Central nervous system depressant effects of fractions of methanol leaf extract of Cissus cornifolia (Baker) Planch.

Cissus cornifolia is an annual herb used in the treatment of mental derangement in the African Traditional Medicine. As part of a continuous research on this medicinal plant to scientifically validate its use in mental derangement, the fractions of the leaf extract were investigated for central nervous system (CNS) depressant effects. Successive fractionation of the methanol leaf extract of C. cornifolia was utilized to obtain the chloroform fraction (CLF), ethyl acetate fraction (EAF) and the residual aqueous fractions (RAF). These fractions were investigated for CNS-depressant effects in mice using diazepam-induced sleep, head-dip and motor-coordination tests. CLF, EAF and RAF significantly (p<0.01) prolonged the duration of sleep in mice. EAF significantly (p<0.05) reduced the mean head-dips in mice at 75 and 150 mg/kg. Similarly, a significant decrease in the mean head-dips (p<0.05, p<0.01 and p<0.005) was produced by RAF at 150, 300 and 600 mg/kg respectively. In the beam-walking assay test, all the fractions did not produce motor coordination deficit in mice. The data obtained revealed the fractions of methanol leaf extract of Cissus cornifolia possess remarkable central nervous system depressant effects.

Modified In Vitro Release of Melatonin Loaded in Nanofibrous Electrospun Mats Incorporated Into Monolayered and Three-Layered Tablets.

Modified release tablet formulations with melatonin (MLT) are clinically more useful in initiating and maintaining sleep in elderly insomniacs, compared with those designed for immediate release. Aiming at the modified release of MLT, monolayered and 3-layered tablets, incorporating nanofibrous mats composed of cellulose acetate and polyvinylpyrrolidone loaded with MLT, were prepared and studied. In vitro dissolution profiles of MLT in gastrointestinal-like fluids revealed tableting pressure/pH-dependence. The release of the hormone from physical mixture tablets was generally slower from the nanofibers-based tablets, thus exhibiting in the latter case properties that are necessary for the control of both the sleep-onset and the maintenance dysfunctions. The nature of the excipients (hydroxypropylmethylcellulose or lactose monohydrate) used in this study to produce 3-layered tablets was also found to affect the release of MLT, adjusting it to the endogenous hormone's chronobiotic profile. The release of MLT from formulation F(nf)2 (nanofiber mats incorporated into 3-layered tablets containing lactose monohydrate both in the upper and lower layers) was found to be in closer alignment with these effects than the other delivery systems.

Altered drug release from Orfiril® long following ethanol consumption - extent and consequences.

Orfiril® long is a widely used antiepileptic drug preparation despite being characterized by features associated with susceptibility to ethanol induced changes to drug release. In vitro dissolution studies revealed that 30 % ethanol was required in order to cause dose dumping of valproic acid within two hours at pH 1. However, after exposure to only 5 % of ethanol for 45 minutes at pH 1, the subsequent release of sodium valproate increased by ~ 10 % for the first two hours in ethanol-free media of pH 6.8. The drug solubility increases with pH, likely to also increase the vulnerability to ethanol. This indicates that Orfiril® long is affected by exposure to low concentrations of ethanol as well, only that this effect was exclusively displayed at an elevated pH value not part of the standard regulatory recommendations. Even so, simplified pharmacokinetic simulations revealed no risk of a lower therapeutic effect. Postponing the drug intake in case of moderate drinking, likely to increase the risk of omission altogether, is therefore not necessary. However, for slim patients with a small volume of distribution and low tolerability, a longer duration of mild side effects such as drowsiness and nausea might be experienced.

Preclinical evaluation of the kappa-opioid receptor antagonist CERC-501 as a candidate therapeutic for alcohol use disorders.

Prior work suggests a role of kappa-opioid signaling in the control of alcohol drinking, in particular when drinking is escalated due to alcohol-induced long-term neuroadaptations. Here, we examined the small molecule selective kappa antagonist CERC-501 in rat models of alcohol-related behaviors, with the objective to evaluate its potential as a candidate therapeutic for alcohol use disorders. We first tested the effect of CERC-501 on acute alcohol withdrawal-induced anxiety-like behavior. CERC-501 was then tested on basal as well as escalated alcohol self-administration induced by 20% alcohol intermittent access. Finally, we determined the effects of CERC-501 on relapse to alcohol seeking triggered by both stress and alcohol-associated cues. Control experiments were performed to confirm the specificity of CERC-501 effects on alcohol-related behaviors. CERC-501 reversed anxiety-like behavior induced by alcohol withdrawal. It did not affect basal alcohol self-administration but did dose-dependently suppress self-administration that had escalated following long-term intermittent access to alcohol. CERC-501 blocked relapse to alcohol seeking induced by stress, but not when relapse-like behavior was triggered by alcohol-associated cues. The effects of CERC-501 were observed in the absence of sedative side effects and were not due to effects on alcohol metabolism. Thus, in a broad battery of preclinical alcohol models, CERC-501 has an activity profile characteristic of anti-stress compounds. Combined with its demonstrated preclinical and clinical safety profile, these data support clinical development of CERC-501 for alcohol use disorders, in particular for patients with negatively reinforced, stress-driven alcohol seeking and use.

Screening of Baccaurea ramiflora (Lour.) extracts for cytotoxic, analgesic, anti-inflammatory, neuropharmacological and antidiarrheal activities.

BACKGROUND: It has been observed that the various part of Baccaurea ramiflora plant is used in rheumatoid arthritis, cellulitis, abscesses, constipation and injuries. This plant also has anticholinergic, hypolipidemic, hypoglycemic, antiviral, antioxidant, diuretic and cytotoxic activities. The present studyaimed to assess the cytotoxic, analgesic, anti-inflammatory, CNS depressant and antidiarrheal activities of methanol extract of Baccaurea ramiflora pulp and seeds in mice model. METHODS: The cytotoxic activity was determined by brine shrimp lethality bioassay; anti-nociceptive activity was determined by acetic acid-induced writhing, formalin- induced licking and biting, and tail immersion methods. The anti-inflammatory, CNS depressant and anti-diarrheal activities were assessed by carrageenan-induced hind paw edema, the open field and hole cross tests, and castor oil-induced diarrheal methods, respectively. The data were analyzed by one way ANOVA (analysis of variance) followed by Dunnett's test. RESULTS: In brine shrimp lethality bioassay, the LC50 values of the methanol extracts of Baccaurea ramiflora pulp and seed were 40 µg/mL and 10 µg/mL, respectively. Our investigation showed that Baccaurea ramiflora pulp and seed extracts (200 mg/kg) inhibited acetic acid induced pain 67.51 and 66.08%, respectively (p < 0.05) that was strongly comparable with that of Ibuprofen (72%) (p < 0.05). The Baccaurea ramiflora pulp and seed extracts (200 mg/kg) significantly (p < 0.05) reduced 58.5 and 53.4 in early and 80.8%, 76.61% in late phase of formalin-induced licking and biting. At 60 and 90 min pulp and seed extracts (200 mg/kg) inhibited nociception of thermal stimulus 50.16 and 62.4%, respectively (p < 0.05) which was comparable with the standard (morphine, 75.9% inhibition). The pulp and seed extracts (200 mg/kg) significantly (p < 0.05) reduced inflammation (42.00 and 55.22%, respectively) in carrageenan-induced hind paw edema and defecations (59.7 and 63.03%, respectively) in castor oil induced diarrhea. Both the extracts showed high sedative activity at 30, 60, 90, and 120 min. CONCLUSION: Our investigation demonstrated significant cytotoxic, analgesic, anti-inflammatory, CNS depressant and antidiarrheal activities of methanol extract of Baccaurea ramiflora pulp and seeds (200 mg/kg).

Prevalence and characteristics of opioid-related deaths involving alcohol in Ontario, Canada.

BACKGROUND: While it is well known that patients receiving opioids should refrain from alcohol consumption, little is known about the involvement of alcohol in opioid-related deaths. METHODS: We conducted a population-based analysis of opioid-related deaths in Ontario with and without alcohol involvement between 1993 and 2013, and reported rates overall and stratified by manner of death. We compared the characteristics of individuals who died of an opioid overdose based on the presence or absence of alcohol involvement. RESULTS: The rate of opioid-related deaths increased 288% from 11.9 per million (95% confidence interval (CI) 9.8-13.9 per million) in 1993-46.2 per million (95% CI 42.6-49.8 per million) in 2013. The rate of opioid-related deaths without alcohol involvement increased 388% from 7.4 per million to 36.1 per million, while deaths involving alcohol increased by 125% from 4.5 per million to 10.1 per million. Therefore, although the annual number of opioid-related deaths involving alcohol rose, the proportion of opioid-related deaths involving alcohol declined from 37.8% in 1993-21.9% by 2013. Generally, opioid-related deaths involving alcohol were less likely to involve other central nervous system depressants, and more likely to occur among men and those with a history of alcohol use disorder. CONCLUSIONS: Although the relative contribution of alcohol in opioid-related deaths has declined, 1 in 5 fatal opioid overdoses still involved alcohol in 2013. Our findings highlight the ongoing need for targeted messaging around risks of opioids alone, and in combination with alcohol and other CNS depressants.

Improving uncertainty in Widmark equation calculations: Alcohol volume, strength and density.

The Widmark equation is probably the most commonly used calculation for medicolegal purposes. Recently the National Research Council (USA) and the Forensic Science Regulator (UK) have called for the uncertainty of all results to be given with all forensic measurements and calculations. To improve the uncertainty of measurement of results from Widmark calculations we have concentrated on the uncertainties of measurement involved in the calculation of amount of alcohol, that of the volume of alcohol, the concentration of alcohol and the density of alcohol as previous studies have investigated some of the other factors involved. Using experimental studies, the scientific literature and legal statutes, we have determined revised and improved uncertainties of the concentration of ethanol for Widmark calculations for both the USA and UK. Based on the calculations that we have performed we recommend the use of Monte Carlo Simulation for the determination of uncertainty of measurement for Widmark Calculations.

Generation and Characterization of Anti-VGLUT Nanobodies Acting as Inhibitors of Transport.

The uptake of glutamate by synaptic vesicles is mediated by vesicular glutamate transporters (VGLUTs). The central role of these transporters in excitatory neurotransmission underpins their importance as pharmacological targets. Although several compounds inhibit VGLUTs, highly specific inhibitors were so far unavailable, thus limiting applications to in vitro experiments. Besides their potential in pharmacology, specific inhibitors would also be beneficial for the elucidation of transport mechanisms. To overcome this shortage, we generated nanobodies (Nbs) by immunization of a llama with purified rat VGLUT1 and subsequent selection of binders from a phage display library. All identified Nbs recognize cytosolic epitopes, and two of the binders greatly reduced the rate of uptake of glutamate by reconstituted liposomes and subcellular fractions enriched with synaptic vesicles. These Nbs can be expressed as functional green fluorescent protein fusion proteins in the cytosol of HEK cells for intracellular applications as immunocytochemical and biochemical agents. The selected binders thus provide valuable tools for cell biology and neuroscience.

In vivo Piroxicam Metabolites: Possible Source for Synthesis of Central Nervous System (CNS) Acting Depressants.

BACKGROUND: Piroxicam has been reported to be convertible to Central Nervous System (CNS) acting agents. It has serious depressant effects at high doses. OBJECTIVE: In view of this, structures of piroxicam metabolites were assessed for possible conversion to CNS depressants. METHODS: Literature search was carried out with intent to identifying piroxicam metabolites and the possibility of converting them to CNS acting depressants. RESULTS: Piroxicam is convertible to hydroxymethylated metabolite which may be converted to barbiturates such as thiopentone and thiamylal. Whereas cyclodehydrated metabolite may be converted to acetylcyclodehydrated compound that may be in turn converted to acetylacetone and cyclohexamide. However, carboxybenzothiazine metabolite may be converted to carboxamide compound, benzolactone which is convertible to phenazone. Carboxybenzothiazine is also convertible to 2-aminopyridine mepyramine and triplenamine. Conversion of carboxybenzothiazine to gamma aminobutyric acid and phenothiazines such as chlorpromazine, thioridazine, fluphenazine and perphenazine is highly possible. CONCLUSION: Structurally, barbituric compounds, carboxamide, cyclodehydrated, benzothiazine and carboxybenzothiazine metabolites may act via dopamine and adrenergic receptors causing depression of CNS activities. Piroxicam metabolites may also act via histamine, melatonin and potassium channel receptors causing CNS depression.

An alcohol-sensing site in the calcium- and voltage-gated, large conductance potassium (BK) channel.

Ethanol alters BK (slo1) channel function leading to perturbation of physiology and behavior. Site(s) and mechanism(s) of ethanol-BK channel interaction are unknown. We demonstrate that ethanol docks onto a water-accessible site that is strategically positioned between the slo1 calcium-sensors and gate. Ethanol only accesses this site in presence of calcium, the BK channel's physiological agonist. Within the site, ethanol hydrogen-bonds with K361. Moreover, substitutions that hamper hydrogen bond formation or prevent ethanol from accessing K361 abolish alcohol action without altering basal channel function. Alcohol interacting site dimensions are approximately 10.7 × 8.6 × 7.1 Å, accommodating effective (ethanol-heptanol) but not ineffective (octanol, nonanol) channel activators. This study presents: (i) to our knowledge, the first identification and characterization of an n-alkanol recognition site in a member of the voltage-gated TM6 channel superfamily; (ii) structural insights on ethanol allosteric interactions with ligand-gated ion channels; and (iii) a first step for designing agents that antagonize BK channel-mediated alcohol actions without perturbing basal channel function.

Development of a fluorescent sensor for illicit date rape drug GHB.

The first fluorescent sensor (GHB Orange) for date rape drug GHB was developed. It exhibits the fluorescence quenching property for GHB and allows its detection in various drinks. The interaction mechanism was elucidated as intramolecular charge transfer induced by a hydrogen bond. This discovery will help in solving the drug facilitated sexual assault problems.

Rab GTPases associate with isolated lipid droplets (LDs) and show altered content after ethanol administration: potential role in alcohol-impaired LD metabolism.

BACKGROUND: Alcoholic liver disease is manifested by the presence of fatty liver, primarily due to accumulation of hepatocellular lipid droplets (LDs). The presence of membrane-trafficking proteins (e.g., Rab GTPases) with LDs indicates that LDs may be involved in trafficking pathways known to be altered in ethanol (EtOH) damaged hepatocytes. As these Rab GTPases are crucial regulators of protein trafficking, we examined the effect EtOH administration has on hepatic Rab protein content and association with LDs. METHODS: Male Wistar rats were pair-fed Lieber-DeCarli diets for 5 to 8 weeks. Whole liver and isolated LD fractions were analyzed. Identification of LDs and associated Rab proteins was performed in frozen liver or paraffin-embedded sections followed by immunohistochemical analysis. RESULTS: Lipid accumulation was characterized by larger LD vacuoles and increased total triglyceride content in EtOH-fed rats. Rabs 1, 2, 3d, 5, 7, and 18 were analyzed in postnuclear supernatant (PNS) as well as LDs. All of the Rabs were found in the PNS, and Rabs 1, 2, 5, and 7 did not show alcohol-altered content, while Rab 3d content was reduced by over 80%, and Rab 18 also showed EtOH-induced reduction in content. Rab 3d was not found to associate with LDs, while all other Rabs were found in the LD fractions, and several showed an EtOH-related decrease (Rabs 2, 5, 7, 18). Immunohistochemical analysis revealed the enhanced content of a LD-associated protein, perilipin 2 (PLIN2) that was paralleled with an associated decrease of Rab 18 in EtOH-fed rat sections. CONCLUSIONS: Chronic EtOH feeding was associated with increased PLIN2 and altered Rab GTPase content in enriched LD fractions. Although mechanisms driving these changes are not established, further studies on intracellular protein trafficking and LD biology after alcohol administration will likely contribute to our understanding of fatty liver disease.

CYP2E1-catalyzed alcohol metabolism: role of oxidant generation in interferon signaling, antigen presentation and autophagy.

Cytochrome P450 2E1 (CYP2E1) is one of two major enzymes that catalyze ethanol oxidation in the liver. CYP2E1 is also unique because it is inducible, as its hepatic content rises after continuous (chronic) ethanol administration, thereby accelerating the rate of ethanol metabolism and affording greater tolerance to heavy alcohol consumption. However, the broad substrate specificity of CYP2E1 and its capacity to generate free radicals from alcohol and other hepatotoxins, places CYP2E1 as a central focus of not only liver toxicity, but also as an enzyme that regulates cytokine signaling, antigen presentation, and macromolecular degradation, all of which are crucial to liver cell function and viability. Here, we describe our own and other published work relevant to the importance of CYP2E1-catalyzed ethanol oxidation and how this catalysis affects the aforementioned cellular processes to produce liver injury.

The role of CYP2E1 in alcohol metabolism and sensitivity in the central nervous system.

Ethanol consumption has effects on the central nervous system (CNS), manifesting as motor incoordination, sleep induction (hypnosis), anxiety, amnesia, and the reinforcement or aversion of alcohol consumption. Acetaldehyde (the direct metabolite of ethanol oxidation) contributes to many aspects of the behavioral effects of ethanol. Given acetaldehyde cannot pass through the blood brain barrier, its concentration in the CNS is primarily determined by local production from ethanol. Catalase and cytochrome P450 2E1 (CYP2E1) represent the major enzymes in the CNS that catalyze ethanol oxidation. CYP2E1 is expressed abundantly within the microsomes of certain brain cells and is localized to particular brain regions. This chapter focuses on the discussion of CYP2E1 in ethanol metabolism in the CNS, covering topics including how it is regulated, where it is expressed and how it influences sensitivity to ethanol in the brain.

Antinociceptive, antidiarrheal, and neuropharmacological activities of Barringtonia acutangula.

CONTEXT: Barringtonia acutangula (L.) Gaertn. (Lecythidaceae) has been used in folk medicine in the treatment of arthralgia, chest pain, dysmenorrhea, inflammation, hemorrhoids, diarrhea, and also in psychological disorders. OBJECTIVE: To investigate the antinociceptive, antidiarrheal, and neuropharmacological effect of the methanol extract of B. acutangula leaves and seeds in mice. MATERIALS AND METHODS: The extracts (200 and 400 mg/kg; p.o.) were tested for antinociceptive activity by acetic acid-induced writhing, hot plate and tail immersion models; castor oil- and magnesium sulphate-induced diarrheal models were used to evaluate antidiarrheal activity whereas hole cross and open field models were employed for testing neuropharmacological activity. RESULTS: Both extracts exhibited significant antinociceptive effect (p < 0.001) in acetic acid and heat induced pain models in a dose-dependent manner. The extracts prolonged the latency period to the thermal stimuli in both hot plate and tail immersion test. The extracts also showed significant inhibition of defecation (p < 0.001, 0.01) in both diarrheal models. Again, the spontaneous motor activity was decreased (p < 0.001) by the extracts in both hole cross and open field test. DISCUSSION AND CONCLUSION: The results of this study suggest that the methanol extracts of B. acutangula leaves and seeds possess good antinociceptive, antidiarrheal, and central nervous system (CNS) depressant activities. This study validates the use of this plant in traditional medicine.

Using molecular docking between organic chemicals and lipid membrane to revise the well known octanol-water partition coefficient of the mixture.

The octanol-water partition coefficient of a mixture has been widely used to predict the baseline toxicity of non-polar narcotic chemical mixtures, since toxic effects are usually generated by multiple mixtures. However, it remains unclear whether the validity of log Kowmix can be demonstrated, because experimental methods cannot be used to determine this parameter. The invalidity and the further revision of log Kowmix were therefore studied by using molecular docking between non-polar narcotic chemicals and lipid membrane (E(binding)). The results show E(binding) is a feasible substitute parameter for log Kow because their relationship is linear. Based on a molecular docking and QSAR model, a new calculated method of log Kowmix was proposed as follows: log(Kowmix)=∑x(i)log Kowi. Comparison of this new method with the established methods demonstrates the invalidity of the latter, and therefore the former is suggested to be used to calculate the log Kowmix of organic chemical mixtures.

Anticonvulsant action of Calotropis procera latex proteins.

Calotropis procera (Ait.) R.Br. is a laticiferous plant belonging to the Apocynaceae family. C. procera latex proteins were evaluated with respect to anticonvulsant and sedative activity in mouse models of pentylenetetrazol (PTZ)-, pilocarpine-, and strychnine-induced convulsions or turning behavior and pentobarbital-induced sleep. In the strychnine- and pilocarpine-induced seizure models, C. procera latex proteins caused no significant alterations in latencies to convulsions and death, as compared with controls. In the PTZ-induced seizure model, administration of C. procera latex proteins in high doses (50 or 100mg/kg) and diazepam caused significant increases in latencies to convulsions and death. C. procera latex proteins (50 or 100mg/kg) and 2mg/kg diazepam caused a decrease in sleep latency and an increase in sleep time compared with the control group and groups treated with 5 or 10mg/kg. Our results suggest that C. procera latex proteins have a central nervous system-depressant activity as reflected in their potentiation of pentobarbital-induced sleeping time and their anticonvulsant action in the PTZ-induced seizure model.

Quinazolinone analogs as potential therapeutic agents.

Quinazolinone scaffold has been considered as a magic moiety possessing myriad spectrum of medicinal activities. Diversity of biological response profile has attracted considerable interest of several researchers across the globe to explore this skeleton for its assorted therapeutic significance. Various novel classes of structurally different quinazolinones have been designed and synthesized depicting potential interventions such as antibacterial, antifungal, antiviral, anticonvulsant, CNS depressant, antiinflammatory, antihistaminic, anticancer and so on. Moreover, the nucleus constitutes an integral structural component in a number of drugs currently employed in several clinical therapies. The present paper is an earnest attempt to provide an insight view on the current medicinal aspects of quinazolinone heterocycles alongwith brief discussion of their chemistry.

Alcohol-binding sites in distinct brain proteins: the quest for atomic level resolution.

Defining the sites of action of ethanol on brain proteins is a major prerequisite to understanding the molecular pharmacology of this drug. The main barrier to reaching an atomic-level understanding of alcohol action is the low potency of alcohols, ethanol in particular, which is a reflection of transient, low-affinity interactions with their targets. These mechanisms are difficult or impossible to study with traditional techniques such as radioligand binding or spectroscopy. However, there has been considerable recent progress in combining X-ray crystallography, structural modeling, and site-directed mutagenesis to define the sites and mechanisms of action of ethanol and related alcohols on key brain proteins. We review such insights for several diverse classes of proteins including inwardly rectifying potassium, transient receptor potential, and neurotransmitter-gated ion channels, as well as protein kinase C epsilon. Some common themes are beginning to emerge from these proteins, including hydrogen bonding of the hydroxyl group and van der Waals interactions of the methylene groups of ethanol with specific amino acid residues. The resulting binding energy is proposed to facilitate or stabilize low-energy state transitions in the bound proteins, allowing ethanol to act as a "molecular lubricant" for protein function. We discuss evidence for characteristic, discrete alcohol-binding sites on protein targets, as well as evidence that binding to some proteins is better characterized by an interaction region that can accommodate multiple molecules of ethanol.

Two alcohol binding residues interact across a domain interface of the L1 neural cell adhesion molecule and regulate cell adhesion.

Ethanol may cause fetal alcohol spectrum disorders (FASD) in part by inhibiting cell adhesion mediated by the L1 neural cell adhesion molecule. Azialcohols photolabel Glu-33 and Tyr-418, two residues that are predicted by homology modeling to lie within 2.8 Å of each other at the interface between the Ig1 and Ig4 domains of L1 (Arevalo, E., Shanmugasundararaj, S., Wilkemeyer, M. F., Dou, X., Chen, S., Charness, M. E., and Miller, K. W. (2008) Proc. Natl. Acad. Sci. U.S.A. 105, 371-375). Using transient transfection of NIH/3T3 cells with wild type (WT-L1) and mutated L1, we found that cysteine substitution of both residues (E33C/Y418C-L1) significantly increased L1 adhesion above levels observed for WT-L1 or the single cysteine substitutions E33C-L1 or Y418C-L1. The reducing agent ß-mercaptoethanol (ßME) reversibly decreased the adhesion of E33C/Y418C-L1, but had no effect on WT-L1, E33C-L1, or Y418C-L1. Thus, disulfide bond formation occurs between Cys-33 and Cys-418, confirming both the close proximity of these residues and the importance of Ig1-Ig4 interactions in L1 adhesion. Maximal ethanol inhibition of cell adhesion was significantly lower in cells expressing E33C/Y418C-L1 than in those expressing WT-L1, E33C-L1, or Y418C-L1. Moreover, the effects of ßME and ethanol on E33C/Y418C-L1 adhesion were non-additive. The cutoff for alcohol inhibition of WT-L1 adhesion was between 1-butanol and 1-pentanol. Increasing the size of the alcohol binding pocket by mutating Glu-33 to Ala-33, increased the alcohol cutoff from 1-butanol to 1-decanol. These findings support the hypothesis that alcohol binding within a pocket bordered by Glu-33 and Tyr-418 inhibits L1 adhesion by disrupting the Ig1-Ig4 interaction.