Agathisflavone as a Single Therapy or in Association With Mesenchymal Stem Cells Improves Tissue Repair in a Spinal Cord Injury Model in Rats.

Agathisflavone is a flavonoid with anti-neuroinflammatory and myelinogenic properties, being also capable to induce neurogenesis. This study evaluated the therapeutic effects of agathisflavone-both as a pharmacological therapy administered in vivo and as an in vitro pre-treatment aiming to enhance rat mesenchymal stem cells (r)MSCs properties-in a rat model of acute spinal cord injury (SCI). Adult male Wistar rats (n = 6/group) underwent acute SCI with an F-2 Fogarty catheter and after 4 h were treated daily with agathisflavone (10 mg/kg ip, for 7 days), or administered with a single i.v. dose of 1 × 106 rMSCs either unstimulated cells (control) or pretreated with agathisflavone (1 µM, every 2 days, for 21 days in vitro). Control rats (n = 6/group) were treated with a single dose methylprednisolone (MP, 60 mg/kg ip). BBB scale was used to evaluate the motor functions of the animals; after 7 days of treatment, the SCI area was analyzed after H&E staining, and RT-qPCR was performed to analyze the expression of neurotrophins and arginase. Treatment with agathisflavone alone or with of 21-day agathisflavone-treated rMSCs was able to protect the injured spinal cord tissue, being associated with increased expression of NGF, GDNF and arginase, and reduced macrophage infiltrate. In addition, treatment of animals with agathisflavone alone was able to protect injured spinal cord tissue and to increase expression of neurotrophins, modulating the inflammatory response. These results support a pro-regenerative effect of agathisflavone that holds developmental potential for clinical applications in the future.

Acetylcholinesterase inhibitory activity of Ocotea pomaderroides extracts: HPLC-MS/MS characterization and molecular modeling studies.

The present work describes the acetylcholinesterase inhibitory activity of Ocotea pomaderroides extracts besides the chemical composition of chromatographic fractions. The hexane, dichloromethane and ethyl acetate extract soluble fractions showed high Electrophorus electricus acetylcholinesterase (EelAChE) inhibition (92.18, 71.86 and 74.25%, respectively) while the butanolic and aqueous extracts showed moderate to low activities (44.48 and 20.74%, respectively). The high-performance liquid chromatography coupled with electrospray ionization multiple-stage mass spectrometry (HPLC-ESI-MSn) analysis led to the identification of the alkaloids and flavonol glycoside derivatives present in these extracts. The binding profile of the alkaloids and their atomic effect on 3D structure of Electrophorus electricus AchE (EelAChE) were assessed with molecular modeling.

Cytotoxic Activity of Tropane Alkaloides of Species of Erythroxylum.

Erythroxylaceae is a family composed of four genera, with Erythroxylum being the only one represented in the Neotropical region. Chemical studies indicate the presence of alkaloids, terpenes, flavonoids, and phenolic compounds as main compounds. The incorporation of cytotoxic activity assays of natural products using cell cultures assists in the selection of potential chemotherapeutic agents. In this work, we describe a revision of the cytotoxicity evaluation studies performed with extracts or pure substances obtained from Erythroxylum species through an integrative review. We found studies that evaluated the cytotoxic activity of 21 species of Erythroxylum against 45 different cell lines. The analysis of the chemical composition of these species shows that the metabolites present in each species influence their cytotoxic potential, especially the presence of disubstituted tropane alkaloid species with the highest cytotoxic potential. MTT and Sulforrodamine B assays were the main in vitro tests used for the evaluation of the cytotoxic activities. From the total species, less than 10% of the Erythroxylum species have already been evaluated for cytotoxic activity. Four of them showed high cytotoxic activity according to the criteria of the NCI plant screening program. Thus, this genus represents a potential source of natural products with antitumor activity.

Reverted effect of mesenchymal stem cells in glioblastoma treated with agathisflavone and its selective antitumoral effect on cell viability, migration, and differentiation via STAT3.

Glioblastoma is the most lethal tumor of the central nervous system, presenting a very poor prognostic, with a survival around 16 months. The interaction of mesenchymal stem cells and tumor cells has been studied, showing a bias in their role favoring or going against aggressiveness. Natural products such as flavonoids have showed their anticancer properties and the synergic potential with the activation of microenvironment cells to inhibit tumor progression. Agathisflavone is a flavonoid studied in neurodegenerative diseases and cancer. The present study investigated the effect of flavonoid in the viability of heterogeneous glioblastoma (GBM) cells considering a coculture or conditioned medium of mesenchymal stem cells (MSCs) effect, as well as the dose-dependent effect of this flavonoid in tumor migration and differentiation via STAT3. Agathisflavone (3-10 µM) induced dose-dependent toxicity to GL-15 and U373 human GBM cells, since 24 h after treatments. It was not toxic to human MSC but modified the pattern of interaction with GBM cells. Agathisflavone also inhibited migration and increased differentiation of human GBM cells, associated with the reduction on the expression of STAT3. These results demonstrate that the flavonoid agathisflavone had a direct anti-glioma effect. However, could be observed its effect in MSCs response that may have an impact in controlling GBM growth and aggressiveness, an important factor to consider for new therapies.

Chemical constituents, antioxidant, anti-inflammatory and, antinociceptive activities of Trichilia ramalhoi.

Trichilia ramalhoi Rizz. is a species from Meliaceae family and its chemical composition and biological activities are still unknown. This work describes the chemical composition and biological activities of the organic extracts of this plant. Therefore, methanolic extract of stem barks and leaves were prepared and submitted to chromatographic procedures. Besides, T. ramalhoi extracts biological evaluation showed antioxidant, antinociceptive and, anti-inflammatory activities. Usual chromatographic procedures of the active extracts permitted to isolate methyl 5-O-caffeoylquinate, apocynin C, cinchonains Ia and Ib, besides ß-sitosterol, stigmasterol and lupeol. The identification of the isolates was based on 13C and 1H NMR (1 D and 2 D) spectroscopic data and mass spectrometry. Although the flavalignans cinchonains Ia and Ib were previously isolated from T. catigua, this is the first occurrence of apocynin C in the Meliaceae family.

Cytotoxic, Antitumor and Toxicological Profile of Passiflora alata Leaf Extract.

Passiflora alata or passion fruit is a native flowering plant from Amazon, geographically spread from Peru to Brazil. The plant has long been used in folks medicine for its pharmacological properties and is included in the Brazilian Pharmacopoeia since 1929. The aim of this study was to evaluate the potential cytotoxic and antitumor activities of Passiflora alata leaf extract (PaLE) in S180-tumor bearing mice. The percentage of cell proliferation inhibition (% CPI) and IC50 in relation to 4 tumor cell lines were determined in PC3, K-562, HepG2 and S180 cell lines using the MTT assay. PaLE showed a CPI > 75% and greater potency (IC50 < 30 µg/mL) against PC3 and S180 cell lines. PaLE showed antitumor activity in treatments intraperitoneally (36.75% and 44.99% at doses of 100 and 150 mg/kg/day, respectively). Toxicological changes were shown in the reduced body mass associated with reduced food consumption, increased spleen mass associated with histopathological increase in the white pulp of the spleen and increased number of total leukocytes with changes in the percentage relationship between lymphocytes and neutrophils. Our outcomes corroborate the conclusion that PaLE has antitumor activity in vitro and in vivo with low toxicity.

Bergenin Reduces Experimental Painful Diabetic Neuropathy by Restoring Redox and Immune Homeostasis in the Nervous System.

Diabetic neuropathy is a frequent complication of diabetes. Symptoms include neuropathic pain and sensory alterations-no effective treatments are currently available. This work characterized the therapeutic effect of bergenin in a mouse (C57/BL6) model of streptozotocin-induced painful diabetic neuropathy. Nociceptive thresholds were assessed by the von Frey test. Cytokines, antioxidant genes, and oxidative stress markers were measured in nervous tissues by ELISA, RT-qPCR, and biochemical analyses. Single (3.125-25 mg/kg) or multiple (25 mg/kg; twice a day for 14 days) treatments with bergenin reduced the behavioral signs of diabetic neuropathy in mice. Bergenin reduced both nitric oxide (NO) production in vitro and malondialdehyde (MDA)/nitrite amounts in vivo. These antioxidant properties can be attributed to the modulation of gene expression by the downregulation of inducible nitric oxide synthase (iNOS) and upregulation of glutathione peroxidase and Nrf2 in the nervous system. Bergenin also modulated the pro- and anti-inflammatory cytokines production in neuropathic mice. The long-lasting antinociceptive effect induced by bergenin in neuropathic mice, was associated with a shift of the cytokine balance toward anti-inflammatory predominance and upregulation of antioxidant pathways, favoring the reestablishment of redox and immune homeostasis in the nervous system. These results point to the therapeutic potential of bergenin in the treatment of painful diabetic neuropathy.

Agathisflavone modulates astrocytic responses and increases the population of neurons in an in vitro model of traumatic brain injury.

Traumatic brain injury (TBI) is a critical health problem worldwide, with a high incidence rate and potentially severe long-term consequences. Depending on the level of mechanical stress, astrocytes react with complex morphological and functional changes known as reactive astrogliosis. In cases of severe tissue injury, astrocytes proliferate in the area immediately adjacent to the lesion to form the glial scar, which is a major barrier to neuronal regeneration in the central nervous system. The flavonoid agathisflavone has been shown to have neuroprotective, neurogenic, and immunomodulatory effects and could have beneficial effects in situations of TBI. In this study, we investigated the effects of agathisflavone on modulating the responses of astrocytes and neurons to injury, using the in vitro scratch wound model of TBI in primary cultures of rat cerebral cortex. In control conditions, the scratch wound induced an astroglial injury response, characterized by upregulation of glial fibrillary acidic protein (GFAP) and hypertrophy, together with the reduction in proportion of neurons within the lesion site. Treatment with agathisflavone (1 µM) decreased astroglial GFAP expression and hypertrophy and induced an increase in the number of neurons and neurite outgrowth into the lesion site. Agathisflavone also induced increased expression of the neurotrophic factors NGF and GDNF, which are associated with the neuroprotective profile of glial cells. These results demonstrate that in an in vitro model of TBI, the flavonoid agathisflavone modulates the astrocytic injury response and glial scar formation, stimulating neural recomposition.

Absence of toxicity in Swiss mice following treatment with 7-acetoxy-4-aryl-3,4-dihydrocoumarin: Acute and repeated-dose toxicity study.

Neoflavonoids, which are classified as 4-arylcoumarin (neoflavone), 3,4-dihydro-4-arylcoumarin and neoflavene, have been the subject of a number of studies with respect to their therapeutic potential and, despite promising in vitro, ex vivo and in vivo pharmacological activities, there is a lack of studies demonstrating their toxicological properties. Therefore, this study aims to evaluate the acute (14 days) and repeated-dose (28 days) toxicity of synthetic neoflavonoid 7-acetoxy-4-aryl-3,4-dihydrocoumarin in Swiss mice through parameters related to changes in body weight, food and water intake, hematological and biochemical parameters. Toxicity studies using acute doses (300 and 2000 mg/kg) and repeated doses (250, 500 and 1000 mg/kg) orally were carried out as per Organization for Economic Co-operation and Development (OECD) guidelines 423 and 407, respectively. Based on the results of this study, treatment with 7-acetoxy-4-aryl-3,4-dihydrocoumarin was found to not cause clinical adverse symptoms and mortality in any animal used in the acute and repeated-dose toxicity study. In addition, no significant changes were observed in body weight and internal organs, food and water intake, hematological and biochemical parameters, compared to control group. Therefore, these results provide an initial understanding regarding the toxicity profile of 7-acetoxy-4-aryl-3,4-dihydrocoumarin, which can be considered a neoflavonoid with toxicity seen at doses higher than 2000 mg/kg in Swiss mice.

Antifungal activities of rotenoids from seeds and roots of Clitoria fairchildiana / Atividade antifúngica dos rotenoides das sementes e raiz de Clitoria fairchildiana

Clitoria fairchildiana (synonym Clitoria racemosa) is a tree belonging to the Leguminosae family growing in several Brazilian regions and it has in its composition rotenoids with unusual structures. The aim of this work is to determinate the antimicrobial activity rotenoids from C. fairchildiana. Clitoriacetal, 6-desoxyclitoriacetal, stemonal and stemonone were isolated from the roots and 11-desoxyclitoriacetal from seeds by different chromatographic techniques and identified by spectrometric data analyzes. The antimicrobial activity was obtained using different culture media and the results confirm the importance of the junction of the ring B/C and the pattern of hydroxylation of these compounds in antifungal activities. This is the first time antimicrobial activities of these rotenoids were determined.(AU)

Clitoria fairchildiana (sinônimo Clitoria racemosa) é uma árvore da família Leguminosa encontrada em várias regiões brasileiras e possui na sua composição rotenoides de estruturas não usuais. O objetivo do presente trabalho é determinar a atividade antimicrobiana de cinco rotenoides isolados das raízes e sementes da C. fairchildiana. Clitoriacetal, 6-desoxiclitoriacetal, stemonal e stemonona foram isolados das raízes e o 11- desoxiclitoriacetal isolado das sementes por meio de diferentes técnicas cromatográficas e identificados através da análise de dados espectrométricos. A atividade antimicrobiana foi obtida utilizando diferentes meios de cultura e os resultados confirmam a importância da junção do anel B/C e o padrão de hidroxilação dos rotenoides na atividade antifúngica. Este é o primeiro relato de atividades antimicrobianas de rotenoides de Clitoria.(AU)

Influence of growth regulators on distribution of trichomes and the production of volatiles in micropropagated plants of Plectranthus ornatus

ABSTRACT The profile of volatile organic compounds, the glandular and non-glandular trichomes of Plectranthus ornatus, obtained by in vitro cultivation, was evaluated in plants grown in Murashide and Skoog medium supplemented with benylaminopurine at 4.5, 9.0, and 18.0 µM + naphthaleneacetic acid at 5.37 µM, kinetin at 4.7, 9.3 and 18.5 µM + naphthaleneacetic acid (5.37 µM) or Murashide and Skoog 0 medium (as a control). Scanning Electron Microscopy was performed on samples of the third leaf node of the 90 days old plants obtained from treatment with 4.5 or 9.0 µM benylaminopurine, and 4.7 or 9.3 µM kinetin. Headspace Solid Phase Micro-Extraction of the 30, 60 and 90 days old in vitro plants permitted to determinate by GC/MS the composition comprised of 62 compounds. The data were analyzed using Principal Component Analysis and Hierarchical Clustering Analysis and, the major constituents of these oils after treatment and aging were monoterpenes and sesquiterpenes. Morphoanatomical analysis of trichomes, by Scanning Electron Microscopy, enabled the identification of non-glandular trichomes and four types of glandular trichomes, which comprised capitate and peltate glandular trichomes that were distributed on both sides of the leaf. We observed that the regulators influenced qualitative and quantitative profiles of the volatile organic compounds and the number and distribution of hairs on the leaf surface.

Terpene Esters from Natural Products: Synthesis and Evaluation of Cytotoxic Activity

ABSTRACT Natural steroids and triterpenes such as b-sitosterol, stigmasterol, lupeol, ursolic and betulinic acids were transformed into its hexanoic and oleic esters, to evaluate the influence of chemical modification towards the cytotoxic activities against tumor cells. The derivatives were evaluated against five tumor cell lines [OVCAR-8 (ovarian carcinoma); SF-295 (glioblastoma); HCT-116 (colon adenocarcinoma); HL-60 (leukemia); and PC-3 (prostate carcinoma)] and the results showed only betulinic acid hexyl ester exhibits cytotoxic potential activity.

Terpene Esters from Natural Products: Synthesis and Evaluation of Cytotoxic Activity.

Natural steroids and triterpenes such as b-sitosterol, stigmasterol, lupeol, ursolic and betulinic acids were transformed into its hexanoic and oleic esters, to evaluate the influence of chemical modification towards the cytotoxic activities against tumor cells. The derivatives were evaluated against five tumor cell lines [OVCAR-8 (ovarian carcinoma); SF-295 (glioblastoma); HCT-116 (colon adenocarcinoma); HL-60 (leukemia); and PC-3 (prostate carcinoma)] and the results showed only betulinic acid hexyl ester exhibits cytotoxic potential activity.

Bergenin from Peltophorum dubium: Isolation, Characterization, and Antioxidant Activities in Non-Biological Systems and Erythrocytes.

BACKGROUND: Bergenin, a compound derived from gallic acid, is a secondary metabolite of the plant Peltophorum dubium (Spreng.) Taub. OBJECTIVE: In this study, we aimed to characterize the ability of bergenin to eliminate the radicals in non-biological systems. METHODS: We evaluated bergenin's ability to protect erythrocytes from oxidative damage in a biological system. We have elucidated bergenin structure using nuclear magnetic resonance, X-ray diffraction, Fourier transform infrared spectroscopy, and differential scanning calorimetry. We then evaluated its antioxidant capacity in vitro against DPPH•, ABTS•+, hydroxyl radicals, and nitric oxide, and determined its ability to transfer electrons owing to its reduction potential and ability to chelate iron. We also evaluated its protective capacity against oxidative damage produced by AAPH in erythrocytes, its hemolytic properties, its ability to inhibit hemolysis, and its ability to maintain intracellular reduced glutathione homeostasis. RESULTS: Bergenin concentrations between 0.1 and 3mM significantly (p < 0.05) and dose dependently decreased formation of ABTS•+, DPPH•, nitrite ions, OH•, reduced formation ferricyanide, ferrozine-Fe2+complex, inhibited AAPH-induced oxidative hemolysis of erythrocytes, raised GSH levels in the presence of AAPH, inhibited AAPH-induced lipid peroxidation in erythrocytes. CONCLUSION: Bergenin may represent a novel alternative antioxidant, with potential applications in various industries, including drugs, cosmetics, and foods.

Poligalen, a new coumarin from Polygala boliviensis, reduces the release of TNF and IL-6 independent of NF-kB downregulation.

An unusually substituted coumarin, named poligalen, was isolated from a chloroform extract of the aerial parts of Polygala boliviensis. This coumarin was identified by one- and two-dimensional NMR techniques, and the structure of the compound was confirmed by X-ray diffraction. Poligalen exhibits immunomodulatory effects, reducing the levels of IL-6 and TNF after LPS stimulation in peritoneal macrophages. However, poligalen potentiates NF-kB activation.

Detection and Quantification of Rotenoids from Clitoria fairchildiana and its Lipids Profile.

This work describes the isolation and quantification of rotenoids from crude organic extracts of different parts of Clitoria fairchildiana R. A. Howard (Leguminosae) by HPLC-DAD. The lipid composition and the Artemia salina cytotoxic activities of the isolates were also conducted. Clitoriacetal (1), 6-deoxyclitoriacetal (2), stemonal and stemonone were isolated by chromatographic procedures and identified by usual spectroscopic and spectrometric techniques. Clitoriacetal and 6-deoxyclitoriacetal were not found in all parts of the plant, such as leaves and petals, but in the roots they occur in higher concentration. The activity against brine shrimp revealed that the root extract (LD50 = 158 ppm) was the more active.

Pre-clinical toxicology of garcinielliptone FC, a tautomeric pair of polyprenylated benzophenone, isolated from Platonia insignis Mart seeds.

BACKGROUND: Garcinielliptone FC (GFC) is a tautomeric pair of polyprenylated benzophenone, which has proven to have antiepileptic, cytotoxic and antioxidant activity. PURPOSE: The aim of this study was to investigate the biochemical, hematological and pathological effects of the acute toxicity study as well as to assess the locomotor activity and motor coordination in mice treated with GFC. METHODS: Swiss mice of both sexes weighing 25-30 g divided into three separate groups of five animals matched by weight and size. GFC was aseptically suspended in 0.05% Tween 80, dissolved in 0.9% saline (vehicle) and administered orally (p.o.) and intraperitoneally (i.p.) (500, 1000 and 2000 mg/kg). The acute toxicity study was performed in compliance with the Anvisa regulations. RESULTS: Behavioral manifestations of toxicity, such as state of consciousness, coordination, muscle tone, reflexes, the activity on the central nervous system (shake, seizures, Straub tail reaction and anesthesia) and the activity of the autonomic nervous system (lacrimation, ptosis, urination, piloerection, hypothermia, breathing and hyperemia) were not seen in any of the animals treated with doses of 500, 1000 and 2000 mg/kg. Additionally, no significant difference in body weight, food and water intake, excreta production or macroscopic changes in the organs of treated animals were detected in comparison with control group. GFC did not affect the locomotor activity and motor coordination of the animals. CONCLUSION: The acute toxicity study indicated that GFC treatment, at selected doses given orally and intraperitoneally, showed relatively low risk of toxicity in all test animals, suggesting that it is safe for further investigation.

Antinoceptive and Anti-inflammatory Activities of the Ethanolic Extract, Fractions and Flavones Isolated from Mimosa tenuiflora (Willd.) Poir (Leguminosae).

The bark of Mimosa tenuiflora (Willd.) Poiret (Leguminosae family), popularly known as "jurema preta" in Brazil, is used by the population of Contendas of Sincorá (Bahia State, Brazil) for the treatment of coughs and wound healing. Thus, the aim of this study was to evaluate the antinociceptive and anti-inflammatory activities of the bark ethanol extract (EEMT) and solvent soluble fractions (hexane-H, DCM-D, EtOAc-E and BuOH-B) of the extract in vivo. Additionally, we synthesized 5,7-dihidroxy-4'-methoxyflavanone (isosakuranetin) and isolated the compound sakuranetin, and both compounds were also tested. The anti-inflammatory and antinociceptive assays performed were: writhing test; nociception induced by intraplantar formalin injection; leukocyte recruitment to the peritoneal cavity; evaluation of vascular permeability (Evans blue test); and evaluation of mechanical hypernociception (von Frey test). Production of TNF-α, IL-10, myeloperoxidase and the expression of ICAM-1 were also evaluated. Statistical analysis was performed by one-way ANOVA followed by the Bonferroni post-test (n = 8), with P < 0.05. The EEMT showed antinociceptive activities in writhing test (100-200 mg/kg), in the second phase of the formalin test (50-200 mg/kg), and in mechanical hypernociception (100 mg/kg). EEMT showed an anti-inflammatory effect by reducing neutrophil migration to the peritoneal cavity and in the plantar tissue detected by the reduction of myeloperoxidase activity (100 mg/kg), reduction of IL-10 levels and expression of ICAM-1 in the peritoneal exudate and the mesentery (100 mg/kg), respectively. The four soluble EEMT fractions showed good results in tests for antinociceptive (H, D, E, B) and anti-inflammation (H, D, E). Only sakuranetin showed reduction of the writhing and neutrophil migration (200 mg/kg). Thus, the EEMT and soluble fractions of M. tenuiflora bark demonstrated great antinociceptive and anti-inflammatory activities, as also sakuranetin. More studies should be conducted to elucidate the mechanism of action of this compound. To the best of our knowledge, this is the first report on the antinociceptive activity of the M. tenuiflora fractions and the bioactive isolated compound sakuranetin in vivo.

In vitro effects of arylhydrocoumarin on free radicals and oxidative stress in erythrocytes and Saccharomyces cerevisiae.

Neoflavonoids comprise a group of natural compounds with varied chemical structures and promising pharmacological properties, including antioxidant capacity. This work describes an evaluation of the in vitro antioxidant capacity of a new coumarin derivative, i.e., 7-acetoxy-4-aryl-3,4-dihydrocoumarin, in terms of its ability to quench the 2,2- diphenyl-1-picrylhydrazyl (DPPH•), 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS•+), hydroxyl (OH•) and superoxide anion (O2(•-)) radicals, as well as its capacity to initiate electron transfer by reducing potential and inhibit lipid peroxidation by TBARS (thiobarbituric acid reactive substances) method. In addition, the antioxidant capacity of 7-acetoxy-4-aryl-3,4-dihydrocoumarin was evaluated against oxidative damage induced by hydrogen peroxide in erythrocyte suspensions and S. cerevisiae strains. In all methodologies investigated, high antioxidant capacities above 65% were demonstrated by 7-acetoxy-4-aryl-3,4-dihydrocoumarin against the DPPH(•), ABTS(•+), OH(•) and O2(•-) radicals. The ability of 7-acetoxy-4-aryl-3,4-dihydrocoumarin to inhibit oxidative damage induced by hydrogen peroxide in erythrocytes and S. cerevisiae strains demonstrates the importance of this compound in the protection against oxidative stress at the cellular level. Thus, the results obtained in this study suggest that 7-acetoxy-4-aryl-3,4-dihydrocoumarin can assist the development of new antioxidant products for possible use in the prevention or reduction of diseases related to oxidative stress.

Determination of Flavanones in Orange Juices Obtained from Different Sources by HPLC/DAD.

Flavanones (hesperidin, naringenin, naringin, and poncirin) in industrial, hand-squeezed orange juices and from fresh-in-squeeze machines orange juices were determined by HPLC/DAD analysis using a previously described liquid-liquid extraction method. Method validation including the accuracy was performed by using recovery tests. Samples (36) collected from different Brazilian locations and brands were analyzed. Concentrations were determined using an external standard curve. The limits of detection (LOD) and the limits of quantification (LOQ) calculated were 0.0037, 1.87, 0.0147, and 0.0066 mg 100 g(-1) and 0.0089, 7.84, 0.0302, and 0.0200 mg 100 g(-1) for naringin, hesperidin, poncirin, and naringenin, respectively. The results demonstrated that hesperidin was present at the highest concentration levels, especially in the industrial orange juices. Its average content and concentration range were 69.85 and 18.80-139.00 mg 100 g(-1). The other flavanones showed the lowest concentration levels. The average contents and concentration ranges found were 0.019, 0.01-0.30, and 0.12 and 0.1-0.17, 0.13, and 0.01-0.36 mg 100 g(-1), respectively. The results were also evaluated using the principal component analysis (PCA) multivariate analysis technique which showed that poncirin, naringenin, and naringin were the principal elements that contributed to the variability in the sample concentrations.