الفهرس 
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Abstract
Summary
Drug-induced photosensitivity refers to a cutaneous adverse event occurring due to the combined interaction of a drug (topically or systemically administered) and radiation from the sun. Phototoxic reactions can manifest within minutes or hours of drug administration and are non-immunological, resulting from direct tissue injury. The ultraviolet radiation that reaches the earth’s surface, more than 95% is the longer wavelengths of UVA, with the small amount UVB. UVA effects are dominated by indirect DNA damage.UVA has the longest wavelength with the lowest energy and can penetrate deeply into the dermis and cause aging effects. One of the most obvious acute effects of UV on the skin is the induction of inflammation.
A quinolone antibiotic is a member of a large group of broad-spectrum bactericides. Treatment with both UV radiation and quinolone showed significantly increased back skin swellings, increase sunburn cells and decreased epidermal Langerhans cells. Ciprofloxacin is one of the most widely used antibiotics. The most common side effects of ciprofloxacin are nausea, diarrhea, vomiting, elevating liver enzymes and skin sensitivity to sunlight.
Antioxidants that are reducing agents can also act as pro-oxidants. For example, vitamin C has antioxidant activity when it reduces oxidizing substances such as hydrogen peroxide, however, it will also reduce metal ions that generate free radicals through the Fenton reaction.
2 Fe3+ + Ascorbate (vit C) → 2 Fe2+ + Dehydroascorbate
2 Fe2+ + 2 H2O2 → 2 Fe3+ + 2 OH· + 2 OH−
This work aimed to investigate the damaging effect of ultraviolet-A radiation on the antibacterial activity of ciprofloxacin in Esch. Coli infected rats and demonstrate the protective role of Vit. C against UV-A induced oxidative stress.
At the beginning of the experiment Fifty six adult male albino rats weighing approximately150-180g were randomly allocated into seven groups. Each group consisted of 8 rats. The animals were treated according to the following scheme:
group 1: normal control rats non exposed to UV-A lamp radiation.
group 2: rats exposed to UV-A lamp radiation for 60 min.
group 3: rats administered ciprofloxacin (100mg/kg; orally; daily) for 7 consecutive days + E.coli in vivo bacterially infected rats non exposed to UV-A lamp radiation.
group 4: rats receiving ciprofloxacin (100mg/kg; orally; daily) for 7 consecutive days + E.coli in vivo bacterially infected rats exposed to UV-A lamp radiation for 30 min.
group 5: rats receiving ciprofloxacin (100mg/kg; orally; daily) for 7 consecutive days + E.coli in vivo bacterially infected rats exposed to UV-A lamp radiation for 45 min.
group 6: rats receiving ciprofloxacin (100mg/kg; orally; daily) for 7consecutive days+ E.coli in vivo bacterially infected rats exposed to UV-A lamp radiation for 60 min and served as positive control group.
group 7: rats receiving ciprofloxacin (100mg/kg; orally; daily) for 7 consecutive days + E.coli in vivo bacterially infected rats exposed to UV-A lamp radiation for 60 min + Vit.C (180mg/kg; orally; daily) for 7 consecutive days.
In all experiments, dorsal side of shaved rats, using sterile surgical blade, is exposed to UV-A lamp radiation at the 5, 6, 7th days from the beginning of the experiment.
Grade of skin reaction (redness, edema, shrinkage, hemorrhage and oozing) at 24, 48 and 72 hr. after UV-A irradiation were conducted once daily,thenmeasured relative weight for organs and oxidative stress (MDA, GSH), inflammatory biomarker tumor necrosis factor-α(TNF-α) in the skin homogenate. Furthermore; total Leukocyte count, liver function parameters such as albumin and total protein levelsin serum by UV spectroscopic analysis.
It is noticeable that skin scores increased were in groups with increasing days of exposure, all the skin scores were increased in comparison with normal control group. The obtained results of MDA, GSH and TNF-α contents indicated the skin MDA and TNF-α contents were increased and decreased GSH content. the obtained results indicated that the total leukocyte count (TLC) in blood was increased and accompanied by a decreased serum total protein (TP) and albumin (ALB) levels, in other hand relative spleen weight were increased and relative thymus weight were decreased, and the histopathological alterations in skin induced due to photosentivity of ciprofloxacin by UV-A radiation was increased by the time exposure.
Treatment rats by Vit.C showed a significant decrease in all skin score parameters and normalized the skin homogenate contents of lipid peroxide (MDA) 56%, glutathione (GSH) 42%, (TNF-α) 72%and the blood leukocyte count 31%. Moreover, by testing serum total protein and albumin levels were they increased by 27% and 20% respectively, whereas the relative organs weights of spleen and thymus were normalized by Vit.C 27% and 49% respectively. Moreover, no histopathological alterations in skin, were noticed.
Treatment rats by Vit.C showed a significant decrease in all skin score parameters and approaches to control values, and skin MDA, TNF-α and TLC decreased accompanied with significant increase in GSH, TP and ALB. Even more normalized relative spleen weight and relative thymus weight. Moreover no histopathological alterations in skin were noticed.
Study concludes that orally administered Vit.C has prophylactic antioxidant and anti-inflammatory effects against ciprofloxacin induced phototoxicity on exposure to UV-A radiation in E.coli systematic infected rats.