Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00750 (PLA)
 16,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The snake venom proteins affect hemostasis by either advancing/delaying blood coagulation. Apart from proteases and phospholipase A(2)s (PLA(2)s), 5'nucleotidase is known to affect hemostasis by inhibiting platelet aggregation. In this study, the possible involvement of Naja naja venom 5'nucleotidase in mediating anticoagulant affect is evaluated. Vanillic acid selectively and specifically inhibited 5'nucleotidase activity among other enzymes present in N. naja venom. It is a competitive inhibitor as evident of inhibition relieving upon increased substrate concentration. Vanillic acid dose dependently inhibited the anticoagulant effect of N. naja venom up to 40%. This partial involvement of 5'nucleotidase in mediating anticoagulant effect is substantiated by concanavalin-A (Con-A) inhibition studies. Con-A, competitively inhibited in vitro protease and 5'nucleotidase activity up to 100%. However, it did not exhibit inhibitory activity on PLA(2). The complete inhibition of anticoagulant effect by Con-A upon recalcification time suggests the participation of both 5'nucleotidase and protease in mediating anticoagulant effect of N. naja venom. Vanillic acid and Con-A inhibition studies together suggest that probably 5'nucleotidase interacts with one or more factors of intrinsic pathway of blood coagulation to bring about anticoagulant effect. Thus, this study for the first time demonstrates the involvement of 5'nucleotidase in mediating N. naja venom anticoagulant effect.
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PMID:Anticoagulant effect of Naja naja venom 5'nucleotidase: demonstration through the use of novel specific inhibitor, vanillic acid. 1689 66

We previously reported that 4-hydroxy-3-methoxybenzaldehyde has the most potent anti-inflammatory and analgesic activity of eight phenolic compounds obtained from the dried roots of Gastrodiaelata (GE) Blume (Orchidaceae); its activity may be related to inhibition of cyclooxygenase activities and oxidation. In the present study, the effects of nine phenolic compounds from GE on immediate-phase (IAR) and late-phase (LAR) asthmatic responses after aerosolized-ovalbumin (OA) challenge were evaluated by determining the specific airway resistance (sRaw) using a double-chambered plethysmograph in conscious guinea pigs with IgE-mediated asthma. Furthermore, recruitment of leukocytes, histamine release, and eosinophil peroxidase (EPO) and phospholipase A(2) (PLA(2)) activities were determined in bronchoalveolar lavage fluids (BALF) 24h after the antigen challenge. 4-Hydroxy-3-methoxybenzyl alcohol (12.5mg/kg) significantly (p<0.05) inhibited sRaw in IAR and in LAR by 51.97+/-4.96% and 39.93+/-3.46%, respectively, compared to that of the controls. Further, hydroxy-3-methoxybenzyl alcohol significantly (p<0.05) inhibited recruitment of leukocytes in accordance with amelioration of eosinophilia and neutrophilia, histamine (30.66+/-5.20%), EPO activity (21.58+/-2.02%), and specific PLA(2) activity (16.60+/-2.52%) in BALF compared with the control. In addition, bis-(4-hydroxyphenyl) methane, 4-hydroxy-3-methoxybenzoic acid, and 4-hydroxy-3-methoxybenzaldehyde (12.5mg/kg) significantly (p<0.05) inhibited sRaw, while bis-(4-hydroxyphenyl) methane, benzyl alcohol, and 4-hydroxybenzaldehyde at 12.5mg/kg significantly (p<0.05) inhibited leukocytes, histamine, EPO and PLA(2) activities in BALF compared with the controls. The phenolic glycoside, parishin had less activity compared to aglycones, 4-hydroxybenzyl compounds. These results suggest that the C(4) hydroxy and C(3) methoxy radicals in benzyl alcohols and aldehydes play important roles in mediating the anti-asthmatic activities of these compounds.
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PMID:Anti-asthmatic activity of phenolic compounds from the roots of Gastrodia elata Bl. 1987 15