Enrichment of Echinacea angustifolia with Bauer Alkylamide 11 and Bauer Ketone 23 Increased Anti-inflammatory Potential through Interference with COX-2 Enzyme Activity

Bauer alkylamide 11 and Bauer ketone 23 were previously found to be partially responsible forEchinacea angustifolia anti-inflammatory properties. This study further tested their importance using the inhibition of prostaglandin E2 (PGE2) and nitric oxide (NO) production by RAW264.7 mouse macrophages in the absence and presence of lipopolysaccharide (LPS) and E. angustifolia extracts, phytochemical enriched fractions, or pure synthesized standards. Molecular targets were probed using microarray, qRT-PCR, Western blot, and enzyme assays. Fractions with these phytochemicals were more potent inhibitors of LPS-induced PGE2 production than E. angustifolia extracts. Microarray did not detect changes in transcripts with phytochemical treatments; however, qRT-PCR showed a decrease in TNF-α and an increase of iNOS transcripts. LPS-induced COX-2 protein was increased by an E. angustifolia fraction containing Bauer ketone 23 and by pure phytochemical. COX-2 activity was decreased with all treatments. The phytochemical inhibition of PGE2 production byEchinacea may be due to the direct targeting of COX-2 enzyme

Stereoselective synthesis, natural occurrence and CB₂ receptor binding affinities of alkylamides from herbal medicines such as 'Echinacea' sp.

A divergent synthesis of (2E,4E,8E,10E)- and (2E,4E,8E,10Z)-N-isobutyldodeca-2,4,8,10-tetraenamides from pent-4-yn-1-ol allowed identification of the (2E,4E,8E,10Z)-isomer for the first time in Echinacea species. A short, stereoselective synthesis of the (2E,4E,8E,10Z)-isomer is also described which allowed further biological evaluation of this material, and the demonstration that this isomer does not occur in 'Spilanthes mauritiana' as previously reported

Synergistic immunopharmacological effects of N-alkylamides in Echinacea purpurea herbal extracts

Echinacea purpurea (L.) Moench extracts are used in the production of standardized herbal medicines for the prevention and treatment of upper respiratory infections. Unsaturated N-alkylamide lipids, the main constituents of E. purpurea and E. angustifolia preparations capable of activating the cannabinoid receptor type-2 (CB2) have been suggested to play a role as potential anti-inflammatory and immune-modulatory principles. Here we show that ethanolic E. purpurea radix and herba extracts produce synergistic pharmacological effects on the endocannabinoid system in vitro. Superadditive action of N-alkylamide combinations were seen at the level of intracellular calcium release as a function of CB2 receptor activation. Likewise, synergism of the radix and herba tinctures was observed in experiments measuring LPS-stimulated cytokine expression from human PBMCs. While the expression of the anti-inflammatory cytokine IL-10 was significantly superstimulated, the expression of the pro-inflammatory TNF-alpha protein was inhibited more strongly upon combination of the extracts. We show that N-alkylamides act in concert and exert pleiotropic effects modulating the endocannabinoid system by simultaneously targeting the CB2 receptor, endocannabinoid transport and degradation

Discovery of novel CB2 receptor ligands by a pharmacophore-based virtual screening workflow

Cannabinoid receptor 2 (CB2 receptor) ligands are potential candidates for the therapy of chronic pain, inflammatory disorders, atherosclerosis, and osteoporosis. We describe the development of pharmacophore models for CB2 receptor ligands, as well as a pharmacophore-based virtual screening workflow, which resulted in 14 hits for experimental follow-up. Seven compounds were identified with K-i values below 25 mu M. The CB2 receptor-selective pyridine tetrahydrocannabinol analogue 8 (K-i = 1.78 mu M) was identified as a CB2 partial agonist. Acetamides 12 (K-i = 1.35 mu M) and 18 (K-i = 2.1 mu M) represent new scaffolds for CB2 receptor-selective antagonists and inverse agonists, respectively. Overall, our pharmacophore-based workflow yielded three novel scaffolds for the chemical development of CB2 receptor ligands

Identification of endocannabinoid system-modulating N-alkylamides from Heliopsis helianthoides var. scabra and Lepidium meyenii.

The discovery of the interaction of plant-derived N-alkylamides (NAAs) and the mammalian endocannabinoid system (ECS) and the existence of a plant endogenous N-acylethanolamine signaling system have led to the re-evaluation of this group of compounds. Herein, the isolation of seven NAAs and the assessment of their effects on major protein targets in the ECS network are reported. Four NAAs, octadeca-2E,4E,8E,10Z,14Z-pentaene-12-ynoic acid isobutylamide (1), octadeca-2E,4E,8E,10Z,14Z-pentaene-12-ynoic acid 2'-methylbutylamide (2), hexadeca-2E,4E,9Z-triene-12,14-diynoic acid isobutylamide (3), and hexadeca-2E,4E,9,12-tetraenoic acid 2'-methylbutylamide (4), were identified from Heliopsis helianthoides var. scabra. Compounds 2-4 are new natural products, while 1 was isolated for the first time from this species. The previously described macamides, N-(3-methoxybenzyl)-(9Z,12Z,15Z)-octadecatrienamide (5), N-benzyl-(9Z,12Z,15Z)-octadecatrienamide (6), and N-benzyl-(9Z,12Z)-octadecadienamide (7), were isolated from Lepidium meyenii (Maca). N-Methylbutylamide 4 and N-benzylamide 7 showed submicromolar and selective binding affinities for the cannabinoid CB1 receptor (Ki values of 0.31 and 0.48 μM, respectively). Notably, compound 7 also exhibited weak fatty acid amide hydrolase (FAAH) inhibition (IC50 = 4 μM) and a potent inhibition of anandamide cellular uptake (IC50 = 0.67 μM) that was stronger than the inhibition obtained with the controls OMDM-2 and UCM707. The pronounced ECS polypharmacology of compound 7 highlights the potential involvement of the arachidonoyl-mimicking 9Z,12Z double-bond system in the linoleoyl group for the overall cannabimimetic action of NAAs. This study provides additional strong evidence of the endocannabinoid substrate mimicking of plant-derived NAAs and uncovers a direct and indirect cannabimimetic action of the Peruvian Maca root