Incensole acetate, an incense component, elicits psychoactivity by activating TRPV3 channels in the brain.

Burning of Boswellia resin as incense has been part of religious and cultural ceremonies for millennia and is believed to contribute to the spiritual exaltation associated with such events. Transient receptor potential vanilloid (TRPV) 3 is an ion channel implicated in the perception of warmth in the skin. TRPV3 mRNA has also been found in neurons throughout the brain; however, the role of TRPV3 channels there remains unknown. Here we show that incensole acetate (IA), a Boswellia resin constituent, is a potent TRPV3 agonist that causes anxiolytic-like and antidepressive-like behavioral effects in wild-type (WT) mice with concomitant changes in c-Fos activation in the brain. These behavioral effects were not noted in TRPV3(-/-) mice, suggesting that they are mediated via TRPV3 channels. IA activated TRPV3 channels stably expressed in HEK293 cells and in keratinocytes from TRPV3(+/+) mice. It had no effect on keratinocytes from TRPV3(-/-) mice and showed modest or no effect on TRPV1, TRPV2, and TRPV4, as well as on 24 other receptors, ion channels, and transport proteins. Our results imply that TRPV3 channels in the brain may play a role in emotional regulation. Furthermore, the biochemical and pharmacological effects of IA may provide a biological basis for deeply rooted cultural and religious traditions.

Potential anti-inflammatory actions of the elmiric (lipoamino) acids.

A library of amino acid-fatty acid conjugates (elmiric acids) was synthesized and evaluated for activity as potential anti-inflammatory agents. The compounds were tested in vitro for their effects on cell proliferation and prostaglandin production, and compared with their effects on in vivo models of inflammation. LPS stimulated RAW 267.4 mouse macrophage cells were the in vitro model and phorbol ester-induced mouse ear edema served as the principal in vivo model. The prostaglandin responses were found to be strongly dependent on the nature of the fatty acid part of the molecule. Polyunsaturated acid conjugates produced a marked increase in media levels of i15-deoxy-PGJ(2) with minimal effects on PGE production. It is reported in the literature that prostaglandin ratios in which the J series predominates over the E series promote the resolution of inflammatory conditions. Several of the elmiric acids tested here produced such favorable ratios suggesting that their potential anti-inflammatory activity occurs via a novel mechanism of action. The ear edema assay results were generally in agreement with the prostaglandin assay findings indicating a connection between them.

Sex and hormonal cycle differences in rat brain levels of pain-related cannabimimetic lipid mediators.

One important function of endocannabinoids and related lipid mediators in mammalian central nervous system is modulation of pain. Evidence obtained during the last decade shows that altered levels of these compounds in the brain accompany decreases in pain sensitivity. Such changes, if sexually dimorphic, could account for sex differences in pain and differences that occur during different phases of the hormonal cycle in females. To examine this possibility, we measured the levels of the pain-modulatory lipids anandamide, 2-arachidonoyl glycerol, N-arachidonoyl glycine, N-arachidonoyl gamma amino butyric acid, and N-arachidonoyl dopamine in seven different brain areas (pituitary, hypothalamus, thalamus, striatum, midbrain, hippocampus, and cerebellum) in male rats, and in female rats at five different points in the estrous cycle. The cerebellum did not demonstrate a change in endocannabinoid production across the estrous cycle, whereas all other areas tested showed significant differences in at least one of the compounds measured. These changes in levels occurred predominantly within the 36-h time period surrounding ovulation and behavioral estrus. Differences between males and females were measured as either estrous cycle-independent (all estrous cycles combined) or cycle-dependent (comparisons of males to each estrous cycle). In cycle-independent analyses, small sex differences were observed in the pituitary, hypothalamus, cerebellum, and striatum, whereas no differences were observed in the thalamus, midbrain, and hippocampus. In cycle-dependent analyses, the hypothalamus and pituitary showed largest sex differences followed by the striatum, midbrain, and hippocampus, whereas no sex differences were measured in thalamus and cerebellum. These data provide a basis for investigations into how differences in sex and hormonal status play a role in mechanisms regulating endocannabinoid production and pain.

Actions of two naturally occurring saturated N-acyldopamines on transient receptor potential vanilloid 1 (TRPV1) channels.

Four long-chain, linear fatty acid dopamides (N-acyldopamines) have been identified in nervous bovine and rat tissues. Two unsaturated members of this family of lipids, N-arachidonoyl-dopamine (NADA) and N-oleoyl-dopamine, were shown to potently activate the transient receptor potential channel type V1 (TRPV1), also known as the vanilloid receptor type 1 for capsaicin. However, the other two congeners, N-palmitoyl- and N-stearoyl-dopamine (PALDA and STEARDA), are inactive on TRPV1. We have investigated here the possibility that the two compounds act by enhancing the effect of NADA on TRPV1 ('entourage' effect). When pre-incubated for 5 min with cells, both compounds dose-dependently enhanced NADA's TRPV1-mediated effect on intracellular Ca(2+) in human embryonic kidney cells overexpressing the human TRPV1. In the presence of either PALDA or STEARDA (0.1-10 microm), the EC(50) of NADA was lowered from approximately 90 to approximately 30 nm. The effect on intracellular Ca(2+) by another endovanilloid, N-arachidonoyl-ethanolamine (anandamide, 50 nm), was also enhanced dose-dependently by both PALDA and STEARDA. PALDA and STEARDA also acted in synergy with low pH (6.0-6.7) to enhance intracellular Ca(2+) via TRPV1. When co-injected with NADA (0.5 micrograms) in rat hind paws, STEARDA (5 micrograms) potentiated NADA's TRPV1-mediated nociceptive effect by significantly shortening the withdrawal latencies from a radiant heat source. STEARDA (1 and 10 micrograms) also enhanced the nocifensive behavior induced by carrageenan in a typical test of inflammatory pain. These data indicate that, despite their inactivity per se on TRPV1, PALDA and STEARDA may play a role as 'entourage' compounds on chemicophysical agents that interact with these receptors, with possible implications in inflammatory and neuropathic pain.