Single high-dose peroral caffeine intake inhibits ultraviolet radiation-induced apoptosis in human lens epithelial cells in vitro.

PURPOSE: The aim of the present study was to determine whether caffeine concentrations in human lens epithelial cells (LECs) achieved from acute peroral caffeine intake inhibit ultraviolet radiation-induced apoptosis in vitro. METHODS: Patients were planned for cataract surgery of both eyes with a caffeine abstinence of 2 weeks in total, starting 1 week before surgery of the first eye. The second eye was scheduled 1 week after the first eye. At the day of the second eye surgery, patients were given coffee containing 180 mg caffeine shortly before surgery. Lens capsules including LEC, harvested after capsulorhexis, were transferred to a cell culture dish and immediately exposed to close to threshold ultraviolet radiation (UVR). At 24 hr after UVR exposure, apoptotic LECs were analysed by TdT-mediated dUTP-biotin nick end labeling (TUNEL) staining. RESULTS: TUNEL-positive cells were detected in UVR-exposed lens capsules both after caffeine intake and in controls. The mean difference in TUNEL-positive cells between caffeine intake and contralateral controls (no caffeine) resulted in a 95% CI 15.3 ± 10.4% (degrees of freedom: 16). CONCLUSION: Peroral caffeine consumption significantly decreased UVR-induced apoptosis in LEC supporting epidemiological findings that caffeine delays the onset of cataract.

Ganoderic acid A protects lens epithelial cells from UVB irradiation and delays lens opacity.

A contributory role of oxidative stress and protection by antioxidant nutrients have been suspected in cataract formation. Ganoderic acid A (GAA), an effective lanostane triterpene, is widely reported as an antioxidant. The aim of this study is to investigate the potential effects of GAA on cataract formation. After lens epithelial cells (LECs) were exposed to UVB radiation for different periods, cell viability, apoptosis-related protein levels, malondialdehyde (MDA) and superoxide dismutase (SOD) activities were monitored. We found that cell viability, the Bcl-2/Bax ratio and SOD activity were increased, while Cleaved caspase-3 levels and MDA activity were decreased compared with those in UVB-impaired LECs after GAA treated. Furthermore, GAA activated PI3K/AKT in UVB-impaired LECs and effectively delayed the occurrence of lens opacity in vitro. In conclusion, these findings demonstrated that GAA exhibited protective functions in SRA01/04 cells and rat lenses against UVB-evoked impairment through elevating cell viability and antioxidant activity, inhibiting cell apoptosis, activating the PI3K/AKT pathway and delaying lens opacity.

[Evaluating Eye Lens Dose of Neurovascular and Cardiac Electrophysiology Interventional Physician].

PURPOSE: The International Commission on Radiological Protection recommended that interventional radiologies (IRs) have high radiation doses and that staff may also be exposed to high doses. In the present study, we measured the radiation exposure dose [3 mm dose equivalent, Hp (3) ] in the eye using an appropriate dosimeter placed next to the physician' s eye during neurovascular intervention procedure (Neuro-IR) and interventional cardiac electrophysiology procedure (EP-IR). METHOD: Physicians wore a direct eye dosemeter just lateral to the left eye and an additional direct eye dosemeter outside the radiation protective glasses close to their left eye. Additionally, a neck badge [0.07 mm dose equivalent, Hp (0.07) ] was worn outside the protective apron to the left of the neck, to compare the direct eye dosimeter estimated doses. The occupational eye lens dose was evaluated over a period of 6-month. RESULTS: The maximum Hp (3) of the Neuro-IR physician was estimated 5.1 mSv without the radiation protective glasses and 1.6 mSv with the radiation protective glasses. On the other hand, the maximum Hp (3) of the EP-IR physician was estimated 29 mSv without the radiation protective glasses and 15 mSv with the radiation protective glasses. CONCLUSION: Physicians eye lens dose [Hp (3) ] tended to be overestimated by the neck badge measurements [Hp (0.07)]. A correct evaluation of the lens dose [Hp (3) ] using the direct eye dosimeter is recommended. Although we found a positive correlation between Hp (0.07) and Hp (3), the value of R2 in the regression equation is low, we recommended that the eye lens dose estimated carefully from Hp (0.07).

Past and present work practices of European interventional cardiologists in the context of radiation protection of the eye lens-results of the EURALOC study.

This paper investigates over five decades of work practices in interventional cardiology, with an emphasis on radiation protection. The analysis is based on data from more than 400 cardiologists from various European countries recruited for a EURALOC study and collected in the period from 2014 to 2016. Information on the types of procedures performed and their annual mean number, fluoroscopy time, access site choice, x-ray units and radiation protection means used was collected using an occupational questionnaire. Based on the specific European data, changes in each parameter have been analysed over decades, while country-specific data analysis has allowed us to determine the differences in local practices. In particular, based on the collected data, the typical workload of a European cardiologist working in a haemodynamic room and an electrophysiology room was specified for various types of procedures. The results showed that when working in a haemodynamic room, a transparent ceiling-suspended lead shield or lead glasses are necessary in order to remain below the recommended eye lens dose limit of 20 mSv. Moreover, the analysis revealed that new, more complex cardiac procedures such as chronic total occlusion, valvuloplasty and pulmonary vein isolation for atrial fibrillation ablation might contribute substantially to annual doses, although they are relatively rarely performed. The results revealed that considerable progress has been made in the use of radiation protection tools. While their use in electrophysiology procedures is not generic, the situation in haemodynamic procedures is rather encouraging, as ceiling-suspended shields are used in 90% of cases, while the combination of ceiling shield and lead glasses is noted in more than 40% of the procedures. However, we find that still 7% of haemodynamic procedures are performed without any radiation protection tools.

Radioprotective efficacy of Ginkgo biloba and Angelica archangelica extract against technetium-99m-sestamibi induced oxidative stress and lens injury in rats.

PURPOSE: Technetium-99m is a radioactive tracer that emits gamma rays. Its half-life time is 6 h. Similar to other ionizing radiations, the main mechanism of radiation-induced effects is initiated through the production of reactive oxygen species (ROS). This study was designed to determine the possible protective effects of Ginkgo biloba and Angelica archangelica against oxidative organ damage that was induced by 99mTc-sestamibi. MATERIALS AND METHODS: The experiments were performed on thirty-six Wistar-rats which were subdivided into control groups and groups exposed to 99mTc-sestamibi. The irradiated groups were either untreated or pre-treated with G. biloba or A. archangelica. For all groups, the levels and/or activities of Catalase (CAT), Glutathione (GSH), Malondialdehyde (MDA) and Superoxide-dismutase (SOD) were measured in blood and lenses. The soluble/insoluble protein ratio was determined and lens-protein profiles were obtained via Sodium-Dodecyl-Sulfate Polyacrylamide Gel-Electrophoresis (SDS-PAGE). RESULTS: There were no significant difference between the pre-treated and irradiated G. biloba group and control group, while both groups were significantly different (p < .05) from the untreated irradiated group. On the other hand, treatment with A. archangelica did not confer any significant protection against 99mTc-sestamibi induced toxicity. CONCLUSIONS: This study demonstrated that G. biloba, through its free radical scavenging and antioxidant properties, successfully attenuated 99mTc-sestamibi radiation-induced oxidative organ injury. The latter is a crucial factor of cataractogenesis in rats, suggesting that G. biloba may have a potential benefit in the protection against radiopharmaceuticals.

Action spectrum for photobleaching of human lenses by short wavelength visible irradiation.

PURPOSE: Cataract is the world-leading cause of blindness. In search for a new treatment of cataract we have found that the yellow discolouration of aged human lenses can be photobleached using a non-invasive, infra-red, femtosecond laser treatment. These results were presented in an earlier PlosOne publication. The objective of the study was to characterize the single-photon photobleaching action spectrum of the aged human lens in vitro. METHODS: Ninety-one human donor lenses were irradiated with continuous wave laser light at 375, 405, 420, 445, 457 or 473 nm. Photobleaching was monitored by photography and transmission measurements. RESULTS: The action spectrum peaked at 420 nm followed by, in order of decreasing effect, 445, 457, 473, 405 and 375 nm. Younger and less absorbent lenses showed smaller changes than older and more absorbent lenses. There was a dose-dependent increase in lens transmission with increasing laser irradiation. CONCLUSIONS: For a 75 year old lens an effect corresponding to elimination of 15 years or more of optical ageing was obtained. This study of the spectral characteristics and intensity needed to bleach the human lens with single-photon laser effects found an action-spectrum peak at 420 nm tailing gradually off toward longer wavelengths and more steeply toward shorter wavelengths. The results may be used to guide experiments with two-photon bleaching.

The radioprotective effect of Nigella sativa on nitrosative stress in lens tissue in radiation-induced cataract in rat.

OBJECTIVE: The aim of this study was to investigate the antioxidant and radioprotective effects of Nigella sativa oil (NSO) and thymoquinone (TQ) against ionizing radiation-induced cataracts in lens after total cranium irradiation (IR) of rats with a single dose of 5 gray (Gy). MATERIALS AND METHODS: Seventy-four Sprague-Dawley rats were used for the experiment. The rats were randomly divided into six groups. Group A received total cranium IR plus NSO (1 g kg(-1) d(-1)) orally through an orogastric tube. Group B received total cranium IR plus TQ (50 mgkg(-1) d(-1)) daily by intraperitoneal injection. Group C received 5 Gy of gamma IR as a single dose to total cranium plus 1 ml saline. Group D1 just received 1 ml saline. Group D2 just received dimethyl sulfoxide. Group D3 did not receive anything. RESULTS: At the end of the 10th d, cataract developed in 80% of the rats in IR group only. After IR, cataract rate dropped to 20% and 50% in groups which were treated with NSO and TQ, respectively, and was limited at grades 1 and 2. Nitric oxide synthase activity, nitric oxide and peroxynitrite levels in the radiotherapy group were higher than those of all other groups. CONCLUSIONS: The results implicate a major role for NSO and TQ in preventing cataractogenesis in ionizing radiation-induced cataracts in the lenses of rats, wherein NSO were found to be more potent.

Dose-response relationship for α-tocopherol prevention of ultraviolet radiation induced cataract in rat.

The purpose of this study is to establish the dose response relationship for α-tocopherol protection of ultraviolet radiation (UVR) induced cataract in the rat. Four groups of 20 six-week-old albino Sprague Dawley rats received 5, 25, 50, and 100 IU/day α-tocopherol, whilst another group of 20 rats without any α-tocopherol feeding was the control group. After 4 weeks of feeding, each rat was unilaterally exposed to 8 kJ/m(2) UVR-300 nm for 15 min. At 1 week after exposure, the rats were sacrificed and lens light scattering was measured quantitatively. Lens total reduced (GSH) and oxidized (GSSG) glutathione; glutathione reductase (GR) and peroxidase (GPx) were determined spectrophotometrically. The UVR-exposed lenses in the α-tocopherol fed groups developed superficial cataract, whereas lenses in the control group developed cortical and equatorial opacities. Light scattering in lenses from the α-tocopherol-supplemented rats was lower than in lenses from the control group. The difference of light scattering between the exposed and contralateral non-exposed lens decreased with increasing doses of α-tocopherol to an asymptote level. UVR-exposure caused a significant depletion of lens GSH in rats without or at low α-tocopherol supplementation. The depletion of GSH became less with higher α-tocopherol supplementation. There was no detectable difference in lens GSSG, GR or GPx at any level of α-tocopherol supplementation. Orally administered α-tocopherol dose dependently protects against UVR-induced cataract. The protection is associated with an α-tocopherol dose-dependent GSH depletion secondary to UVR exposure. UVR-induced light scattering only occurs if the GSH depletion exceeds a threshold.

Dietary zerumbone prevents against ultraviolet B-induced cataractogenesis in the mouse.

PURPOSE: To investigate the preventive effect of dietary zerumbone against UVB-induced cataractogenesis. METHODS: A total of 50 six-week-old female ICR mice were split into five groups (each contained 10 mice) and exposed to UVB (0.72 J/cm(2)/daily) at noon for 7 days, except for the blank control group. The mice with UVB exposure were fed with zerumbone as a dietary supplement at 0, 1, 10, and 100 mg/kg of bodyweight, respectively, starting from one day before UVB exposure. On day 7, at 4 h after UVB exposure, all mice were subjected to cataract examination and lens opacity scoring, in correlation with levels of MDA (malondialdehyde), GSH (glutathione), GR (GSH reductase), GPx (glutathione peroxidase), and SOD (superoxide dismutase) in the lens. RESULTS: Dietary zerumbone at 100 mg/kg after UVB exposure was effective in decreasing lens opacity scores (p<0.001) and to reduce MDA (p<0.001), while GSH and GR levels were significantly increased (both p<0.001) in the lens. SOD was also increased with dietary zerumbone at 100 mg/kg (p=0.115), whereas GPx (p=0.171) levels were lower as compared with those without zerumbone after UVB exposure. CONCLUSIONS: These results suggest that zerumbone may protect against UVB-induced cataractogensis through reducing lipid peroxides and enhancing the endogenous antioxidant GSH level and GR activity.

Coenzyme Q10 prevents human lens epithelial cells from light-induced apoptotic cell death by reducing oxidative stress and stabilizing BAX / Bcl-2 ratio.

BACKGROUND: Cataract is one of the most prevalent eye disease and a major cause for legal blindness in the world. Beside others, cumulative light-exposure and apoptotic cell death are significantly associated with cataract development. In contrast, supplementation with antioxidants has been suggested to prevent premature cataractogenesis. This study investigates possible protective effects of Coenzyme Q10 (CoQ10) regarding light-induced stress and apoptotic cell death in human lens epithelial cells (LEC). METHODS: Human LEC were either pre-incubated with CoQ10 or not and then exposed to white light. After 10-40 min of irradiation viability, induction of intracellular reactive oxygen species (ROS), apoptosis and cell death was determined. Expression of apoptotic BAX and anti-apoptotic Bcl-2 protein and their mRNA were determined by RT-PCR and Western blot analysis. RESULTS: Light exposure decreased LEC viability and Bcl-2 expression and increased intracellular ROS, apoptotic cell death, and BAX expression in a time-of-irradiation-dependent manner. Phototoxic cell death and apoptosis, as well as decrease of Bcl-2 and increase in BAX expression was significantly reduced, when cells were pre-incubated with CoQ10. CONCLUSIONS: In this study, CoQ10 significantly reduced light-induced LEC-damage and attenuated phototoxic effects on BAX and Bcl-2 expression. Therefore, CoQ10 supplementation might also be useful in preventing LEC death and consecutive cataract formation in vivo.

UV-B-induced damage to the lens in vitro: prevention by caffeine.

Ultraviolet (UV) irradiation is one of the significant risk factors in the genesis of cataracts. Pathogenetically, the process can be triggered by the intraocular generation of various reactive species of oxygen that are well known to be initiated by the penetration of light, especially of the UV frequencies. The contribution of UV exposure in the etiology of this disease is likely to increase further due to ozone depletion in the upper atmosphere. The present studies were undertaken to examine if the UV effects can be attenuated with the xanthine-based alkaloids primarily present in tea and coffee. We have examined this possibility by in vitro lens culture studies with caffeine. As expected, mice lenses incubated in Tyrode solution exposed to UV at 302 nm are physiologically damaged, as evidenced by the inhibition of the active transport of (86)Rb(+), an ion acting as a surrogate of the K(+). There was a simultaneous decrease in the levels of adenosine triphosphate and glutathione. The addition of caffeine to the medium prevented such deleterious effects. That caffeine and perhaps other xanthinoids have a protective effect against cataract formation induced by UV has hence been demonstrated for the first time.

The effect of single and repeated UVB radiation on rabbit lens.

BACKGROUND: In our previous investigations, a significant cumulative effect of ultraviolet radiation (UVR) on the corneal and aqueous humour metabolic profiles was revealed. The purpose of the present study was to monitor the alterations in the rabbit lenses under the same experimental design and thereby supplement and complete prior findings. METHODS: Albino rabbit eyes were exposed to single (312 nm, 3.12 J/cm2) or repeated (312 nm, 3 x 1.04 J/cm2) UVB irradiations of the same overall doses. Lenticular samples were analysed by high resolution magic angle spinning proton nuclear magnetic resonance (HR-MAS 1H NMR) spectroscopy. Special grouping patterns between the UVB-irradiated and untreated control samples were evaluated using principal component analysis (PCA). Percentage alterations in the lenticular metabolite concentrations from UVR-B exposed rabbits were calculated relative to the levels in the control group. RESULTS: UVB irradiation of the albino rabbit lenses resulted in a significant decrease in the concentrations of antioxidants (glutathione), osmolytes (taurine, myoinositol) and amino acids (alanine), and a concomitant elevation in the contents of a sugar-related compound, sorbitol. Repeated UVR-B exposure of the rabbit eye had a stronger effect on the lenticular metabolic profile than a single irradiation of the same overall dose. CONCLUSIONS: This study reveals the cumulative effect of repeated UVB irradiations, and shows that even a 48-hour interval between subsequent UVR-B exposures is not sufficient for the healing processes to restore lenticular integrity.

Drinking water supplementation with ascorbate is not protective against UVR-B-induced cataract in the guinea pig.

PURPOSE: To study if ascorbate supplementation decreases ultraviolet radiation (UVR)-induced cataract development in the guinea pig. METHODS: Sixty 6-9-week-old pigmented guinea pigs received drinking water supplemented with or without 5.5 mm l-ascorbate for 4 weeks. After supplementation, 40 animals were exposed unilaterally in vivo under anaesthesia to 80 kJ/m(2) UVR-B. One day later, the animals were killed and lenses were extracted. Degree of cataract was quantified by measurement of intensity of forward lens light scattering. Lens ascorbate concentration was determined with high-performance liquid chromatography (HPLC) with UVR detection at 254 nm. Twenty animals were used as non-exposed control. RESULTS: Supplementation increased lens ascorbate concentration significantly. In UVR-exposed animals, mean 95% confidence intervals (CIs) for animal-averaged lens ascorbate concentration (micromol/g wet weight lens) were 0.54 +/- 0.07 (no ascorbate) and 0.83 +/- 0.05 (5.5 mm ascorbate). In non-exposed control animals, mean 95% CIs for animal-averaged lens ascorbate concentration (micromol/g wet weight lens) were 0.72 +/- 0.12 (0 mm ascorbate) and 0.90 +/- 0.15 (5.5 mm ascorbate). All non-exposed lenses were devoid of cataract. Superficial anterior cataract developed in all UVR-exposed lenses. The lens light scattering was 39.2 +/- 14.1 milli transformed equivalent diazepam concentration (m(tEDC)) without and 35.9 +/- 14.0 m(tEDC) with ascorbate supplementation. CONCLUSION: Superficial anterior cataract develops in lenses exposed to UVR-B. Ascorbate supplementation is non-toxic to both UVR-B-exposed lenses and non-exposed control lenses. Ascorbate supplementation does not reduce in vivo lens forward light scattering secondary to UVR-B exposure in the guinea pig.

[Influence of (460 MHz) electromagnetic fields on the induced lipid peroxidation in the structures of visual analyzer and hypothalamus in experimental animals].

Changes in the intensity of ascorbate- and NADPN2-dependent induced lipid peroxidation (LPO) were studied in exposure of the visual analyzer and hypothalamus of 3- and 12-month-old rats to radiation with microwaves of high and low intensity. The exposure to microwaves of high intensity stimulated basal LPO but suppressed activity of LPO-inducing systems. This suggests disturbances in the activity of different sources of active oxygen forms. Microwaves of low intensity activated systems of induced LPO. This is accompanied with synchronous activity of the antioxidant defense system maintaining a normal oxidation-reduction balance of the cell. The conclusion is that, depending on their intensity, microwaves can be either beneficial to health or be a factor of oxidative stress.

Growth retardation and bilateral cataracts followed by anaplastic meningioma 23 years after high-dose cranial and whole-body irradiation for acute lymphoblastic leukemia: case report and review of the literature.

We report a case of meningioma diagnosed 23 years after high-dose cranial and whole-body irradiation for the treatment of acute lymphocytic leukemia (ALL). Radiotherapy in this case also caused early radiation injury to the lenses and the pituitary gland, with growth retardation and mineralizing angiopathy. Radiation-induced meningiomas are more commonly malignant, more commonly multiple, and more likely to recur after resection than non-radiation-induced meningiomas. Survivors of childhood ALL treated with high-dose cranial irradiation are at risk both for early radiation injury in radiosensitive organs, such as the lens and pituitary gland, and for the later development of a radiation-induced meningioma.

Vitamin E can protect against ultraviolet radiation-induced cataract in albino rats.

PURPOSE: To investigate if vitamin E protects against ultraviolet B radiation (UVB)-induced cataract. METHODS: Albino Sprague-Dawley rats were divided into two groups: one group was fed vitamin E, while the other group was used as a control. Both groups were exposed to UVB. The rats were sacrificed, lenses extracted, forward light scattering was measured, and vitamin E and glutathione (GSH) contents were determined. RESULTS: Lenses in the vitamin E group developed slight opacities, while lenses in the control group developed nuclear cataracts. Forward light scattering in lenses of the control group was higher than in lenses in the vitamin-E-supplemented group. Vitamin E and GSH concentrations were higher in lenses treated with vitamin E than in the untreated group. CONCLUSIONS: Vitamin E protects the lens against UVB-induced cataract. Vitamin E protects directly as an antioxidant and/or indirectly through increased levels of GSH.

Phototoxicity in human lens epithelial cells promoted by St. John's Wort.

St. John's Wort (SJW), an over-the-counter antidepressant, contains hypericin, which absorbs light in the UV and visible ranges and is phototoxic to skin. To determine if it also could be phototoxic to the eye, we exposed human lens epithelial cells to 0.1-10 microM hypericin and irradiated them with 4 J/cm2 UV-A or 0.9 J/cm2 visible light. Neither hypericin exposure alone nor light exposure alone reduced cell viability. In contrast, cells exposed to hypericin in combination with UV-A or visible light underwent necrosis and apoptosis. The ocular antioxidants lutein and N-acetyl cysteine did not prevent damage. Thus, ingested SJW is potentially phototoxic to the eye and could contribute to early cataractogenesis. Precautions should be taken to protect the eye from intense sunlight while taking SJW.

Effects of oral Ginkgo biloba supplementation on cataract formation and oxidative stress occurring in lenses of rats exposed to total cranium radiotherapy.

PURPOSE: To determine the antioxidant role of Ginkgo biloba (GB) in preventing radiation-induced cataracts in the lens after total-cranium irradiation of rats with a single radiation dose of 5 Gy. METHODS: Sprague-Dawley rats were randomly divided into three groups. Group 1 received neither GB nor irradiation (control group). Group 2 was exposed to total-cranium irradiation of 5 Gy in a single dose [radiation therapy (RT) Group], and group 3 received total cranium irradiation from a cobalt-60 teletherapy unit, plus 40 mg/kg per day GB (RT+GB group). At the end of the tenth day, the rats were killed and their eyes were enucleated to measure the antioxidant enzymes, the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and the lipid peroxidation level [malondialdehyde (MDA)]. RESULTS: Irradiation significantly increased both the MDA level and the activity of GSH-Px, and significantly decreased the activity of SOD in the rat lenses. GB supplementation significantly increased the activities of SOD and GSH-Px enzymes and significantly decreased the MDA level. Total cranium irradiation of 5 Gy in a single dose promoted cataract formation, and GB supplementation protected the lenses from radiation-induced cataracts. CONCLUSIONS: We suggest that Ginkgo biloba is an antioxidant that protects the rat lens from radiation-induced cataracts.

Identification of genes responsive to UV-A radiation in human lens epithelial cells using complementary DNA microarrays.

UV-A radiation produces cataract in animals, enhances photoaging of the lens and skin and increases the phototoxicity of drugs. However, the nature of genes that are activated or repressed after cellular exposure to UV-A radiation remains enigmatic. Because lens epithelial cells exposed to UV-A radiation undergo apoptosis 4 h after exposure to the stress, we sought to establish the change in gene expression in cells by UV-A radiation using gene expression profiling using complementary DNA microarrays containing about 12 000 genes. We identified 78 genes abnormally expressed in UV-A-irradiated cells (showing >2.5-fold change at P < 0.05). These genes are implicated in various biological processes, including signal transduction and nucleic acid binding, and genes encoding enzymes. A majority of the genes were downregulated. Our analysis revealed that the expression of genes for the transcription factors ATF-3 and Pilot increased four-fold, whereas the gene for the apoptosis regulator NAPOR-1 decreased five-fold. These changes were confirmed by real-time quantitative reverse transcriptase-polymerase chain reaction. The calpain large polypeptide 3 (CANP3) gene also increased nine-fold after UV-A radiation. In addition, peroxisomal biogenesis factor 7, glucocorticoid receptor-alpha and tumor-associated calcium signal transducer genes decreased three- to eight-fold. Western blot analysis further confirmed the increase in protein expression of ATF-3 and CANP3 and decreased expression of glucocorticoid receptor-alpha in the irradiated cells. Surprisingly, most of these genes had not been previously shown to be modulated by UV-A radiation. Our results show that human lens epithelial cells respond to a single dose of UV-A radiation by enhancing or suppressing functionally similar sets of genes, some of which have opposing functions, around the time at which apoptosis occurs. These studies support the intriguing concept that activation of competing pathways favoring either cell survival or death is a means to coordinate the response of cells to UV-A stress.

The effect of N-acetyl serotonin on ultraviolet-radiation-induced cataracts in rats.

AIMS: To investigate the effects of ultraviolet radiation (UVR) on cataract development in rat lenses and whether or not N-acetyl serotonin has an effect on changes in these lenses. MATERIAL AND METHODS: The study was performed using 5 groups of Sprague-Dawley albino rats, with each group consisting of 15 rats. The 5th group being the control group did not receive any applications, whilst the other 4 groups received a daily dose of 0.2 J/cm(2)/day UVR (305 nm wavelength) for 60 days. A dose of 4 mg/kg/0.1 ml N-acetyl serotonin was injected intraperitoneally to group 1 and group 2 every day and on alternate days, respectively. Group 3 received an intraperitoneal injection of 0.1 ml phosphate buffer solution every day, whilst group 4 received no injection. On the 60th day, an intracardiac withdrawal of blood was performed, after the rats had been anesthetized with ether. Following the withdrawal of blood, the rats were killed using a high dose of ether and their eyes were enucleated. The lens fresh weights, plasma malondialdehyde (P-MDA), erythrocyte glutathione peroxidase (E-GSHPx), erythrocyte glutathione reductase, blood reduced glutathione (B-RGSH), erythrocyte catalase (E-CAT), lenticular malondialdehyde, lenticular superoxide dismutase (L-SOD), lenticular glutathione peroxidase (L-GSHPx) and lenticular glutathione (L-GSH) levels were all assessed. RESULTS: The lens fresh weights were determined to be lower in group 1 and in the control group in comparison with the other groups (p < 0.01). Whilst the P-MDA level was found to be lower (p < 0.001), the E-GSHPx level was higher (p < 0.01) in the control group than in the other groups. The E-GSHPx level was higher in groups 1 and 2 than in groups 3 and 4 (p < 0.01). The B-RGSH level was higher in the control group than in the other groups (p < 0.001). The E-CAT level was higher in both the control group and group 1 than in groups 2, 3 and 4 (p < 0.01), whilst it was higher in group 2 when compared to groups 3 and 4 (p < 0.01). The L-SOD levels were found to be higher in the control group and group 1 than in groups 2, 3 and 4 (p < 0.001). Whilst the L-GSHPx levels were determined to be higher only in the control group (p < 0.001), the L-GSH levels were higher in the control group and group 1 than in the other groups (p < 0.001). CONCLUSIONS: In recent years, the depletion of the atmospheric ozone layer has resulted in the penetration of more UVR to the earth, which causes various effects on different tissues of organisms. N-acetyl serotonin, a melatonin precursor, may well be effective in the prevention of the negative effects induced by the UVR upon the lens tissue, in which case the capability of melatonin to capture free radicals as well as its antioxidative properties should be taken into consideration.