were treated by principal component analysis to explore and visualise correlation and discrimination among collections of C. spinosa samples. Copyright © 2016 John Wiley & Sons, Ltd.

Pharmacological Effects of Capparis spinosa L

Medicinal plants have been known as one of the most important therapeutic agents since ancient times. During the last two decades, much attention has been paid to the health-promoting effects of edible medicinal plants, because of multiple beneficial effects and negligible adverse effects. Capparis spinosa L. is one of the most common medicinal plants, used widely in different parts of the world to treat numerous human diseases. This paper aims to critically review the available scientific literature regarding the health-promoting effects of C. spinosa, its traditional uses, cultivation protocols and phytochemical constituents. Recently, a wide range of evidence has shown that this plant possesses different biological effects, including antioxidant, anticancer and antibacterial effects. Phytochemical analysis shows that C. spinosa has high quantities of bioactive constituents, including polyphenolic compounds, which are responsible for its health-promoting effects, although many of these substances are present in low concentrations and significant changes in their content occur during processing. In addition, there is negligible scientific evidence regarding any adverse effects. Different health promotion activities, as well as tremendous diversity of active constituents, make C. spinosa a good candidate for discovering new drugs. However these findings are still in its infancy and future experimental and clinical studies are needed. Copyright © 2016 John Wiley & Sons, Ltd.

Quercetin and Its Anti-Allergic Immune Response

Quercetin is the great representative of polyphenols, flavonoids subgroup, flavonols. Its main natural sources in foods are vegetables such as onions, the most studied quercetin containing foods, and broccoli; fruits (apples, berry crops, and grapes); some herbs; tea; and wine. Quercetin is known for its antioxidant activity in radical scavenging and anti-allergic properties characterized by stimulation of immune system, antiviral activity, inhibition of histamine release, decrease in pro-inflammatory cytokines, leukotrienes creation, and suppresses interleukin IL-4 production. It can improve the Th1/Th2 balance, and restrain antigen-specific IgE antibody formation. It is also effective in the inhibition of enzymes such as lipoxygenase, eosinophil and peroxidase and the suppression of inflammatory mediators. All mentioned mechanisms of action contribute to the anti-inflammatory and immunomodulating properties of quercetin that can be effectively utilized in treatment of late-phase, and late-late-phase bronchial asthma responses, allergic rhinitis and restricted peanut-induced anaphylactic reactions. Plant extract of quercetin is the main ingredient of many potential anti-allergic drugs, supplements and enriched products, which is more competent in inhibiting of IL-8 than cromolyn (anti-allergic drug disodium cromoglycate) and suppresses IL-6 and cytosolic calcium level increase.