Influence of gamma-irradiation and microwaves on the antioxidant property of some essential oils

The antioxidant property of anise, caraway, cumin and fennel essential oils extracted from untreated, gamma-irradiated and microwaved fruits against sunflower oil oxidative rancidity was evaluated. The fruits were exposed to gamma-irradiation at 10 KGy and to microwaves at low oven power setting for 1 min. The essential oils were added individually (200 ppm) to sunflower oil and the rate of oil oxidation was followed by determining the peroxide value during storage at room temperature. The irradiated and microwaved essential oils exhibited an antioxidant activity and was superior to that of sunflower oil catalysed by a mixture of BHT + BHA (200 ppm) in most cases. The present data show that gamma-irradiation and microwave treatments did not affect the antioxidant property of the essential oils under study. In addition the essential oils extracted from the gamma-irradiated fruits were more effective as an antioxidant in sunflower oil than those produced from microwaved fruits.

[Effect of aluminum poisoning and gamma-irradiation on the antioxidant system of the body and study of possibilities for correction]

The influence of selenium and rutin on the antioxidant protection system of the organisms in connection with Al-intoxication and gamma-irradiation was investigated. It has been determined that selenium increases the antioxidant protection caused by aluminium. Under simultaneous action of aluminium and gamma-irradiation upon the organism selenium stimulated accumulation of toxic lipids peroxide oxidation products. Rutin action in the situations under investigation caused weakening of antioxidant protection.

Does small-dose gamma-ray radiation induce endogenous antioxidant potential in vivo?

The induction of in vivo antioxidant potential following small doses of gamma-ray irradiation was investigated in C57BL/6 mice. The antioxidant capacity of various organs was assessed in terms of the scavenging activity of cytosol fractions against 1,1-diphenyl-2-picrylhydrazyl (DPPH), a chemically stable radical. Significant elevations in the scavenging activity were recognized in several organs, including the liver, pancreas and brain, soon after post-irradiation with 50 cGy of gamma-ray. These increases persisted for 24 h. gamma-Radiation of the liver at 25-50 cGy elevated its cytosolic antioxidant capacity, but this was lowered at 200 cGy. In order to assess which antioxidants underlie this phenomenon, the content of a reduced form of glutathione (GSH) in liver was assayed as a function of time after gamma-irradiation at a dose of 50 cGy. The GSH content was significantly increased from 6 h after irradiation, and this change was consistent with that of the total radical scavenging potency of the liver against DPPH. Further, the elevation of GSH content was accompanied by elevated GSSG reductase activity induced by gamma-irradiation.

Change of glutathione S-transferases in the skin by ultraviolet B irradiation

Glutathione S-transferases (GSTs) may play an important role in protecting skin from ultraviolet radiation (UVR). However, the study on the response of GST to UVR is limited at present. We have examined the effects of a single exposure to ultraviolet B (UVB) radiation on GST in cultured human keratinocytes and the epidermis of SKH/hr-1 hairless mice. We have also investigated the changes of skin GST by chronic irradiation of UVB on the hairless mice. Significant decreases in GST activities in vitro and in vivo were observed at 24 h after 30 and 50 mJ/cm2 UVB irradiation. Chronic UVB exposure also caused decrease in GST activities of the skin tissue. However, any changes in mRNA expression or protein amount of GST have not been observed by Northern blot analysis and Western blot analysis after 30 mJ/cm2 UVB irradiation in cultured human keratinocytes, which suggests that mRNA expression and protein amount of GST are not affected by UVB. These results suggest that UVB irradiation results in inhibitory effect on GST activity in the skin.

Bleaching of the red anthocyanin induced by superoxide radical

Red anthocyanin prepared from petals of Hibiscus rosa-sinensis L. was photobleached in the EDTA-riboflavin system. The rate of bleaching monitored at 565 nm depended on the light intensity and EDTA concentrations. Anaerobic conditions and/or addition of superoxide dismutase prevented the bleaching of anthocyanin, whereas mannitol and catalase did not. A similar bleaching was observed under dark conditions in the xanthine-xanthine oxidase system. The results indicate that anthocyanin is bleached by the nonenzymatic reaction with the superoxide radical and suggest that the pigment can function as an antioxidant. The antioxidative efficiency of cyanidin to superoxide was 10-fold higher than that of cyanidin-3-sophoroside as a Hibiscus anthocyanin.

Chronic UVB irradiation induces superoxide dismutase activity in human epidermis in vivo

In order to study the effects of repeated UVB exposures on the epidermal antioxidant defence system, we obtained epidermis samples from male volunteers who were exposed to chronic UVB irradiation. Chronic UVB irradiation was shown to be accompanied by induction of epidermal superoxide dismutase (SOD) activity in vivo, while the activities of the other antioxidant enzymes were not significantly changed. The repeated exposure of the epidermis to UVB irradiation was not accompanied by accumulation of products of lipid peroxidation reactions. As superoxide dismutase is of major importance in scavenging the reactive oxygen species, the UVB-induced changes in SOD activity might provide the epidermis a way of defending itself against the effects of chronic UVB irradiation.

[The correction of free-radical oxidation processes in patients with chronic cholecystitis subjected to ionizing radiation exposure]

An activation was found of lipid peroxidation system as well as suppression of antioxidant defence tending to be more profound in blood erythrocytes, in 47 patients with chronic cholecystitis having been in the zone of abnormal radiation. Correction of the above alterations revealed unithiol, clinical and biochemical effects to be pronounced compare with those or tocopherol. Direct antioxidant effect or unithiol, its capability of serving as an antidote of heavy of heavy metals are believed to account for the above observation.

[The metabolic aspects of the sequelae of the accident at the Chernobyl Atomic Electric Power Station in the course of kidney diseases]

As many as 159 patients with chronic pyelonephritis and 100 those with glomerulonephritis residing in ecologically favourable, and on contaminated territories for 6-8 years after Chernobyl accident, were examined for indices of lipid peroxidation, antioxidant system and energy exchange. The above renal disease were found to be accompanied by a rise in the activity of lipid peroxidation and accumulation of excess of their products in cellular membranes and urine. In the antioxidant system, the activity of NAD-H2-dependent factors and an inhibitor of free radical oxidation of superoxiddismutase tends to decrease. There occur changes in isoenzyme spectrum of lactate and malatedehydrogenases. The above shifts appear to be manifest in those persons having been exposed to low radiation doses. Antioxidants and stabilizers of the biological membranes were shown to be useful in correcting the above metabolic processes.

Recovery of antioxidants and reduction in lipid hydroperoxides in murine epidermis and dermis after acute ultraviolet radiation exposure

In previous studies we have found that a single acute dose of ultraviolet radiation to murine skin causes a large degree of destruction of enzymic and non-enzymic antioxidants immediately after irradiation. In the present study, we wished to elucidate the recovery of antioxidants after a single dose of ultraviolet (UV) radiation. We measured antioxidants and lipid hydroperoxides (as a marker of membrane damage) in murine epidermis and the dermis at 0, 3, 12, 24, 72 and 120 h after exposure to UV radiation (25 J/cm2, UVA+UVB). Lipid hydroperoxides showed the highest values immediately after UV exposure and returned to control values within 24 h in both epidermis and dermis. The activities of catalase, glutathione peroxidase and glutathione reductase showed the lowest activities immediately after UV exposure; superoxide dismutase activities reached a minimum at 3 h postexposure. The pattern of recovery was different for each enzyme and for epidermis and dermis. The activities of superoxide dismutase and catalase decreased remarkably and recovered slowly. Superoxide dismutase in the dermis recovered full activity by 120 h and in the epidermis by 12 h. Catalase activity in both epidermis and dermis had returned to only 50% of control activity at 120 h, although the epidermis showed a temporary increase (to 93%) at 24 h. Glutathione peroxidase and glutathione reductase were slightly decreased immediately after irradiation, recovered to 100% at 3 h and then increased to 200-250% in both the epidermis and the dermis at various times; values had returned to 100% in epidermis by 120 h but remained elevated in dermis.(ABSTRACT TRUNCATED AT 250 WORDS)

[The function of the oxidant-antioxidant system in patients with laryngeal cancer]

Lipid peroxidation and antioxidant system were studied at hospital admission, on postoperative day 1, 3 weeks and half a year after surgery in 86 patients with different stages of laryngeal cancer. A correlation is stated between lipid peroxidation disturbances and the defects in the protective antioxidant system. Low-frequency laser irradiation of autoblood produced a clinically beneficial effect and stabilized biochemically the relations between lipid peroxidation and antioxidant systems.

Dose-response effects of acute ultraviolet irradiation on antioxidants and molecular markers of oxidation in murine epidermis and dermis

There has not as yet been an integrated, comprehensive study of the responses of dermis and epidermis in vivo to a wide range of ultraviolet (UV) doses, encompassing all major antioxidants and a sensitive marker of oxidative damage. We have irradiated hairless mice with simulated solar light at doses of 2, 5, 12.5, and 25 J/cm2 combined UVA and UVB (0.8 to 10 MED) and measured enzymic and non-enzymic antioxidants as well as lipid hydroperoxides in both epidermis and dermis to elucidate the response of cutaneous antioxidant defense mechanisms to UV stress. Among the nonenzymic antioxidants two different dose-response patterns were seen. Ascorbate was rapidly depleted at doses between 0 and 5 J/cm2 but was less affected between 5 and 25 J/cm2. In contrast, glutathione, ubiquinol/one, and alpha-tocopherol levels remained approximately equal to control levels between 0 and 5 J/cm2, then decreased to varying degrees from 5 to 25 J/cm2; ubiquinol was almost completely depleted, whereas alpha-tocopherol dropped only 30%. The concentration of lipid hydroperoxides increased throughout the dose range. These results may be explained partly by direct destruction of some antioxidants by UV light, partly by the separate antioxidant functions of the compounds, and partly by recycling of some antioxidants (e.g., alpha-tocopherol) at the expense of others (e.g., ubiquinol). Even at the lowest dose (0.8 MED) lipid hydroperoxide formation was observed. Among the enzymic antioxidants, superoxide dismutase activity decreased significantly (to 63.6% of initial activity for epidermis and 51.5% for dermis at 25 J), whereas activities of glutathione peroxidase and glutathione reductase decreased slightly. Catalase activity decreased dramatically at doses above 5 J (to 11.8% of initial activity in epidermis and 27.7% in dermis at 25 J). The dramatic loss of catalase is almost entirely accounted for by direct destruction by the simulated solar light, but superoxide dismutase was unaffected by direct exposure; hence its destruction must be due to indirect effects, either mediated by free radicals or other harmful species formed upon irradiation. At low doses of UV light many components of the cutaneous antioxidant system were damaged, whereas at high doses all components were damaged and some were almost completely destroyed.

[Pro-oxidant and antioxidant homeostasis in guinea pigs following fractionated x-ray irradiation at low doses and the correction of disorders with an antioxidant complex]

The state of pro-oxidant-antioxidant homeostasis in guinea pigs exposed to whole-body fractionated X irradiation (5 fractions of 0.2 Gy at a 24 hr interval, up to total dose of 1.0 Gy, at a dose rate of 0.425 R/min) and a possibility of its disturbance correction with the complex of vitamins C, E and P was studied. Accumulation of primary and secondary lipid peroxidation products, decrease of the ascorbic acid content, increase of the content of its oxidized forms (dehydroascorbic acid and diketogulonic acid) in radiosensitive (spleen and small intestine) and radioresistant organs were found. Antioxidant complex administration reduced the disturbances of pro-oxidant-antioxidant homeostasis, but did not provide complete normalization.

[The blood antioxidant system in patients with ischemic heart disease undergoing laser therapy]

Catalyse activity and lipid peroxidation were studied in the sera of patients with coronary heart disease who had been exposed to red and infrared low-energy laser radiation (LLR) applied to the skin projections of the heart and its reflexogenic areas. It was found that the optimal normalizing effect occurred with the red band of LLR applied in the rehabilitative period to patients with prior myocardial infarction concurrent with hypertensive disease and stable angina of functional classes I and II. In functional class III stable angina, infrared LLR had advantages over the red on when they acted on the blood antioxidative system.

[Effect of health resort treatment on the status of the oxidant and antioxidant systems in women with disordered reproductive function residing in the area of the Chernobyl Atomic Power Plant accident]

Lipid peroxidation system and its reaction to balneotherapy (hydrogen sulfide and iodine bromide exposure) were examined in 60 women with reproductive system disorders living in radionuclide pollution zone after the Chernobyl accident. Certain specificities of lipid peroxidation system in this patient population were detected and a favorable effect of the said balneotherapy noted.

Effects of electron beam irradiation on the migration of antioxidants and their degradation products from commercial polypropylene into food simulating liquids

The influence of electron beam irradiation on migrational behaviour of additives present in food packaging material was studied. The migration experiments were carried out on irradiated and non-irradiated polypropylene pouches containing aqueous food simulating liquids (FSL) for 10 days at 40 degrees C. The controls were irradiated and non-irradiated pouches without FSL contact. After the contact period, the polypropylene and the FSL were analysed. A comparison between the results obtained by the two analyses showed the migration of three products of antioxidant degradation from the polypropylene into the FSL, and a partial decomposition of these migrants in the FSL.

[Changes in lipid peroxidation and the antioxidant system in patients with acute radiation sickness]

Peroxide oxidation of lipids and antioxidant system perform an important role for making an adequate response of cells, organs and systems to radiation influence. The results which were obtained made it possible to forward a supposition concerning the efficiency of antioxidant drugs for prophylaxis and treatment of radiation injuries. It seems to be perspective for military medicine to study the efficiency of antioxidants for prophylaxis of injuries among personnel in radioactive contamination zones.

[Human physiological blood protection systems in the late periods after ionizing radiation exposure related to the accident at the Chernobyl Atomic Electric Power Station]

During a 5-year follow-up of rescue party members exposed to radioactive effects of the Chernobyl accident no material changes were observed versus healthy donors in the content of calcium, cholesterol, atherogenic lipoproteins, dienic conjugates, insulin, thyroxin, triiodothyronine, thyroglobulin, IgA, IgG and fibrinogen. Inhibition of peroxidation and emergence of hypocoagulation are attributed to a reduced respiratory splash of the neutrophils. Concentrations of hydrocortisone, testosterone, IgM rose, while the activity of some antioxidant enzymes remained stable.

Effects of chronic exposure ultraviolet-A including 2% ultraviolet-B on free radical reduction systems in hairless mice

Chronic ultraviolet (UV) irradiation is known to cause a variety of changes in the skin, including wrinkles, pigmented spots and carcinogenesis. To explore time dependent changes in several parameters with chronic UV irradiation, we examined the molecular changes in connective tissue, intracellular defence enzymes and free radical antioxidant substances in hairless mice skin caused by chronic exposure to UV-A including 2% UV-B. Connective tissue changes were estimated using hydroxyproline and isodesmosine assays as a measure of collagen and elastin concentrations, respectively. After 6 weeks irradiation, the insoluble collagen and elastin were both substantially elevated, as were the activities of glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD). Continued UV irradiation resulted in a steady decline in SOD and lipid soluble antioxidants, while the GSH-Px remained elevated, suggesting that SOD and lipid soluble antioxidants in the skin may be involved in protecting it from UV damage and deteriorate with chronic irradiation.

Effects of ultraviolet A and B irradiation on lipid peroxidation and activity of the antioxidant enzymes in keratinocytes in culture

Human keratinocytes (NCTC 2544) in culture were exposed to various combinations of ultraviolet A (UVA) and UVB irradiation and at 0.5 h postirradiation the level of lipid peroxidation and activities of antioxidant enzymes were measured. The results suggest that UV irradiation is capable of inducing lipid peroxidation reactions, as parameters of which the amount of thiobarbituric acid-reactive material and the number of conjugated diene double bonds were measured. Both UVA and UVB irradiation were also found to affect the activities of antioxidant enzymes. Following UVB irradiation the activity of superoxide dismutase (Cu/Zn form) was decreased, and combination of increasing doses of UVA irradiation to a given dose of UVB irradiation decreased the activity of both catalase and superoxide dismutase. In summary, this study suggests that both UVA and UVB irradiation are capable of inducing lipid peroxidation reactions and an impairment of the enzymic antioxidant system in human keratinocytes in culture.

Vitamin E and correlated antioxidants: a gamma radiolysis study

gamma irradiations of Vit.E-Vit.C aerated ethanolic solutions have been performed for several ratios (Vit.E)/(Vit.C) between 0.1 and 50. The obtained results show that Vit.C is able to regenerate Vit.E from its oxidized radical, this regeneration being total for a ratio (Vit.E)/(Vit.C) greater than or equal to 27 in our conditions of irradiation. The ratio (Vit.E)/(Vit.C) seems to be the main factor of this synergestic effect towards peroxyl radicals scavenging.

Effects of antioxidants on lipid peroxide formation in irradiated synthetic diets

The effect of the antoxidants, vitamin E, propyl gallate (PG), 2-t-butyl-4-methoxy phenol (BHA), 2,6-di-t-butyl-4-methoxy phenol (BHT), nordihydroguaiaretic acid (NDGA) and diphenyl-p-phenylene diamine (DPPD) in concentrations ranging between 0.001 per cent and 0.1 per cent have been tested on lipid peroxide formation in synthetic diet mixtures containing herring oil (10 per cent) mixed with starch (90 per cent) irradiated with gamma-ray doses of 100-2000 krad. On a weight basis NDGA, DPPD, BHA and BHT were most effective and vitamin E and propyl were least effective. An antioxidant concentration of 0.01 per cent normally protected against peroxide formation after a dose of 500 krad but if the dose was increased to 1000 or 2000 krad, much higher doses of antoxidant, up to 0.1 per cent, were required to give protection. Antioxidants prevented peroxide developing during post-irradiation storage even when added after irradiation. Antioxidants were partially or completely destroyed by irradiation with doses of 100 krad or more. The percentage of total antioxidant destroyed depended on the concentration; much greater destruction occurred in dilute solutions than in concentrated solutions. Vitamin E and propyl gallate were most sensitive whereas NDGA was relatively resistant. Antioxidant destruction was much enhanced if irradiation was carried out in presence of herring oil. Free radicals formed in unsaturated fatty acids of the herring oil are believed to be responsible. Lecithin and citric acid, which have been described as antioxidant synergists when added with vitamin E, caused a limited enhancement of its antioxidant action against radiation-induced peroxidation.