Reactive oxygen species (ROS) performs a pivotal function as a signaling mediator in receptor-mediated signaling. However, the sources of ROS in this signaling have yet to be determined, but may include lipoxygenases (LOXs) and NADPH oxidase. The stimulation of lymphoid cells with TNF-alpha, IL-1beta, and LPS resulted in significant ROS production and NF-kappaB activation. Intriguingly, these responses were markedly abolished via treatment with the LOXs inhibitor nordihydroguaiaretic acid (NDGA). We further examined in vivo anti-inflammatory effects of NDGA in allergic airway inflammation. Both intraperitoneal and intravenous NDGA administration attenuated ovalbumin (OVA)-induced influx into the lungs of total leukocytes, as well as IL-4, IL-5, IL-13, and TNF-alpha levels. NDGA also significantly reduced serum levels of OVA-specific IgE and suppressed OVA-induced airway hyperresponsiveness to inhaled methacholine. The results of our histological studies and flow cytometric analyses showed that NDGA inhibits OVA-induced lung inflammation and the infiltration of CD11b+ macrophages into the lung. Collectively, our findings indicate that LOXs performs an essential function in pro-inflammatory signaling via the regulation of ROS regulation, and also that the inhibition of LOXs activity may have therapeutic potential with regard to the treatment of allergic airway inflammation.
Animals ; Antioxidants/metabolism ; Asthma/complications/metabolism/pathology/physiopathology ; Bronchial Hyperreactivity/drug therapy/pathology ; Bronchial Provocation Tests ; Bronchoalveolar Lavage Fluid/cytology ; Cells, Cultured ; Drug Evaluation, Preclinical ; Humans ; Inflammation/*etiology/metabolism ; Jurkat Cells ; Lipoxygenase/*physiology ; Lipoxygenase Inhibitors/pharmacology/therapeutic use ; Lymphocytes/drug effects/metabolism ; Male ; Mice ; Mice, Inbred BALB C ; Nordihydroguaiaretic Acid/pharmacology/therapeutic use ; Reactive Oxygen Species/*adverse effects/*metabolism

5-Lipoxygenase inhibitor and human recombinant erythropoietin might accelerate renal recovery in cisplatin-induced acute renal failure rats. Male Sprague-Dawley rats were randomized into four groups: 1) normal controls; 2) Cisplatin group-cisplatin induced acute renal failure (ARF) plus vehicle treatment; 3) Cisplatin+nordihydroguaiaretic acid (NDGA) group-cisplatin induced ARF plus 5-lipoxygenase inhibitor treatment; 4) Cisplatin+erythropoietin (EPO) group-cisplatin induced ARF plus erythropoietin treatment. On day 10 (after 7 daily injections of NDGA or EPO), urea nitrogen and serum Cr concentrations were significantly lower in the Cisplatin+NDGA and Cisplatin+EPO groups than in the Cisplatin group, and 24 hr urine Cr clearances were significantly higher in the Cisplatin+EPO group than in the Cisplatin group. Semiquantitative assessments of histological lesions did not produce any significant differences between the three treatment groups. Numbers of PCNA(+) cells were significantly higher in Cisplatin, Cisplatin+NDGA, and Cisplatin+EPO groups than in normal controls. Those PCNA(+) cells were significantly increased in Cisplatin+NDGA group. These results suggest that EPO and also NDGA accelerate renal function recovery by stimulating tubular epithelial cell regeneration.
Animals ; Arachidonate 5-Lipoxygenase/administration & dosage ; Blood Urea Nitrogen ; Cisplatin/*toxicity ; Creatinine/urine ; Epithelial Cells/drug effects ; Erythropoietin/administration & dosage/*therapeutic use ; Kidney/metabolism ; Kidney Failure, Acute/*chemically induced/*drug therapy ; Kidney Tubules/drug effects ; Male ; Nordihydroguaiaretic Acid/*therapeutic use ; Rats ; Rats, Sprague-Dawley ; Regeneration