Marine Inspired 2-(5-Halo-1H-indol-3-yl)-N,N-dimethylethanamines as Modulators of Serotonin Receptors: An Example Illustrating the Power of Bromine as Part of the Uniquely Marine Chemical Space.

In previous studies, we have isolated several marine indole alkaloids and evaluated them in the forced swim test (FST) and locomotor activity test, revealing their potential as antidepressant and sedative drug leads. Amongst the reported metabolites to display such activities was 5-bromo-N,N-dimethyltryptamine. Owing to the importance of the judicious introduction of halogens into drug candidates, we synthesized two series built on a 2-(1H-indol-3-yl)-N,N-dimethylethanamine scaffold with different halogen substitutions. The synthesized compounds were evaluated for their in vitro and in vivo antidepressant and sedative activities using the mouse forced swim and locomotor activity tests. Receptor binding studies of these compounds to serotonin (5-HT) receptors were conducted. Amongst the prepared compounds, 2-(1H-indol-3-yl)-N,N-dimethyl-2-oxoacetamide (1a), 2-(5-bromo-1H-indol-3-yl)-N,N-dimethyl-2-oxoacetamide (1d), 2-(1H-indol-3-yl)-N,N-dimethylethanamine (2a), 2-(5-chloro-1H-indol-3-yl)-N,N-dimethylethanamine (2c), 2-(5-bromo-1H-indol-3-yl)-N,N-dimethylethanamine (2d), and 2-(5-iodo-1H-indol-3-yl)-N,N-dimethylethanamine (2e) have been shown to possess significant antidepressant-like action, while compounds 2c, 2d, and 2e exhibited potent sedative activity. Compounds 2a, 2c, 2d, and 2e showed nanomolar affinities to serotonin receptors 5-HT1A and 5-HT7. The in vitro data indicates that the antidepressant action exerted by these compounds in vivo is mediated, at least in part, via interaction with serotonin receptors. The data presented here shows the valuable role that bromine plays in providing novel chemical space and electrostatic interactions. Bromine is ubiquitous in the marine environment and a common element of marine natural products.

Chemical diversity and pharmacological significance of the secondary metabolites of nutmeg (Myristica fragrans Houtt.).

Nutmeg is a valued kitchen spice that has been used for centuries all over the world. In addition to its use in flavoring foods and beverages, nutmeg has been used in traditional remedies for stomach and kidney disorders. The antioxidant, antimicrobial and central nervous system effects of nutmeg have also been reported in literature. Nutmeg is a rich source of fixed and essential oil, triterpenes, and various types of phenolic compounds. Many of the secondary metabolites of nutmeg exhibit biological activities that may support its use in traditional medicine. This article provides an overview of the chemistry of secondary metabolites isolated from nutmeg kernel and mace including common methods for analysis of extracts and pure compounds as well as recent approaches towards total synthesis of some of the major constituents. A summary of the most significant pharmacological investigations of potential drug leads isolated from nutmeg and reported in the last decade is also included.

Indirect modulation of the endocannabinoid system by specific fractions of nutmeg total extract.

CONTEXT: Nutmeg [Myristica fragrans Houtt. (Myristicaceae)] has a long-standing reputation of psychoactivity. Anecdotal reports of nutmeg use as a cheap marijuana substitute, coupled to previous studies reporting a cannabimimetic-like action, suggest that nutmeg may interact with the endocannabinoid system. OBJECTIVE: The study evaluates nutmeg fractions for binding capacity with various CNS receptors and their potential interaction with the endocannabinoid system. MATERIALS AND METHODS: Dichloromethane (DF) and ethyl acetate (EF) fractions were prepared from the methanol extract of powdered whole nutmeg. The HPLC-profiled fractions were assayed by the NIMH Psychoactive Drug Screening Program (PDSP) in a panel of CNS targets at a 10 µg/mL concentration. The fractions were also screened for fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) inhibition, initially at a concentration of 500 µg/mL, then by concentration-dependent inhibition studies. RESULTS: None of the tested fractions showed significant binding to CNS receptors included in the PDSP panel. However, both fractions exerted significant inhibition of the FAAH and MAGL enzymes. The DF fraction inhibited FAAH and MAGL enzymes at IC50 values of 21.06 ± 3.16 and 15.34 ± 1.61 µg/mL, respectively. Similarly, the EF fraction demonstrated FAAH and MAGL inhibition with IC50 values of 15.42 ± 3.09 and 11.37 ± 6.15 µg/mL, respectively. DISCUSSION AND CONCLUSION: The study provides the first piece of evidence that nutmeg interacts with the endocannabinoid system via inhibition of the endocannabinoid catabolizing enzymes. This mechanism provides insight into reported cannabis-like action as well as expands the potential therapeutic utility of nutmeg.

Isolation and Pharmacological Evaluation of Minor Cannabinoids from High-Potency Cannabis sativa.

Seven new naturally occurring hydroxylated cannabinoids (1-7), along with the known cannabiripsol (8), have been isolated from the aerial parts of high-potency Cannabis sativa. The structures of the new compounds were determined by 1D and 2D NMR spectroscopic analysis, GC-MS, and HRESIMS as 8α-hydroxy-Δ(9)-tetrahydrocannabinol (1), 8ß-hydroxy-Δ(9)-tetrahydrocannabinol (2), 10α-hydroxy-Δ(8)-tetrahydrocannabinol (3), 10ß-hydroxy-Δ(8)-tetrahydrocannabinol (4), 10α-hydroxy-Δ(9,11)-hexahydrocannabinol (5), 9ß,10ß-epoxyhexahydrocannabinol (6), and 11-acetoxy-Δ(9)-tetrahydrocannabinolic acid A (7). The binding affinity of isolated compounds 1-8, Δ(9)-tetrahydrocannabinol, and Δ(8)-tetrahydrocannabinol toward CB1 and CB2 receptors as well as their behavioral effects in a mouse tetrad assay were studied. The results indicated that compound 3, with the highest affinity to the CB1 receptors, exerted the most potent cannabimimetic-like actions in the tetrad assay, while compound 4 showed partial cannabimimetic actions. Compound 2, on the other hand, displayed a dose-dependent hypolocomotive effect only.

Anxiolytic action of pterostilbene: involvement of hippocampal ERK phosphorylation.

Pterostilbene, a natural analog of resveratrol, has diverse health-beneficial properties. However, the neurological activities of this compound are largely unexplored. Here, we report that pterostilbene shows anxiolytic-like actions by down-regulating phosphorylated levels of extracellular regulated kinases in the hippocampus of mice. Adult male mice administered pterostilbene (1-10 mg/kg, p. o.) were subjected to the elevated plus maze test. Pterostilbene manifested anxiolytic activity at 1 and 2 mg/kg doses, demonstrated by increases in % permanence time and number of open arm entries. The locomotor activity of the animals was unaffected at all doses. Western blot analysis revealed a decrease in both extracellular regulated kinase 1 and extracellular regulated kinase 2 phosphorylation in hippocampal homogenates from mice treated with 1 and 2 mg/kg pterostilbene. Moreover, pterostilbene was detected in the plasma and brains of mice following single oral administration. Anxiolytic activity was not observed at the higher doses (5 and 10 mg/kg). However, no impairment of motor function was observed either, suggesting a favorable safety index for the compound. These results suggest that pterostilbene has the potential for therapeutic drug development for anxiety disorders.

Phenolic compounds from nutmeg (Myristica fragrans Houtt.) inhibit the endocannabinoid-modulating enzyme fatty acid amide hydrolase.

OBJECTIVES: The study aimed to identify nutmeg compounds that indirectly interact with the endocannabinoid system through inhibition of the fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) enzymes. METHODS: Thirteen compounds were screened for FAAH and MAGL inhibition. Compounds demonstrating significant FAAH inhibition were evaluated to determine the halfmaximal inhibitory concentration (IC50 ). The most potent compound was investigated in the elevated plus maze (EPM) rodent anxiety model. KEY FINDINGS: Three compounds, licarin A (9), 5'-methoxylicarin A (8) and malabaricone C (6) were most active in inhibiting FAAH with IC50 of 7.02 µm ± 2.02, 4.57 µm ± 0.66 and 38.29 µm ± 6.18, respectively. None of the purified compounds showed significant MAGL inhibition. Because of its relative high potency and selectivity, compound 8 was further evaluated in the EPM animal model of anxiety. The compound showed significant increase in number of open arm entries (P < 0.05) when administered at 120 mg/kg dose. No effect was observed on the locomotor activity. CONCLUSIONS: Results collected introduce active nutmeg compounds as potential leads for further development. Of the three compounds, 8 possesses highest potency and FAAH selectivity as well as anxiolytic activity. Furthermore, in vivo testing in appropriate behavioural animal paradigms is warranted.

Non-cannabinoid constituents from a high potency Cannabis sativa variety.

Six new non-cannabinoid constituents were isolated from a high potency Cannabis sativa L. variety, namely 5-acetoxy-6-geranyl-3-n-pentyl-1,4-benzoquinone (1), 4,5-dihydroxy-2,3,6-trimethoxy-9,10-dihydrophenanthrene (2), 4-hydroxy-2,3,6,7-tetramethoxy-9,10-dihydrophenanthrene (3), 4,7-dimethoxy-1,2,5-trihydroxyphenanthrene (4), cannflavin C (5) and beta-sitosteryl-3-O-beta-d-glucopyranoside-2'-O-palmitate (6). In addition, five known compounds, alpha-cannabispiranol (7), chrysoeriol (8), 6-prenylapigenin (9), cannflavin A (10) and beta-acetyl cannabispiranol (11) were identified, with 8 and 9 being reported for the first time from cannabis. Some isolates displayed weak to strong antimicrobial, antileishmanial, antimalarial and anti-oxidant activities. Compounds 2-4 were inactive as analgesics.

Amelioration of the cardiovascular manifestations of the yellow scorpion Leiurus quinquestriatus envenomation in rats by red grape seeds proanthocyanidins.

The study attempts to determine the involvement of oxidative stress in cardiovascular manifestations during Leiurus quinquestriatus quinquestriatus (LQQ) scorpion envenomation and to examine the possible protective role of red grape seed proanthocyanidins (GSP) against such effects. Lethality studies conducted in mice demonstrated a significant (p<0.01) protection of GSP against venom lethality. Pretreatment with GSP (200 mg kg(-1), p.o., 10 days) prior to venom injection (350 microg kg(-1), s.c.) resulted in a significant decrease in percent mortality as well as in significant prolongation of the animal's survival time (p<0.01). Monitoring the cardiovascular effects elicited by venom injection in anesthetized rats revealed a marked protection of GSP against the increase in mean arterial blood pressure evoked by LQQ venom. Moreover, pretreatment with GSP reduced the characteristic signs of conduction defects, myocardial ischemia, and infarction observed by venom injection. Biochemical analyses showed that scorpion envenomation caused significant (p<0.001) elevation in serum lactate dehydrogenase as well as creatine kinase-MB activities. Such elevation was ameliorated by GSP (p<0.001). Oxidative stress parameters revealed that scorpion venom significantly increased (p<0.001) the level of lipid peroxidative damage in cardiac tissues and reduced the activity of both glutathione reductase and glutathione peroxidase enzymes in cardiac tissues (p<0.05). In the meantime, GSP offered significant protection against lipid peroxidative damage (p<0.05) and enhanced cardiac glutathione reductase activity (p<0.001). In summary, the current study demonstrates that pretreatment with GSP offers significant protection against LQQ envenomation possibly via enhancement of the antioxidant defense systems.

Review of available studies of the neurobiology and pharmacotherapeutic management of trichotillomania.

Trichotillomania (TTM) is a psychiatric disorder characterized by an irresistible urge to pull out one's hair. Currently there are no FDA approved treatments for TTM, which makes it difficult for clinicians to select an appropriate therapeutic plan. The clinical studies that have been performed do not provide sufficient or consistent evidence regarding which drug classes should be administered. Unfortunately, most of the available data consist of case reports and clinical trials with limited sample size. This review provides an overview of currently available clinical literature that targets TTM. A summary of clinical trials as well as case reports is provided. The most common rating scales used for clinical assessment are also reviewed. The etiology of TTM remains unclear. Studies that examine various neuroanatomical, neurobiologic, as well as genetic factors associated with TTM are thoroughly discussed in this review. It is evident that clear understanding of TTM is crucial to provide better recognition, assessment, and treatment to patients of this disorder. Finally, despite research efforts for establishing pharmacological options for treatment, it is clear that new targets are warranted in order to ensure a clinically supported effective pharmacological approach to treat TTM.

Effect of 17beta-estradiol and testosterone on the expression of flavin-containing monooxygenase and the toxicity of aldicarb to Japanese medaka, Oryzias latipes.

Previous studies in our laboratory indicated gender differences in salinity-enhanced acute toxicity of aldicarb in Japanese medaka with females being more susceptible. In the current study, the effects of the sex steroids, 17beta estradiol (E2) and testosterone (T) on aldicarb toxicity was examined. Adult Japanese medaka were separated by sex and exposed to 100 microg/l E2 or T for 6 days followed by exposure to the 96-h LC50 (0.5 mg/l) of aldicarb. The toxicity of aldicarb to adult males was significantly lowered by E2 and T whereby the mortality percentage was reduced to 23.3 +/- 5.8% and 3.3 +/- 5.8%, respectively, compared to the fish not receiving steroids (46.7 +/- 5.8% mortality). In females, T caused significant reduction in aldicarb toxicity to 16.7 +/- 5.8%, while E2 significantly enhanced the toxicity to 96.7 +/- 5.8% mortality. Since the flavin-containing monooxygenase (FMO) enzyme system had been shown to play a critical role in aldicarb toxicity, the effect of E2 and T on FMO expression was examined. Gill FMO activity showed a direct correlation with the overall toxicity of aldicarb in both male and female medaka. Expression of FMO1-like protein was significantly reduced by T in male livers and gills, and T did not affect the expression of FMOs in female tissues. In contrast, E2 significantly reduced FMO1-like protein expression in male gills and female livers, as well as FMO3 expression in both male and female livers, but significantly increased gill FMO1 expression in females. Since aldicarb acts by inhibiting the enzyme cholinesterase (ChE), the effect of sex hormones on the activity of this enzyme was also examined. In both male and female medaka, T counteracted the inhibitory effect of aldicarb on muscle ChE. In male fish, E2 had similar effects but did not seem to counteract the ChE inhibition in females. In conclusion, E2 and T modulation of aldicarb toxicity in Japanese medaka seems to be mediated via alteration of gill FMO and ChE actitivies.

Gender differences in the effect of salinity on aldicarb uptake, elimination, and in vitro metabolism in Japanese medaka, Oryzias latipes.

Toxicity studies have shown that salinity enhances the toxicity of aldicarb to female Japanese medaka. Although previous studies indicated that biotransformation may be important in these effects, other dispositional factors may play a role in this scenario. Male and female medaka were separately acclimated to three salinity regimens: 1.5, 12, and 20 parts per thousand (per thousand) for 2 weeks. The fish were then aqueously exposed to 96 h LC(20) of [(14)C]aldicarb for 24 h. [(14)C]aldicarb equivalents (aldicarb and its metabolites) were measured in whole-fish homogenates of half the fish. The other half of the population was transferred to clean water for 48 h. During this 48 h period, fish were removed and whole animal homogenates were measured radiometrically at 0, 2, 4, 8, 12, and 24 h time points. Salinity did not have an effect on the uptake of aldicarb in either male or female medaka. Elimination data showed that elimination of [(14)C]aldicarb equivalents was biphasic. Salinity did not have an effect on the elimination half life in either males or females. In vitro metabolism using gill and liver microsomes from fish acclimated to three salinity regimens showed that aldicarb sulfoxide production by male gill microsomes increased 6-fold by salinity compared to a 9-fold increase in female gills. In conclusion, the increased sensitivity of female medaka to salinity enhanced toxicity seems to be caused by a higher metabolic activation of aldicarb to the sulfoxide compared to the males. This study supports the hypothesis that the differential expression and regulation of FMOs is an important factor in determining the sensitivity of euryhaline fish to aldicarb, especially at high salinity regimens.

Synthesis and pharmacological screening for muscle relaxant, anticonvulsant, and sedative activities of certain organic compounds produced by Michael addition.

Michael addition of certain nucleophiles on alpha, beta-unsaturated ketones 1 led to the formation of adducts 2-7 as well as the reaction of arylidene derivatives with secondary amines afforded the amino compounds 9 and 11. Also, dialkylmalonates were treated with alpha-cyano cinnamide to afford 13. On the other hand, double Michael cycloaddition of ethylcyanoacetate or tetrachlorophthalic anhydride to the suitable divinylketone were synthesized to produce 15-17. Selected compounds (13 and 6) were screened for muscle relaxant, anticonvulsant, and sedative activities using established pharmacological models. Their activities were compared with that of phenobarbital sodium taken as standard. Compound 6 was the most potent muscle relaxant while compounds 13a and 13c offered the highest anticonvulsant activity. Meanwhile compound 13c showed the highest potentiation of phenobarbital induced sleep in mice.

Neurobehavioral and transcriptional effects of acrylamide in juvenile rats.

Acrylamide is a type-2 alkene monomer with established human neurotoxic effects. While the primary source of human exposure to acrylamide is occupational, other exposure sources include food, drinking water, and smoking. In this study, neurobehavioral assays coupled with transcriptional profiling analysis were conducted to assess both behavioral and gene expression effects induced by acrylamide neurotoxicity in juvenile rats. Acrylamide administration in rat pups induced significant characteristic neurotoxic symptoms including increased heel splay, decrease in grip strength, and decrease in locomotor activity. Transcriptome analysis with the Affymetrix Rat Genome 230 2.0 array indicated that acrylamide treatment caused a significant alteration in the expression of a few genes that are involved in muscle contraction, pain, and dopaminergic neuronal pathways. First, expression of the Mylpf gene involved in muscle contraction was downregulated in the spinal cord in response to acrylamide. Second, in sciatic nerves, acrylamide repressed the expression of the opioid receptor gene Oprk1 that is known to play a role in neuropathic pain regulation. Finally, in the cerebellum, acrylamide treatment caused a decrease in the expression of the nuclear receptor gene Nr4a2 that is required for development of dopaminergic neurons. Thus, our work examining the effect of acrylamide at the whole-genome level on a developmental mammalian model has identified a few genes previously not implicated in acrylamide neurotoxicity that might be further developed into biomarkers for assessing the risk of adverse health effects induced by acrylamide exposure.

Antidepressant-like effect of delta9-tetrahydrocannabinol and other cannabinoids isolated from Cannabis sativa L.

The antidepressant action of cannabis as well as the interaction between antidepressants and the endocannabinoid system has been reported. This study was conducted to assess the antidepressant-like activity of Delta(9)-THC and other cannabinoids. Cannabinoids were initially evaluated in the mouse tetrad assay to determine doses that do not induce hypothermia or catalepsy. The automated mouse forced swim (FST) and tail suspension (TST) tests were used to determine antidepressant action. At doses lacking hypothermic and cataleptic effects (1.25, 2.5, and 5 mg/kg, i.p.), both Delta(9)-THC and Delta(8)-THC showed a U-shaped dose response with only Delta(9)-THC showing significant antidepressant-like effects at 2.5 mg/kg (p<0.05) in the FST. The cannabinoids cannabigerol (CBG) and cannabinol (CBN) did not produce antidepressant-like actions up to 80 mg/kg in the mouse FST, while cannabichromene (CBC) and cannabidiol (CBD) exhibited significant effect at 20 and 200mg/kg, respectively (p<0.01). The antidepressant-like action of Delta(9)-THC and CBC was further confirmed in the TST. Delta(9)-THC exhibited the same U-shaped dose response with significant antidepressant-like action at 2.5 mg/kg (p<0.05) while CBC resulted in a significant dose-dependent decrease in immobility at 40 and 80 mg/kg doses (p<0.01). Results of this study show that Delta(9)-THC and other cannabinoids exert antidepressant-like actions, and thus may contribute to the overall mood-elevating properties of cannabis.