• Korean Journal of Pharmacognosy
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• v.20 no.3
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• pp.154-161
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• 1989

Effects of panaxydol, panaxynol and panaxytriol isolated from Panax ginseng C.A. Meyer on some enzyme activities were determined. Activities of ATPase, membrane-bound enzyme from Sarcoma 180 and rat liver were slightly inhibited by panaxydol. Activities of 5'-nucleotidase, membrane-bound enzyme and succinate cytochrome c reductase in mitochonidria from sarcoma 180 and rat livers were significantly inhibited in a dose-dependent manner by panaxynol. The inhibitory effects of panaxydol and panaxynol on succinate cytochrome c reductase activities were more potent than those on 5'-nucleotidase activities and panaxynol was found to be a very potent inhibitor of succinate cytochrome c reductase. Activities of glucose-6-phosphatase in endoplasmic reticulum from Sarcoma 180 and rat livers were not affected by all three polyacetylenes. These results suggested that the inhibitory effects of panaxydol and panaxynol on enzyme activities might contribute to their biological activities.

• BMB Reports
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• v.37 no.4
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• pp.454-459
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• 2004

Experimental hyperoxia represents a suitable in vitro model to study some pathogenic mechanisms related to oxidative stress. Moreover, it allows the investigation of the molecular pathophysiology underlying oxygen therapy and toxicity. In this study, a modified experimental set up was adopted to accomplish a model of moderate hyperoxia (50% $O_2$, 96 h culture) to induce oxidative stress in the human leukemia cell line, U-937. Spectrophotometric measurements of mitochondrial respiratory enzyme activities, NMR spectroscopy of culture media, determination of antioxidant enzyme activities, and cell proliferation and differentiation assays were performed. The data showed that moderate hyperoxia in this myeloid cell line causes: i) intriguing alterations in the mitochondrial activities at the levels of succinate dehydrogenase and succinate-cytochrome c reductase; ii) induction of metabolic compensatory adaptations, with significant shift to glycolysis; iii) induction of different antioxidant enzyme activities; iv) significant cell growth inhibition and v) no significant apoptosis. This work will permit better characterization the mitochondrial damage induced by hyperoxia. In particular, the data showed a large increase in the succinate cytochrome c reductase activity, which could be a fundamental pathogenic mechanism at the basis of oxygen toxicity.

• Applied Biological Chemistry
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• v.27 no.2
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• pp.100-106
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• 1984

Five subcellular fractions were obtained by successive centrifugation from the liver of rats within 6 hours of life and characterized by comparing marker compound or marker enzyms. After incubating $3{\beta}$-hydroxy-$5{\alpha}$-pregnan-20-one with the each fraction, the steroids were analyzed by TLC, GLC and GC-MS. A $6{\alpha}$-hydroxylase which hydroxylizes the tetra-hydrogenated compound of progesterone, $3{\beta}$-hydroxy-$5{\alpha}$-pregnan-20-one, was localized in the crude plasma membrane fraction, but not in the microsome fraction. The maximum 6α-hydroxylation was observed at pH 7.0. While this 6α-steroid hydroxylase was not able to hydroxlyze the progesterone, the $3{\alpha}$-isomer was hydroxylized at the $6{\alpha}$-position.