Antioxidant capacity of Myrciaria cauliflora seed extracts by spectrophotometric, biochemical, and electrochemical methods and its protective effect against oxidative damage in erythrocytes.

This study aimed to investigate the antioxidant activity of extracts obtained from jabuticaba (Myrciaria cauliflora) seeds. Ethanolic (ETJS), methanolic (MEJS), aqueous (AQJS), and propanone (PRJS) extracts was assessed by measuring spectrophotometrically their ability to scavenge DPPH· , ABTS·+ , HOCl, and O2 ·- radicals. Electrochemical methods were employed, and the obtained data presented a good correlation with the radical scavenging results. The extracts were also able to attenuate lipid peroxidation induced by Fe2+ ions in phospholipids due to their chelation ability. The extracts protected human erythrocytes against oxidative cellular damage caused by AAPH, which was confirmed by using FESEM analysis. PRJS extract demonstrated the highest effect in all assays used in this work. Our findings prove that jabuticaba seeds are an important source of antioxidants which act by different mechanisms. This study opens new frontiers regarding the use of this fruit byproduct as a food additive. PRACTICAL APPLICATIONS: Jabuticaba seeds are usually discarded as waste by food industries, but they are rich in bioactive products and present interesting biological properties. Herein, we demonstrated that their extracts show remarkable antioxidant power against different reactive oxygen species, which are involved in several human pathologies. In this way, this by-product can be further used in the development of products to protect the human body against diseases related to oxidative stress.

Aqueous extract of Paullinia cupana attenuates renal and hematological effects associated with ketoprofen.

This study aimed to evaluate the effect of aqueous extract of Paullinia cupana (AEG) against ketoprofen side effects, through biochemical, hematological, and histological parameters. AEG showed antioxidant activity in the DPPH• scavenging (IC50  = 17.00 ± 1.00 µg/ml) and HPLC analysis revealed that this extract is constituted by antioxidants (caffeine, catechins, theobromine, and polyphenols). In vivo experiments in female Wistar rats demonstrated that alterations in urea, creatinine, and uric acid levels promoted (p < .05) by ketoprofen were reversed when AEG was co-administered. Ketoprofen significantly decreased the catalase levels of animal tissues (p < .05), which were restored when AEG was co-administered with the mentioned drug. Histological analysis showed that AEG protected tissues from damages caused by ketoprofen. Moreover, AEG reestablished the number of white blood cells, which had decreased when ketoprofen was administered. In conclusion, this study suggested that the association between ketoprofen and AEG may be an alternative to reduce health damages caused by this drug. PRACTICAL APPLICATIONS: Paullinia cupana, popularly known as guaraná, is commonly consumed as a beverage in Brazil and exhibits pharmacological and beneficial effects to humans. Ketoprofen is an efficacious drug employed in the treatment of inflammatory processes. However, this drug can cause several side effects in humans. Thus, the usage of natural products and plant extracts that can reduce such undesirable effects consists in a valuable strategy to be applied in therapeutic interventions.

Polyphenolic compounds of Euphorbia umbellata (Pax) Bruyns (Euphorbiaceae) improved endothelial dysfunction through arginase inhibition.

Euphorbia umbellata is used for its anti-inflammatory properties; however, there are limited data available regarding its effects on vascular function. Its bark is rich in polyphenolic compounds, which potentially improve endothelial dysfunction (ED). This study proposes to investigate the effects of E. umbellata bark extracts and its polyphenolic compounds on arginase (ARG) activity and nitric oxide (NO)-related targets. Chromatographic procedures were used for the chemical characterisation of the extracts. Furthermore, in silico (molecular docking), in vitro (ARG inhibition), in vivo (streptozotocin-induced hyperglycemia model), and ex vivo (l-arginine metabolism, vascular reactivity, western blot, and biochemical) techniques were carried out. Quercetin, gallic acid, and ellagic acid were identified in the extracts. In silico screening predicted that gallic acid and quercetin would have the most promising interactions with ARG -identified cavities. This was confirmed in vitro as both compounds had a direct inhibitory effect on ARG, as was the case regarding the extracts. Oral treatment preserved endothelium-dependent vasodilation through ARG inhibition together with an increase in l-arginine bioavailability and endothelial NO synthase expression. Biochemical parameters determined the lack of toxicity for sub-chronic treatment. E. umbellata bark extracts and its compounds can contribute to ED treatment, at least partly, through the inhibition of vascular ARG.

Effects of Gender and Geographical Origin on the Chemical Composition and Antiradical Activity of Baccharis myriocephala and Baccharis trimera.

This study aimed to characterize and compare essential oils and ethyl acetate fractions obtained in basic and acidic conditions from both male and female Baccharis species (Baccharis myriocephala and Baccharis trimera) from two different Brazilian regions. Samples were characterized according to their chemical compositions and antiradical activity by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays. Principal component analysis (PCA) provided a clear separation regarding the chemical composition of essential oils from the samples obtained from different regions by using gas chromatography-mass spectrometry with flame-ionization detection (GC-MS-FID). PCA also revealed that gender and region of plant collections did not influence the chemical composition and antiradical activity of ethyl acetate fractions, which was corroborated with hierarchical cluster analysis (HCA) data. High performance liquid chromatography with diode-array detector (HPLC-DAD) identified significant quantities of flavonoids and phenolic acids in the fractions obtained in basic and acidic fractions, respectively. The obtained results clearly demonstrated that the geographical region of plant collection influenced the chemical composition of essential oils from the studied Baccharis species. Moreover, the obtained fractions were constituted by several antiradical compounds, which reinforced the usage of these species in folk medicine.

Anti-ulcer mechanisms of polyphenols extract of Euphorbia umbellata (Pax) Bruyns (Euphorbiaceae).

ETHNOPHARMACOLOGICAL RELEVANCE: Euphorbia umbellata (leitosinha) is used in southern Brazilian folk medicine to treat gastric problems, as well as for its analgesic and anti-inflammatory properties. AIM OF STUDY: To evaluate the anti-ulcer effects of methanolic bark fraction (MF) against in vivo and in vitro assays, as well as an antioxidant, antibacterial and chromatographic study of this fraction. MATERIALS AND METHODS: In vivo anti-ulcer activity was performed using ethanol and indomethacin models with different MF concentrations (50, 100 or 200mg/Kg). The stomachs of the animals were applied to histological evaluation, and the serum to evaluate the ABTS(•+) radical capture. The 200mg/Kg dose was used to analyze the mechanisms involved in antiulcerogenic properties of methanolic fraction. The in vitro activity was performed using several different antioxidant assays, in addition to anti-Helicobacter pylori and anti-urease experiments. The chromatographic study was carried out by LC-MS analysis. RESULTS: Pharmacological investigation of the MF showed an anti-ulcer potential in ethanol and indomethacin in vivo assays. The material presented a high antioxidant activity for several oxidant in vitro systems (DPPH(•), ABTS(•+), O2(•-), HOCl, TauCl and HRP), as well as an ABTS(•+) capture increasing (7.5%) by the treated animals serum (when compared to the negative control). Prostaglandins, nitric oxide/ cyclic guanosine monophosphate pathway and involvement of the protein components of the glutathione complex are some of the mechanisms related with this potential anti-ulcer action. The histological examination of the stomachs of the animals showed that the MF also prevents local action of offensive agents. Chemical analysis using LC-QTOF-MS revealed the presence of ellagic and gallic acid derivatives and flavonols. CONCLUSION: The findings provide scientific basis to the ethnopharmacological purpose of the studied plant and the biological activities of MF of E. umbellata stem bark may be due to the presence of phenolic compounds.

Salacia campestris root bark extract: peroxidase inhibition, antioxidant and antiradical profile / Salacia campestris extrato da casca da raiz: inibição da peroxidase, antioxidante e anti-radicalar perfil

Reactive oxygen species (ROS) and free radical species have been implicated in initiating or accompanying many diseases in living organisms; there is thus, a continual need for antioxidants molecules to inactivate ROS/free radicals. Many studies of plants crude extracts have demonstrated free-radical scavenging and antioxidant action. Salacia species have long been used, in several countries, as traditional medicines against certain diseases and for their anti-inflammatory properties. In this study, Salacia campestris Walp (Hippocrateaceae) root bark ethanol extract (ScEtOH) was assessed for its ability to scavenge free radicals and reactive oxygen species; the results were expressed as percentage inhibition of the active species. ScEtOH was efficient against studied species: DPPH radical (obtained inhibition = 30 percent), ABTSò+ (IC50 = 1.8±0.8 μg/mL), HOCl (IC50 = 1.7 ± 0.1 μg/mL), O2ò- (obtained inhibition = 32 percent), and NOò (obtained inhibition = 18 percent). Peroxidase activity inhibition was evaluated through the guaiacol oxidation reaction catalyzed by hemin, HRP and myeloperoxidase (MPO); data showed that ScEtOH at 10 μg/mL led to 54 and 51 percent of inhibition, respectively, for the hemin and HRP systems. In the MPO system, ScEtOH promoted a 50 percent inhibition at 8.9 μg/mL, whereas quercetin, a powerful MPO inhibitor, inhibited this system at 1.35 μg/mL.

Espécies reativas do oxigênio (ERO) e radicais livres estão relacionados ao início ou à exacerbação de muitas doenças em organismos vivos; existindo portanto uma necessidade contínua por moléculas antioxidantes que inativem as ERO e radicais livres. Muitos estudos com extratos brutos de plantas têm demonstrado propriedades antioxidantes e sequestradoras de radicais livres. Espécies de Salacia são utilizadas, em muitos países, como remédio tradicional contra certas doenças e por suas propriedades antiinflamatórias. Neste estudo, o extrato bruto etanólico da casca da raiz da Salacia campestris Walp (Hippocrateaceae) foi avaliado quanto à sua habilidade em seqüestrar radicais livres e espécies reativas do oxigênio; os resultados são expressos como porcentagem de inibição das espécies ativas. ScEtOH mostrou-se eficiente frente as espécies estudadas: radical DPPH (inibição obtida = 30 por cento), ABTSò+ (IC50 = 1,8±0,8 μg/mL), HOCl (IC50 = 1,7 ± 0,1 μg/mL), O2ò- (inibição obtida = 32 por cento), and NOò (inibição obtida = 18 por cento). A inibição da atividade peroxidásica foi avaliada através da oxidação do guaiacol catalisada pela hemina, HRP e mieloperoxidase (MPO); os dados mostram que 10 μg/mL de ScEtOH promovem 54 e 51 por cento de inibição, respectivamente para os sistemas da hemina e da HRP. No sistema da MPO, ScEtOH promoveu 50 por cento de inibição na dose de 8,9 μg/mL, enquanto a quercetina, um potente inibidor da MPO promoveu tal inibição com 1,35 μg/mL.

Flavonols from Pterogyne nitens and their evaluation as myeloperoxidase inhibitors.

A myeloperoxidase inhibitory kaempferol derivative, namely pterogynoside (1), was isolated from fruits of Pterogyne nitens, along with six known flavonols, kaempferol, afzelin, kaempferitrin, quercetin, isoquercetrin and rutin. The structures of all compounds were elucidated primarily from 1D and 2D NMR spectroscopic analyses, as well as by high resolution mass spectrometry. All flavonols were screened to identify secondary metabolites as potential myeloperoxidase (MPO) inhibitors, and at concentrations of 0.50-50nM, quercetin (5), isoquercitrin (6) and rutin (7) exhibited strong inhibitory effects with IC50 values of 1.22+/-0.01, 3.75+/-0.02 and 3.60+/-0.02, respectively. The MPO activity detected for the new derivative 1 was markedly decreased (IC(50) 10.3+/-0.03) when compared with known flavonols 5-7, and interestingly increased when tested against ABTS scavenging activity.

Profile of Maytenus aquifolium action over free radicals and reactive oxygen species

Reactive oxygen species (ROS) and free radical species have been implicated in initiating, accompanying or causing many diseases in living organisms; there is thus, a continual need for antioxidants molecules to inactivate ROS/free radicals. Many studies of plants crude extracts have demonstrated free-radical scavenging and antioxidant action. Maytenus species have long been used, in several countries, as traditional medicines against gastric ulcers, dyspepsia and others gastric problems and for their anti-inflammatory properties. In this study, Maytenus aquifolium (Celastraceae) root bark ethanol extract was assessed for its ability to scavenge free radicals and reactive oxygen species. The results were expressed as percentage inhibition of the active species. The extract was efficient against studied reactive species: DPPH radical (obtained inhibition = 35.5 ± 1.3 percent), ABTSò+ (IC50 = 0.0036 ± 0.0003 mg/mL), HOCl (IC50 = 0.002 ± 0.0001 mg/mL ), O2ò- (obtained inhibition = 36.0 ± 2.1 percent), and NOò (obtained inhibition = 18.3 ± 0.4 percent).

Espécies Reativas do Oxigênio (ERO) e radicais livres têm tido implicações na iniciação e evolução de muitas doenças ou nas causas das mesmas em organismos vivos; há portanto, necessidade contínua por moléculas antioxidantes para inativar ERO/radicais livres. Estudos sobre extratos brutos de plantas têm demonstrado suas ações antioxidante e seqüestradora de radicais livres. Espécies do gênero Maytenus são utilizadas, em vários países, como medicamentos tradicionais no combate a úlceras gástricas, dispepsia e outras desordens gástricas, bem como por suas propriedades antiinflamatórias. Neste estudo, o extrato bruto etanólico da raiz da Maytenus aquifolium (Celastraceae) foi avaliado quanto à sua habilidade em seqüestrar radicais livres e outras espécies reativas do oxigênio. Os resultados são expressos como porcentagem de inibição das espécies ativas. O extrato foi eficiente contra as espécies estudadas: radical DPPH (inibição alcançada = 35,5 ± 1,3 por cento), ABTSò+ (IC50 = 0,0036 ± 0,0003 mg/mL), HOCl (IC50 = 0,002 ± 0,0001 mg/mL ), O2ò- (inibição alcançada = 36,0 ± 2,1 por cento), and NOÀ (inibição alcançada = 18,3 ± 0,4 por cento).