Photosensitizing Mechanism and Identification of Levofloxacin Photoproducts at Ambient UV Radiation

Abstract

Levofloxacin (LVFX) is a broad spectrum third generation fluoroquinolone antibiotic, used in the treatment of severe or life-threatening bacterial infections. Photosensitizing mechanism of LVFX was investigated under the ambient environmental intensities of UV-A, UV-B and sunlight exposure. Phototoxic effects of LVFX were assessed on NIH-3T3 and HaCaT cell lines. Results identified first time three photoproducts of LVFX at ambient levels of UV-R by LC-MS/MS. The generation of reactive oxygen species (ROS) was investigated photochemically as well as intracellularly in HaCaT cell line. ROS were significantly quenched by specific quenchers like DABCO, NaN(3), D-mannitol and NAC. Photosensitized LVFX caused lipid peroxidation at different concentrations. Quenching study with superoxide dismutase confirms the LVFX-induced lipid photoperoxidation. Further, photocytotoxicity of LVFX showed significant reduction in cell viability by MTT and neutral red uptake assays. LVFX caused cell arrest in G2/M phases as well as induced apoptosis through ROS-dependent pathway. In addition, photosensitized LVFX also induced upregulation of p21 and Bax/Bcl-2 genes ratio. India is a tropical country and most of the human activities such as agriculture, commerce, sports, etc. take place in bright sunlight; therefore, photosensitive LVFX may lead to skin/ocular disorders and immune suppression. Information is needed regarding the phototoxicity of LVFX for human safety.

Involvement of cathepsin B in mitochondrial apoptosis by p-phenylenediamine under ambient UV radiation

“…DCFDA assay shows generation of intracellular ROS in cells. Previous study proves this finding that photosensitized drugs such as levofloxacin induced a ROS generation and concentration dependent decrease in cell viability [11]. To know the role of DNA damage in photocytotoxicity, single strand breakage (comet assay) and chromosomal aberration (photo-micronuclei formation) were done which shows significant DNA damage and micronuclei formation in photosensitized PPD treated cells in comparison to control cells.…”

“…Zero air and nitrogen gas were used as source and curtain gas, respectively. The optimized declustering potential for PPD was 90 V. At these optimized conditions, Q1 scan for control and test sample was performed [11]. The generation of O 2 •− was monitored by recording the photosensitized reduction of nitroblue tetrazolium (NBT) to nitroblue diformazan (NBF) spectrophotometrically at 560 nm.…”

Inactivation of bacteria via photosensitization of vitamin K3 by UV-A light

“…Production of 1 O 2 was monitored by measuring the decrease in RNO absorbance at 440 nm. Generation of 1 O 2 was further substantiated by the addition of NaN 3 as a specific quencher (Dwivedi et al ., ). Data are represented as mean ± SD ( n = 3) (Fig.…”

“…The generation of 1 O 2 under aerobic condition in bacteriafree PBS solution was measured following conditions described previously (Dwivedi et al, 2012). RNO solution (0.4 9 10 À5 M) was prepared in 0.025 M potassium phosphate buffer (pH = 7.0), and l-histidine (10 À2 M) was added as a selective acceptor of 1 O 2 .…”

Ambient UVA‐Induced Expression of p53 and Apoptosis in Human Skin Melanoma A375 Cell Line by Quinine

“…A solution of sodium phosphate buffer (0.025 m , pH 7.0) containing RNO (0.35–0.4 × 10 −5 m ) and 10 −2 m l ‐Histidine (a selective acceptor of 1 O 2 ) was prepared. The reaction mixture (10 mL) was taken in a Petri dish with or without Q and irradiated under UVA (2.7–10.8 J cm −2 ) . The production of 1 O 2 was measured as a decrease in absorbance at 440 nm using a spectrophotometer (Varian UV‐visible‐ Carry‐300).…”