• The Korean Journal of Physiology and Pharmacology
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• v.22 no.1
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• pp.81-89
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• 2018

This study evaluated the anti-asthmatic activities of 2,6-di-tert-butyl-4-hydroxymethylphenol (DBHP) that is a potent phenolic antioxidant in edible vegetable oil. The effects of DBHP on bronchial asthma were evaluated by determining the specific airway resistance (sRaw) and tidal volume (TV) during the immediate asthmatic response (IAR) and the late-phase asthmatic response (LAR) in guinea pigs with aerosolized ovalbumin-induced asthma. Recruitment of leukocytes and the levels of biochemical inflammatory mediators were determined in the bronchoalveolar lavage fluids (BALFs), and histopathological surveys performed in lung tissues. DBHP significantly inhibited the increased sRaw and improved the decreased TV on IAR and LAR, and also inhibited recruitment of eosinophils and neutrophils into the lung, and release of biochemical inflammatory mediators such as histamine and phospholipase $A_2$ from these infiltrated leukocytes, and improved pathological changes. However, anti-asthmatic activities of DBHP at oral doses of 12.5 to 50 mg/kg was less than those of dexamethasone (5 mg/kg, p.o.) and cromoglycate (10 mg/kg, p.o.), but more potent or similar to that of salbutamol (5 mg/kg, p.o.). These results in the present study suggest that anti-asthmatic effects of DBHP in the guinea pigs model of OVA-induced asthmatic responses principally are mediated by inhibiting the recruitments of the leukocytes and the release of biochemical inflammatory mediators from these infiltrated leukocytes.

• Tribology and Lubricants
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• v.18 no.6
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• pp.396-401
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• 2002

ln this paper, the fuction of molybdenum dialkyl dithiophosphate (MoDTP) as an oxidation inhibitor of mineral oils was investigated and compared with 2,6-Di-tert-Butyl-4-Methylphenol (DBMP). Oxidation tests were conducted using an oxygen absorption apparatus. MoDTP showed anti-oxidation property, and length of induction time prolonged by increasing MoDTP concentration. However the induction time of DBMP was longer than those of MoDTP. The anti-oxidation property of MoDTP was found to be inferior to that of DBMP The capability of hydroperoxide decomposition ability with MoDTP was much greater than that with DBMP. However the rate constant of radical scavenging with MoDTP was much better than that with DBMP. It was found that the performance of MoDTP is exellent with respect to hydroperoxide decomposition but it is susceptible to chemical decomposition. From the fact that formation of phenol was observed when MoDTP was added to hexane solution of cumene hydroperoxide (CHPO), it is indicated that the decomposition of hydroperoxide with MoDTP occurs by means of ionic mechanism.

• Korean Journal of Environmental Biology
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• v.22
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• pp.47-53
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• 2004

Among the phthalic esters, di-butyl phthalate (DBP) and di-2-ethylhexyl phthalate (DEHP), which are categorized endocrine disrupting chemicals, account toy up to 80％ of the world production. Nine phthalic esters were quantitatively determined in water and in sediment samples from Gawngyang Bay and Seomjin River estuary. This might be the first report in contamination of phthalates in the marine environment of Korea. DBP and DEHP were detected with the high concentration and high frequency, while the other phthnlic compounds were below the detection limits. The aveyage concentyations of DBP and DEBP in sediment from Gawngyang Bay were 33.8 ng g$\^$-1/ and 67.4 ng g$\^$-1/ on a dry weight basis, respectively. The concentrations in surface watey from Seomjin River estuary were in the range of 62.7∼333.8 ng L$\^$-1/ for DBP and 25.6 ng L$\^$-/∼116.1 ng L$\^$-1/ for DBHP. In sediments from Seomjin River estuary, DBP ranged 9.1∼149.3 ng g$\^$-1/, and DEHP 46.3∼156.3 ng g$\^$-1/. Phthalic esters concentrations found in Seomjin River estuary were much less than those in other rivers in Korea. Distribution pattern of DBP and DEHP concentrations in Seonliin River estuary indicates that both compounds aye introduced to Gwangyang Bay through run-off.

• Korean Journal of Environmental Biology
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• v.17 no.3
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• pp.285-292
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• 1999

Di-(2-ethylhexyl) phthalate (DEHP) is a plasticizer known as one of endocrine disruptors. The present study was carried out to investigate the alterations of function and ultrastructure in rat testes after oral intubation of DEHP in dosages of 1g/kg/day, 2 g/kg/day or 3 g/kg/day in 0.5 ml of corn oil for 15 days. DEHP reduced the growth of body and testes, inhibited apermatogenesis and induced structural changes on various cell types of the rat testis. Leydig cells, Sertoli cells and the developing germ cells seemed to be impaired their differentiations in terms of the structural changes of cell organelles. The increase of heterochromatin in amount were common features in all 3 cell types. In addition, the Leydig cells were characterized by the swelling of smooth endoplasmic reticulum and perinuclear space, the increases in number and size of Iysosomes. The Sertoli cells became irregular in nuclear envelope and the number of Iysosomes and vacuoles seemed to be increased. There were some indications of necrosis of the germ cells, such as vacuolized nucleus and segregated nucleolus. And also, DEHP lowered the level of testosterone in experimental rat serum. DEHP suppressed apermatogenesis decreasing developing germ cells and these effects of DEHP on the rat testis were dose dependent. The detrimental effect of DEHP on apermatogenesis and ultrastructure of rat testes seems to be derived from the decreased level of testosterone by Leydig cells, followed by the abnomalities of Sertoli cells and the germ cells.