4-nerolidylcatechol and Edema

We have investigated the anti-inflammatory and antinociceptive effects of (E)-4-(3,7-dimethylocta-2,6-dienylamino)phenol (LQFM-015), which was designed through molecular simplification strategy from 4-nerolidylcatechol.. The possible anti-inflammatory and antinociceptive effects were assayed on carrageenan-induced paw oedema and pleurisy, acetic acid-induced abdominal writhing and formalin tests in mice..  LQFM-015 reduced the activity of PLA₂ enzyme in vitro by 18%. Docking studies into the catalytic site of PLA₂ were used to identify the binding mode of the LQFM-015. LQFM-015 showed a moderate antinociceptive effect, since this compound reduced the number of writhings by approximately up to 40% in the acetic acid-induced pain model; this antinociceptive activity also emerged in the second phase of the formalin-induced pain model (58% of inhibition). The anti-inflammatory action of LQFM-015 was confirmed in acute inflammation models, in which it reduced the formation of oedema to 52.78 ± 8.6 and 46.64 ± 5.2 at the second and third hour of carrageenan-induced paw oedema, respectively. Also in the carrageenan-induced pleurisy model, LQFM-015 reduced the migration of leucocytes by 26.0% and decrease myeloperoxidase activity by 50%. LQFM-015 showed different concentrations to inhibit 50% of isoenzyme cyclooxygenase activity (IC50); COX-1 IC50 = 36 μM) and COX-2 IC50 = 28 μM.. LQFM-015 demonstrated inhibition of both PLA₂ and COX enzymes; thus, the moderate antinociceptive effect of this compound could be attributed to its anti-inflammatory activity.

Topics: Abdominal Pain; Analgesics; Animals; Anti-Inflammatory Agents, Non-Steroidal; Catalytic Domain; Catechols; Cell Movement; Dose-Response Relationship, Drug; Drug Design; Edema; Enzyme Inhibitors; Lymphocytes; Male; Mice; Molecular Conformation; Molecular Docking Simulation; Oxidoreductases; Phospholipase A2 Inhibitors; Phospholipases A2; Pleurisy; Stereoisomerism

Phospholipases A(2) (PLA(2)) are important constituents of snake venoms, being responsible for several of their toxic actions. Extracts from plants used in folk medicine were screened for inhibition of the enzymatic activity of myotoxin I, a PLA(2) from Bothrops asper. Piper umbellatum and Piper peltatum extracts tested positive, and their fractionation resulted in the isolation of 4-nerolidylcatechol. Its inhibitory effects towards toxic activities of two Bothrops myotoxins, representing catalytically active (Asp49) and catalytically inactive (Lys49) types of group II PLA(2)s, respectively, were characterized. The enzyme activity of B. asper myotoxin I was completely inhibited by 4-nerolidylcatechol at an inhibitor:toxin ratio of 10:1 (wt/wt) with an IC50 of approximately 1mM. In addition, 4-nerolidylcatechol inhibited representatives of groups I and III of PLA(2)s. Its preincubation with Bothrops myotoxins significantly reduced their myotoxic and edema-inducing activities in animal experiments. However, when 4-nerolidylcatechol was administered in situ, immediately after toxin injection, its inhibitory ability was substantially lower or negligible. This might be explained by the rapid action of these toxins in vivo, together with the slow inactivation of PLA(2) activity observed in vitro. Electrophoretic and chromatographic analyses of myotoxins ruled out major changes in protein charge, hydrophobicity, or gross molecular mass being involved in the inhibition mechanism. Mass spectrometry determinations are consistent with the covalent modification of myotoxin by one molecule of 4-nerolidylcatechol. Finally, a novel compound was isolated from both Piper species, sharing the nerolidyl skeleton, but nevertheless not being inhibitory towards the PLA(2)s studied.

Topics: Animals; Bothrops; Catechols; Crotalid Venoms; Edema; Group II Phospholipases A2; Mice; Molecular Structure; Muscle, Skeletal; Neurotoxins; Phospholipases A; Piper; Plant Extracts; Reptilian Proteins