Superoxide Radical Scavenging Assays Research Articles

Antioxidant activity of low molecular weight alginate produced by thermal treatment

By definition, antioxidants are molecules that inhibit the oxidation of other molecules. Therefore, such compounds have very important clinical roles. In this study alginate polymer was depolymerized by heat treatment. The resulting low molecular weight alginates were investigated by UV–visible spectroscopy, Viscometry, Dynamic light scattering and FT-IR spectroscopy techniques. Antioxidant properties of these heat products were studied by ABTS and superoxide radical scavenging assays. Results showed that heating caused breaks in the polymer chain and so generation of low molecular weight alginates. Antioxidant measurements confirmed antioxidant activity of alginate increased upon a decrease in molecular weight. Therefore, low molecular weight alginate produced by heating could be considered as a stronger antioxidant than alginate polymer. These products could be useful for industrial and biomedical applications.

Antioxidant and cytotoxic activities of three species of tropical seaweeds.

BackgroundThree species of seaweeds (Padina tetrastromatica, Caulerpa racemosa and Turbinaria ornata) are widely consumed by Asians as nutraceutical food due to their antioxidant properties. Studies have shown that these seaweeds exhibit bioactivities which include antimicrobial, antiviral, anti-hypertensive and anticoagulant activities. However, investigations into the mechanisms of action pertaining to the cytotoxic activity of the seaweeds are limited. The aim of this study was to determine the antioxidant and cytotoxic activities of whole extracts of P. tetrastromatica, C. racemosa and T. ornata, including the cellular events leading to the apoptotic cell death of the extract treated-MCF-7 cells. Bioassay guided fractionation was carried out and the compounds identified.MethodsPowdered samples were sequentially extracted for 24 h. Their antioxidant activities were assessed by the DPPH radical, superoxide, nitric oxide and hydroxyl radical scavenging assays. The cytotoxic activity of the extract-treated MCF-7cells was assessed using the MTT assay. The most potent fraction was subjected to bioassay guided fractionation with column chromatography. All the fractions were tested for cytotoxic activity, caspase activity and effect on DNA fragmentation.ResultsAll three seaweeds showed potent radical scavenging activities in the various assays. The activity of the cellular antioxidant enzymes, superoxide dismutase, catalase and glutathione reductase, in MCF-7 cells, decreased in a time-dependent manner. The partially purified fractions exhibited higher cytotoxic activity, as assessed by the MTT assay, than the whole extracts in the breast adenocarcinoma cell line, MCF-7. LC-MS analysis revealed the presence of bioactive alkaloids such as camptothecin, lycodine and pesudopelletierine.ConclusionBased on the results obtained, all three seaweeds are rich sources of enzymatic and non-enzymatic antioxidants which could contribute to their reported medicinal benefits.

Regioselective sulfation of Artemisia sphaerocephala polysaccharide: Solution conformation and antioxidant activities in vitro

Regioselective modification is an effective approach to synthesize polysaccharides with different structure features and improved properties. In this study, regioselective sulfation of Artemisia sphaerocephala polysaccharide (SRSASP) was prepared by using triphenylchloromethane (TrCl) as protecting precursor. The decrease in fractal dimension (df) values (1.56–2.04) of SRSASP was observed in size-exclusion chromatography combined with multi angle laser light scattering (SEC-MALLS) analysis. Compared to sample substituted at C-6, SRSASP showed a more expanded conformation of random coil, which was attributed to the breakup of hydrogen bonds and elastic contributions. Circular dichroism (CD), methylene blue (MB) and congo red (CR) spectrophotometric method and atomic force microscopy (AFM) results confirmed the conformational transition and stiffness of the chains after sulfation. SRSASP exhibited enhanced antioxidant activities in the DPPH, superoxide and hydroxyl radical scavenging assay. Sulfation at C-2 or C-3 was favorable for the chelation which might prevent the generation of hydroxyl radicals. It concluded that the degree of substitution and substitution position were the factors influencing biological activities of sulfated polysaccharides.

Optimization extraction, characterization and antioxidant activities of pectic polysaccharide from tangerine peels

Response surface methodology (RSM) was employed to optimize the microwave-assisted extraction (MAE) process of pectic polysaccharide (TPPs) from tangerines peel. The optimal extraction conditions were as follows: microwave power 704W, extraction temperature 52.2°C, and extraction time 41.8min Under these conditions, the experimental yield was 19.9±0.2%. The purified pectic polysaccharide TPPs-2-1 was successfully obtained by anion-exchange and gel filtration chromatography. TPPs-2-1, linked mainly by α-glycosidic bonds, consisted of galacturonic acid (GalA), arabinose (Ara), galactose (Gal), rhamnose (Rha), glucose (Glc) and mannose (Man) with the average molecular weight of 17.8kDa, and had typical IR spectra characteristic of pectic polysaccharides. Antioxidant activities were investigated on the basis of ferric-reducing antioxidant power (FRAP), hydroxyl radical (OH), 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and superoxide radical (O2−) scavenging assay. TPPs-2-1 exhibited significant antioxidant activity in a concentration-dependent manner and might be exploited as effective natural antioxidant applied in functional food and medicine.

Synthesis of newer piperidinyl chalcones and their anticancer activity in human cancer cell lines

Newer tetrahydropyridine chalcones were synthesized and tested for their antioxidant and anticancer activity. These molecules showed significant anticancer activity at IC50 < 50 μM in human cancer cell lines such as A549 (lung adenocarcinoma), HepG2 (hepatocellular liver carcinoma), HeLa (cervical cancer), HCT-116 (colon carcinoma cells), MCF-7 (breast cancer cell line), and MDA MB 231 (breast cancer cells) cancer cells. The test compounds significantly inhibited cancer cell migrations in scratch wound assay for angiogenesis. Further, the test compounds bearing naphthalene substituents on the main ring showed in vitro antioxidant activity at <100 µM by 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation, superoxide radical scavenging, O-phenonthroline, and lipid peroxidation assays. In conclusion, two test compounds bearing naphthalene substitutions exhibited potent anticancer activity that could be attributed to their ability to induce apoptosis, inhibit cancer cell migrations, provide anti-angiogenic properties, and also partly by reducing oxidative stress by scavenging free radicals.

Phytochemicals of Salacia oblonga responsible for free radical scavenging and antiproliferative activity against breast cancer cell lines (MDA-MB-231).

Salacia oblonga, an inhabitant of tropical regions has been used in traditional Indian medicinal systems. Phytochemicals were extracted in methanol from the plant and analyzed for various biological activities. The results of biochemical tests for total phenolics (297±0.005 and 275±0.006) and flavonoids (95±0.004 and 61.6±0.004) in the aerial and root parts were indicated as Gallic acid and quercetin equivalents respectively. The Aerial and root extracts showed strong reducing ability based on reducing power and FRAP assays. The extracts exhibited significant IC50 values in DPPH, super oxide and nitric oxide radical scavenging assays. The extracts displayed low IC50 values (<50μg/ml) when assessed for antiproliferative activity against breast cancer cell lines using the MTT assay. GC-MS analysis of methanolic extracts have revealed the presence of compounds viz. n-Hexadecanoic acid, N-Methoxy-N-methylacetamide, Ursa-9(11), 12-dien-3-ol, Gamma-sitosterol etc., that might be potential candidates for the biological activity exhibited by the extract.

Antioxidant and antimicrobial activity of a mangrove plant Avicennia marina (Forsk.)

Objective: To evaluate the antioxidant and antimicrobial potential of different parts (leaf, stem and pneumatophore) of a mangrove plant Avicennia marina (Forsk.) Vierh (Avicenniaceae). Methods: The extraction was done by cold percolation method using solvents of hexane, ethyl acetate, acetone, methanol and water. Total phenol and flavonoid content were measured by Folin-Ciocalteu's reagent and aluminium chloride colorimetric method respectively. The antioxidant activity was evaluated using antioxidant assays of 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity, superoxide radical scavenging assay, 2,2'-azino-bis-(3-ethyl) benzothiazoline-6-sulfonic acid, ferric reducing antioxidant power and reducing capacity assessment. The antibacterial activity was done by agar well diffusion method against four Gram-positive, four Gram-negative bacteria and four fungi. Results: Different antioxidant assays showed different levels of activity in different parts and different solvent extracts. Overall, acetone extract of stem showed the best antioxidant activity. The Gram-positive bacteria were more susceptible than Gram-negative bacteria and fungi. Conclusions: The results indicated extract of Avicennia marina can be used as a promising source of natural antioxidant.

In Vitro Antioxidant Activity of the Anthocyanins in Sageretia theezans Brongn Fruit

Antioxidant activities of the extract containing anthocyanins from fruit of Sageretia theezans Brongn were investigated in this work. The fruit of Sageretia theezans Brongn was treated with 0.001 mol·L–1 HCl in a solid (g): liquid (mL) ratio 1:10 to give extract. Total anthocyanins content was 253.10 ± 2.31 mg in 100 g fruit. The anthocyanins in extract were determined as cyanidin-3-sophorose-5-glucoside (Cy-3-Sp-5-Glu), petunidin-3-(6′-malonyl)-glucoside (Pt-3-(6’-Mal)-Glu), malvinidin-3-glucosid (Mv-3-Glu), and peonidin-3-(6′-malonyl)-glucoside (Pn-3-(6’-Mal)Glu) in 0.38, 22.57, 44.32, and 30.86%, respectively, by high performance liquid chromatography-mass spectrometry method. Antioxidant activities of the anthocyanins in extract were evaluated by methods of ferric reducing antioxidant power, hydroxyl radical scavenging assay, and superoxide radical scavenging assay. The anthocyanins in extract exhibited obvious antioxidative activities. These results suggested that the fruit of Sageretia theezans Brongn could be considered as a good source of natural antioxidants.

Indole Alkaloids from Chaetomium globosum

Two new indole alkaloids chaetocochin J (1) and chaetoglobinol A (8), along with chetomin (2), chetoseminudin A (3), cochliodinol (9), and semicochliodinol (10), were isolated from the rice culture of the fungus Chaetomium globosum. Their structures were elucidated by spectral analysis. Three new epipolythiodioxopiperazines, chaetocochins G-I (5-7), were identified by the combination of UPLC and mass spectrometric analysis. Chaetocochin I contained two sulfur bridges, one formed by three sulfur atoms between C-3 and C-11a, and the other formed by four sulfur atoms between C-3' and C-6'. Chaetocochin I was readily transformed into chetomin (2), chetoseminudin A (3), chaetocochin D (4), chaetocochin G (5), and chaetocochin H (6) by losing sulfur atoms. Compounds 1-3, and 8 exhibited antibacterial activities against Bacillus subtilis with MICs of 25, 0.78, 0.78, and 50 μg/mL, respectively, but not against Gram-negative bacterium (Escherichia coli). Compounds 2 and 8 were inactive against Candida albicans, Fusarium graminearum, Fusarium vasinfectum, Saccharomyces cerevisiae, and Aspergillus niger even at the high concentrations of 200 and 100 μg/mL, respectively. Compound 8 showed free radical scavenging capacity against the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid radical (ABTS(+•)), with IC50 values of 143.6 and 45.2 μM, respectively. The free radical scavenging capacity rates of compounds 1-3 on the DPPH and ABTS(+•) were less than 20% at the test concentrations (89.9-108.3 μM). The superoxide anion radical scavenging assay indicated that compounds 1-3, and 8 showed 14.8% (90.9 μM), 18.1% (90.9 μM), 51.5% (88.3 μM), and 30.4% (61.3 μM) superoxide anion radical scavenging capacity, respectively.

Antioxidant, antiproliferative, genotoxic and cytoprotective effects of the methanolic extract of Padina tetrastromatica on human breast adenocarcinoma and embryonic fibroblast cell lines

The in vitro antioxidant, antiproliferative, genotoxic and cytoprotective effects of the methanolic extract of the seaweed Padina tetrastromatica were assayed using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, superoxide, nitric oxide and hydroxyl radical scavenging assays, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and comet assays. The methanolic extract of P. tetrastromatica showed considerable antioxidant activity through inhibition of DPPH and hydroxyl radicals, with median inhibitory concentration (IC50) values of 45.57 ± 1.63 and 36.58 ± 2.13 µg/ml, respectively. Treatment of the human breast adenocarcinoma cell line MCF-7 with the methanolic extract, at a concentration range of 0–500 µg/ml, showed considerable antiproliferative effects, with an IC50 value of 125 ± 2.03 µg/ml. The genotoxic and cytoprotective effects of the extract on the human breast adenocarcinoma cell line MCF-7 and the embryonic fibroblast cell line 3T3-L1 were evaluated by the in vitro comet assay, and the extract demonstrated a genotoxic effect on MCF-7 and antigenotoxic and cytoprotective effects on 3T3-L1 cells. The methanolic extract of P. tetrastromatica was more effective in inducing a genotoxic effect in MCF-7 cells and a cytoprotective effect in 3T3-L1 cells, compared with the standard cancer chemotherapy drug doxorubicin, which induced greater DNA damage in the normal 3T3 cells.

Phytochemical analysis and antioxidant potential of the leaves of Garcinia travancorica Bedd.

Phytochemical analysis of the leaves of Garcinia travancorica, a hitherto uninvestigated endemic species to the Western Ghats of south India, resulted in isolation and characterisation of the polyisoprenylated benzophenones 7-epi-nemorosone (1) and garcinol (2) along with biflavonoids GB-1a (3), GB-1 (4), GB-2 (5), morelloflavone (6) and morelloflavone-7″-O-β-d-glycoside or fukugiside (7). The compounds were identified using various spectroscopic techniques, mainly through NMR and MS. The methanol extract and the biflavonoids 3, 4, 5 and 7 showed potential in vitro antioxidant activities. The IC50 value of the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of compound 7 was 8.34 ± 2.12 μg/mL, comparable to that of standard ascorbic acid (3.2 ± 0.50 μg/mL). In the superoxide radical scavenging assay, compound 7 gave IC50 value of 6.95 ± 1.33 μg/mL close to standard ascorbic acid with IC50 value of 5.8 ± 0.25 μg/mL. Validated HPTLC estimation revealed G. travancorica as a rich source of morelloflavone-7″-O-β-d-glycoside (7.12% dry wt. leaves).

Antioxidant activity of polyphenolic extract of Phyllanthus emblica against lead acetate induced oxidative stress

Phyllanthus emblica (Euphorbiaceae) possesses a vast ethnomedical history and represents a phytochemical reservoir of heuristic medicinal value. Polyphenolic extract of P. emblica fruits, was investigated for antioxidant potential against lead acetate induced toxicity in female Wistar rats. The liver of female Wistar rats treated with lead acetate at different concentrations showed significant increase in lipid peroxidation and decrease in activities of superoxide dismutase and catalase. Furthermore, lead acetate also caused decrease in reduced glutathione content in rat liver. However, the co-incubation of extract and lead acetate showed significant protection in concentration-dependent manner. Furthermore, the polyphenolic extract of P. emblica fruits also found to have potent free radical scavenging activity as assessed by reducing power assay, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical (IC50 15.5 μg/mL), superoxide radical (IC50 26 μg/mL) and hydrogen peroxide scavenging assays (IC50 22 μg/mL) under in vitro conditions. Moreover the phytochemical characterization of the extract was also measured by determining total phenolic, flavonoids and tannin contents. This activity of the extract may be due to the total polyphenolic contents present in it. The present study concluded that a polyphenolic rich fraction of P. emblica fruits is a potential source of natural antioxidants and thus could prevent oxidative stress induced by heavy metal toxicants.

The antioxidant capacity and immunomodulatory activity of stingless bee honeys proceeding from Costa Rica

Objective: Medihoney® is considered up to date the only antioxidant therapy specifically approved by the United States Food and Drug Administration (FDA) for wound healing. This is the first study that evaluates the antioxidant capacity and immunomodulatory activity of stingless bee honeys in comparison to Medihoney®. The goal of this study was to evaluate in vitro the potentials of Meliponini honey from Costa Rica as an antioxidant wound dressing agent. Materials and Methods: A total of fifty-seven honeys belonging to the Tetragonisca angustula (n = 36) and Melipona beecheii (n = 21) species were studied. Following tests were carried out: screening of radical scavenging activity by the 2,2-diphenyl-1-picryl hydrazyl (DPPH) assay, superoxide anion radical scavenging assay, inhibition of xanthine oxidase (XO), total phenolic content by the Folin-Ciocalteu reagent, and the oxygen radical absorbance capacity (ORAC) assay. Furthermore, the effect of honey over reactive oxygen species (ROS) produced by human polymorphonuclear leucocytes (PMNL) was evaluated using luminol and a Cypridina luciferin analog as luminescence probes. Results: The positive correlation between the total phenolic content and the ORAC value reported herein, suggests that the antioxidant capacities of the stingless bee honeys examined are given in a major grade to their phenolic constituents. According to present results, the in vitro immunomodulatory activities are explained mainly due to the radical scavenging effect and to the XO inhibition. Both mechanisms may play a role in the impairment of the inflammatory process and the promotion of redox homeostasis. Conclusion: The T.angustula honeys showed antioxidant capacities not statistically different to Medihoney®. In addition, their radical scavenging activity over ROS produced by human PMNLs and inhibition of XO justify their ethnopharmacological use as a wound dressing and further research towards novel wound-healing developments.

Evaluation of Ethanol and Aqueous extracts of Cinnamomum verum Leaf Galls for Potential Antioxidant and Analgesic activity.

In the present study, ethanol and aqueous extracts of leaf galls of Cinnamomum verum were prepared to evaluate the antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl free radical scavenging assay and superoxide radical scavenging assay with ascorbic acid as a standard, and analgesic activity by tail immersion test and acetic acid-induced writhing test methods using diclofenac sodium as the reference drug. Swiss albino mice maintained under standard laboratory conditions were used for analgesic tests. In the 2,2-diphenyl-1-picrylhydrazyl assay it was found that the aqueous and the ethanol extract possessed almost equal capacity to inhibit free radicals (IC50=13.3 and 13.53 µg/ml) but found less than ascorbic acid (IC50=9.96 µg/ml). And in superoxide assay the ethanol extract was found to be more potent in scavenging super oxide radicals when compared to ascorbic acid and the aqueous extract (IC50=237.1 and 197.8 µg/ml) with the IC50=119.7 µg/ml. For analgesic activity, ethanol extract showed the maximum time required for response against thermal stimuli (6.75±0.47 s) and maximum % of writhing inhibition (44.57%) when compared to aqueous extract (5.25±0.48 s and 32.61%), whereas diclofenac showed response in 7.25±0.25 s 67.39% inhibition in tail immersion and writhing tests, respectively. These results demonstrate that the ethanol extracts of leaf galls possessed high antioxidant and analgesic activity.

Antioxidant, Hepatoprotective Potential and Chemical Profiling of Propolis Ethanolic Extract from Kashmir Himalaya Region Using UHPLC-DAD-QToF-MS.

The aim of this study was to examine hepatoprotective effect of ethanolic extract of propolis (KPEt) from Kashmir Himalaya against isoniazid and rifampicin (INH-RIF) induced liver damage in rats. Hepatic cellular injury was initiated by administration of INH-RIF combination (100 mg/kg) intraperitoneal (i.p.) injection for 14 days. We report the protective effects of KPEt against INH-RIF induced liver oxidative stress, inflammation, and enzymatic and nonenzymatic antioxidants. Oral administration of KPEt at both doses (200 and 400 mg/kg body weight) distinctly restricted all modulating oxidative liver injury markers and resulted in the attenuation of INH-RIF arbitrated damage. The free radical scavenging activity of KPEt was evaluated by DPPH, nitric oxide, and superoxide radical scavenging assay. The components present in KPEt identified by ultra high performance liquid chromatography diode array detector time of flight-mass spectroscopy (UHPLC-DAD-QToF-MS) were found to be flavonoids and phenolic acids. The protective efficacy of KPEt is possibly because of free radical scavenging and antioxidant property resulting from the presence of flavonoids and phenolic acids.

In Vitro Antibacterial, Antifungal, Antibiofilm, Antioxidant, and Anticancer Properties of Isosteviol Isolated from Endangered Medicinal Plant Pittosporum tetraspermum.

This study aimed to investigate the in vitro antibacterial, antifungal, antibiofilm, antioxidant, and anticancer properties of isosteviol isolated from endangered medicinal plant Pittosporum tetraspermum. Pure compound was obtained and characterized by column chromatography followed by 1H NMR, 13C NMR, IR, and mass spectral analysis. The antimicrobial activities of the compound were assessed by the broth microdilution method and the antioxidant properties were determined using reducing ability assay, DPPH scavenging assay, hydroxyl radical scavenging activity, and superoxide radical scavenging assay. Anticancer study was evaluated by following MTT assay. Column purification and spectrocopical analysis lead to identifying isosteviol from the crude ethyl acetate extract. The compound exhibited significant activity against bacteria such as Staphylococcus epidermidis (125 µg/mL), Staphylococcus aureus (125 µg/mL), and Klebsiella pneumoniae (62.5 µg/mL). The MIC of the compound against Candida albicans, Aspergillus niger, and Trichophyton mentagrophytes was 62.5, 125, and 500 µg/mL, respectively. The compound showed comparatively better antibiofilm activity against E. coli, S. typhi, and P. aeruginosa. Furthermore, it exhibited good antioxidant properties. Anticancer properties of the compound against Vero and MCF7 cell lines were its advantage. Novel isosteviol would be useful to reduce the infectious diseases caused by pathogenic microorganisms or slow the progress of various oxidative stress-related diseases.

Influence of Processing on Phytochemical Characteristics and in vitro antioxidant actvity of Ficus carica l. (FIG) products

The present study was undertaken to assess the effect of processing into jam and nectar on phytochemical characteristics, in vitro antioxidant activity viz. reducing power, iron chelating activity, DPPH, ABTS, nitric oxide, superoxide and hydrogen peroxide radical scavenging assays of figure Ficus carica L. fruit. Figure pulp extracts exhibited significantly higher antioxidant activity than fig jam and fig nectar extracts. Total phenolics however to decreased by 10 and 55 %, flavonoids by 98 and 45%, anthocyanins by 79 and 33% and tannins by 83 and 77% in fig jam and fig nectar, respectively, when compared with the fig pulp. However, in vivo studies to determine the antioxidant potential of the fruit need to conducted before it can be recommended as nutritional substitutes.

Gastroprotective activity and mechanisms of action of &lt;i&gt;Bauhinia purpurea&lt;/i&gt; Linn (Leguminoseae) leaf methanol extract

Purpose: To determine the gastroprotective activity and mechanisms of protection of the methanol extract of Bauhinia purpurea leaves (MEBP) using ethanol-induced gastric ulcer model. Methods: Male Sprague Dawley rats (n = 6) were administered orally with 10 % DMSO, 100 mg/kg ranitidine or MEBP (50, 250 and 500 mg / kg) daily for 7 consecutive days prior to subjection to the ethanol-induced gastric ulcer assay. The mechanisms of gastroprotection were determined based on: i) antisecretory activity via pylorus ligation assay; ii) the role of nitric oxide (NO) and sulfhydryl group via pre-treatment of MEBP-treated rats with the respective N-nitro-L-arginine methyl ester (L-NAME) or carbenoxolone (CBX) followed by the ethanol-induced assay; and iii) antioxidant activity using superoxide anion radical scavenging assay and, oxygen radical absorbance capacity (ORAC) assay. Ranitidine (100 mg / kg) was used as the reference drug. . Results: MEBP exhibited a significant (p < 0.05) and dose-dependent gastroprotective activity against ethanol-induced gastric ulcer with ulcer formation ranging between 0 and 74 % (indicated by decrease in ulcer area from 21.3 to 5.5 mm 2 ). The macroscopic observation was in line with the microscopic findings and further supported by the histological scores suggesting the antiulcer potential of MEBP. MEBP also significantly (p < 0.05) reduced volume gastric juice, as well as its free and total acidity wh ile increasing its pH. Moreover, this activity was significantly (p < 0.05) modulated in the presence of sulfhydryl group, but not NO. The extract also exhibited significant (p < 0.05) antioxidant activity. Conclusion: MEBP exerts gastroprotective activity partly via its antisecretory and antioxidant activities, as well as by modulation of sulfhydryl group, but not NO action.

In vitro anticoagulant and antioxidant activities of Jatropha gossypiifolia L. (Euphorbiaceae) leaves aiming therapeutical applications.

BackgroundJatropha gossypiifolia L. (Euphorbiaceae) is a medicinal plant largely used in folk medicine. Teas from the leaves are popularly used as an antithrombotic agent and the branches are frequently employed as a "thick blood" agent. Considering that the anticoagulant activity associated with antioxidant properties could be beneficial for various cardiovascular diseases, this study’s aim is the evaluation of anticoagulant and antioxidant activities of J. gossypiifolia leaves, seeking new therapeutic purposes for this plant.MethodsThe aqueous leaf crude extract (CE) was prepared by decoction and was fractionated by liquid-liquid partition with solvents of increasing polarity. The phytochemical analysis was performed by thin layer chromatography (TLC) and by the spectrophotometric quantification of sugars, proteins and phenolic compounds. The anticoagulant activity was evaluated by prothrombin time (PT) and activated partial thromboplastin time (aPTT) tests. The capacity to act in the fibrinolytic system (fibrinolytic and fibrinogenolytic activities) was also assessed. The antioxidant activity was evaluated by total antioxidant capacity, reducing power, copper chelating activity, iron chelating activity, hydroxyl radical scavenging activity and superoxide radical scavenging assays. The potential toxicity was evaluated using hemolytic assay and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) assay on HEK-293 cells.ResultsCE showed significant anticoagulant activity in aPTT test, while no action was observed in PT test, suggesting a preferential action toward the intrinsic and/or common pathway of coagulation. No effect was observed in the fibrinolytic system. Using the aPTT test, it was observed that the residual aqueous (RA) fraction was the most active, being two times more active than CE. RA presented very significant antioxidant activity in all models tested comparable to or even higher than CE. Regarding the safety, CE and RA did not produce significant cytotoxicity in both tests employed. Phytochemical analysis revealed the presence of alkaloids, flavonoids, proteins, tannins, steroids and/or terpenoids and sugars.ConclusionsCE and RA possessed significant anticoagulant and antioxidant activity and absence of cytotoxic effect in vitro, thus showing the potential of the plant, especially RA fraction, as a new source of bioactive molecules for therapeutic purposes, with particular emphasis on the treatment of cardiovascular diseases.

Bioactive Compound Contents and Antioxidant Activity in Aronia (Aronia melanocarpa) Leaves Collected at Different Growth Stages.

The bioactive compounds and antioxidant activity of aronia leaves at different stages of maturity were identified and evaluated. Young and old leaves were approximately 2 months of age and 4 months of age, respectively. The young leaves contained more polyphenols and flavonoids than the old leaves. Three phenolic compounds (i.e., chlorogenic acid, p-coumaric acid, and rutin) were detected by HPLC. Antioxidant activity was measured using 2,2-di-phenyl-1-picrylhydrazyl (DPPH) radical, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical, and superoxide anion radical scavenging assays. The reducing power of aronia leaf extracts increased in a concentration-dependent manner (0~100 μg/mL). The antioxidant activity of the 80% ethanol extract was greater than that of distilled water extract. The high phenolic compound content indicated that these compounds contribute to antioxidant activity. The overall results indicate that aronia leaves contain bioactive compounds, and that younger aronia leaves may be more favorable for extracting antioxidative ingredients because they contain more polyphenols.