RESUMO
Sparfloxacin (SPFX) is a broad spectrum antibiotic which inhibits bacterial DNA gyrase enzyme activity. However, photodegradation in the presence of UVA limits its antibacterial activity and induces phototoxicity. Thus, to encounter this problem, we have developed poly d,l-lactic-co-glycolic acid (PLGA) loaded SPFX nanoparticles. Here, we have performed a comparative antibacterial activity of SPFX and its nanoparticles (NPs) through molecular docking and plate sensitivity assay. Under environmental UVA exposure, photoexcited SPFX significantly generates ROS, DNA damage and mitochondrial mediated cell death in comparison to PLGA-SPFX-NPs (nano SPFX) in human skin cell line (HaCaT). In presence of UVA, bulk SPFX induced cell cycle arrest with appearance of sub-G1 peak showing apoptosis while nano SPFX did not show any change. SPFX triggered apoptosis via alteration in membrane integrity of mitochondria and lysosome in comparison to PLGA-SPFX-NPs. Involvement of mitochondrial mediated cell death was confirmed by down-regulation of anti-apoptotic Bcl-2 and procaspase-3 and upregulation of pro-apoptotic Bax, cytochrome-c and caspase-3 proteins expression. Specific caspase inhibitor, Z-VAD-FMK showed involvement of caspase cascade pathway in apoptosis. Our finding suggests that controlled release of SPFX from PLGA-SPFX-NPs can reduce its side effects and enhance its antibacterial activity. Thus, nanotization of fluoroquinolones will be a significant step to reduce the problem of resistance and phototoxicity of this group.
Assuntos
Antibacterianos/farmacologia , Composição de Medicamentos/métodos , Fluoroquinolonas/farmacologia , Ácido Láctico/química , Fotólise/efeitos da radiação , Ácido Poliglicólico/química , Antibacterianos/química , Apoptose/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular , Dano ao DNA/efeitos dos fármacos , Portadores de Fármacos/química , Estabilidade de Medicamentos , Fluoroquinolonas/química , Humanos , Queratinócitos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Simulação de Acoplamento Molecular , Estrutura Molecular , Nanopartículas/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Espécies Reativas de Oxigênio/metabolismo , Raios Ultravioleta/efeitos adversosRESUMO
Pefloxacin (PFLX) is an antibiotic, which shows broad spectrum antimicrobial activities. It is an important derivative of fluoroquinolones (FLQs) group. Ultraviolet radiation (200-400nm) causes major problem for living being which comes at the earth surface naturally through sunlight and increasing regularly due to ozone depletion. PFLX was photodegraded in 5h and forms photoproduct under UVA exposure. At the non photocytotoxic dose PFLX, shows reduced phagocytosis activity, NO (nitric oxide) production, large vacuole formation and down regulated IL-6, TNF-α and IL-1 in BALB/c macrophages at both genes and proteins levels. At higher doses (photocytotoxic doses), PFLX induced a concentration dependent decrease in cell viability of human keratinocyte cell line (HaCaT) and peritoneal macrophages of BALB/c mice. Our molecular docking suggests that PFLX binds only to the cleaved DNA in the DNA-human TOP2A complex. Topoisomerase assay confirmed that PFLX inhibits human topoisomerase by forming an adduct with DNA. Photosensitized PFLX also caused intracellular ROS mediated DNA damage and formation of micronuclei and cyclobutane pyrimidine dimers (CPDs). Increase intracellular ROS leads to apoptosis which was proved through lysosomal destabilization and reduced mitochondrial membrane potential (MMP). Our present study shows that ambient UVA exposure in the presence of PFLX caused immunomodulatory as well as photogenotoxic effects. Therefore, patients under PFLX drug treatment should avoid sunlight exposure, especially during peak hours for their photosafety.
