Phytochemical Profile, Antioxidant, Anti-Alzheimer, And α-Glucosidase Inhibitory Effect Of Algerian Peganum harmala Seeds Extract.

Peganum harmala seeds crude hydro-methanolic extract and their fractions (obtained with ethyl acetate and butan-1-ol) were analyzed and compared for their chemical profiles of alkaloids and polyphenols content. Moreover, their antioxidant, a-glucosidase, acetylcholinesterase, and butyrylcholinesterase inhibitory activities were evaluated. The butan-1-ol fraction revealed the highest total phenolic content and exhibited the highest antioxidant capacity. From the inhibitory enzyme evaluations, it should be highlighted the butan-1-ol fraction inhibitory potential of ɑ-glucosidase (the IC50= 141.18±4µg/mL), which was better than the acarbose inhibitory effect (IC50= 203.41±1.07 µg/mL). The extracts' chemical profile analysis revealed several compounds, in which quercetin dimethyl ether, harmine and harmaline emerged as the major compounds. The different solvents used impacted Peganum harmala seed contents and biological responses. Statistical analysis showed a significant correlation between bioactive compounds and biological activities. Thus, Peganum harmala seeds could be a promising natural source of bioactive compounds at the crossroads of many human diseases, and its cultivation may be encouraged.

Biostimulation of Salicornia europaea L. crops with plant growth-promoting bacteria in laboratory and field conditions: effects on growth and metabolite profile.

AIM: The objective of the work was to assess the effect of biostimulation with selected plant growth-promoting bacteria on growth and metabolite profile of Salicornia europaea. METHODS AND RESULTS: Salicornia europaea seeds were inoculated with different combinations of plant growth-promoting bacteria Brevibacterium casei EB3, Pseudomonas oryzihabitans RL18, and Bacillus aryabhattai SP20. Plants germinated from inoculated seeds were grown either in laboratory conditions or in a saline crop field. Fresh and dry weight were determined at the end of the experiment, for biomass quantification. The microbiological quality of fresh shoots for human consumption as salad greens was assessed, and the persistence of the inoculated strains in the plant rhizosphere was confirmed by next-generation sequencing (Illumina) of the 16S rDNA gene. The primary metabolite profile of biostimulated plants was characterized by GC-TOF-MS.In laboratory conditions, inoculation with the two strains Br. casei EB3 and Ps. oryzihabitans RL18 caused the most significant increase in biomass production (fresh and dry weight), and caused a shift in the central metabolic pathways of inoculated plants toward amino acid biosynthesis. In the field experiment, no significant biostimulation effect was detected with any of the tested inoculants. Seed inoculation had no significant effect on the microbiological quality of the edible parts. The persistence of inoculants was confirmed in both experiments. CONCLUSIONS: Manipulation of the plant microbiome can trigger primary metabolic reconfiguration and modulate the plant metabolism while promoting plant growth.

Domestication shapes the endophytic microbiome and metabolome of Salicornia europaea.

AIMS: We aim at understanding the effect of domestication on the endophytic microbiome and metabolome of Salicornia europaea and collecting evidence on the potential role of microbial populations and metabolites in the adaptation of plants to different ecological contexts (wild vs crops). METHODS AND RESULTS: Samples were collected from a natural salt marsh (wild) and an intensive crop field (crop). High-throughput sequencing of the 16S rRNA gene, gas chromatography-mass spectrometry (GC-MS) and ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) were used to analyze the endophytic bacterial communities and the metabolite profiles of S. europaea roots, respectively. The elemental analysis of the plant shoots was performed by Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS).Overall, significant differences were found between the microbiome of wild and cultivated plants. The later showed a higher relative abundance of the genera Erythrobacter, Rhodomicrobium, and Ilumatobacter than wild plants. The microbiome of wild plants was enriched in Marinobacter, Marixanthomonas, and Thalassospira. The metabolite profile of crop plants revealed higher amounts of saturated and non-saturated fatty acids and acylglycerols. In contrast, wild plants contained comparatively more carbohydrates and most macroelements (i.e. Na, K, Mg, and Ca). CONCLUSIONS: There is a strong correlation between plant metabolites and the endosphere microbiome of S. europaea. In wild populations, plants were enriched in carbohydrates and the associated bacterial community was enriched in genes related to primary metabolic pathways such as nitrogen metabolism and carbon fixation. The endosphere microbiome of crop plants was predicted to have higher gene counts related to pathogenesis. Crop plants also exhibited higher amounts of azelaic acid, an indicator of exposure to phytopathogens.

Observation of the two-photon transition enhanced first hyperpolarizability spectra in cinnamaldehyde derivatives: A femtosecond regime study.

The application of nonlinear optical effects in optoelectronic devices is still scarce because the irradiance threshold necessary to induce a specific effect is very high. In this context, knowing the frequency-resolved first order molecular hyperpolarizability (ß) is essential to identifying regions where this response is intense enough to allow for applications in commercial devices. Thus, herein, we have determined the ß spectral dependence of five new push-pull cinnamylidene acetophenone derivatives using femtosecond laser-induced Hyper-Rayleigh Scattering (HRS). A considerable increase in ß values was observed in molecules. We found remarkable ß values in regions near the two-photon resonance, which are mediated by electron withdrawing and donating groups. This effect was mapped using wavelength-tunable femtosecond Z-scan technique. Furthermore, it was modeled in light of the sum-over-states approach for the second- and third-order nonlinearities. Finally, our outcomes suggest a strategy to obtain large ß values mediated by the 2PA transition.

Inula viscosa (L.) Aiton Ethanolic Extract Inhibits the Growth of Human AGS and A549 Cancer Cell Lines.

The present study shows the chemical profile and cytotoxic properties of the ethanolic extracts of Inula viscosa from Northeast Algeria. The extract was obtained by maceration using ethanol. Its phenolic profile was determined using ultra-high-performance liquid chromatography coupled with a diode array detector and an electrospray mass spectrometer (UHPLC-DAD-ESI/MS), which allowed the identification and quantification of 17 compounds, 1,5-O-caffeoylquinic acid being the most abundant. The cytotoxic activity was assessed against human gastric cancer (AGS) and human non-small-cell lung cancer (A549) cell lines, whereas ethanolic extract elicited nearly 60 % and 40 % viability loss toward AGS and A549 cancer cells, respectively. Results also showed that cell death is caspase-independent and confirmed the involvement of RIPK1 and the necroptosis pathway in the toxicity induced by the I. viscosa extract. In addition, the ethanolic extract would not provoke morphological traits in the cancer cells. These findings suggest that I. viscosa can be a source of new antiproliferative drugs or used in preparation plant-derived pharmaceuticals.

Insights into the Antioxidant/Antiradical Effects and In Vitro Intestinal Permeation of Oleocanthal and Its Metabolites Tyrosol and Oleocanthalic Acid.

(1) Background: In recent years, numerous studies have highlighted the beneficial effects of extra virgin olive oil (EVOO) as an active ingredient against chronic diseases. The properties of EVOO are due to its peculiar composition, mainly to its rich content of polyphenols. In fact, polyphenols may contribute to counteract oxidative stress, which often accompanies chronic diseases. In this work, the antioxidant effects of high-value polyphenol oleocanthal (OC) and its main metabolites, tyrosol (Tyr) and oleocanthalic acid (OA), respectively, have been investigated along with their impact on cell viability. (2) Methods: OC, Tyr, and OA have been evaluated regarding antiradical properties in term of scavenging capacity towards biologically relevant reactive species, including O2●-, HOCl, and ROO●, as well as their antioxidant/antiradical capacity (FRAP, DPPH●, ABTS●+). Moreover, the ability to permeate the intestinal membrane was assessed by an intestinal co-culture model composed by Caco-2 and HT29-MTX cell lines. (3) Results: The capacity of OC and Tyr as radical oxygen species (ROS) scavengers, particularly regarding HOCl and O2●-, was clearly demonstrated. Furthermore, the ability to permeate the intestinal co-culture model was plainly proved by the good permeations (>50%) achieved by all compounds. (4) Conclusions: OC, OA, and Tyr revealed promising properties against oxidative diseases.

Macroalgae Specialized Metabolites: Evidence for Their Anti-Inflammatory Health Benefits.

Inflammation is an organism's response to chemical or physical injury. It is split into acute and chronic inflammation and is the last, most significant cause of death worldwide. Nowadays, according to the World Health Organization (WHO), the greatest threat to human health is chronic disease. Worldwide, three out of five people die from chronic inflammatory diseases such as stroke, chronic respiratory diseases, heart disorders, and cancer. Nowadays, anti-inflammatory drugs (steroidal and non-steroidal, enzyme inhibitors that are essential in the inflammatory process, and receptor antagonists, among others) have been considered as promising treatments to be explored. However, there remains a significant proportion of patients who show poor or incomplete responses to these treatments or experience associated severe side effects. Seaweeds represent a valuable resource of bioactive compounds associated with anti-inflammatory effects and offer great potential for the development of new anti-inflammatory drugs. This review presents an overview of specialized metabolites isolated from seaweeds with in situ and in vivo anti-inflammatory properties. Phlorotannins, carotenoids, sterols, alkaloids, and polyunsaturated fatty acids present significant anti-inflammatory effects given that some of them are involved directly or indirectly in several inflammatory pathways. The majority of the isolated compounds inhibit the pro-inflammatory mediators/cytokines. Studies have suggested an excellent selectivity of chromene nucleus towards inducible pro-inflammatory COX-2 than its constitutive isoform COX-1. Additional research is needed to understand the mechanisms of action of seaweed's compounds in inflammation, given the production of sustainable and healthier anti-inflammatory agents.

Marine-Derived Xanthone from 2010 to 2021: Isolation, Bioactivities and Total Synthesis.

Marine life has proved to be an invaluable source of new compounds with significant bioactivities, such as xanthones. This review summarizes the advances made in the study of marine-derived xanthones from 2010 to 2021, from isolation towards synthesis, highlighting their biological activities. Most of these compounds were isolated from marine-derived fungi, found in marine sediments, and associated with other aquatic organisms (sponge and jellyfish). Once isolated, xanthones have been assessed for different bioactivities, such as antibacterial, antifungal, and cytotoxic properties. In the latter case, promising results have been demonstrated. Considering the significant bioactivities showed by xanthones, efforts have been made to synthesize these compounds, like yicathins B and C and the secalonic acid D, through total synthesis.

Bio-Guided Optimization of Cystoseira abies-marina Cosmeceuticals Extraction by Advanced Technologies.

Cystoseira abies-marina (reclassified as Gongolaria abies-marina) is a brown seaweed species rich in meroterpenoids, presenting interesting antioxidant, antitumor, and anti-inflammatory activities. However, there is still a lot to uncover regarding the bioactive potential of this species, as evidenced by the lack of records of antiaging activities from Cystoseira abies-marina, making this macroalga an excellent candidate for studies of its cosmeceutical potential. Ultrasound-(UAE) and microwave-assisted extraction (MAE) are advanced sustainable technologies that are very efficient in enhancing bioactive compound extraction. Applying these extraction techniques to a new biological matrix often calls for optimizing the parameters toward the best extraction yield. Since Cystoseira abies-marina is a new matrix for both UAE and MAE techniques, the present work proposes the optimization of the extraction process, using a novel approach: instead of only focusing on increasing the yield, the goal of this work is to determine the parameters for UAE and MAE that lead to extracts with better antiaging activities. For this bio-guided approach, several Cystoseira abies-marina extracts were prepared by UAE and MAE under varying conditions of solvent, time, and algae/solvent ratios. Their antiaging activities were then determined, and all the results combined to unveil the conditions yielding extracts with higher cosmeceutical potential. Using statistical tools, it was found that, for UAE, the best conditions were ethyl acetate, 15 min, and a ratio of 1:4, which led to an extract with high yield, and causing the strong inhibition of tyrosinase and elastase. In turn, ethanol, 10 min, and a ratio of 1:4 were the best conditions for MAE, leading to the extract with the best antioxidant activity. The results show that the proposed bio-guided approach was effective in obtaining extracts with high cosmeceutical potential, unveiling the possibility of modulating an extract's activity by changing the extraction method.

Overview of Phlorotannins' Constituents in Fucales.

Fucales are an order within the Phaeophyceae that include most of the common littoral seaweeds in temperate and subtropical coastal regions. Many species of this order have long been a part of human culture with applications as food, feedand remedies in folk medicine. Apart from their high nutritional value, these seaweeds are also a well-known reservoir of multiple bioactive compounds with great industrial interest. Among them, phlorotannins, a unique and diverse class of brown algae-exclusive phenolics, have gathered much attention during the last few years due to their numerous potential health benefits. However, due to their complex structural features, combined with the scarcity of standards, it poses a great challenge to the identification and characterization of these compounds, at least with the technology currently available. Nevertheless, much effort has been taken towards the elucidation of the structural features of phlorotannins, which have resulted in relevant insights into the chemistry of these compounds. In this context, this review addresses the major contributions and technological advances in the field of phlorotannins extraction and characterization, with a particular focus on Fucales.

Chemical Variability of Hexane Extracts from Five Subspecies of Calendula suffruticosa from Spain.

The chemical profile of the hexane extracts of the subspecies carbonellii, greuteri, marginata, trialata, and vejerensis of Calendula suffruticosa growing in Spain, herein described for the first time, were studied to access their value as a chemo taxonomical tool and search for potentially useful compounds. The subsp. greuteri and carbonellii showed higher extract yields. Terpenoids were the most abundant chemical class in subsp. carbonellii, greuteri, trialata, and vejerensis, while alkanes were the most abundant in subsp. marginata. Differences in chemical constituents were identified among the subspecies of C. suffruticosa analysed, which the PCA can prove. The subsp. trialata and greuteri showed more significant phytochemical similarity, which might indicate genetic proximity between these two subspecies. C. suffruticosa subsp. marginata presented the fewest number of compounds and in the smallest quantities, and C. suffruticosa subsp. vejerensis presented the largest number, however, both showed no alcohols. Furthermore, some of the compounds found in significant amounts are known for their pharmacological and nutraceutical properties, denoting potential use.

Phytochemical and Antioxidant Profile of the Medicinal Plant Melia azedarach Subjected to Water Deficit Conditions.

Environmental stress triggered by climate change can alter the plant's metabolite profile, which affects its physiology and performance. This is particularly important in medicinal species because their economic value depends on the richness of their phytocompounds. We aimed to characterize how water deficit modulated the medicinal species Melia azedarach's lipophilic profile and antioxidant status. Young plants were exposed to water deficit for 20 days, and lipophilic metabolite profile and the antioxidant capacity were evaluated. Leaves of M. azedarach are rich in important fatty acids and oleamide. Water deficit increased the radical scavenging capacity, total phenol, flavonoids, and catechol pools, and the accumulation of ß-sitosterol, myo-inositol, succinic acid, sucrose, d-glucose and derivatives, d-psicofuranose, d-(+)-fructofuranose, and the fatty acids stearic, α-linolenic, linoleic and palmitic acids. These responses are relevant to protecting the plant against climate change-related stress and also increase the nutritional and antioxidant quality of M. azedarach leaves.

New Perspectives on the Sustainable Employment of Chestnut Shells as Active Ingredient against Oral Mucositis: A First Screening.

Oral mucositis (OM), a common side effect of oncological treatment, is an oral mucosal disorder characterized by painful ulcerations and increased risk of infection. The use of natural antioxidants to suppress the redox imbalance responsible for the OM condition has emerged as an interesting approach to prevent/treat OM. This study aims to explore the chestnut (Castana sativa) shells as potential active ingredient against OM. Therefore, chestnut shells were extracted at different temperatures (110-180 °C) by Subcritical Water Extraction (SWE), aiming to recover antioxidants. The extracts were also evaluated against microorganisms present in the oral cavity as well as on human oral cell lines (TR146 and HSC3). The highest phenolic content was obtained with the extraction temperature of 110 °C, exhibiting the best antioxidant/antiradical activities and scavenging efficiencies against HOCl (IC50 = 4.47 µg/mL) and ROO• (0.73 µmol TE/mg DW). High concentrations of phenolic acids (e.g., gallic and protocatechuic acids) and flavanoids (catechin, epicatechin and rutin) characterized the phenolic profile. The antimicrobial activity against several oral microorganisms present in the oral cavity during OM, such as Streptococcus, Staphylococcus, Enterococcus, and Escherichia, was demonstrated. Finally, the effects on HSC3 and TR146 cell lines revealed that the extract prepared at 110 °C had the lowest IC50 (1325.03 and 468.15 µg/mL, respectively). This study highlights the potential effects of chestnut shells on OM.

Camel (Camelus spp.) Urine Bioactivity and Metabolome: A Systematic Review of Knowledge Gaps, Advances, and Directions for Future Research.

Up to the present day, studies on the therapeutic properties of camel (Camelus spp.) urine and the detailed characterization of its metabolomic profile are scarce and often unrelated. Information on inter individual variability is noticeably limited, and there is a wide divergence across studies regarding the methods for sample storage, pre-processing, and extract derivatization for metabolomic analysis. Additionally, medium osmolarity is not experimentally adjusted prior to bioactivity assays. In this scenario, the methodological standardization and interdisciplinary approach of such processes will strengthen the interpretation, repeatability, and replicability of the empirical results on the compounds with bioactive properties present in camel urine. Furthermore, sample enlargement would also permit the evaluation of camel urine's intra- and interindividual variability in terms of chemical composition, bioactive effects, and efficacy, while it may also permit researchers to discriminate potential animal-intrinsic and extrinsic conditioning factors. Altogether, the results would help to evaluate the role of camel urine as a natural source for the identification and extraction of specific novel bioactive substances that may deserve isolated chemical and pharmacognostic investigations through preclinical tests to determine their biological activity and the suitability of their safety profile for their potential inclusion in therapeutic formulas for improving human and animal health.

Metabolite Profiling, Antioxidant and Key Enzymes Linked to Hyperglycemia Inhibitory Activities of Satureja hispidula: An Underexplored Species from Algeria.

In the present study, two extracts from the aerial parts of the endemic species Satureja hispidula were analyzed for the first time by ultra-high-performance liquid chromatography coupled with a diode array detector and an electrospray mass spectrometer (UHPLC-DAD-ESI/MS) method in order to identify and quantify their phenolic compounds. These extracts' antioxidant, α-glucosidase and α-amylase inhibitory activities were also evaluated. UHPLC-DAD-ESI/MS allowed the identification of 28 and 20 compounds in the ethanolic and aqueous extracts, respectively; among them, 5-O-caffeoylquinic acid was the most abundant in both extracts. The biological assay results indicate that the species S. hispidula, besides its high antioxidant power, is also potentially useful for inhibiting the α-glucosidase enzyme. In both antioxidant and α-glucosidase inhibitory assays, the aqueous extract exhibited the most promising results, significantly better than the standards used as positive controls.

Improved Adsorption of the Toxic Herbicide Diuron Using Activated Carbon Obtained from Residual Cassava Biomass (Manihot esculenta).

The production and consumption of cassava (Manihot esculenta) occur in several places worldwide, producing large volumes of waste, mostly in the form of bark. This study sought to bring a new purpose to this biomass through producing activated carbon to use as an adsorbent to remove the herbicide Diuron from water. It was observed that the carbon contains the functional groups of methyl, carbonyl, and hydroxyl in a strongly amorphous structure. The activated carbon had a surface area of 613.7 m2 g-1, a pore volume of 0.337 cm3 g-1, and a pore diameter of 1.18 nm. The Freundlich model was found to best describe the experimental data. It was observed that an increase in temperature favored adsorption, reaching a maximum experimental capacity of 222 mg g-1 at 328 K. The thermodynamic parameters showed that the adsorption was spontaneous, favorable, and endothermic. The enthalpy of adsorption magnitude was consistent with physical adsorption. Equilibrium was attained within 120 min. The linear driving force (LDF) model provided a strong statistical match to the kinetic curves. Diffusivity (Ds) and the model coefficient (KLDF) both increased with a rise in herbicide concentration. The adsorbent removed up to 68% of pollutants in a simulated effluent containing different herbicides. Activated carbon with zinc chloride (ZnCl2), produced from leftover cassava husks, was shown to be a viable alternative as an adsorbent for the treatment of effluents containing not only the herbicide Diuron but also a mixture of other herbicides.

Actinidia arguta Pulp: Phytochemical Composition, Radical Scavenging Activity, and in†Vitro Cells Effects.

Hardy kiwifruit (Actinidia arguta) is a highly appreciated exotic fruit endowed with outstanding bioactive compounds. The present work proposes to characterize the pulp from A. arguta organic fruits, emphasizing its radicals scavenging capacity and effects on intestinal cells (Caco-2 and HT29-MTX). The physicochemical properties and phenolic profile were also screened. The total phenolic and flavonoid contents (TPC and TFC, respectively) of pulp were 12.21 mg GAE/g on dry weight (DW) and 5.92 mg CE/g DW, respectively. A high antioxidant activity was observed (FRAP: 151.41 µmol FSE/g DW; DPPH: 12.17 mg TE/g DW). Furthermore, the pulp did not induce a toxic effect on Caco-2 and HT29-MTX cells viability up to 1000 µg/mL. Regarding in vitro scavenging capacity, the pulp revealed the highest scavenging power against NO. (IC50 =3.45 µg/mL) and HOCl (IC50 =12.77 µg/mL). These results emphasize the richness of A. arguta fruit pulp to be used in different food products.

Chemical Composition and Antioxidant, Antiparasitic, Cytotoxicity and Antimicrobial Potential of the Algerian Limonium Oleifolium Mill. Essential Oil and Organic Extracts.

This work aimed to investigate, for the first time, the chemical composition, antioxidant, antiparasitic, cytotoxicity, and antimicrobial activities of the aromatic plant Limonium oleifolium Mill. essential oil (EO) and organic extracts. L. oleifolium aerial parts essential oil was analyzed by GC-FID and GC-MS, and 46 constituents representing 98.25±1.12 % of the oil were identified. γ-Muurolene (10.81±0.07 %), cis-caryophyllene (7.71±0.06 %), o-cymene (7.07±0.01 %) and α-copaene (5.02±0.05 %) were the essential oil main compounds. The antioxidant activity of L. oleifolium EO and organic extracts (MeOH, CHCl3 , AcOEt, BuOH) was explored using 2,2-diphenyl-1-picrylhydrazyl (DPPH), ABTS, ß-carotene/linoleic acid, cupric reducing antioxidant capacity (CUPRAC), and ferric reducing power assays. The results showed that L. oleifolium EO exhibit antioxidant capacity (IC50 =17.40±1.32 µg/mL for DPPH assay, IC50 =29.82±1.08 µg/mL for ß-carotene assay, IC50 =25.23±1.01 µg/mL for ABTS assay, IC50 =9.11±0.08 µg/mL for CUPRAC assay and IC50 =19.41±2.06 mg/mL for reducing power assay). Additionally, the EO showed significant activity against trophozoite form of Acanthamoeba castellanii (IC50 =7.48±0.41 µg/mL) and promastigote form of Leishmania amazonensis (IC50 =19.36±1.06 µg/mL) and low cytotoxicity on murine macrophages (LC50  90.23±1.09 µg/mL), as well as good antimicrobial activity against Staphylococcus aureus, Escherichia coli, Klebsiella oxytoca, and Pseudomonas aeruginosa. These results suggest that L. oleifolium essential oil is a valuable source of bioactive compounds presenting antioxidant, antiparasitic, and antimicrobial activities. Furthermore, it is considered nontoxic.

Inter-Individual versus Inter-Population Variability of Calendula suffruticosa subsp. algarbiensis Hexane Extracts.

Calendula suffruticosa subsp. algarbiensis (Boiss.) Nyman is very common on the Portuguese coast, but it has only recently begun to be studied chemically and belongs to a genus of difficult taxonomic classification. To improve the knowledge on the chemical variability of this taxon and evaluate the possible use of this tool for taxonomical purposes, the aim of this work was to determine the extent of chemical variation between individuals collected in the same geographic region, and to compare with samples mixing fragments of several individuals each (populations) from different local environments. Overall, hexane extract analysis by GC/MS allowed to identify 42 compounds, eight fatty acids, 24 terpenoids, three alcohols, five alkanes, and two pollutants. Greater chemical differences were found between individuals, grown in the same region, than were found between population samples from different regions. Additionally, 25 phytochemicals were identified for this taxon for the first time and may be used for taxonomic classification, even to distinguish between subspecies of C. suffruticosa. Furthermore, plants collected near urban areas accumulated pollutants, indicating the importance of controlling local environmental conditions when C. suffruticosa cultivation is for human consumption.

Plant Flavonoids: Chemical Characteristics and Biological Activity.

In recent years, more attention has been paid to natural sources of antioxidants. Flavonoids are natural substances synthesized in several parts of plants that exhibit a high antioxidant capacity. They are a large family, presenting several classes based on their basic structure. Flavonoids have the ability to control the accumulation of reactive oxygen species (ROS) via scavenger ROS when they are formed. Therefore, these antioxidant compounds have an important role in plant stress tolerance and a high relevance in human health, mainly due to their anti-inflammatory and antimicrobial properties. In addition, flavonoids have several applications in the food industry as preservatives, pigments, and antioxidants, as well as in other industries such as cosmetics and pharmaceuticals. However, flavonoids application for industrial purposes implies extraction processes with high purity and quality. Several methodologies have been developed aimed at increasing flavonoid extraction yield and being environmentally friendly. This review presents the most abundant natural flavonoids, their structure and chemical characteristics, extraction methods, and biological activity.