olvanil and arvanil

In spite of the rapid advances in our understanding of vanilloid-receptor pharmacology in the PNS, the function of vanilloid receptors in the brain has remained elusive. Recently, the endocannabinoid anandamide has been proposed to function as an endogenous agonist at the vanilloid receptor VR1. This is an exciting hypothesis because the localization of VR1 overlaps with that of anandamide and its preferred cannabinoid receptor CB(1) in various brain areas. The interaction of anandamide and/or related lipid metabolites with these two completely separate receptor systems in the brain clearly places VR1 in a much broader role than pain perception. At a practical level, the overlapping ligand recognition properties of VR1 and CB(1) might be exploited by medicinal chemistry. For example, arvanil, a 'chimeric' ligand that combines structural features of capsaicin and anandamide, promises to be an interesting lead for new drugs that interact at both vanilloid and cannabinoid receptors.

Topics: Animals; Arachidonic Acids; Brain Chemistry; Cannabinoid Receptor Modulators; Capsaicin; Diterpenes; Drug Design; Endocannabinoids; Forecasting; Ganglia, Spinal; Glycerides; Humans; Ligands; Nerve Tissue Proteins; Neurons, Afferent; Polyunsaturated Alkamides; Rats; Receptors, Cannabinoid; Receptors, Drug; Structure-Activity Relationship

Due to the unique structures of arvanil and olvanil, the drugs combine certain properties of both cannabinoids and vanilloids, which makes them able to stimulate both TPRV1 and CB1 receptors and causes them to be interesting agents in the setting of carcinoma treatment. The aim of this study was to investigate the cytotoxic and anti-proliferative effects of arvanil and olvanil when administered alone and in combination with cisplatin (CDDP) and mitoxantrone (MTX), using various primary (A375, FM55P) and metastatic (SK-MEL 28, FM55M2) human malignant melanoma cell lines. The results indicate that both arvanil and olvanil inhibited (dose-dependently) the viability and proliferation of various malignant melanoma cells, as demonstrated by MTT and BrdU assays. The safety profile of both arvanil and olvanil tested in human keratinocytes (HaCaT) and normal human melanocytes (HEMa-LP) revealed that neither arvanil nor olvanil caused significant cytotoxicity in HaCaT and HEMa-LP cell lines in LDH and MTT assays. Isobolographically, it was found that both arvanil and olvanil exerted additive interactions with MTX and antagonistic interactions with CDDP in the studied malignant melanoma cell lines. In conclusion, the combinations of arvanil or olvanil with MTX may be considered as a part of melanoma multi-drug therapy; however, the combination of these compounds with CDDP should be carefully considered due to the antagonistic interactions observed in the studied malignant melanoma cell lines.

Topics: Antineoplastic Agents; Cell Line, Tumor; Cisplatin; Humans; Melanoma; Mitoxantrone

Transient receptor potential vanilloid type-1 (TRPV1) channels have crucial roles in inflammatory hyperalgesia. Different inflammatory mediators can modulate TRPV1 sensitization. Bradykinin is an algogenic substance released at the site of inflammation. The aim of the present study is to investigate the desensitization of TRPV1 receptor by nonpungent agonists and to determine how bradykinin and prostaglandin E2 receptors (EP3 and EP4) modulate the resensitization of TRPV1 receptor after being desensitized by nonpungent agonists. Tail flick test was used to investigate capsaicin-induced thermal hyperalgesia and the desensitization of TRPV1 by the nonpungent agonists (olvanil and arvanil) in male BALB/c mice weighed (22-25 g). Resensitization of TRPV1 by bradykinin and the role of prostaglandin receptors in mediating sensitization of TRPV1 were also investigated. Intraplantar injection of capsaicin (0.3 µg) produced a robust thermal hyperalgesia in mice, while olvanil (0.3 µg) or arvanil (0.3 µg) produced no hyperalgesia, emphasizing their lack of pungency. Olvanil and arvanil significantly attenuated capsaicin-induced thermal hyperalgesia in mice. Bradykinin significantly reversed the desensitizing effects of arvanil, but not olvanil. EP4 but not EP3 receptors mediate the sensitization of TRPV1 By bradykinin in vivo. The present study provides evidence for a novel signaling pathway through which bradykinin can regulate the TRPV1 ion channel function via EP4 receptor.

Topics: Animals; Bradykinin; Capsaicin; Hyperalgesia; Male; Mice; Mice, Inbred BALB C; Nociception; Receptors, Prostaglandin E, EP3 Subtype; Receptors, Prostaglandin E, EP4 Subtype; Sensory System Agents; TRPV Cation Channels

Recent evidence reveals therapeutic potential for cannabinoids to reduce seizure frequency, severity and duration. Animal models are useful tools to determine the potential antiseizure or antiepileptic effects of cannabinoids. The objective of this study was evaluation of the effect of arvanil, olvanil, AM 1172 and LY 2183240, the compounds interacted with endocannabinoid and/or endovanilloid systems, on convulsions in the commonly used model of convulsions in mice.. Arvanil and olvanil were injected intraperitoneally (ip) 30min and AM 1172 and LY 2183240 were administered ip 60min before the maximal electroshock seizure threshold (MEST) test. The criterion for convulsant activity was tonic hindlimb extension.. Arvanil, olvanil, AM 1172 and LY 2183240 dose-dependently increased the electroconvulsive threshold in mice. The TID. This study identified anticonvulsant effects of arvanil, olvanil, AM 1172 and LY 2183240. The order of the magnitude of the anticonvulsant effects of the examined compounds was following: arvanil>olvanil>AM 1172>LY 2183240.

Topics: Animals; Arachidonic Acids; Benzamides; Brain; Brain Waves; Cannabinoid Receptor Agonists; Capsaicin; Disease Models, Animal; Dose-Response Relationship, Drug; Electroshock; Heterocyclic Compounds, 1-Ring; Male; Mice; Receptor, Cannabinoid, CB1; Seizures; Signal Transduction; Urea

The nutritional compound capsaicin inhibits the invasion of many types of human cancers. The clinical development of capsaicin as an anti-cancer drug is limited due to its unfavorable side effects like burning sensation, stomach cramps, gut pain and nausea. This study compared the anti-invasive activity of capsaicin to non-pungent long chain capsaicin analogs, namely arvanil and olvanil, in human small cell lung cancer cells. Boyden chamber invasion assays revealed that arvanil and olvanil displayed improved anti-invasive activity relative to capsaicin in human SCLC cells. The results of the Boyden chamber assay were confirmed by the spherical invasion assay, and similar results were obtained. The anti-invasive activity of arvanil, olvanil and capsaicin were independent of TRPV and CB1 receptors. Furthermore, the anti-invasive activity of arvanil, olvanil and capsaicin was mediated by the AMPK pathway. Depletion of AMPK levels by siRNA methodology abrogated the anti-invasive activity of arvanil, olvanil and capsaicin. The non-pungent capsaicin analogs arvanil and olvanil display improved anti-invasive activity relative to capsaicin in human SCLC cells. These agents may represent the second generation of capsaicin-like compounds which are more potent than the parent molecule and have a better side effect profile.

Topics: Adenylate Kinase; Animals; Capsaicin; Cell Line, Tumor; Humans; Lung Neoplasms; Neoplasm Invasiveness; Receptor, Cannabinoid, CB1; Signal Transduction; Small Cell Lung Carcinoma; Time Factors; TRPV Cation Channels

The discovery that paracetamol is metabolized to the potent TRPV1 activator N-(4-hydroxyphenyl)-5Z,8Z,11Z,14Z-eicosatetraenamide (AM404) and that this metabolite contributes to paracetamol's antinociceptive effect in rodents via activation of TRPV1 in the central nervous system (CNS) has provided a potential strategy for developing novel analgesics. Here we validated this strategy by examining the metabolism and antinociceptive activity of the de-acetylated paracetamol metabolite 4-aminophenol and 4-hydroxy-3-methoxybenzylamine (HMBA), both of which may undergo a fatty acid amide hydrolase (FAAH)-dependent biotransformation to potent TRPV1 activators in the brain. Systemic administration of 4-aminophenol and HMBA led to a dose-dependent formation of AM404 plus N-(4-hydroxyphenyl)-9Z-octadecenamide (HPODA) and arvanil plus olvanil in the mouse brain, respectively. The order of potency of these lipid metabolites as TRPV1 activators was arvanil = olvanil>>AM404> HPODA. Both 4-aminophenol and HMBA displayed antinociceptive activity in various rodent pain tests. The formation of AM404, arvanil and olvanil, but not HPODA, and the antinociceptive effects of 4-aminophenol and HMBA were substantially reduced or disappeared in FAAH null mice. The activity of 4-aminophenol in the mouse formalin, von Frey and tail immersion tests was also lost in TRPV1 null mice. Intracerebroventricular injection of the TRPV1 blocker capsazepine eliminated the antinociceptive effects of 4-aminophenol and HMBA in the mouse formalin test. In the rat, pharmacological inhibition of FAAH, TRPV1, cannabinoid CB1 receptors and spinal 5-HT3 or 5-HT1A receptors, and chemical deletion of bulbospinal serotonergic pathways prevented the antinociceptive action of 4-aminophenol. Thus, the pharmacological profile of 4-aminophenol was identical to that previously reported for paracetamol, supporting our suggestion that this drug metabolite contributes to paracetamol's analgesic activity via activation of bulbospinal pathways. Our findings demonstrate that it is possible to construct novel antinociceptive drugs based on fatty acid conjugation as a metabolic pathway for the generation of TRPV1 modulators in the CNS.

Topics: Amidohydrolases; Aminophenols; Analgesics; Animals; Arachidonic Acids; Benzylamines; Brain; Capsaicin; Inhibitory Concentration 50; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Motor Activity; Nociception; Rats; Rats, Sprague-Dawley; Receptor, Cannabinoid, CB1; TRPV Cation Channels; Vasodilation

TRPV1 (transient receptor potential vanilloid 1) is a ligand-gated ion channel expressed predominantly in nociceptive primary afferents that plays a key role in pain processing. In vivo activation of TRPV1 receptors by natural agonists like capsaicin is associated with a sharp and burning pain, frequently described as pungency. To elucidate the mechanisms underlying pungency we investigated a series of TRPV1 agonists that included both pungent and non-pungent compounds covering a large range of potencies. Pungency of capsaicin, piperine, arvanil, olvanil, RTX (resiniferatoxin) and SDZ-249665 was evaluated in vivo, by determining the increase in the number of eye wipes caused by direct instillation of agonist solutions into the eye. Agonist-induced calcium fluxes were recorded using the FLIPR technique in a recombinant, TRPV1-expressing cell line. Current-clamp recordings were performed in rat DRG (dorsal root ganglia) neurons in order to assess the consequences of TRPV1 activation on neuronal excitability. Using the eye wipe assay the following rank of pungency was obtained: capsaicin>piperine>RTX>arvanil>olvanil>SDZ-249665. We found a strong correlation between kinetics of calcium flux, pungency and lipophilicity of TRPV1 agonists. Current-clamp recordings confirmed that the rate of receptor activation translates in the ability of agonists to generate action potentials in sensory neurons. We have demonstrated that the lipophilicity of the compounds is directly related to the kinetics of TRPV1 activation and that the latter influences their ability to trigger action potentials in sensory neurons and, ultimately, pungency.

Topics: Action Potentials; Alkaloids; Animals; Benzodioxoles; Capsaicin; Diterpenes; Ganglia, Spinal; Kinetics; Lipid Metabolism; Male; Neurons, Afferent; Pain; Patch-Clamp Techniques; Piperidines; Polyunsaturated Alkamides; Rats; Rats, Sprague-Dawley; Recombinant Proteins; Sensory Receptor Cells; Solubility; TRPV Cation Channels; Urea

The endocannabinoid anandamide is an emerging potential signalling molecule in the cardiovascular system. Anandamide causes vasodilatation, bradycardia and hypotension in animals and has been implicated in the pathophysiology of endotoxic, haemorrhagic and cardiogenic shock, but its vascular effects have not been studied in man. Human forearm blood flow and skin microcirculatory flow were recorded using venous occlusion plethysmography and laser-Doppler perfusion imaging (LDPI), respectively. Each test drug was infused into the brachial artery or applied topically on the skin followed by a standardized pin-prick to disrupt the epidermal barrier. Anandamide failed to affect forearm blood flow when administered intra-arterially at infusion rates of 0.3-300 nmol min(-1). The highest infusion rate led to an anandamide concentration of approximately 1 microM in venous blood as measured by mass spectrometry. Dermal application of anandamide significantly increased skin microcirculatory flow and coapplication of the transient receptor potential vanilloid 1 (TRPV1) antagonist capsazepine inhibited this effect. The TRPV1 agonists capsaicin, olvanil and arvanil all induced concentration-dependent increases in skin blood flow and burning pain when administered dermally. Coapplication of capsazepine inhibited blood flow and pain responses to all three TRPV1 agonists. This study shows that locally applied anandamide is a vasodilator in the human skin microcirculation. The results are consistent with this lipid being an activator of TRPV1 on primary sensory nerves, but do not support a role for anandamide as a circulating vasoactive hormone in the human forearm vascular bed.

Topics: Adult; Arachidonic Acids; Benzylamines; Capsaicin; Endocannabinoids; Female; Forearm; Humans; Laser-Doppler Flowmetry; Male; Microcirculation; Middle Aged; Muscle, Skeletal; Plethysmography; Polyunsaturated Alkamides; Regional Blood Flow; Skin; TRPV Cation Channels

On the basis of temperature dependency, saturability, selective inhibition, and substrate specificity, it has been proposed that an anandamide transporter exists. However, all of these studies have examined anandamide accumulation at long time points when downstream effects such as metabolism and intracellular sequestration are operative. In the current study, we have investigated the initial rates (<1 min) of anandamide accumulation in neuroblastoma and astrocytoma cells in culture and have determined that uptake is not saturable with increasing concentrations of anandamide. However, anandamide hydrolysis, after uptake in neuroblastoma cells, was saturable at steady-state time points (5 min), suggesting that fatty acid amide hydrolase (FAAH) may be responsible for observed saturation of uptake at long time points. In general, arvanil, olvanil, and N-(4-hydroxyphenyl)arachidonylamide (AM404) have been characterized as transport inhibitors in studies using long incubations. However, we found these "transport inhibitors" did not inhibit anandamide uptake in neuroblastoma and astrocytoma cells at short time points (40 sec or less). Furthermore, we confirmed that these inhibitors in vitro were actually inhibitors of FAAH. Therefore, the likely mechanism by which the transport inhibitors raise anandamide levels to exert pharmacological effects is by inhibiting FAAH, and they should be reevaluated in this context. Immunofluorescence has indicated that FAAH staining resides mainly on intracellular membranes of neuroblastoma cells, and this finding is consistent with our observed kinetics of anandamide hydrolysis. In summary, these data suggest that anandamide uptake is a process of simple diffusion. This process is driven by metabolism and other downstream events, rather than by a specific membrane-associated anandamide carrier.

Topics: Arachidonic Acids; Astrocytoma; Biological Transport; Cannabinoids; Capsaicin; Carrier Proteins; Endocannabinoids; Humans; Immunohistochemistry; Kinetics; Neuroblastoma; Polyunsaturated Alkamides; Tumor Cells, Cultured

We investigated the effect of changing the length and degree of unsaturation of the fatty acyl chain of N-(3-methoxy-4-hydroxy)-benzyl-cis-9-octadecenoamide (olvanil), a ligand of vanilloid receptors, on its capability to: (i) inhibit anandamide-facilitated transport into cells and enzymatic hydrolysis, (ii) bind to CB1 and CB2 cannabinoid receptors, and (iii) activate the VR1 vanilloid receptor. Potent inhibition of [(14)C]anandamide accumulation into cells was achieved with C20:4 n-6, C18:3 n-6 and n-3, and C18:2 n-6 N-acyl-vanillyl-amides (N-AVAMs). The saturated analogues and Delta(9)-trans-olvanil were inactive. Activity in CB1 binding assays increased when increasing the number of cis-double bonds in a n-6 fatty acyl chain and, in saturated N-AVAMs, was not greatly sensitive to decreasing the chain length. The C20:4 n-6 analogue (arvanil) was a potent inhibitor of anandamide accumulation (IC(50) = 3.6 microM) and was 4-fold more potent than anandamide on CB1 receptors (Ki = 0.25-0.52 microM), whereas the C18:3 n-3 N-AVAM was more selective than arvanil for the uptake (IC(50) = 8.0 microM) vs CB1 receptors (Ki = 3.4 microM). None of the compounds efficiently inhibited [(14)C]anandamide hydrolysis or bound to CB2 receptors. All N-AVAMs activated the cation currents coupled to VR1 receptors overexpressed in Xenopus oocytes. In a simple, intact cell model of both vanilloid- and anandamide-like activity, i.e., the inhibition of human breast cancer cell (HBCC) proliferation, arvanil was shown to behave as a "hybrid" activator of cannabinoid and vanilloid receptors.

Topics: Amidohydrolases; Animals; Arachidonic Acids; Binding Sites; Biological Transport; Capsaicin; Cell Division; Cell Line; Cell Membrane; Diffusion; Electric Conductivity; Endocannabinoids; Fatty Acids, Unsaturated; Humans; Ligands; Mice; Oocytes; Polyunsaturated Alkamides; Rats; Receptor, Cannabinoid, CB2; Receptors, Cannabinoid; Receptors, Drug; Xenopus laevis