Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01350 (gastrin)
 9,683 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Resveratrol is a phytoalexin with several biological and pharmacological activities including the "French paradox". We investigated the effect of resveratrol on cytolytic activity by oxygen reactive species and on soluble and particulate tyrosine kinases from human placenta and human prostatic adenoma. These effects were compared with those of piceatannol, quercetin, catechin and epicatechin. Fifty percent of erythrocyte lysis due to H2O2-lactoperoxidase-KI incubation, in which I3-, OI- and oxygen singlet are produced, was obtained after 22 +/- 7 (SD) min in the absence of the tested compounds. The 50% lysis was obtained after 66 +/- 15, 129 +/- 35, 196 +/- 21, 240 +/- 63 and 420 +/- 80 min with 40 microM piceatannol, quercetin, resveratrol, epicatechin and catechin respectively. Protection was concentration dependent. The assay of tyrosine kinase activity was performed using two different substrates as follows: substrate A corresponded to the sequence 1-17 of gastrin, and substrate B to sequence 6-20 of cell division kinase p34cdc2. In all experiments, initial velocity was measured. When assayed with both substrates, tyrosine kinase activities from particulate and cytosolic fractions of placenta were more inhibited by piceatannol and quercetin. Resveratrol significantly inhibited the particulate fraction and the cytosolic fraction respectively when substrates A and B were employed: Catechin acted as an inhibitor with substrate A and particulate fraction while in the other experimental conditions it acted as an activator. Resveratrol inhibited the tyrosine kinase of particulate and cytosolic fractions of prostatic adenoma assayed with substrate A and B.
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PMID:Effect of resveratrol and some other natural compounds on tyrosine kinase activity and on cytolysis. 1037 Aug 68

beta-Amyloid peptide (beta-AP) is the main component of amyloid deposits around the cerebral vessel and in the brain parenchyma in Alzheimer's disease and Down's syndrome. In vitro studies in neuronal cells or in PC12 and Hela cell lines have shown that the aggregate form of beta-AP is toxic. Many genetic and environmental factors including metal ions, proteoglycans, plasma proteins and antioxidants modify beta-AP toxicity. We investigated the effect of two plant polyphenols--resveratrol and catechin--on soluble and particulate tyrosine kinase activity from PC12 cells and the protective action of these compounds against beta-AP (1-41) toxicity. beta-AP (1-41) decreased PC12 viability with an IC50 value of 1.1 +/- 0.14 x 10(-8) M. Resveratrol and catechin protected PC12 cells from beta-AP (1-41) toxicity. With 25 microM resveratrol the IC50 value increased to 2.2 +/- 0.19 x 10(-7) M. In the presence of beta-AP (1-41) resveratrol showed a concentration-dependent biphasic effect, and at a concentration of up to 40 microM it protected PC12 cells from beta-AP (1-41) toxicity. At concentrations higher than 40 microM, an inhibitory activity on cell proliferation appeared. This antiproliferative effect was also seen in the absence of beta-AP (1-41). With 100 microM catechin the IC50 value increased from 1.1 +/- 0.14 x 10(-8) M to 3.2 +/- 0.25 x 10(-7) M beta-AP (1-41). The protective effect was concentration dependent. Resveratrol and catechin had a synergistic protective action. In the presence of 40 microM catechin and 10 microM resveratrol or 20 microM resveratrol and 10 microM catechin, the toxicity determined by 10(-7) M beta-AP (1-41) was almost completely removed. Resveratrol and catechin had different effects on PC12 tyrosine kinase activity. With peptide 1-17 of gastrin as substrate, resveratrol inhibited particulate tyrosine kinases while it had no effect on soluble activity. With the same substrate, catechin increased the activity of soluble fraction while it inhibited particulate activity. When peptide 6-20 of cell division kinase p34cdc2 was utilized, catechin showed an opposite effect, inhibiting soluble tyrosine kinase activity and increasing particulate activity. With peptide 6-20, resveratrol inhibited both soluble and particulate activities. These results demonstrate that resveratrol and catechin have different activities on the signal transduction pathway involving protein phosphorylation. These differences may contribute not only to the different effects of these compounds on PC12 growth but also to the synergistic effect against beta-AP (1-41) toxicity. The different activity of resveratrol and catechin on signal transduction pathways, as well as the differences in metal chelation, partition coefficient between water and lipids, hydrogen donation redox potential and enzyme inhibition may be at least in part based on synergistic protection against beta-AP (1-41) toxicity.
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PMID:Effect of resveratrol and catechin on PC12 tyrosine kinase activities and their synergistic protection from beta-amyloid toxicity. 1513 81