RESUMEN
The aims of this study were to synthesize chlorophyll derivatives, pheophytins and Zn-pheophytins, from chlorophylls extracted from spinach, characterize them, and evaluate their antioxidant and anti-inflammatory activities. The chlorophylls isolated from spinach were identified by means of FT-IR and NMR spectroscopies. The synthesis of pheophytins and Zn-pheophytins was confirmed by UV-Vis spectral analyses. The antioxidant activity of chlorophylls, pheophytins, and Zn-pheophytins was studied. The results revealed that the Zn-pheophytins showed the highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and ß-carotene bleaching activities, followed by chlorophylls and pheophytins. Additionally, Zn-pheophytins showed substantial inhibitory activity against lipopolysaccharide (LPS)-induced NO production in RAW 264.7 cells. Furthermore, Zn-pheophytins remarkably suppressed LPS-induced expression of inducible nitric oxide synthase (iNOS) in RAW 264.7 cells and showed no cytotoxicity. Our findings indicated that Zn-pheophytins have strong antioxidant and anti-inflammatory properties and can therefore be a potential source of bioactive compounds for nutraceutical, cosmetic, and pharmaceutical applications.
Asunto(s)
Clorofila/química , Feofitinas/química , Extractos Vegetales/química , Spinacia oleracea/química , Animales , Antiinflamatorios/síntesis química , Antiinflamatorios/química , Antiinflamatorios/farmacología , Antioxidantes/síntesis química , Antioxidantes/química , Antioxidantes/farmacología , Clorofila/síntesis química , Clorofila/farmacología , Lipopolisacáridos/farmacología , Macrófagos/efectos de los fármacos , Macrófagos/enzimología , Macrófagos/metabolismo , Ratones , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa de Tipo II/genética , Óxido Nítrico Sintasa de Tipo II/metabolismo , Feofitinas/síntesis química , Feofitinas/farmacología , Extractos Vegetales/farmacología , Espectroscopía Infrarroja por Transformada de Fourier , Zinc/química , beta Caroteno/químicaRESUMEN
BACKGROUND: Pheophorbide a (Pa) is a chlorine-based photosensitizer derived from an ethnopharmacological herb, and our group recently synthesized Pa by the removal of a magnesium ion and a phytyl group from chlorophyll-a. In this study, the effect of photodynamic therapy (PDT) with synthesized Pa was examined in a human oral squamous cell carcinoma (OSCC) cells. METHODS: Cells were treated with PDT with Pa, and reactive oxygen species (ROS) and mitochondrial membrane potential [ΔΨ (m)] were examined. Apoptosis was measured using annexin V staining and immunoblot. Autophagy was characterized by the increase in LC3B-II and the formation of autophagosome and acidic vesicular organelles (AVOs). RESULTS: Pa-PDT inhibited the proliferation of OSCC cells in a dose-dependent manner. Pa-PDT increased the number of apoptotic cells by inactivating ERK pathway. Pa-PDT also induced autophagy in OSCC cells evidenced by the increased levels of LC3 type II expression and the accumulation of AVOs. The inhibition of autophagy enhanced Pa-PDT-mediated cytotoxicity through an increase in necrosis. CONCLUSIONS: These results suggest that synthesized Pa-PDT exerts anti-tumor effects by inducing apoptosis and autophagy and provide novel evidence that Pa-PDT induces autophagy, and autophagy inhibition enhances Pa-PDT-mediated necrosis in OSCC cells.