Mira Popovic

Screening for antioxidant properties of Salvia reflexa hornem.

The antioxidant properties of the wild growing sage species, Salvia reflexa Hornem., were investigated. The presence of superoxide (O2·−) and hydroxyl (·OH) radicals, malonyldialdehyde (MDA), reduced glutathione (GSH) and total flavonoids were observed in the above‐ground parts of plant, as well as activities of the antioxidant enzymes superoxide‐dismutase (SOD) and peroxidase (P‐ase). The potential antioxidant activity of the methanol:water extract has been assessed based on scavenging activity of stable DPPH free radicals. By the means of TLC and LC/MS a screening for secondary plant products was performed. Significant quantities of O2·−, ·OH and MDA were observed. Thus, this species exhibited high SOD and P‐ase activities as well as a content of total flavonoids. The dominant naturally occurring compound was rosmarinic acid. The results obtained suggested a high antioxidant activity of Salvia reflexa Hornem. Copyright

Antioxidant Capacity of Ocimum basilicum L. and Origanum vulgare L. Extracts

The antioxidant properties of five different extracts (Et2O, CHCl3, EtOAc, n-BuOH, and H2O) of Ocimum basilicum L. and Origanum vulgare L. were studied. Antioxidant activity was assessed in six different model systems. Free radical scavenging capacity (RSC) was evaluated by measuring the scavenging capacity of extracts on DPPH, NO, O2•− and OH radical, as well as on hydrogen peroxide (H2O2). In addition, the protective effects on lipid peroxidation in liposomes (LPx) were evaluated by TBA-assay using the Fe2+/ascorbate induction system. The amount of total phenolic compounds and content of total flavonoids was also determined. EtOAc, n-BuOH and H2O extracts of O. basilicum and O. vulgare expressed very strong scavenger activity. Furthermore, the mentioned extracts showed notable inhibition of LPx. On the other hand, Et2O and CHCl3 extracts showed much weaker effect in the neutralization of DPPH, NO and O2•− radicals and the neutralization of H2O2. When examining the production of OH radicals and inhibition of LPx, the Et2O and CHCl3 extracts showed weak prooxidative properties. The observed differences in antioxidant activity could be partially explained by the levels of phenolics and flavonoids in the investigated O. basilicum and O. vulgare extracts.

Medicinal and edible lignicolous fungi as natural sources of antioxidative and antibacterial agents

The antioxidant activity of organic extracts of eight fungal species, Ganoderma lucidum, Ganoderma applanatum, Meripilus giganteus, Laetiporus sulphureus, Flammulina velutipes, Coriolus versicolor, Pleurotus ostreatus and Panus tigrinus, was evaluated for free radical (DPPH· and OH·) scavenging capacity and an effect on lipid peroxidation, and the antibacterial activity was tested by the agar well diffusion method. The highest DPPH· scavenging activity was found in the methanol extract of G. applanatum (12.5 μg/mL, 82.80%) and the chloroform extract of G. lucidum (510.2 μg/mL, 69.12%). The same extracts also showed the highest LP inhibition (91.83%, 85.09%) at 500 μg/mL, while the methanol extracts of G. applanatum and L. sulphureus showed the highest scavenging effect on OH· radicals (68.47%, 57.06%, respectively) at 400 μg/mL. A strong antibacterial activity against Gram‐positive bacteria was also manifested. The antioxidative potencies correlated generally with the total phenol content (0.19–9.98 mg/g). The HPLC determination showed that the majority of analysed species contained gallic and protocatechic acids. Consequently, these fungi are shown to be potential sources of antioxidative and antibacterial agents. Copyright

Liquid chromatography/tandem mass spectrometry study of anti-inflammatory activity of plantain (Plantago L.) species.

To evaluate anti-inflammatory activity of selected Plantago species (P. lanceolata L. and P. major L.) an optimized in vitro test for determination of cyclooxygenase-1 (COX-1) and 12-lipoxygenase (12-LOX) inhibition potency was undertaken. By using intact cell system (platelets) as a source of COX-1 and 12-LOX enzymes and highly sensitive and specific LC-MS/MS technique for detection of main arachidonic acid metabolites formed by COX-1 and 12-LOX, this test provides efficient method for evaluation of anti-inflammatory potential of plant extracts and isolated compounds. Our results validated the well-known COX-1 inhibitory activity of P. lanceolata and P. major methanol extracts (concentration required for 50% inhibition (IC(50)) was 2.00 and 0.65 mg/ml, respectively). Furthermore, 12-LOX inhibitory activity of examined extracts was reported for the first time (IC(50)=0.75 and 1.73 mg/ml for P. lanceolata and P. major, respectively). Although renowned inhibitors, such as acetylsalicylic acid and quercetin showed higher activity, this study verifies P. lanceolata and P. major as considerable anti-inflammatory agents.

Herbicide Induced Oxidative Stress in Lettuce, Beans, Pea Seeds and Leaves

The effects of different paraquat, alachlor and metolachlor concentrations on superoxide dismutase (SOD), catalase (CAT), guaiacol peroxidase (GPX) activities and pigment contents in lettuce, bean and pea seeds and leaves were studied. Under paraquat (1.0 and 2.0 μM) treatment declined SOD and CAT activities were observed in seeds and undetectable ativity of GPX. Germination of all investigated seeds was completely inhibited. All used concentrations of alachlor and metolachlor inhibited antioxidant enzyme activities in seeds but did not prevent germination and growth. In leaves, lower concentrations of these herbicides increased activities of antioxidant enzymes but at the highest herbicide concentrations (200 μM) activities of investigated enzymes declined. The pigment contents the leaves decreased due to alachlor and metolachlor treatment in a concentration dependent manner.

Antioxidant Activities of Celery and Parsley Juices in Rats Treated with Doxorubicin

We have examined the influence of diluted pure celery and parsley leaf and root juices and their combinations with doxorubicin on the antioxidant status [as measured by the content of reduced glutathione (GSH) and ferric reducing antioxidant power (FRAP)] in liver homogenate and hemolysate and on the contents of cytochrome P450 in liver homogenate. It was found that doxorubicin significantly decreased the content of reduced glutathione and the total antioxidative status (FRAP) in liver homogenate and hemolysate, while celery and parsley juices alone and in combination with doxorubicin had different actions. Doxorubicin and celery juice had no effect on content of cytochrome P450. However, in combination with doxorubicin, parsley root juice significant increased, and parsley leaves juice decreased the cytochrome P450 content (compared to doxorubicin treated animals). Only parsley root juice significantly increased the content of cytochrome P450.

Cytotoxic effects of the Viscum album L. extract on Ehrlich tumour cells in vivo.

To date most pharmacological studies on mistletoe (Viscum album L.) have focused on the therapeutic properties of its polar extracts. This study examined the non‐polar constituents of Viscum album and their biological activities. Supercritical CO2 extraction coupled with gas chromatography/mass spectrometry (GC/MS) was used to selectively extract and identify compounds in Viscum album leaves. Several non‐polar classes of compounds were identified in the extract. In addition, a volatile fraction was identified that contained several novel terpene molecules. The hypothesis was tested that the Viscum album extract exhibits cytotoxic properties in Ehrlich carcinoma (EAC) cells in vivo due to the induction of oxidative stress. A significant reduction in the incidence of cancer was observed in all groups that received the Viscum album extract compared with the EAC control group. The largest decrease was observed in mice pretreated with the Viscum album extract, although significantly reduced numbers of EAC cells were also observed in animals with developed carcinoma. The activities of antioxidative enzymes in the EAC cells suggested the absence of oxidative stress. However, changes in the antioxidative enzymes activities observed after administration of the Viscum album extract might be due to the induction of oxidative stress in the EAC cells. Copyright

Antioxidant properties of Marrubium peregrinum L. (Lamiaceae) essential oil.

The antioxidant activity of Marrubium peregrinum essential oil, collected from three different locations [Backo Gradiste - Rimski Sanac (No.1), Novi Knezevac (No.2) and Senta (No.3)] was evaluated as free radical scavenging capacity (RSC), together with inhibition on xanthine-oxidase and effects on lipid peroxidation (LP). RSC was assessed measuring the scavenging activity of the essential oils on 2,2-diphenyl-1-picrylhydrazyl (DPPH•), super oxide anion (O2•−), nitric-oxide (NO•) and hydroxyl (OH•) radicals. The activities of xanthine-oxidase (XOD) was determined by the nitrite method. Effects on LP were evaluated by following the activities of essential oils in the Fe2+/ascorbate induction system. Experimental results indicate that the essential oil of M. peregrinum from Senta (No.3) exhibited the strongest inhibitory effect, as the IC50 value was achieved with the lowest concentration. The same result was obtained in investigation of influence of essential oil on XOD and LP. The chemical profile of essential oil was evaluated by the means of gas chromatography-mass spectrometry (GC-MS). According to the analysis, the most powerful scavenging compounds were sesquiterpene hydrocarbons (β-caryophyllene, bicyclogermacrene and germacrene-D) and oxygenated sesquiterpenes (spathulenol and caryophyllene oxide).

Stress Tolerance Parameters in Different Genotypes of Soybean

Free proline content, superoxide-dismutase activity, and lipid peroxidation were measured in sixteen Yugoslav and introduced genotypes of soybean. More tolerant genotypes with higher free proline content and high superoxide-dismutase activity, and low lipid peroxidation were chosen. The selected genotypes could be used in field production, as well as in breeding.

Antioxidant systems in sunflower as affected by oxalic acid

Changes in antioxidant systems in sunflower (Helianthus annuus L.) inbred lines were studied in relation to different concentrations (0, 2, 3 and 4 mM) of oxalic acid. A great variability of the total superoxide dismutase (SOD) activity was observed in different genotypes after application of oxalic acid. Genotypes showing no change in SOD activity, as well as those with decreased and increased activities, have been found. The highest guaiacol peroxidase (GPX) activity was recorded in the leaves of Ha-26A genotype where the activity of SOD was low. In genotypes with increased GPX activity the malonyldialdehyde content was low. The increase in reduced glutathione content occured in almost all of the genotypes studied with the increase in oxalate concentration. Some genotypes such as PR-ST-3B, showed distinctive and combined activity of several antioxidant systems. Also, obtained results for the content of total phenols support the idea of using soluble phenols as molecular markers and confirm the hypothesis of the defensive role of these compounds in plants.