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Alam MS, Ghosh G, Kabir-ud-Din. Light Scattering Studies of Amphiphilic Drugs Promethazine Hydrochloride and Imipramine Hydrochloride in Aqueous Electrolyte Solutions. J Phys Chem B 2008; 112:12962-7. [DOI: 10.1021/jp804238k] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Md. Sayem Alam
- Department of Chemistry, Aligarh Muslim University, Aligarh-202 002, India
- UGC-DAE Consortium for Scientific Research, Trombay, Mumbai- 400 085, India
| | - Goutam Ghosh
- Department of Chemistry, Aligarh Muslim University, Aligarh-202 002, India
- UGC-DAE Consortium for Scientific Research, Trombay, Mumbai- 400 085, India
| | - Kabir-ud-Din
- Department of Chemistry, Aligarh Muslim University, Aligarh-202 002, India
- UGC-DAE Consortium for Scientific Research, Trombay, Mumbai- 400 085, India
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Barbosa LRS, Itri R, Caetano W, de Sousa Neto D, Tabak M. Self-Assembling of Phenothiazine Compounds Investigated by Small-Angle X-ray Scattering and Electron Paramagnetic Resonance Spectroscopy. J Phys Chem B 2008; 112:4261-9. [DOI: 10.1021/jp710332t] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | | | - Wilker Caetano
- DFQB, Faculdade de Ciências e Tecnologia, UNESP, CEP 19060-900, Presidente Prudente, SP, Brazil
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Li MJ, Lin SY. Vibrational Spectroscopic Studies on the Disulfide Formation and Secondary Conformational Changes of Captopril–HSA Mixture after UV-B Irradiation. Photochem Photobiol 2005; 81:1404-10. [PMID: 16354113 DOI: 10.1562/2005-04-25-rn-497] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The effects of pH and ultraviolet-B (UV-B) irradiation on the secondary structure of human serum albumin (HSA) in the absence or presence of captopril were investigated by an attenuated total reflection (ATR)/Fourier transform infrared (FTIR) spectroscopy. The UV-B exposure affecting the stability of captopril before and after captopril-HSA interaction was also examined by using confocal Raman microspectroscopy. The results indicate that the transparent pale-yellow solution for captopril-HSA mixture in all pH buffer solutions, except pH 5.0 approximately 7.0, changed into a viscous form then a gel form with UV-B exposure time. The secondary structural transformation of HSA in the captopril-HSA mixture with or without UV-B irradiation was found to shift the maxima amide I peak in IR spectra from 1652 cm(-1) assigned to alpha-helix structure to 1622 cm(-1) because of a beta-sheet structure, which was more evident in pH 3.0, 8.0 or 9.0 buffer solutions. The Raman shift from 1653 cm(-1) (alpha-helix) to 1670 cm(-1) (beta-sheet) also confirmed this result. Captopril dissolved in distilled water with or without UV-B irradiation was determined to form a captopril disulfide observed from the Raman spectra of 512 cm(-1), which was exacerbated by UV-B irradiation. There was little disulfide formation in the captopril-HSA mixture even with long-term UV-B exposure, but captopril might interact with HSA to change the protein secondary structure of HSA whether there was UV-B irradiation or not. The pH of the buffer solution and captopril-HSA interaction may play more important roles in transforming the secondary structure of HSA from alpha-helix to beta-sheet in the corresponding captopril-HSA mixture than UV-B exposure. The present study also implies that HSA has the capability to protect the instability of captopril in the course of UV-B irradiation. In addition, a partial unfolding of HSA induced by pH or captopril-HSA interaction under UV-B exposure is proposed.
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Affiliation(s)
- Mei-Jane Li
- Biopharmaceutics Laboratory, Department of Medical Research and Education, Taipei Veterans General Hospital, Shih-Pai, Taipei, Taiwan, Republic of China
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Rijnkels JM, Moison RMW, Podda E, van Henegouwen GMJB. Photoprotection by antioxidants against UVB-radiation-induced damage in pig skin organ culture. Radiat Res 2003; 159:210-7. [PMID: 12537526 DOI: 10.1667/0033-7587(2003)159[0210:pbaaur]2.0.co;2] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Topically applied antioxidants constitute an important group of protective agents against skin damage induced by ultraviolet radiation. The current study was performed to investigate whether a recently developed ex vivo pig skin model was suitable for short-term studies of the mechanism(s) of UVB-radiation-induced skin damage; the protective effect of topical application of alpha-tocopherol, l-ascorbic acid, alpha-lipoic acid, glutathione ethylester and N-acetylcysteine was tested. Increasing doses of the antioxidants were applied topically on ex vivo pig skin explants and allowed to penetrate for 60 min. Epidermal antioxidant bioavailability was measured before and 60 min after exposure to an ultraviolet B (UVB) radiation of 7.5 kJ/m2. Cell viability (trypan blue dye exclusion) and apoptosis were measured 48 h later in isolated keratinocytes. UVB-radiation-induced epidermal lipid peroxidation was determined immediately after exposure of the skin to a UVB dose of 28 kJ/m2. All antioxidants tested became bioavailable in pig skin epidermis, and none of them were depleted after UVB-radiation exposure. Increasing doses of the antioxidants tested decreased UVB-radiation-induced cell death and apoptosis. The highest doses of antioxidants prevented UVB-radiation-induced lipid peroxidation; alpha-lipoic acid only tended to decrease lipid peroxidation. In conclusion, a single topical dose of the above antioxidants on ex vivo pig skin can reduce UVB-radiation-induced oxidative stress and lipid peroxidation and thereby reduce apoptotic stimuli and cell death. Furthermore, the ex vivo pig skin model was a useful tool for testing compounds for their antioxidant activity.
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Affiliation(s)
- Jolanda M Rijnkels
- Department of Medicinal Photochemistry, Leiden/Amsterdam Center for Drug Research, University of Leiden, P.O. Box 9502, 2300 RA Leiden, The Netherlands
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Emonet N, Leccia MT, Favier A, Beani JC, Richard MJ. Thiols and selenium: protective effect on human skin fibroblasts exposed to UVA radiation. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 1997; 40:84-90. [PMID: 9301047 DOI: 10.1016/s1011-1344(97)00041-9] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The sensitivity of human dermal fibroblasts to UVA radiation has been linked to a decrease in intracellular glutathione (GSH) levels. GSH (gamma-glutamyl-cysteinyl-glycine) is a radical scavenger and a cofactor for protective enzymes such as selenium-dependent GSH peroxidases. In this study, we examine the possibility of a cooperative interaction between three cysteine delivery systems and selenium in protecting human cultured fibroblast exposed to UVA radiation. Cells were irradiated (9, 15 and 20 J cm-2) following incubation with N-acetyl-cysteine (NAC, 5 mM), N-acetyl-homocysteine-thiolactone (citiolone (CIT), 1 mM) or L-2-oxothiazolidine-4-carboxylate (OTC, 1 mM). The modulation of the intracellular GSH levels by the addition of the different compounds was determined by enzymatic and separative methods. Cells were harvested for survival analysis by measuring the ability of the cell to adhere and proliferate. Treatments with NAC and CIT resulted in a significant rise in GSH levels compared with control cells, with protection against UVA radiation. OTC did not induce any rise in GSH level; nevertheless, the protective effect afforded by OTC is similar to that observed with NAC and CIT. Moreover, selenium (0.1 mg 1-1), as sodium selenite, significantly increased the protective efficiency of NAC and CIT, but not of OTC. Although the precise mechanism is not known, thiol molecules can inhibit the deleterious effects of UVA radiation. These results provide evidence that compounds capable of inducing GSH synthesis can act with selenium to protect cells against UVA damage.
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Affiliation(s)
- N Emonet
- Service de Dermatologie, Université Joseph Fourier, Grenoble, France
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7
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van Iperen HP, Beijersbergen van Henegouwen GM. Clinical and mechanistic aspects of photopheresis. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 1997; 39:99-109. [PMID: 9225456 DOI: 10.1016/s1011-1344(96)07432-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Photopheresis is an extracorporeal form of photochemotherapy with 8-methoxypsoralen (8-MOP) and ultraviolet A (UVA) radiation. Photopheresis is used for the management of T-cell-mediated diseases, and such treatment leads to the induction of antigen-specific immune suppression directed to the pathogenic clone of T cells. Photopheresis is used to treat a wide variety of diseases--such as cutaneous T-cell lymphoma, systemic sclerosis; rheumatoid arthritis, lupus erythematosus--and is also successfully applied in the suppression of graft rejection. In addition to the clinical achievements, attention will be paid to results from animal studies. An important outcome of these studies is that photopheresis can be used to treat airway hyperreactivity. Furthermore, it was shown that the therapeutic strategy can be changed drastically: the presence of plasma during irradiation should be avoided and the amount of blood that must be treated to obtain the desired antigen-specific immunosuppression can be greatly decreased. Also, results from cellular experiments are discussed. An example of this is the increase in the major histocompatibility complex expression on the surface of cells found after treatment. The mechanism that underlies photopheresis has not yet been elucidated, but progress has been made. The following related points will be reviewed: models for investigation; and mechanistic aspects, with the emphasis on cellular biomacromolecules and on photosensitizers (drugs) other than 8-MOP.
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Affiliation(s)
- H P van Iperen
- Leiden/Amsterdam Center for Drug Research, Department of Medicinal Photochemistry, The Netherlands
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Gaullier JM, Valla A, Bazin M, Giraud M, Dubertret L, Santus R. N-conjugates of 2,5-disubstituted pyrrole and glutathione. Evaluation of their potency as antioxidants against photosensitization of NCTC 2544 keratinocytes by excess endogenous protoporphyrin IX. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 1997; 39:24-9. [PMID: 9210319 DOI: 10.1016/s1011-1344(96)07466-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A novel glutathione compound in which the amino group has been derivatized by a 2,5-dimethyl pyrrole is shown to be very effective against cell photosensitization in vitro. Protoporphyrin IX either added to the medium or produced endogenously by incubation of NCTC 2544 keratinocytes with 5-aminolevulinic acid has been chosen as the photosensitizer. The antioxidant effectiveness of glutathione-pyrrole derivatives against protoporphyrin photosensitization depends critically on the type of 2,5 substitution on the pyrrole ring. This structure-function relationship may be attributed to the difference in compartmentation and/or uptake of the various glutathione-pyrrole derivatives under study. The 2,5-dimethyl pyrrole derivative is much more effective than glutathione as a protective agent against phototoxic reactions induced by protoporphyrin IX.
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Affiliation(s)
- J M Gaullier
- Laboratoire de Photobiologie (INSERM U312), Muséum National d'Histoire Naturelle, Paris, France
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9
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van Iperen HP, Beijersbergen van Henegouwen GM. Singlet oxygen producing photosensitizers in photophoresis. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 1997; 38:203-8. [PMID: 9203382 DOI: 10.1016/s1011-1344(96)07442-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
In this study, the immunosuppressive properties of two photosensitizers (benzoporphyrin derivative monoacid ring A (BPD) and Photofrin (HPD)), used for the photodynamic therapy of cancer, were investigated. The investigations were performed in our rat model for photophoresis. The validity of this model has been amply demonstrated. It enables a distinction to be made between antigen-specific and antigen non-specific immune suppression. With this model, the immune response which can be specifically suppressed is the contact hypersensitivity (CHS). CHS is induced by 2,4-dinitrofluorobenzene (DNFB). Both BPD and HPD are able to suppress CHS induced by DNFB. Furthermore, this generated suppression is transferable by the spleen cells of treated animals and is antigen non-specific.
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Affiliation(s)
- H P van Iperen
- Leiden/Amsterdam Centre for Drug Research, Department of Medicinal Photochemistry, Netherlands.
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Beijersbergen van henegouwen GM. Medicinal Photochemistry: Phototoxic and Phototherapeutic Aspects of Drugs. ACTA ACUST UNITED AC 1997. [DOI: 10.1016/s0065-2490(97)80014-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2023]
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van Iperen HP, Beijersbergen van Henegouwen GM. Photopheresis; the risk of photoallergy. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 1996; 34:225-8. [PMID: 8810540 DOI: 10.1016/1011-1344(95)07277-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Photopheresis is a therapy for several T-cell-mediated disorders, aiming at a specific immune response against the pathogenic clone of T cells involved. With photopheresis, a mixture of patients' buffy coat and plasma, which contains 8-methoxypsoralen (8-MOP), is diluted with phosphate-buffered saline (PBS) and exposed to ultraviolet A radiation (UVA). After the irradiation the treated fraction is reinfused. As photomodification of biomacromolecules is considered to be crucial in photopheresis, the presence of plasma during irradiation can pose a problem. The fact is that photomodification of plasma proteins is supposed to be the causal step in the occurrence of photoallergy. Whether the presence of plasma during photopheresis is a risk for photoallergy was investigated with 8-MOP and chlorpromazine (CPZ; well-established photoallergen). It proved that both sensitizers can induce photoallergy, although the concentration of 8-MOP needed to induce photoallergy is 4.5 times higher than that of CPZ. It is concluded that the presence of plasma during irradiation should be avoided in order to prevent the risk of induction of photoallergy.
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Affiliation(s)
- H P van Iperen
- Department of Medicinal Photochemistry, Leiden/Amsterdam Center for Drug Research, Netherlands
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12
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Hemelaar PJ, Beijersbergen van Henegouwen GM. The protective effect of N-acetylcysteine on UVB-induced immunosuppression by inhibition of the action of cis-urocanic acid. Photochem Photobiol 1996; 63:322-7. [PMID: 8881338 DOI: 10.1111/j.1751-1097.1996.tb03034.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A recent study has shown that N-acetylcysteine (NAC) not only has sun-protective properties but also inhibits the UVB-induced suppression of contact hypersensitivity (CHS) in mice. Because NAC does not absorb any UVA (320-400 nm radiation) or UVB (290-320 nm radiation) we have studied the underlying mechanism of protection. Irradiation of solutions of plasmid DNA with UVC (200-290 nm radiation) (10 J m-2) resulted in the formation of cyclobutane pyrimidine dimers, but the extent to which this occurred was not affected by the presence of NAC as was determined by an in vitro T4 endonuclease assay. N-acetylcysteine proved not to have any effect on the photoisomerization of trans-urocanic acid (UCA) to its cis-form in vitro; at equilibrium, approximately 55% cis-UCA was formed. The same percentage was also found in vivo on exposure of mice to UVB (15 kJ m-2). Topical application of NAC 30 min prior to irradiation did not have any influence as well on the photoisomerization of trans- to cis-UCA. These in vivo experiments were performed under the same conditions used previously to show the protective effect of NAC against UVB-induced suppression of CHS. We conclude that this protection of NAC is at least partly based on interference in the role of cis-UCA in UVB-induced suppression of CHS. This conclusion is supported by the observation that NAC completely inhibits the suppression of CHS by cis-UCA administered to mice that were always kept in the dark. In the same range of doses as used in the present study, it was shown in our previous study that NAC alone does not affect the CHS response.
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Affiliation(s)
- P J Hemelaar
- Department of Medicinal Photochemistry, Leiden University, Netherlands
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Tariq M, Al-Deeb S, Al-Moutairy K, Ahmad Khan H. Cysteamine attenuates iminodipropionitrile (IDPN) induced dyskinesia in rats. Int J Neurosci 1995; 83:165-75. [PMID: 8869425 DOI: 10.3109/00207459508986336] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The present investigation was undertaken to study the effect of cysteamine on experimental dyskinesia in rats. The movement disorders were produced by intraperitoneal administration of iminodipropionitrile (IDPN) in the dose of 100 mg/kg per day for 11 days. Cysteamine was administered (i.p.), daily 30 minutes before IDPN in the doses of 25 mg/kg, 50 mg/kg and 100 mg/kg bodyweight in three different groups of rats. Twenty four hours after the last dose of IDPN, animals were observed for neurobehavioural changes including vertical and horizontal head weaving, circling, backwalking, grip strength and righting reflex. Immediately after behavioural studies brain specimens were collected for analysis of vitamin E and total glutathione levels. The results of behavioural studies showed that co-treatment with cysteamine protected rats against IDPN-induced dyskinesia. Our biochemical studies showed that IDPN produced a depletion of vitamin E in cerebrum, cerebellum and brain stem. Concomitant treatment with cysteamine in doses of 50 and 100 mg/kg attenuated IDPN-induced decrease in vitamin E in cerebrum and cerebellum. There was a significant decrease in cerebral glutathione in IDPN treated rats, which was attenuated by cysteamine. No significant change was observed in the glutathione levels in cerebellum and brain stem. Further studies are deemed necessary to elucidate the mode of action of cysteamine and to determine therapeutic and/or prophylactic value of this drug in the treatment of movement disorders.
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Affiliation(s)
- M Tariq
- Neuroscience Research Group, Armed Forces Hospital, Riyadh, Saudi Arabia
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Beijersbergen van Henegouwen GM, Junginger HE, de Vries H. Hydrolysis of RRR-alpha-tocopheryl acetate (vitamin E acetate) in the skin and its UV protecting activity (an in vivo study with the rat). JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 1995; 29:45-51. [PMID: 7472802 DOI: 10.1016/1011-1344(95)90251-1] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Vitamin E acetate is often used rather than vitamin E as an ingredient of skin care products and dermatological preparations, because it lacks the free phenolic OH group. However, because of this the acetate as such is biologically inactive. In spite of this intrinsic inactivity, the skin is protected against the harmful effects of sunlight after topical application of vitamin E acetate. Therefore it is supposed that hydrolysis takes place in the skin and that the reaction product, the radical scavenger vitamin E, is responsible for the protection observed. In this in vivo study with the rat, we have investigated the hydrolysis of RRR-alpha-tocopheryl acetate (vitamin E acetate) in the epidermis in relation to UV radiation protection. (As a measure of protection, we used the UV-induced binding of 8-methoxypsoralen to epidermal biomacromolecules.) After a period of 5 h from a single application of vitamin E acetate, hydrolysis into free vitamin E was not observed. No protection was found at this time point, corresponding with the absence of vitamin E. After treatment for 5 days, consisting of one topical application daily, the percentage of acetate present in the stratum corneum which was hydrolysed into free vitamin E was less than 1%, whereas the corresponding value for the viable layer of the epidermis was about 5%. The hydrolysis of vitamin E acetate in the epidermis proceeded very slowly. As a result, the absolute amount of free vitamin E, found in the total epidermis after treatment for 5 days with the acetate, was only a few times higher than the normal level. Yet, this very small amount of free vitamin E proved to be sufficient for maximal protection in this animal model. The results show that vitamin E acetate acts as a prodrug, which very slowly releases minute amounts of active vitamin E.
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Van den Broeke LT, Beijersbergen van Henegouwen GM. UV radiation protecting efficacy of cysteine derivatives, studies with UVA-induced binding of 8-MOP and CPZ to rat epidermal biomacromolecules in vivo. Int J Radiat Biol 1995; 67:411-20. [PMID: 7738404 DOI: 10.1080/09553009514550471] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
With the aim of optimizing the UV radiation protecting efficacy of N-acetylcysteine (NAC), the following topically applied cysteine derivatives were investigated: N-acetylcysteine ethylester (NACET), S-acetylcysteine ethylester (SACET), cysteine ethylester (CYSET), N,S-diacetylcysteinamide (SNACA), N,S-diacetylcysteine (SNAC) and N,S-diacetylcysteine ethylester (SNACET). As a measure for protection the inhibition of in vivo irreversible photobinding of the labelled phototoxic drugs chlorpromazine (CPZ) and 8-methoxypsoralen (8-MOP) to rat epidermal biomacromolecules was used. The duration of protection of the cysteine derivatives was shortened by S-acetylation, N-acetylation and carboxyl derivatization. Compounds with a free thiol group showed a long-lasting presence in the stratum corneum, probably by the formation of mixed disulphides with proteins. The intrinsic protecting efficacy with respect to the total epidermis increased in the order CYSET < SNACET,SNACA,SACET < NACET, SNAC,NAC. The results of this study are discussed in view of susceptibility to oxidation, epidermal bioavailability and metabolic activation. With respect to the viable epidermis we postulate that NACET and SNAC have the most promising properties as UV protective agents.
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Affiliation(s)
- L T Van den Broeke
- Department of Medicinal Photochemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, The Netherlands
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van den Broeke LT, Beijersbergen van Henegouwen GM. Topically applied N-acetylcysteine as a protector against UVB-induced systemic immunosuppression. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 1995; 27:61-5. [PMID: 7699524 DOI: 10.1016/1011-1344(94)07061-r] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The potential protective efficacy of N-acetylcysteine against systemic immunosuppression in mice, as a result of UVB exposure, was investigated. The contact hypersensitivity response to trinitrochlorobenzene applied at a distant, non-irradiated site, was used to assess the systemic immunosuppression. Topical application of N-acetylcysteine (0.4-3.2 mumol cm-2), 30 min prior to irradiation (15 kJ m-2), markedly inhibited the UVB-induced immunosuppression. Because N-acetylcysteine does not absorb UVA or UVB radiation, the mechanism of protection must be different from that of sunscreens. The results of this study may have important practical implications in protecting human beings against the deleterious effects of UVB radiation.
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Affiliation(s)
- L T van den Broeke
- Department of Medicinal Photochemistry, Leiden/Amsterdam Centre for Drug Research, Leiden University, Netherlands
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17
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van den Broeke LT, Beijersbergen GM, van Henegouwen B. The effect of N-acetylcysteine on the UVB-induced inhibition of epidermal DNA synthesis in rat skin. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 1994; 26:271-6. [PMID: 7853119 DOI: 10.1016/1011-1344(94)07042-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The effect of N-acetylcysteine (NAC), on the UVB-induced inhibition of epidermal DNA synthesis in rat skin was investigated. Topical application of NAC, 30 min prior to UVB irradiation (20 kJ m-2), significantly reduced the UVB-induced inhibition of the epidermal (methyl-1',2'-3H)-thymidine uptake. These results indicate that NAC affords protection against at least some of the damaging effects of UVB radiation on epidermal DNA, probably by neutralization of UVB induced reactive species.
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Affiliation(s)
- L T van den Broeke
- Department of Medicinal Photochemistry, Leiden/Amsterdam Center for Drug Research, Leiden University, Netherlands
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Zarebska Z. Cell membrane, a target for PUVA therapy. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 1994; 23:101-9. [PMID: 8040751 DOI: 10.1016/1011-1344(94)06944-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The photochemical reactions occurring in the cell membranes, sensitized photo-oxidation and psoralen photoaddition to lipids, are briefly reviewed. Phospholipid dynamics in the membrane structure, based on erythrocyte lipid organization, are described. Evidence for alterations of cell membrane functions under psoralen plus UVA radiation (PUVA) treatment in a variety of mammalian cells is presented. Cell receptor dysfunctions under PUVA treatment are demonstrated in a number of biological investigations. The purpose of this survey is to illustrate the feasibility of studying psoralen photobiology with phospholipids. The reaction of psoralens with phospholipids is considered to be one of the triggering mechanisms of the subsequent physiological responses, which may be relevant to PUVA photochemotherapy.
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Affiliation(s)
- Z Zarebska
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw
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