Antiproliferative activity, antioxidant capacity and tannin content in plants of semi-arid northeastern Brazil

The objective of this study was to evaluate antiproliferative activity, antioxidant capacity and tannin content in plants from semi-arid northeastern Brazil (Caatinga). For this study, we selected 14 species and we assayed the methanol extracts for antiproliferative activity against the HEp-2 (laryngeal cancer) and NCI-H292 (lung cancer) cell lines using the (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazole) (MTT) method. In addition, the antioxidant activity was evaluated with the DPPH (2,2-diphenyl-2-picrylhydrazyl) assay, and the tannin content was determined by the radial diffusion method. Plants with better antioxidant activity (expressed in a dose able to decrease the initial DPPH concentration by 50%, or IC50) and with higher levels of tannins were: Poincianella pyramidalis (42.95±1.77 μg/mL IC50 and 8.17±0.64 tannin content), Jatropha mollissima (54.09±4.36μg/mL IC50 and 2.35±0.08 tannin content) and Anadenanthera colubrina (73.24±1.47 μg/mL IC50 and 4.41±0.47 tannin content). Plants with enhanced antiproliferative activity (% living cells) were Annona muricata (24.94±0.74 in NCI-H292), Lantana camara (25.8±0.19 in NCI-H292), Handroanthus impetiginosus (41.8±0.47 in NCI-H292) and Mentzelia aspera (45.61±1.94 in HEp-2). For species with better antioxidant and antiproliferative activities, we suggest future in vitro and in vivo comparative studies with other pharmacological models, and to start a process of purification and identification of the possible molecule(s) responsible for the observed pharmacological activity. We believe that the flora of Brazilian semi-arid areas can be a valuable source of plants rich in tannins, cytotoxic compounds and antioxidant agents.     

Phenolic composition, antioxidant capacity and antibacterial activity of selected Irish Brassica vegetables

Vegetables belonging to the Brassicaceae family are rich in polyphenols, flavonoids and glucosinolates, and their hydrolysis products, which may have antibacterial, antioxidant and anticancer properties. In the present study, phenolic composition, antibacterial activity and antioxidant capacity of selected Brassica vegetables, including York cabbage, Brussels sprouts, broccoli and white cabbage were evaluated after extraction with aqueous methanol. Results obtained showed that York cabbage extract had the highest total phenolic content, which was 33.5, followed by 23.6, 20.4 and 18.4 mg GAE/g of dried weight (dw) of the extracts for broccoli, Brussels sprouts and white cabbage, respectively. All the vegetable extracts had high flavonoid contents in the order of 21.7, 17.5, 15.4 and 8.75 mg QE/g of extract (dw) for York cabbage, broccoli, Brussels sprouts and white cabbage, respectively. HPLC-DAD analysis showed that different vegetables contain a mixture of distinct groups of phenolic compounds. All the extracts studied showed a rapid and concentration dependent antioxidant capacity in diverse antioxidant systems. The antibacterial activity was determined against Gram-positive and Gram-negative bacteria. York cabbage extract exhibited significantly higher antibacterial activity against Listeria monocytogenes (100%) and Salmonella abony (94.3%), being the most susceptible at a concentration of 2.8%, whereas broccoli, Brussels sprouts and white cabbage had moderate to weak activity against all the test organisms. Good correlation (r2 0.97) was found between total phenolic content obtained by spectrophotometric analysis and the sum of the individual polyphenols monitored by HPLC-DAD.     

Radical scavenging activity and antioxidant capacity of bay leaf extracts

Bay leaves (BL) (Laurus nobilis L., Family: Lauraceae) are traditionally used orally to treat the symptoms of gastrointestinal problems, such as epigastric bloating, impaired digestion, eructation, and flatulence. In this study, lyophilized extracts (both water and ethanol) of BL were studied for their antioxidant properties. The antioxidant activity, reducing power, free radical scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging and metal chelating activities were evaluated to determine the total antioxidant capacity of both BL extracts. Both extracts exhibited strong total antioxidant activity in linoleic acid emulsion. Concentrations of 20, 40, and 60 μg ml^?1 showed 84.9, 95.7, 96.8, and 94.2, 97.7, and 98.6% inhibition of lipid peroxidation of linoleic acid emulsion, for water and ethanol extracts, respectively. On the other hand, 60 μg ml^?1 of the standard antioxidants butylated hydroxyianisole (BHA), butylated hydroxytoluene (BHT), and α-tocopherol exhibited 96.6, 99.1, and 76.9% inhibition of lipid peroxidation in linoleic acid emulsion, respectively. In addition, the both BL extracts had effective reducing power, DPPH? free radical scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging and metal chelating activities at 20, 40, and 60 μg ml^?1. The total amount of phenolic compounds in each BL extract was determined as gallic acid equivalents.     

Alterations in osmoregulation, antioxidant enzymes and indole alkaloid levels in Catharanthus roseus exposed to water deficit

Catharanthus roseus (L.) G. Don plants were grown in different water regimes in order to study the drought induced osmotic stress and proline (PRO) metabolism, antioxidative enzyme activities and indole alkaloid accumulation. The plants under pot culture were subjected to 10, 15 and 20 days interval drought (DID) stress from 30 days after sowing (DAS) and regular irrigation was kept as control. The plants were uprooted on 41 DAS (10 DID), 46 DAS (15 DID) and 51 DAS (20 DID). The drought stressed plants showed increased aminoacid (AA), glycine betaine (GB) and PRO contents and decreased proline oxidase (PROX) and increased γ-glutamyl kinase (γ-GK) activities when compared to control. The antioxidative enzymes like peroxidase (POX) and polyphenol oxidase (PPO) increased to a significant level in drought stressed plants when compared to control. The drought stressed C. roseus plants showed an increase in total indole alkaloid content in shoots and roots when compared to well-watered control plants. Our results suggest that the cultivation of medicinal plants like C. roseus in water deficit areas would increase its PRO metabolism, osmoregulation, defense system and the level of active principles.     

Structure effect of benzofuranone on the antioxidant activity in polypropylene

This work deals with the antioxidant activity of benzofuranone compounds in polypropylene (PP). The antioxidant activities of ten benzofuranone compounds in PP were compared using melt flow index (MFI) values of PP stabilized by benzofuranone compounds primarily. The results show: firstly, that the increase of electron donating ability of substituent in 3-substituted benzene ring is beneficial to the improvement of antioxidant activity. Secondly, it has been verified that the steric hindrance of 2′-position substituent can weaken the antioxidant activity of benzofuranone. But when 2′-position substituent forms a hydrogen bond with 3-position reactive hydrogen, the steric hindrance is offset efficiently. Finally, the methyl and tert-butyl groups in the 5 and 7-position of parent benzene ring do not affect the antioxidant activity of benzofuranone compounds in PP obviously.     

Synthesis, characterization and antioxidant capacity of naringenin-oxime

The recognition of the benefits of polyphenolic antioxidants is eliciting increasing interest in the search for new polyphenolic derivatives with improved antioxidant activity. Since naringenin (4',5,7-trihydroxyflavanone) (NG) is one of the most abundant citrus and grapefruit polyphenolics and flavanone oximes were used in the synthesis of anticancer and radioprotector compounds having antiradical activity, the corresponding oxime of NG, naringenin oxime (NG-Ox), was synthesized and investigated. The structure of NG-Ox was characterized by FT-IR, (1)H NMR, elemental analysis, and the synthesized compound was screened for its antioxidant capacity by using the cupric reducing antioxidant capacity (CUPRAC) method. Trolox equivalent antioxidant capacity (TEAC) of NG-Ox was measured to be higher than that of the parent compound, NG. Other parameters of antioxidant activity (scavenging effects on *OH, O(2)*-, and H(2)O(2)) of NG-Ox were also determined.     

Phenolic profile,antioxidant capacity and anti-inflammatory activity of Anethum graveolens L. essential oil

This study reports the chemical composition, antioxidant and anti-inflammatory properties of Anethum graveolens essential oil and its main compounds. The essential oil was obtained from the aerial parts of the plant by hydrodistillation and analysed by using GC/MS. α-Phellandrene (19.12%), limonene (26.34%), dill ether (15.23%), sabinene (11.34%), α-pinene (2%), n-tetracosane (1.54%), neophytadiene (1.43%), n-docosane (1.04), n-tricosane (1%), n-nonadecane (1%), n-eicosane (0.78%), n-heneicosane (0.67%), β-myrcene (0.23%) and α-tujene (0.21%) were found to be the major constituents of the oil. A. graveolens oil exhibit a higher activity in each antioxidant system with a special attention for β-carotene bleaching test (IC₅₀: 15.3 μg/mL) and reducing power (EC₅₀: 11.24 μg/mL). The TLC-bioautography screening and fractionation resulted in the separation of the main antioxidant compounds, which were identified as limonene (45%) and sabinene (32%). The essential oil and its main compounds exhibited a potent NO-scavenging effect and inhibited the expression of inducible NO synthase.     

Effect of paeonol on antioxidant and immune regulatory activity in hepatocellular carcinoma rats

The study investigated the immunity and antioxidant potential of paeonol by employing a hepatocellular carcinoma (HCC) rat model. Three doses of paeonol (20, 40, 60 mg/kg b.w. orally) were administrated to diethylnitrosamine (DEN)-induced HCC rats. Results showed that paeonol significantly reduced the serum AST, ALT, ALP, GGT, AFU and liver MDA levels, increased serum WBC, TP, ALB, A/G, TNF-α and IFN-γ and liver antioxidant enzymes activities (SOD, CAT, GSH-Px, GR) in HCC rats. Altogether, these results suggest that the paeonol could effectively decrease oxidative injury and improve immunity function in HCC rats.     

Antioxidant enzymes expression and activity in liver of stressed wistar rat

Altered activities of antioxidant defence system enzymes and the levels of free radicals scavengers have been found to correlate with various physiological or pathological conditions, including stress. The aim of this study was to determine the effects of chronic 21 day isolation stress on antioxidant enzymes (AOEs) expression and activity in Wistar rat liver tissue. The serum corticosterone (CORT) and glucose (GLU) levels were also measured, as one of the most important indicators of stress. Our data revealed that in chronic stress conditions, when both CORT and GLU were low, the AOEs expression was markedly induced. This increase in MnSOD, CuZnSOD, and catalase exhibited similar trend implying efficient detoxification of and H₂O₂. However, this trend was not followed by the respective enzyme activity. While the total SOD activity was induced by the stress, catalase activity remained unaltered. This discrepancy led us to a conclusion that chronic isolation stress may cause oxidant-antioxidant imbalance in rat liver tissue, favoring H₂O₂ accumulation. The article is published in the original.     

Cytotoxicity,antioxidant and glutathione S-transferase inhibitory activity of palladium(II) chloride complexes bearing nucleobase ligands

Palladium(II) chloride complexes bearing the nucleobases, adenine, cytosine and guanine, have been synthesized and characterized by UV–vis spectrophotometric methods, magnetic susceptibility, molar conductivity, elemental analysis, FTIR and ¹H-NMR. The complexes were found to have the general composition PdCl₂(NH₃L) (where L = adenine, cytosine or guanine). Square-planar geometry is proposed for these Pd(II) complexes based on magnetic evidence and electronic spectra. The complexes as well as the free nucleobase ligands show varying degrees of cytotoxicity on human promyelocytic leukemia (HL60) and human histiocytic leukemia (U937) cell lines, with cis-[PdCl₂(NH₃)(Gua)] showing IC₅₀ values of 48.03 ± 9.67 and 11.12 ± 3.42 µM against HL60 and U937, respectively. The complexes as well as the ligands did not show anti-proliferative activity against a normal human cell line (NB1RGB). The complexes also show significant antioxidant activity against 2,2-diphenyl-1-picrylhydrazyl radical as well as glutathione S-transferase inhibitory activity.     

Role of pyruvate and ascorbate production in regulation of antioxidant enzymes and membrane LPO levels in Fusarium Acuminatum

The role of pyruvate and ascorbate in the regulation of superoxide dismutase (SOD); catalase (CAT); glutathione peroxidase enzymes; and, therefore, membrane lipid peroxidation (LPO) levels in Fusarium acuminatum was investigated in media containing either glycerin or glucose as a carbon source, depending on the incubation period, in the range of 5–25 g/L. Increasing SOD activity between d 9 and 16 of the incubation period showed a positive correlation with a significant increase in pyruvate production up to 15 g/L of glycerin and glucose. In addition, maximum ascorbate production was observed at 15 g/L of glycerin as 82.5 ± 2.1 and 20 g/L of glucose as 54±1.51, whereas CAT activity decreased with an increased concentration of both carbon sources. When compared with the LPO levels determined in media supplemented with glycerin and glucose, the minimum LPO level was 1.88±0.028 nmol of malondialdehyde/g wet wt at 15 g/L of glycerin on d 16, at which it was also observed to have a maximum pyruvate and ascorbate production and SOD, CAT, and GSH-Px activities of 75±1.42 μg/mL, 82.5±2.1 μg/mL, 32.5±0.634 μg/mL, 86.8±2.58 IU/mg, and 1.867 IU/mg, respectively. These results indicate that the biosynthesis of pyruvate and ascorbate may be involved in the regulation of antioxidant enzymes, depending on the glycerin and glucose concentrations, and also this defense network was effective in preventing membrane damage from oxidative stress.     

竹叶提取物的抗氧化活性研究

一般认为黄酮是竹叶提取物中抗氧化作用的有效成分,黄酮含量越高,抗氧化能力越强[1-3]。本实验对不同溶媒竹叶提取物的抗氧化能力做了比较研究,发现抗氧化作用与黄酮含量并不完全成正比关系;并通过进一步的定性实验,证明黄酮并不是竹叶提取物中的唯一的抗氧化有效成分,还有其它     

超声波辅助提取茶叶总黄酮及抗氧化活性分析

采用超声波辅助法探讨了铁观音茶叶中总黄酮的最佳提取工艺条件,并测定了铁观音茶叶总黄酮清除羟基自由基的能力.结果表明,超声波功率400 W,料液比1∶30 g·mL~(-1),浸提时间30 min,乙醇浓度50%为超声波辅助提取铁观音茶叶总黄酮的最佳工艺条件,总黄酮提取率为4.74%;抗氧化实验表明随着铁观音茶叶总黄酮浓度的增大,其对羟基自由基的清除能力增大,当浓度达到0.80 g/L,清除率为65.14%,与BHT相比具有较强的抗氧化能力.     

Determination of the effect of Quercetinon oxidant- antioxidant parameters in the blood and liver tissues of rats given sodium fluoride experimentally

AimThe purpose of the study is to research the effect of quercetin, which has a good antioxidant characteristic in rats exposed to sodium fluoride (NaF) toxication, on oxidant and antioxidant activity in liver tissue and erythrocyte.Material and method40 Swiss albino male rats with a weight of approximately 20–25 gr were used in the study. The rats were separated into 4 equal groups (n = 10). The first group, the control group, was given normal drinking water; the second group was given 12 mg/kg/day NaF; the third group was given 40 mg/kg/day quercetin; the fourth group was given 12 mg/kg/day NaF+40 mg/kg/day quercetin orally for 30 days. As a result of the experiment, plasma AST and ALT activities were found. Total oxidant capacity (TOC) and total antioxidant capacity (TAC) analyses were made in liver tissue and erythrocyte hemogenisate. Histopathological analyses of the liver tissue were conducted.ResultsNo changes were found in plasma ALT activities between groups. Increases were found in AST activity of all groups. While erythrocyte TAC level was found to increase in fluorine and fluorine + quercetin group when compared with the control group, erythrocyte TOC level was found to increase in all groups when compared with the control group. No significant change was found in TOC and TAC levels in the liver tissue. In liver tissue histopathology, while hydropic degeneration and cellular necrosis were found in vena centralis area in fluorine group, hydropic degeneration was found in heptocytes in centrilobular area in the quercetin group. In the fourth group, hydropic degeneration and centrilobular necrosis were more severe. It was found that in rats which are given NaF experimentally, fluorine and quercetin caused histopathological degenerations in the liver tissue during this time.ConclusionWhile no changes were found in TOC and TAC levels of liver tissue, antioxidant capacity was found to be stimulated in fluorine groups in erythrocyte.     

Lycopus europaeus: phenolic fingerprint,antioxidant activity and antimicrobial effect on clinical Staphylococcus aureus strains

Lycopus europaeus L. leaves water extract (LEL) was subjected to phytochemical analysis, and evaluated for its antibacterial and antioxidant effects. Antibacterial activity testing was performed on Staphylococcus aureus clinical strains from catheter-related and skin infections by broth microdilution test. LEL showed bactericidal activity at concentrations from 2500 to 5000 μg/mL against all, including methicillin resistant and polyresistant nosocomial, strains. Antioxidant activity was examined using DPPH and ABTS (11.3 and 9.8 μg/mL, respectively) and by ferric reducing ability of the plasma method (891 μmol AAE/g dry extract). Phytochemical analysis of LEL was performed by LC-DAD-MS/MS. Ten phenolic compounds were identified; two minor compounds (glucopyranosyl rosmarinic acid and sagerinig acid) have not been described in Lycopus yet. The major compounds, considered to be responsible for biological activities detected in the study, were determined as rosmarinic acid (76 mg/g) and luteolin-7-O-glucuronide (23 mg/g). L. europaeus arises from our study as a promising source of antibacterial agent for topical usage.     

Biochemical relevance of Cr(III) complexes of isoniazid: synthesis,characterization, DFT,antibacterial screening,antioxidant activity and glucose-lowering effect in STZ-induced diabetic rats

Molecular mechanism suggests that the incorporation of an antioxidant organic moiety to chromium will be a sound strategy for the synthesis of safer and more effective hypoglycemic compounds. Two Schiff base ligands were derived by condensation of isonicotinyl hydrazide with salicylaldehyde/o-hydroxyacetophenone which further yield four novel chromium(III) complexes of types [Cr(L)Cl₂(H₂O)] and [Cr(L)₂]Cl. The ligands and complexes were characterized by analytical and spectroscopic techniques. DFT study at the basic set B3LYP and TD-SCF/6-311-G level was employed to confirm the geometry of the investigated compounds. Ligands were tested for their antioxidant activity and exhibited good antioxidant activity. Assessment of insulin-like activity of the complexes was initially performed in vitro by measuring the inhibition of α-amylase. The complex with highest in vitro activity was investigated for in vivo antidiabetic activity on the model of STZ-induced diabetic rats, which demonstrated that complex 4 significantly lowers the blood glucose level in rats. Toxicity level and antioxidant activity of the complex were also tested, which exhibit good tolerance level and antioxidant activity. Histological analysis of the pancreas of animals under investigation reveals the good condition of the pancreas treated with the complex. Ligands and complexes were also tested for antibacterial activity against Escherichia coli.