Low dose anandamide affects food intake, cognitive function, neurotransmitter and corticosterone levels in diet-restricted mice

N-Acylethanolamines in human reproductive fluids

N-Acylethanolamines (NAEs) are an important family of lipid-signaling molecules. Arachidonylethanolamide (anandamide) (AEA), palmitoylethanolamide (PEA), and oleoylethanolamide (OEA) are co-produced from similar phospholipid precursors when neurons are stimulated. AEA is an endogenous agonist (endocannabinoid) for cannabinoid receptors. It binds with higher affinity to type CB1 than to type CB2 cannabinoid receptors. PEA does not bind to CB1, while the hypothesis that it reacts with putative CB2-like receptors has been questioned. OEA does not activate currently known cannabinoid receptors, but it mimics the effects of AEA and cannabinoids in reducing the fertilizing capacity of sea urchin sperm. OEA and PEA also act as entourage compounds by inhibiting the hydrolysis of AEA by fatty acid amide hydrolase. Cannabinoid receptors and/or AEA are present in mammalian reproductive organs including the testis, epididymis, prostate, ovary, uterus, sperm, preimplantation embryo and placenta, as well as prostatic and mammary carcinomas. We now report that analysis by high-performance liquid chromatography/mass spectrometry (HPLC/MS) shows the presence of AEA, PEA, and OEA in human seminal plasma, mid-cycle oviductal fluid, follicular fluid, amniotic fluid, milk, and fluids from malignant ovarian cysts. Previous studies showed that AEA-signaling via cannabinoid receptors regulates capacitation and fertilizing potential of human sperm, early embryonic development and blastocyst implantation into the uterine mucosa of rodents, as well as proliferation of human mammary and prostatic carcinomas. Current results imply that NAEs also may modulate follicular maturation and ovulation, normal and pathological ovarian function, placental and fetal physiology, lactation, infant physiology, and behavior. Collectively, these findings suggest that NAEs in human reproductive fluids may help regulate multiple physiological and pathological processes in the reproductive system, and imply that exogenous cannabinoids delivered by marijuana smoke might impact these processes. This study has potential medical and public policy ramifications because of the incidence of marijuana abuse by adolescents and adults in our society, previously documented reproductive effects of marijuana, and the ongoing debate about medicinal use of marijuana and cannabinoids.

Estrogen stimulates arachidonoylethanolamide release from human endothelial cells and platelet activation

Estrogen replacement therapy has been associated with reduction of cardiovascular events in postmenopausal women, though the mechanism for this benefit remains unclear. Here we show that at physiological concentrations estrogen activates the anandamide membrane transporter of human endothelial cells and leads to rapid elevation of calcium (apparent within 5 minutes) and release of nitric oxide (within 15 minutes). These effects are mediated by estrogen binding to a surface receptor, which shows an apparent dissociation constant (K(d)) of 9.4 +/- 1.4 nM, a maximum binding (B(max)) of 356 +/- 12 fmol x mg protein(-1), and an apparent molecular mass of approximately 60 kDa. We also show that estrogen binding to surface receptors leads to stimulation of the anandamide-synthesizing enzyme phospholipase D and to inhibition of the anandamide-hydrolyzing enzyme fatty acid amide hydrolase, the latter effect mediated by 15-lipoxygenase activity. Because the endothelial transporter is shown to move anandamide across the cell membranes bidirectionally, taken together these data suggest that the physiological activity of estrogen is to stimulate the release, rather than the uptake, of anandamide from endothelial cells. Moreover, we show that anandamide released from estrogen-stimulated endothelial cells, unlike estrogen itself, inhibits the secretion of serotonin from adenosine diphosphate (ADP)-stimulated platelets. Therefore, it is suggested that the peripheral actions of anandamide could be part of the molecular events responsible for the beneficial effects of estrogen.

Chronic food restriction is associated with subtle dendritic alterations in granule cells of the rat hippocampal formation

The hippocampal formation undergoes significant morphological and functional changes after prolonged feeding with low-protein diets. In this study we tested whether prolonged food restriction causes deleterious alterations in this brain region as well. It was found that the total number of dentate granule cells and hippocampal CA3 and CA1 pyramidal neurons did not differ between controls and rats submitted to food restriction (40%) for 36 weeks. Likewise, no effects of this dietary regimen have been detected on the morphology of the dendritic trees of hippocampal pyramids, and on the total number of the mossy fiber-CA3 synapses. By contrast, the dendritic arborizations of granule cells were found to have a reduced number of segments in food-restricted rats. However, the spine density on the distal segments of their dendritic trees and the total number of axospinous synapses in the outer molecular layer of the dentate gyrus were increased in these animals. In addition, the total dendritic length of the granule cells and the overall surface area of the active zones of the synapses in the outer molecular layer were preserved, indicating that the capacity of dentate granule cells to process afferent stimuli is likely to be unaffected by this dietary treatment. Supporting this view are the results obtained in the water maze experiment which show that food-restricted rats exhibit unimpaired spatial abilities, which are known to be dependent on the entorhinal drive towards the hippocampal formation. These results show that, among hippocampal neurons, dentate granule cells are selectively vulnerable to food restriction. Nonetheless, the reorganization which takes place in their dendrites and synapses is capable of minimizing the functional impairments that were expected to occur following changes in the hippocampal neuronal circuitry induced by this type of dietary restriction.

Down-regulation of cannabinoid-1 (CB-1) receptors in specific extrahypothalamic regions of rats with dietary obesity: a role for endogenous cannabinoids in driving appetite for palatable food?

Agonists at cannabinoid-1 (CB-1) receptors stimulate feeding and particularly enhance the reward aspects of eating. To investigate whether endogenous cannabinoids might influence appetite for palatable food, we compared CB-1 receptor density in the forebrain and hypothalamus, between rats fed standard chow (n=8) and others given palatable food (n=8) for 10 weeks to induce dietary obesity. CB-1 receptor density was significantly decreased by 30-50% (P<0.05) in the hippocampus, cortex, nucleus accumbens and entopeduncular nucleus of diet-fed rats. Furthermore, CB-1 receptor density in the hippocampus, nucleus accumbens and entopeduncular nucleus was significantly inversely correlated with intake of palatable food (r(2)=0.25-0.35; all P<0.05). By contrast, CB-1 receptor binding in the hypothalamus was low and not altered in diet-fed rats. CB-1 receptor down-regulation is consistent with increased activation of these receptors by endogenous cannabinoids. Acting in areas such as the nucleus accumbens and hippocampus, which are involved in the hedonic aspects of eating, cannabinoids may therefore drive appetite for palatable food and thus determine total energy intake and the severity of diet-induced obesity. However, cannabinoids in the hypothalamus do not appear to influence this aspect of eating behaviour.

Restricted feeding facilitates time-place learning in adult rats

Many species can acquire time-of-day discrimination when tested in food reinforced place learning tasks. It is believed that this type of learning is dependent upon the ability of animals to consult their internal circadian pacemakers entrained by various environmental zeitgebers, such as light-dark cycles and scheduled restricted feeding. In the present study, we examined, (1) whether rats can acquire time-of-day discrimination in an aversively motivated water maze task wherein an escape platform is located in one position in the morning and in another position in the afternoon; (2) whether time-of-day cues provided by the light- and feeding-entrainable pacemakers may have divergent impacts upon the ability of rats to learn this task. Two groups of rats, both maintained on 12-h light:12-h dark cycle, were used; in one group, animals had free access to food, whereas in the other, they were subjected to a restricted feeding protocol (60% of food consumed by rats fed ad libitum, once daily). Despite the heightened difficulty of the task, food-restricted rats were apparently able to acquire associations between two different platform positions and two different times of day, as indicated by the fact that the percentage of discrimination errors in this group declined progressively, as a function of training, and stabilized at the level of 22+/-9%. In contrast, rats that were fed ad libitum, even after extensive training, failed to perform the task above level of chance. These data indicate that time-place learning is a universal, reward-nonspecific, cognitive phenomenon. They furthermore suggest that the ability of animals to integrate spatial and temporal information can be dependent on the access to timing stimuli provided by the feeding-entrainable circadian system.

Tetrahydrocannabinol and endocannabinoids in feeding and appetite

The physiological control of appetite and satiety, in which numerous neurotransmitters and neuropeptides play a role, is extremely complex. Here we describe the involvement of endocannabinoids in these processes. These endogenous neuromodulators enhance appetite in animals. The same effect is observed in animals and in humans with the psychotropic plant cannabinoid Delta(9)-tetrahydrocannabinol, which is an approved appetite-enhancing drug. The CB(1) cannabinoid receptor antagonist SR141716A blocks the effects on feeding produced by the endocannabinoids. If administered to mice pups, this antagonist blocks suckling. In obese humans, it causes weight reduction. Very little is known about the physiological and biochemical mechanisms involved in the effects of Delta(9)-tetrahydrocannabinol and the cannabinoids in feeding and appetite.

Endocannabinoid levels in rat limbic forebrain and hypothalamus in relation to fasting, feeding and satiation: stimulation of eating by 2-arachidonoyl glycerol

Endocannabinoids are implicated in appetite and body weight regulation. In rodents, anandamide stimulates eating by actions at central CB1 receptors, and hypothalamic endocannabinoids may be under the negative control of leptin. However, changes to brain endocannabinoid levels in direct relation to feeding or changing nutritional status have not been investigated. We measured anandamide and 2-arachidonoyl glycerol (2-AG) levels in feeding-associated brain regions of rats, during fasting, feeding of a palatable food, or after satiation. Endocannabinoid levels were compared to those in rats fed ad libitum, at a point in their daily cycle when motivation to eat was absent. Fasting increased levels of anandamide and 2-AG in the limbic forebrain and, to a lesser extent, of 2-AG in the hypothalamus. By contrast, hypothalamic 2-AG declined as animals ate. No changes were detected in satiated rats. Endocannabinoid levels in the cerebellum, a control region not directly involved in the control of food intake, were unaffected by any manipulation. As 2-AG was most sensitive to variation during feeding, and to leptin regulation in a previous study, we examined the behavioural effects of 2-AG when injected into the nucleus accumbens shell, a limbic forebrain area strongly linked to eating motivation. 2-AG potently, and dose-dependently, stimulated feeding. This effect was attenuated by the CB1 receptor antagonist SR141716. These findings provide the first direct evidence of altered brain levels of endocannabinoids, and of 2-AG in particular, during fasting and feeding. The nature of these effects supports a role for endocannabinoids in the control of appetitive motivation.

New drugs for the anorexia-cachexia syndrome

Anorexia and cachexia accompany advancing cancer to a greater extent than any other symptom. Cachexia alone causes 22% of cancer deaths. The pathophysiology of cachexia is distinctly different from that of starvation. Resting energy expenditures are elevated, and abnormal intermediary metabolism, proteolysis, and lipolysis occur independently of caloric intake. A facilatative interaction between catecholamines, prostaglandins, and inflammatory cytokines is responsible for cachexia. Successful treatment requires reduction of energy expenditures, reversal of anorexia, and correction of abnormal intermediary metabolism, lipolysis, and proteolysis. Multiple appetite stimulants can be used in combination. Several new potentially useful biologic agents have been tested in animal tumor models. Several of the anticachectic agents have demonstrated in vivo or in vitro antitumor activity. The biologic and clinical activity of each drug is reviewed herein, and potentially useful combinations are listed.

Obesity therapy: altering the energy intake-and-expenditure balance sheet

Obesity is associated with numerous health complications, which range from non-fatal debilitating conditions such as osteoarthritis, to life-threatening chronic diseases such as coronary heart disease, diabetes and certain cancers. The psychological consequences of obesity can range from lowered self-esteem to clinical depression. Despite the high prevalence of obesity and the many advances in our understanding of how it develops, current therapies have persistently failed to achieve long-term success. This review focuses on how fat mass can be reduced by altering the balance between energy intake and expenditure.

Discovery of endocannabinoids and some random thoughts on their possible roles in neuroprotection and aggression

A short history of the discovery of the main plant cannabinoid, Delta(9)-tetrahydrocannabinol and of the endogenous cannabinoids anandamide, 2-arachidonoyl glycerol and 2-arachidonyl glyceryl ether (noladin ether) is presented. The role of the cannabinoids in neuroprotection, with emphasis on the endocannabinoids, is described. The unexpected production of aggression by Cannabis and cannabinoids under stressful conditions, published mainly in the past, is summarized.

The role of endocannabinoids in the hypothalamic regulation of visceral function

The hypothalamus plays an important role in the regulation of several visceral processes, including food intake, thermoregulation and control of anterior pituitary secretion. Endogenous cannabinoids and CB(1) cannabinoid receptors have been found in the hypothalamus. In the present review, we would like to clarify the role of the endocannabinoid system in the regulation of the above-mentioned visceral functions. There is historical support for the role of marihuana (i.e. exogenous cannabinoids) in the regulation of appetite. Endocannabinoids also stimulate food intake. Furthermore, the specific CB(1) receptor antagonist SR141716 reduces food intake. Leptin treatment decreases endocannabinoid levels in normal rats and ob/ob mice. These findings provide evidence for the role of the hypothalamic endocannabinoid system in food intake and appetite regulation. Cannabinoids can change body temperature in a dose-dependent manner. High doses cause hypothermia while low doses cause hyperthermia. Cannabinoid administration decreases heat production. It seems that the effects of can- nabinoids on thermoregulation is exerted by altering some neurochemical mediator effects at both the presynaptic and postsynaptic level.THC and endocannabinoids have mainly inhibitory effects on the regulation of reproduction. Administration of anandamide (AEA) decreases serum luteinizing hormone (LH) and prolactin (PRL) levels. AEA causes a prolongation of pregnancy in rats and temporarily inhibits the postnatal development of the hypothalamo-pituitary axis in offspring. The action of AEA on the reproductory parameters occurs at both the hypothalamic and pituitary level. CB(1) receptors have also been found in the anterior pituitary. Further, LH levels in CB(1) receptor-inactivated mice were decreased compared with wild-type mice. Taken together, all these observations suggest that the endocannabinoid system is playing an important part in the regulation of the mentioned visceral functions and it provides the bases for further applications of cannabinoid receptor agonists and/or antagonists in visceral diseases regulated by the hypothalamus.

Biosynthesis and degradation of anandamide and 2-arachidonoylglycerol and their possible physiological significance

N -arachidonoylethanolamine (anandamide) was the first endogenous cannabinoid receptor ligand to be discovered. Dual synthetic pathways for anandamide have been proposed. One is the formation from free arachidonic acid and ethanolamine, and the other is the formation from N -arachidonoyl phosphatidylethanolamine (PE) through the action of a phosphodiesterase. These pathways, however, do not appear to be able to generate a large amount of anandamide, at least under physiological conditions. The generation of anandamide from free arachidonic acid and ethanolamine is catalyzed by a degrading enzyme anandamide amidohydrolase/fatty acid amide hydrolase operating in reverse and requires large amounts of substrates. As for the second pathway, arachidonic acids esterified at the 1-position of glycerophospholipids, which are mostly esterified at the 2-position, are utilized for the formation of N -arachidonoyl PE, a stored precursor form of anandamide. In fact, the actual levels of anandamide in various tissues are generally low except in a few cases. 2-Arachidonoylglycerol (2-AG) was the second endogenous cannabinoid receptor ligand to be discovered. 2-AG is a degradation product of arachidonic acid-containing glycerophospholipids such as inositol phospholipids. Several investigators have demonstrated that 2-AG is produced in a variety of tissues and cells upon stimulation. 2-AG acts as a full agonist at the cannabinoid receptors (CB1 and CB2). Evidence is gradually accumulating and indicates that 2-AG is the most efficacious endogenous natural ligand for the cannabinoid receptors. In this review, we summarize the tissue levels, biosynthesis, degradation and possible physiological significance of two endogenous cannabimimetic molecules, anandamide and 2-AG.

Reversal of delta 9-THC hyperphagia by SR141716 and naloxone but not dexfenfluramine

Presatiated adult male Lister hooded rats received oral administration of the exogenous cannabinoid Delta-9-tetrahydrocannabinol (Delta(9)-THC; 1.0 mg/kg) in combination with subcutaneous injection of either the cannabinoid CB1 antagonist N-piperidino-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methylpyrazole-3-carboxamide (SR141716; 0, 0.05, 0.1, 0.5 or 1.0 mg/kg), the CB2 antagonist N-[(1S)-endo-1,3,3-trimethyl bicyclo[2.2.1]heptan-2-yl]-5-(4-chloro-3-methylphenyl)-1-(4-methylbenzyl)-pyrazole-3-carboxamide (SR144528; 0, 0.05, 0.1, 0.5 or 1.0 mg/kg), the general opioid antagonist naloxone (0.1, 0.5, 1.0 or 5.0 mg/kg) or the 5-HT agonist dexfenfluramine (0.05, 0.1, 0.5, 1.0 or 5.0 mg/kg). Food (chow) intake was measured over 2 h from the onset of the dark period. Delta(9)-THC induced significant hyperphagia, which was attenuated by subanorectic doses of SR141716 and naloxone. Neither SR144528 nor dexfenfluramine affected Delta(9)-THC-induced feeding. These data confirm mediation of Delta(9)-THC hyperphagia by central-type CB1 receptors, and support a functional relationship between cannabinoid and opioid systems in relation to appetite regulation. Stimulation of CB1 receptors may promote feeding by actions on food reward rather than by inhibition of serotonergic satiety mechanisms.

Anandamide administration into the ventromedial hypothalamus stimulates appetite in rats

This investigation reports the possible role of the endocannabinoid anandamide in modulating appetitive behaviour. Given that cannabinoids have been used clinically to stimulate appetite in HIV and cancer chemotherapy patients, there has been a renewed interest in the involvement of cannabinoids in appetite modulation. This is the first report on the administration of anandamide into the ventromedial hypothalamus. Pre-satiated rats received an intrahypothalamic injection of anandamide (50 ng x 0.5 microl(-1)) followed by measurement of food intake at 3 h post injection. Administration of anandamide induced significant hyperphagia. Pretreatment with the selective CB1 cannabinoid antagonist SR 141716 (30 microg x 0.5 microl(-1)), 30 min prior to anandamide injection resulted in an attenuation of the anandamide-induced hyperphagia (P<0.001). This study demonstrates that intrahypothalamic anandamide initiates appetite by stimulation of CB1 receptors, thus providing evidence on the involvement of hypothalamic endocannabinoids in appetite initiation.

Novel physiologic functions of endocannabinoids as revealed through the use of mutant mice

The presence in the mammalian brain of specific receptors for marijuana triggered a search for endogenous ligands, several of which have been recently identified. There has been growing interest in the possible physiological functions of endocannabinoids, and mutant mice that lack cannabinoid receptors have become an important tool in the search for such functions. To date, studies using CB1 knockout mice have supported the possible role of endocannabinoids in retrograde synaptic inhibition in the hippocampus, in long-term potentiation and memory, in the development of opiate dependence, and in the control of appetite and food intake. They also suggested the existence of as yet unidentified cannabinoid receptors in the cardiovascular and central nervous systems. The use of CB2 receptor knockout mice suggested a role for this receptor in macrophage-mediated helper T cell activation. Further studies will undoubtedly reveal many additional roles for this novel signaling system.

Endocannabinoids Part II: pathological CNS conditions involving the endocannabinoid system and their possible treatment with endocannabinoid-based drugs

Changes in the levels of either the cannabinoid CB(1) receptors or of their endogenous ligands, anandamide and 2-arachidonoylglycerol, appear to be casual or consequential in many neurological disorders. Several examples of how such diseases may be treated by substances capable of selectively manipulating endocannabinoid levels and action are presented, using animal models of neuropathological conditions, such as motor disorders, multiple sclerosis, neuronal damage, chronic and inflammatory pain, anorexia, cachexia and motivational disturbances. These examples indicate that new therapeutic agents, lacking the undesirable psychotropic side effects of Cannabis, may be developed from current studies on the endocannabinoid system.

Critical role of the endogenous cannabinoid system in mouse pup suckling and growth

Delta9-tetrahydrocannabinol, the active principle in marijuana, is a cannabinoid receptor agonist. Both the crude drug and delta9-tetrahydrocannabinol have been used as appetite promoters. The endogenous cannabinoid, arachidonoyl ethanolamide (anandamide), likewise a cannabinoid receptor agonist, has been shown to have the same effect. In contrast, the cannabinoid CB1 receptor antagonist N-(piperidin-1-yl)-5(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1-H-pyrazole-3-carboxamide (SR141716A) reduces food intake. Here, we report that administration of SR141716A to newly born mouse pups (either a single administration on postnatal day 1, or daily for a week as of postnatal day 2) had a devastating effect on milk ingestion and growth. The first 24 h after birth appeared the most critical for the growth stunting effect of SR141716A. Death followed within 4-8 days. Co-administration of delta9-tetrahydrocannabinol almost fully reversed the effect of the antagonist in the week-long regimen. Co-administration of 2-arachidonoyl glycerol, an endocannabinoid, with 2-palmitoyl glycerol and 2-linoleoyl glycerol, which enhance 2-arachidonoyl glycerol potency, resulted in a significant delay in mortality rates caused by the antagonist. We conclude that the endocannabinoid system plays a vital role in milk suckling, and hence in growth and development during the early stages of mouse life.

Leptin-regulated endocannabinoids are involved in maintaining food intake

Leptin is the primary signal through which the hypothalamus senses nutritional state and modulates food intake and energy balance. Leptin reduces food intake by upregulating anorexigenic (appetite-reducing) neuropeptides, such as alpha-melanocyte-stimulating hormone, and downregulating orexigenic (appetite-stimulating) factors, primarily neuropeptide Y. Genetic defects in anorexigenic signalling, such as mutations in the melanocortin-4 (ref. 5) or leptin receptors, cause obesity. However, alternative orexigenic pathways maintain food intake in mice deficient in neuropeptide Y. CB1 cannabinoid receptors and the endocannabinoids anandamide and 2-arachidonoyl glycerol are present in the hypothalamus, and marijuana and anandamide stimulate food intake. Here we show that following temporary food restriction, CB1 receptor knockout mice eat less than their wild-type littermates, and the CB1 antagonist SR141716A reduces food intake in wild-type but not knockout mice. Furthermore, defective leptin signalling is associated with elevated hypothalamic, but not cerebellar, levels of endocannabinoids in obese db/db and ob/ob mice and Zucker rats. Acute leptin treatment of normal rats and ob/ob mice reduces anandamide and 2-arachidonoyl glycerol in the hypothalamus. These findings indicate that endocannabinoids in the hypothalamus may tonically activate CB1 receptors to maintain food intake and form part of the neural circuitry regulated by leptin.

Separation-induced body weight loss, impairment in alternation behavior, and autonomic tone: effects of tyrosine

We have investigated the effects of tyrosine on alternation behavior and hippocampal adrenergic and cholinergic tone in a model of self-induced weight loss caused by separation stress. Separation decreased body weight in mice (P < .001) and spontaneous alternations in the T-maze (P < .001). This impairment was associated with depletion of both norepinephrine (NE, P < .001) and dopamine (P < .01) while increasing MHPG (P < .05) and the ratio of MHPG/NE (P < .05). Increasing tyrosine availability restored performance to control levels (P < .001) and repleted dopamine (P < .05) and presumably also NE (indicated by increases in both MHPG, P < .001, and MHPG/NE, P < .05). Stress increased adrenergic alpha(2)-receptor density (P < .001) without changing its K(d) and the B(max) and K(d) of beta-receptors, suggesting that it decreased NE transmission through action on alpha(2)-receptors. The balance between beta- and alpha(2)-receptors appeared to be related to alternation behavior as shown by the decrease (P < .01) and increase (P < .05) in their ratios induced by stress and tyrosine, respectively. With regard to cholinergic tone, separation stress increased M1 receptor density (P < .05) and its mRNA signal (P < .001). Tyrosine further increased M1 receptor density of stressed mice (P < .05). Tyrosine might be a potential therapy for cognitive and mood problems associated with the maintenance of a reduced body weight in the treatment of obesity and in the extreme case of anorexia nervosa.

Endocannabinoids and fatty acid amides in cancer, inflammation and related disorders

The long history of the medicinal use of Cannabis sativa and, more recently, of its chemical constituents, the cannabinoids, suggests that also the endogenous ligands of cannabinoid receptors, the endocannabinoids, and, particularly, their derivatives may be used as therapeutic agents. Studies aimed at correlating the tissue and body fluid levels of endogenous cannabinoid-like molecules with pathological conditions have been started and may lead to identify those diseases that can be alleviated by drugs that either mimic or antagonize the action of these substances, or modulate their biosynthesis and degradation. Hints for the therapeutic applications of endocannabinoids, however, can be obtained also from our previous knowledge of marijuana medicinal properties. In this article, we discuss the anti-tumor and anti-inflammatory activity of: (1) the endocannabinoids anandamide (arachidonoylethanolamide) and 2-arachidonoyl glycerol; (2) the bioactive fatty acid amides palmitoylethanolamide and oleamide; and (3) some synthetic derivatives of these compounds, such as the N-acyl-vanillyl-amines. Furthermore, the possible role of cannabimimetic fatty acid derivatives in the pathological consequences of cancer and inflammation, such as cachexia, wasting syndrome, chronic pain and local vasodilation, will be examined.