Sung-Hyeuk Park

Comparative toxicity and biodistribution of copper nanoparticles and cupric ions in rats.

Despite widespread use and prospective biomedical applications of copper nanoparticles (Cu NPs), their biosafety issues and kinetics remain unclear. Thus, the aim of this study was to compare the detailed in vivo toxicity of Cu NPs and cupric ions (CuCl2; Cu ions) after a single oral dose. We determined the physicochemical characteristics of Cu NPs, including morphology, hydrodynamic size, zeta potential, and dissolution in gastric (pH 1.5), vehicle (pH 6.5), and intestinal (pH 7.8) conditions. We also evaluated the kinetics of Cu following a single equivalent dose (500 mg/kg) of Cu NPs and Cu ions. Cu NPs had highest dissolution (84.5%) only in gastric conditions when compared with complete dissolution of Cu ions under various physiological milieus. Kinetic analysis revealed that highest Cu levels in blood and tested organs of Cu NP-treated rats were 15%–25% lower than that of Cu ions. Similar to the case of Cu ions, Cu levels in the tested organs (especially liver, kidney, and spleen) of Cu NP-treated rats increased significantly when compared with the vehicle control. However, delay in reaching the highest level and biopersistence of Cu were observed in the blood and tested organs of Cu NP-treated rats compared with Cu ions. Extremely high levels of Cu in feces indicated that unabsorbed Cu NPs or absorbed Cu ions were predominantly eliminated through liver/feces. Cu NPs exerted apparent toxicological effects at higher dose levels compared with Cu ions and showed sex-dependent differences in mortality, biochemistry, and histopathology. Liver, kidney, and spleen were the major organs affected by Cu NPs. Collectively, the toxicity and kinetics of Cu NPs are most likely influenced by the release of Cu dissociated from Cu NPs under physiological conditions.

Protective effects of diallyl disulfide against acetaminophen-induced nephrotoxicity: A possible role of CYP2E1 and NF-κB.

Diallyl disulfide (DADS) is a degradation product of allicin which is contained in garlic. This study investigated the protective effects of DADS against acetaminophen (AAP)-induced nephrotoxicity and the molecular mechanisms of nephroprotective effects in rats. AAP caused severe nephrotoxicity as evidenced by significant increases in renal tubular cell apoptosis, mitochondria-mediated apoptosis, and up-regulation of nuclear transcription factor kappa-B (NF-κB), cyclooxygenase-2 (Cox-2), and tumor necrosis factor-α (TNF-α) in the kidney with histopathological alterations. After AAP administration, glutathione content and activities of catalase, superoxide dismutase, and glutathione reductase were significantly decreased whereas malondialdehyde content was significantly increased, indicating that AAP-induced kidney injury was mediated through oxidative stress. In contrast, DADS pretreatment significantly attenuated AAP-induced nephrotoxic effects, including oxidative damage, histopathological lesions, and apoptotic changes in the kidney. DADS also attenuated AAP-induced up-regulation of NF-κB, Cox-2, and TNF-α in the kidney, and microsomal CYP2E1 expression in liver and kidney. These results indicated that DADS could prevent AAP-induced nephrotoxicity. The protective effects of DADS might be due to its ability to decrease metabolic activation of AAP by inhibiting CYP2E1 and its potent antioxidant, antiapoptotic, and antiinflammatory effects via inhibition of NF-κB.

Role of mitogen-activated protein kinases and nuclear factor-kappa B in 1,3-dichloro-2-propanol-induced hepatic injury.

In this study, the potential hepatotoxicity of 1,3-dichloro-2-propanol and its hepatotoxic mechanisms in rats was investigated. The test chemical was administered orally to male rats at 0, 27.5, 55, and 110 mg/kg body weight. 1,3-Dichloro-2-propanol administration caused acute hepatotoxicity, as evidenced by an increase in serum aminotransferases, total cholesterol, and total bilirubin levels and a decrease in serum glucose concentration in a dose-dependent manner with corresponding histopathological changes in the hepatic tissues. The significant increase in malondialdehyde content and the significant decrease in glutathione content and antioxidant enzyme activities indicated that 1,3-dichloro-2-propanol-induced hepatic damage was mediated through oxidative stress, which caused a dose-dependent increase of hepatocellular apoptotic changes in the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling assay and immunohistochemical analysis for caspase-3. The phosphorylation of mitogen-activated protein kinases caused by 1,3-dichloro-2-propanol possibly involved in hepatocellular apoptotic changes in rat liver. Furthermore, 1,3-dichloro-2-propanol induced an inflammatory response through activation of nuclear factor-kappa B signaling that coincided with the induction of pro-inflammatory mediators or cytokines in a dose-dependent manner. Taken together, these results demonstrate that hepatotoxicity may be related to oxidative stress-mediated activation of mitogen-activated protein kinases and nuclear factor-kappa B-mediated inflammatory response.

Protective effects of garlic oil against 1,3-dichloro-2-propanol-induced hepatotoxicity: role of CYP2E1 and MAPKs

Abstract1,3-Dichloro-2-propanol (1,3-DCP) is a well-known food contaminant that can be detected during the production of a wide range of foods. We investigated whether garlic oil (GO) has protective effects against 1,3-DCP-induced hepatotixicy and oxidative damage in rats. GO significantly attenuated the 1,3-DCP-induced increase in serum aminotransferase activities. This effect was accompanied by attenuation of the histopahological alterations in liver caused by 1,3-DCP. In 1,3-DCP-treated rats, GO prevented formation of hepatic malondialdehyde and depletion of reduced glutathione content, and promoted hepatic antioxidant enzymes activities. 1,3-DCP caused apoptosis in the liver with increases phosphorylation of mitogen-activated protein kinases (MAPKs); GO significantly attenuated these alterations and suppressed the expression of hepatic cytochrome P450 2E1 (CYP2E1). These results suggest that the protective effects of GO against 1,3-DCP-induced hepatotoxicity involve the ability to induce antioxidant enzymes, block metabolic activation of 1,3-DCP by suppressing CYP2E1 expression, and induce antiapoptotic activity by inhibiting phosphorylation of MAPKs.

Protective effect and mechanism of action of diallyl disulfide against acetaminophen-induced acute hepatotoxicity

The aim of this study was to investigate the potential protective effects of diallyl disulfide (DADS) against acetaminophen (AAP)-induced acute hepatotoxicity and elucidate the molecular mechanisms underlying these protective effects in rats. Treatment with AAP caused acute hepatotoxicity manifested by elevated levels of aspartate aminotransferase and alanine aminotransferase with corresponding histopathological changes and high levels of oxidative stress in the livers. AAP treatment also caused hepatocellular apoptosis with phosphorylation of c-Jun-N-terminal protein kinase (JNK). In addition, AAP caused activation of nuclear factor kappaB (NF-κB) concurrent with induction of inflammatory mediators. In contrast, pretreatment with DADS effectively attenuated acute liver injury and oxidative stress caused by AAP. DADS pretreatment suppressed cytochrome P450 2E1 (CYP2E1) levels in a dose-dependent manner and inhibited elevation of CYP2E1 activity induced by AAP. DADS pretreatment suppressed the phosphorylation of JNK and attenuated hepatocellular apoptotic changes. In addition, DADS inhibited the nuclear translocation of NF-κB and subsequent induction of inflammatory mediators. Overall, these results indicate that DADS confers a protective effect against oxidative stress-mediated JNK activation and apoptotic changes caused by AAP in the rat livers. This may be due to its ability to inhibit CYP2E1, enhance antioxidant enzymes activities, and suppress NF-κB activation.

Protective effect of HwangRyunHaeDok-Tang water extract against chronic obstructive pulmonary disease induced by cigarette smoke and lipopolysaccharide in a mouse model

ETHNOPHARMACOLOGICAL RELEVANCE Hwangryunhaedok-tang is an oriental herbal formula treated to cure inflammation and gastric disorders in China, Japan, and Korea. We explored the protective effects of Hwangryunhaedok-tang water extract (HRWE) against airway pathophysiological changes caused by cigarette smoke (CS) and lipopolysaccharide (LPS) in a mouse. MATERIALS AND METHODS We performed quantitative analyses of five marker components, namely geniposide, baicalin, coptisine, plamatine, and berberine, using high-performance liquid chromatography. Animals were received CS exposure (1h per day) for 7 days. LPS was administered intranasally on day 4. Mice were received HRWE at dose of 100 or 200mg/kg for 1h before CS exposure. RESULTS Treatment with HRWE significantly suppressed the increased inflammatory cell count induced by CS and LPS exposure. In addition, reduction in IL-6, TNF-α and IL-1β in broncho-alveolar lavage fluid (BALF) was observed after HRWE treatment. HRWE not only decreased inflammatory cell infiltration in lung, but also decreased the expression of iNOS, NF-κB and matrix metallopeptidase (MMP)-9 in lung tissues. CONCLUSION This study showed that HRWE can attenuate respiratory inflammation caused by CS and LPS exposure. Therefore, HRWE has potential for treating airway inflammatory disease.

Artemisia argyi attenuates airway inflammation in ovalbumin-induced asthmatic animals

ETHNOPHARMACOLOGICAL RELEVANCE Artemisia argyi is a traditional herbal medicine in Korea and commonly called as mugwort. It is traditionally used as food source and tea to control abdominal pain, dysmenorrhea, uterine hemorrhage, and inflammation. AIM OF THE STUDY We investigated the effects of A. argyi (TOTAL) and dehydromatricarin A (DA), its active component on ovalbumin (OVA)-induced allergic asthma. MATERIALS AND METHODS The animals were sensitized on day 0 and 14 by intraperitoneal injection of OVA with aluminum hydroxide. On day 21, 22 and 23 after the initial sensitization, the animals received an airway challenge with OVA for 1h using an ultrasonic nebulizer. TOTAL (50 and 100mg/kg) or DA (10 and 20mg/kg) were administered to mice by oral gavage once daily from day 18-23. Airway hyperresponsiveness (AHR) was measured 24h after final OVA challenge. RESULT TOTAL and DA treated animals reduced inflammatory cell counts, cytokines and AHR in asthmatic animals, which was accompanied with inflammatory cell accumulation and mucus hypersecretion. Furthermore, TOTAL and DA significantly declined Erk phosphorylation and the expression of MMP-9 in asthmatic animals. CONCLUSION In conclusion, we indicate that Total and DA suppress allergic inflammatory responses caused by OVA challenge. It was considered that A. argyi has a potential for treating allergic asthma.

4-Hydroxycinnamic acid protects mice from cigarette smoke-induced pulmonary inflammation via MAPK pathways

Cigarette smoke (CS) is the main etiological cause of chronic obstructive pulmonary disease, the prevalence of which has continuously increased in recent years. 4-Hydroxycinnamic acid (HA) is a plant phenolic acid that has anti-inflammatory activities. In this study, we explored the therapeutic effects of HA on airway inflammation caused by CS and lipopolysaccharide (LPS) in mice. The animals received 1 h of CS exposure for 7 days and intranasal instillation of LPS on day 4. HA (10 and 20 mg/kg) was administered to animals via oral gavage 1 h before CS exposure. HA treatment significantly decreased the accumulation of inflammatory cells and production of cytokines, including tumor necrosis factor-α, interleukin (IL)-6, and IL-1β, caused by CS and LPS exposure. After histological examination, we observed that HA treatment significantly reduced the infiltration of inflammatory cells into lung tissue caused by CS and LPS exposure. Furthermore, HA-treated groups showed significantly decreased phosphorylation of extracellular signal-regulated kinase, c-Jun N-terminal kinase, p38, and nuclear factor-κB, and activity of cytochrome c oxidase subunit-2 caused by CS and LPS. In conclusion, HA effectively suppresses the airway inflammatory response induced by CS and LPS exposure, and is closely associated with the downregulation of mitogen-activated protein kinases signaling.

Ameliorative effects of pine bark extract on cisplatin-induced acute kidney injury in rats

Abstract Objective: This study investigated the dose–response effects of pine bark extract (PBE, pycnogenol®) on oxidative stress-mediated apoptotic changes induced by cisplatin (Csp) in rats. Materials and methods: The ameliorating potential of PBE was evaluated after orally administering PBE at doses of 10 or 20 mg/kg for 10 days. Acute kidney injury was induced by a single intraperitoneal injection of Csp at 7 mg/kg on test day 5. Results: Csp treatment caused acute kidney injury manifested by elevated levels of serum blood urea nitrogen (BUN) and creatinine (CRE) with corresponding histopathological changes, including degeneration of tubular epithelial cells, hyaline casts in the tubular lumen, and inflammatory cell infiltration (interstitial nephritis). Csp also induced significant apoptotic changes in renal tubular cells. In addition, Csp treatment induced high levels of oxidative stress, as evidenced by an increased level of malondialdehyde, depletion of the reduced glutathione (GSH) content, and decreased activities of glutathione S-transferase, superoxide dismutase, and catalase in kidney tissues. On the contrary, PBE treatment lowered BUN and CRE levels and effectively attenuated histopathological alterations and apoptotic changes induced by Csp. Additionally, treatment with PBE suppressed lipid peroxidation, prevented depletion of GSH, and enhanced activities of the antioxidant enzymes in kidney tissue. Conclusions: These results indicate that PBE has a cytoprotective effect against oxidative stress-mediated apoptotic changes caused by Csp in the rat kidney, which may be attributed to both increase of antioxidant enzyme activities and inhibition of lipid peroxidation.

Melatonin suppresses fibrotic responses induced by cigarette smoke via downregulation of TGF-β1

Cigarette smoke (CS) is the most important risk factor in the development of chronic obstructive pulmonary disease (COPD). Pulmonary fibrosis is an irreversible response and important feature of COPD. In this study, we investigated the effects of melatonin on fibrotic response in development of COPD using a CS and lipopolysaccharide (LPS) induced COPD model and cigarette smoke condensate (CSC)-stimulated NCI-H292 cells, a human mucoepidermoid cell line. Mice were exposed to CS for 1 h per day (8 cigarettes per day) from day 1 to day 7 and were treated intranasally with LPS on day 4. Melatonin (10 or 20 mg/kg) was injected intraperitoneally 1 h before CS exposure. Melatonin decreased the inflammatory cell counts in bronchoalveolar lavage fluid (BALF), with a reduction in transforming growth factor (TGF)-β1. Melatonin inhibited the expression of TGF-β1, collagen I and SMAD3 phosphorylation in lung tissue exposed to CS and LPS. In CSC-stimulated H292 cells, melatonin suppressed the elevated expression of fibrotic mediators induced by CSC treatment. Melatonin reduced the expression of TGF-β1, collagen I, SMAD3 and p38 phosphorylation in CSC-stimulated H292 cells. In addition, cotreatment with melatonin and TGF-β1 inhibitors significantly limited fibrotic mediators, with greater reductions in the expression of TGF-β1, collagen I, SMAD3 and p38 phosphorylation than those of H292 cells treated with TGF-β1 inhibitor alone. Taken together, melatonin effectively inhibited fibrotic responses induced by CS and LPS exposure, which was related to the downregulation of TGF-β1. Therefore, our results suggest that melatonin may suppress the pulmonary fibrotic response induced by CS.