Galina Nikolova

Studies on Antioxidant Properties before and after UV- And Γ-Irradiation of Bulgarian Lavender Essential Oil Isolated from Lavandula Angostifolia Mill

ABSTRACT At present there is not enough data about different types of radiation on Bulgarian essential oils isolated from medicinal plants. Here we report for the first time our studies on the effects of UV-radiation (290 nm to 320 nm) and γ-radiation (doses of 5 Gy, 10 Gy, 20 Gy and 30 Gy) on Bulgarian lavender essential oil isolated from Lavandulla angustifolia Mill. A spectrophotometry method was used for evaluation of the changes in the reducing power of the Bulgarian lavender oil before and after radiation. The electron donation potential of non-irradiated oil was found to be lower (0.268 ± 0.0244) than those of both, UV-irradiated (0.336 ± 0.0121) and γ-irradiated, oil samples (0.427 ± 0.0251 at 5 Gy radiation, 0.341 ± 0.0371 at 10 Gy; 0.328 ± 0.0173 at 20 Gy). By direct electron paramagnetic resonance (EPR) spectroscopy, single almost symmetrical EPR signals with different values of the g-factor were registered in non-irradiated (g = 2.0047 ± 0.0002), UV-irradiated (g = 2.01050 ± 0.00005) and γ-irradiated oil samples (g = 2.0017 ± 0.0002), respectively. EPR spectroscopy was used for assessment of the radical scavenging capacity of the non-irradiated and UV- and γ-irradiated samples of the Bulgarian lavender oil towards the stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH). Excellent DPPH radical scavenging capacities were found for UV- and 30 Gy-irradiated lavender oil samples. Based on these preliminary results, we consider that, after proper UV- or γ-radiation treatment, Bulgarian lavender oil might find application as a good radioprotector and antioxidant in cosmetics and medicine.

Analysis of the parameters of oxidative stress in patients with Parkinson’s disease

The increasing data provides enough evidences confirming the involvement of free radicals and other reactive oxygen species (ROS) superoxide radical (.O2−), nitric oxide (NO.), hydrogen peroxide (H2O2) and hydroxyl radicals (.OH) in a number of physiological and pathological processes. Imbalance between levels of ROS resulting in the body and the capacity of antioxidant defense mechanisms occur oxidative stress (OS). OS is related to a number of structural and functional damages to cells and is involved in the pathogenesis of many diseases, including neurodegenerative diseases such as Alzheimer’s disease, Parkinson’s disease (PD), amyotrophic lateral sclerosis, and Huntington disease. Defects in oxidative phosphorylation and oxidative damage play an important role in neurodegenerative diseases. The aim of this study was to investigate some biomarkers of OS such as the level of lipid peroxidation measured as malondialdehyde (MDA) reactive products and activity of antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) in the blood of PD patients compared with control group of healthy volunteers. By the present research we report higher levels of MDA products and an imbalance in SOD and CAT enzyme activities in PD patients compared to the control group.

Radical Scavenging Capacity of Seeds and Leaves Ethanol Extracts of Cynara Scolymus L.—A Comparative Study

ABSTRACT Artichoke with scientific name Cynara scolymus L. is an herbal medicinal plant widely used in traditional European medicine. This medicinal plant possesses many properties, including hepatoprotective ability and antioxidant effect. It has been reported that seeds and leaves of the artichoke contain different constituents such as caffeoylquinic acid derivatives, mono- and di- caffeoylquinic acids, bitter sesquiterpene such as cynatriol and cynaropicrin and flavonoids glycosides like apigenin, luteolin cynaroside, scolimoside, quercitine and others. The aim of the present study was by an Electron Paramagnetic Resonance (EPR) method and visible spectrophotometry to evaluate and compare the radical scavenging capacity towards 1,1 -diphenyl-2-picrylhydrazyl (DPPH) of ethanol extracts prepared from Cynara scolymus L. seeds and leaves. By both methods we have demonstrated that at any studied concentration of the seeds extract the percent of the scavenged DPPH radicals was considerably higher than that calculated for the leaves extract.

Oxidative-protective effects of Tinospora cordifolia extract on plasma and spleen cells after experimental ochratoxicosis

The importance of Tinospora cordifolia extract was investigated for its possible protective effect in spleen and blood in male ICR albino mice against ochratoxin A-induced toxicity (OTA). OTA instigates oxidative changes and results in the overproduction of free radicals, changes in body/organ weight, and the food consumption and is considered as a risk factor for animals and humans. Reactive oxygen species (ROS), reactive nitrogen species (RNS), and consequent lipid-peroxidative damages caused by OTA are considered to be the main mechanisms leading to oxidative stress disorders in organs and blood. TC oral administrations prevent the physiological status of animals and improve the biochemical parameters of the urine and plasma. Moreover, EPR analysis show that TC administration decreased Asc• and NO• radicals and ROS productions in the spleen and serum, even in OTA-treated group. The significant decrease in MDA formation in the spleen and serum and the increased expression of SOD activity in TC and TC + OTA groups confirm the positive modulatory effect of TC extract on the cellular antioxidant system. TC and TC + OTA treatment caused significant reduction of genotoxic potential (8-OHdG) of OTA, followed by a decreased oxidative activity and gradual recovery of ROS-induced DNA damage. The results suggested that TC extract protect against OTA-induced oxidative disorders and other abnormalities. As typical antioxidant TC could protect splenic macrophages and regain intracellular antioxidant capacity.

Effect of antigen stimulation on the oxidative stress parameters in sperm of outbred and inbred rabbits

ABSTRACT The presence of an increased oxidative stress during antigen stimulation was established in the sperm of inbred rabbits by evaluation of the level of real-time free radical formation (ROS and Asc•), final products of oxidation of lipids (MDA) and the activities of antioxidant defence enzymes superoxide dismutase (SOD) and catalase (CAT). There was not a significant difference between levels of ROS, Asc• and MDA in inbred and outbred rabbits before immunization. The immune response, represented by levels of ROS and Asc• of inbread and outbread rabbits were statistically significantly higher compared to those before immunization (p = 0.0001 and p = 0.00001) Moreover, the levels of ROS in the sperm of inbread rabbits were statistically significantly higher compared to outbread rabbits (p < 0.05). Oxidative stress was accompanied by an adaptive increase of SOD and CAT activities during the immune response, compared to those before immunization. Furthermore, the increased SOD and CAT activities appeared to be sufficient to inactivate the oxidative stress. We measured reduced levels of ROS, Asc• and MDA 30 days after immunization. When immune response reduced, the observed SOD and CAT activities tended to return to the values before immunization. That might have been connected with the decreased oxidative burden. However, CAT activities remained about 1.5 times higher than that before immunization. In conclusion, our results indicate that the administered antigen stimulation induces oxidative stress in both groups inbred and outbred rabbits.