• Biomedical Science Letters
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• v.9 no.4
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• pp.241-248
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• 2003

Sodium salicylate, a plant stress hormone that plays an important role(s) in defenses against pathogenic microbial and herbivore attack, has been shown to induce a variety of cell responses such as anti-inflammation, cell cycle arrest and apoptosis in animal cells. p38MAPK plays a critical role(s) in the cell regulation by sodium salicylate. However, the signal pathway for sodium salicylate-induced p38MAPK activation is yet unclear. In this study, we show that although sodium salicylate enhances reactive oxygen species (ROS) production, N-acetyl-L-cysteine, a general ROS scavenger, did not prevent sodium salicylate-induced p38MAPK, indicating ROS-independent activation of p38MAPK by sodium salicylate. Sodium salicylate-activated p38MAPK appeared to be very rapidly down-regulated 2 min after removal of sodium salicylate. Interestingly, sodium salicylate-pretreated cells remained fully responsive to re-induction of p38MAPK activity by a second sodium salicylate stimulation or by other stresses, $H_2O$$_2$ and methyl jasmonate (MeJA), thereby indicating that sodium salicylate does not exhibit both homologous and heterologous desensitization. In contrast, pre-exposure to MeJA, $H_2O$$_2$, heat shock, or hyperosmotic stress reduced the responsiveness to subsequent homologous stimulation. Sodium salicylate was able to activate p38MAPK in cells desensitized by other heterologous p38MAPK activators. These results indicate that there is a sensing mechanism highly specific to sodium salicylate for activation of p38MAPK, distinct trom pathways used by other stressors such as MeJA, $H_2O$$_2$ heat shock, and hyperosmotic stress.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.1
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• pp.87-94
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• 2016

Skin damage is mainly caused by environmental factors such as ultraviolet light, heat, and smoking. It is known that reactive oxygen species production is commonly involved in the pathogenesis of skin damage induced by these factors, causing skin aging. Pyrus pyrifolia Nakai continues to be a popular and highly consumed fruit in many countries with known beneficial effects including antitumor, antioxidative, and anti-inflammatory effects. However, there is no evidence of a therapeutic effect of Pyrus pyrifolia extract (PPE) against skin aging via inhibition of mitochondria-mediated apoptosis. In this study, we investigated PPE protective effect against photoaging induced by UVB ($50mJ/cm^2$) in HS68 human dermal fibroblasts. Lactate dehydrogenase assay showed that PPE significantly protected HS68 cells against UVB-induced damage in a dose-dependent manner. Other assays using DCF-DA demonstrated that PPE protected HS68 cells by regulating reactive oxygen species production. PPE also regulated mitochondrial dysfunction and mitochondrial membrane potential induced by UVB, and inhibited UVB-induced caspase-3 activity. These results indicate that PPE protects human dermal fibroblasts from UVB-induced damage by regulating the oxidative defense system.

• Journal of radiological science and technology
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• v.39 no.3
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• pp.451-459
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• 2016

The development of radioprotector is being actively conducted in order to reduce the damage from over radiation exposure at radiation accident or radiation therapy. So this study was confirmed for radiation protective effects using the Cynanchi wilfordii Radix that has been known to be effective for antioxidant activity, anti-cancer, immune enhancing effects. The method of this study was administered orally Cynanchi wilfordii Radix ethanol extracts to Sprague Dawley Rat(SD Rat) for 14 days once a day, while measuring changed blood cell, spleen index, liver and uterus tissue along the change in time of 1, 4, 7 and 21 days after X-ray beam of 7 Gy irradiation. As the result of the experiment, the experimental group's rats which are administered with Cynanchi Wilfordii Radix ethanol extracts showed a rapid recovery in white blood cell count(p < 0.05) and spleen index(p < 0.05). In addition, condensation of nuclei, cytoplasmic swelling, and inflammatory cell infiltration in experimental group's liver cell was decreased more than in irradiation group's component. Further, experimental group's Uterine gland decreased the apoptosis more than irradiation group's components did. It is expected that Cynanchi Wilfordii Radix extracts will be useful as a new radioprotector. With above in mind, this paper may provide appropriate implications with the field of emergency management such as radiation accident.