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The renewed interest in dimeric salicylates as broad-spectrum anti-inflammatory and anti-diabetic agents provided a rationale to investigate the dimerization of the substituted salicylate Δ 9-tetrahydrocannabinolic acid (THCA-A, 3a) as a strategy to solve its instability to decarboxylation and to generate analogues and/or pro-drugs of this native pre-cannabinoid. Activation of the carboxylic group with the DCC-HOBt-DMAP protocol afforded a high yield of the OBt ester 4 , that was next converted into the highly crystalline di-depsidic dimer 5 upon treatment with DMAP. The mono-depsidic dimer 6 was also formed when the reaction was carried out with partially decarboxylated THCA-A samples. The structure of the depsidic dimers was established by spectroscopic methods and by aminolysis of 5 into the pre-cannabinoid amide 7. Both dimers showed excellent shelf stability and did not generate significant amounts of Δ 9-THC upon heating. However, only the didepsidic dimer 5 activated PPAR- γ , the major target of pre-cannabinoids, but strong binding to serum proteins abolished this activity, also shielding it from the action of esterases. THCA-A was dimerized to a highly crystalline bis-depsidic analogue by carboxylate activation as HOBt ester followed by treatment with DMAP. The dimer was stable toward decarboxylation and partially retained the PPAR- γ -activating properties of THCA-A. Image 1 [ABSTRACT FROM AUTHOR]

The discovery of taste receptors hTAS2Rs expression in extra oral tissue, especially in the gastrointestinal tract and in the respiratory system, has endowed bitter receptors of functionalities that exceed the simple perception of taste and flavour. In particular, stimulation of hTAS2Rs by bitter agents in the airway smooth muscle triggers bronchodilation of possible pharmacological relevance. To study the receptor localization in pulmonary smooth muscle cells and to investigate their biological response to hTAS2R38 activation, we have developed a fluorescent probe for hTAS2R38 starting from the sesquiterpene lactone costunolide, available in multigram amounts from Artemisia umbelliformis Lam. The N -methylanthranilate-containing probe demonstrated a very low cytotoxicity compared to the natural product toward human airway smooth muscle cells and epithelial bronchial cells, but fully retained its binding to hTAS2R38, making it possible the fluorescent detection of cells expressing this bitter receptor. [ABSTRACT FROM AUTHOR]

Helichrysum umbraculigerum Less. has been reported to be a prolific producer of phytocannabinoids from the alkyl-, aralkyl-, normal-, and abnormal types. Investigation of an acetone extract from the aerial parts of the plant afforded two novel amorfrutin-type phytocannabinoids ( 3b , 4 ) and the new geranylated phloroglucinol 5a . The presence of cannabigerol (CBG, 1a ) and its acidic precursor (pre-CBG, CBGA, 1b ), previously reported from this plant, could not be confirmed, but the phenethyl analogue of CBG (Heli-CBG, 2a) and the methyl ester of its carboxylated version ( 2b ) were isolated. Heli-CBG ( 2a ) was assayed against a series of metabotropic (CB 1 and CB 2 )- and ionotropic (thermo-TRPs) targets of phytocannabinoids, comparing its profile with the one of cannabigerol (CBG). A decreased affinity for cannabinoid receptor was observed, along with substantial retention of the thermo-TRP profile. The biogenetic relationships between the isoprenylated phenolics from H. umbraculigerum are discussed, highlighting the relevance of this species for biogenetic investigations on phytocannabinoids [ABSTRACT FROM AUTHOR]

This study was aimed to investigate whether treatment with purified cannabidiol (CBD) may counteract the development of experimental multiple sclerosis (MS), by targeting the PI3K/Akt/mTOR pathway. Although the PI3K/Akt/mTOR pathway was found to be activated by cannabinoids in several immune and non-immune cells, currently, there is no data about the effects of CBD in the PI3K/Akt/mTOR activity in MS. Experimental Autoimmune Encephalomyelitis (EAE), the most common model of MS, was induced in C57BL/6 mice by immunization with myelin oligodendroglial glycoprotein peptide (MOG) 35–55 . After EAE onset, which occurs approximately 14 days after disease induction, mice were daily intraperitoneally treated with CBD (10 mg/kg mouse) and observed for clinical signs of EAE. At 28 days from EAE-induction, mice were euthanized and spinal cord tissues were sampled to perform immunohistochemical evaluations and western blot analysis. Our results showed a clear downregulation of the PI3K/Akt/mTOR pathway following EAE induction. CBD treatment was able to restore it, increasing significantly the phosphorylation of PI3K, Akt and mTOR. Also, an increased level of BNDF in CBD-treated mice seems to be involved in the activation of PI3K/Akt/mTOR pathway. In addition, our data demonstrated that therapeutic efficacy of CBD treatment is due to reduction of pro-inflammatory cytokines, like IFN-γ and IL-17 together with an up-regulation of PPARγ. Finally, CBD was found to promote neuronal survival by inhibiting JNK and p38 MAP kinases. These results provide an interesting discovery about the regulation of the PI3K/Akt/mTOR pathway by cannabidiol administration, that could be a new potential therapeutic target for MS management. [ABSTRACT FROM AUTHOR]

Abstract: This study examines the protective effect of arzanol, a pyrone–phloroglucinol etherodimer from Helichrysum italicum subsp. microphyllum, against the oxidative modification of lipid components induced by Cu2+ ions in human low density lipoprotein (LDL) and by tert-butyl hydroperoxide (TBH) in cell membranes. LDL pre-treatment with arzanol significantly preserved lipoproteins from oxidative damage at 2h of oxidation, and showed a remarkable protective effect on the reduction of polyunsaturated fatty acids and cholesterol levels, inhibiting the increase of oxidative products (conjugated dienes fatty acids hydroperoxides, 7β-hydroxycholesterol, and 7-ketocholesterol). Arzanol, at non-cytotoxic concentrations, exerted a noteworthy protection on TBH-induced oxidative damage in a line of fibroblasts derived from monkey kidney (Vero cells) and in human intestinal epithelial cells (Caco-2), decreasing, in both cell lines, the formation of oxidative products (hydroperoxides and 7-ketocholesterol) from the degradation of unsaturated fatty acids and cholesterol. The cellular uptake and transepithelial transport of the compound were also investigated in Caco-2 cell monolayers. Arzanol appeared to accumulate in Caco-2 epithelial cells. This phenol was able to pass through the intestinal Caco-2 monolayers, the apparent permeability coefficients (P app) in the apical-to-basolateral and basolateral-to-apical direction at 2h were 1.93±0.36×10−5 and 2.20±0.004×10−5 cm/s, respectively, suggesting a passive diffusion pathway. The results of the work qualify arzanol as a potent natural antioxidant with a protective effect against lipid oxidation in biological systems. [Copyright &y& Elsevier]

Parkinson's disease (PD) is a neurodegenerative disorder characterized by the degeneration of the nigrostriatal dopaminergic pathway with loss of substantia nigra pars compacta neurons and dopamine depletion. Various natural compounds showed protective actions against PD. In this work, the protective effects of cannabidiol (CBD), obtained from Cannabis sativa , were evaluated in retinoic acid differentiated SH-SY5Y cells exposed to 1-methyl-4-phenylpyridinium (MPP+), an in vitro PD model. In order to evaluate which receptor is involved in CBD actions CB1, CB2 and TRPV1 receptor antagonists were used. CBD counteracted the loss of cell viability caused by MPP+, reducing apoptosis as demonstrated by the reduction of Bax and caspase 3. Moreover, CBD reduced the nuclear levels of PARP-1. The protective effects of CBD seem to be mediated by the activation of ERK and AKT/mTOR pathways. The treatment with AKT1/2 inhibitor and the mTOR inhibitor rapamycin abolished CBD protective effects. The CBD-induced ERK activation may be mediated by CBD interaction with CB2 and TRPV1. We also investigated the protein levels of the autophagic proteins LC3 and beclin 1. CBD reduced the MPP+-induced increase of LC3 by CB2 and TRPV1 receptors. These data suggested the involvement of ERK in the modulation of autophagy. However, beclin 1 levels were not modified neither by MPP+ nor by CBD. These results indicated that CBD may exert preventive and protective actions in PD. Unlabelled Image • CBD counteracted the loss of cell viability induced by MPP+. • CBD protection was mediated by the activation of ERK and AKT/mTOR pathways. • CBD reduced the MPP+-induced increase of LC3. [ABSTRACT FROM AUTHOR]

The Alpine wormwood Artemisia vallesiaca All. was considered the most valuable ingredient of vermouth, a celebrated aromatized wine. A. vallesiaca has a very limited geographical distribution, and the booming market of vermouth decimated its natural population, resulting in the eventual replacement of this rare species with more common and less expensive wormwoods like A. absinthium L.. Over the past years, attempts to revive the original recipe(s) of vermouth have fostered the establishment of cultivations of A. vallesiaca in pre-montane settings. In order to assist these projects, the phytochemical profile of cultivated plants and of several native populations of A. vallesiaca from the Swiss Valais were comparatively evaluated, focusing on sesquiterpene lactones and on lipophilic flavonoids, the hallmark constituents of Artemisia species. Remarkably, no significant difference was detected between the samples, despite the different origins. The lipophilic flavonoids of A. vallesiaca were similar to those of related species used in the production of vermouth, but the presence of C-9 oxygenated 11β-methyl germacranolides and eudesmanolides (herbolides) made its sesquiterpene lactone profile peculiar. In addition to known compounds, two novel germacranolides were also characterized (herbolides J and K), and the major sesquiterpene lactone from the plant, the bitter germacranolide herbolide D (4), was detected and quantified by 1H NMR in a bitter liqueur aromatized with A. vallesiaca. Taken together, these observations qualify herbolides as marker to identify A. vallesiaca in aromatized alcohol matrixes. Unlabelled Image [ABSTRACT FROM AUTHOR]

The biochemical class of the polymethoxylated flavonoids represents uncommon phenolic compounds in plants presenting a more marked lipophilic behavior due to the alkylation of its hydroxylic groups. As a polymethoxylated flavone, which concerns a different bioavailability, artemetin (ART) has been examined in vitro against lipid oxidation and its impact on cancer cells has been explored. Despite this flavone only exerted a slight protection against in vitro fatty acid and cholesterol oxidative degradation, ART significantly reduced viability and modulated lipid profile in cancer Hela cells at the dose range 10–50 μM after 72 h of incubation. It induced marked changes in the monounsaturated/saturated phospholipid class, significant decreased the levels of palmitic, oleic and palmitoleic acids, maybe involving an inhibitory effect on de novo lipogenesis and desaturation in cancer cells. Moreover, ART compromised normal mitochondrial function, inducing a noteworthy mitochondrial membrane polarization in cancer cells. A dose-dependent absorption of ART was evidenced in HeLa cell pellets (15.2% of the applied amount at 50 μM), coupled to a marked increase in membrane fluidity, as indicate by the dose-dependent fluorescent Nile Red staining (red emissions). Our results validate the ART role as modulatory agent on cancer cell physiology, especially impacting viability, lipid metabolism, cell fluidity, and mitochondrial potential. [Display omitted] [ABSTRACT FROM AUTHOR]

Type 2 taste receptors (TAS2R) areGprotein-coupled receptors first described in the gustatory system, but have also been shown to have extraoral localizations, including airway smooth muscle (ASM) cells, in which TAS2R have been reported to induce relaxation. TAS2R46 is an unexplored subtype that responds to its highly specific agonist absinthin. Here, we first demonstrate that, unlike other bitter-taste receptor agonists, absinthin alone (1 UM) in ASM cells does not induce Ca2+ signals but reduces histamine-induced cytosolic Ca2+ increases. To investigate this mechanism, we introduced into ASM cells aequorin-based Ca2+ probes targeted to the cytosol, subplasma membrane domain, or the mitochondrial matrix. We show that absinthin reduces cytosolic histamine-induced Ca2+ rises and simultaneously increases Ca2+ influx into mitochondria. We found that this effect is inhibited by the potent human TAS2R46 (hTAS2R46) antagonist 3'-hydroxydihydrocostunolide and is no longer evident in hTAS2R46-silenced ASM cells, indicating that it is hTAS2R46-dependent. Furthermore, these changes were sensitive to the mitochondrial uncoupler carbonyl cyanide p-(trifluoromethoxy)phenyl-hydrazone (FCCP); the mitochondrial calcium uniporter inhibitor KB-R7943 (carbamimidothioic acid); the cytoskeletal disrupter latrunculin; and an inhibitor of the exchange protein directly activated by cAMP (EPAC), ESI-09. Similarly, the 2 agonist salbutamol also could induce Ca2+ shuttling from cytoplasm to mitochondria, suggesting that this new mechanism might be generalizable. Moreover, forskolin and an EPAC activator mimicked this effect in HeLa cells. Our findings support the hypothesis that plasma membrane receptors can positively regulate mitochondrial Ca2+ uptake, adding a further facet to the ability of cells to encode complex Ca2+ signals. [ABSTRACT FROM AUTHOR]

One key to animal survival is the detection and avoidance of potentially harmful compounds by their bitter taste. Variable numbers of taste 2 receptor genes expressed in the gustatory end organs enable bony vertebrates (Euteleostomi) to recognize numerous bitter chemicals. It is believed that the receptive ranges of bitter taste receptor repertoires match the profiles of bitter chemicals that the species encounter in their diets. Human and mouse genomes contain pairs of orthologous bitter receptor genes that have been conserved throughout evolution. Moreover, expansions in both lineages generated species-specific sets of bitter taste receptor genes. It is assumed that the orthologous bitter taste receptor genes mediate the recognition of bitter toxins relevant for both species, whereas the lineagespecific receptors enable the detection of substances differently encountered by mice and humans. By challenging 34 mouse bitter taste receptors with 128 prototypical bitter substances in a heterologous expression system, we identified cognate compounds for 21 receptors, 19 of which were previously orphan receptors. We have demonstrated that mouse taste 2 receptors, like their human counterparts, vary greatly in their breadth of tuning, ranging from very broadly to extremely narrowly tuned receptors. However, when compared with humans, mice possess fewer broadly tuned receptors and an elevated number of narrowly tuned receptors, supporting the idea that a large receptor repertoire is the basis for the evolution of specialized receptors. Moreover, we have demonstrated that sequence-orthologous bitter taste receptors have distinct agonist profiles. Species-specific gene expansions have enabled further diversification of bitter substance recognition spectra. [ABSTRACT FROM AUTHOR]

Inflammatory response plays an important role in the activation and progress of many debilitating diseases. Natural products, like cannabidiol, a constituent of Cannabis sativa , and moringin, an isothiocyanate obtained from myrosinase-mediated hydrolysis of the glucosinolate precursor glucomoringin present in Moringa oleifera seeds, are well known antioxidants also endowed with anti -inflammatory activity. This is due to a covalent-based mechanism for ITC, while non-covalent interactions underlie the activity of CBD. Since these two mechanisms are distinct, and the molecular endpoints are potentially complementary, we investigated in a comparative way the protective effect of these compounds alone or in combination on lipopolysaccharide-stimulated murine macrophages. Our results show that the cannabidiol (5 μM) and moringin (5 μM) combination outperformed the single constituents that, at this dosage had only a moderate efficacy on inflammatory (Tumor necrosis factor-α, Interleukin-10) and oxidative markers (inducible nitric oxide synthase, nuclear factor erythroid 2-related factor 2, nitrotyrosine). Significant upregulation of Bcl-2 and downregulation of Bax and cleaved caspase-3 was observed in cells treated with cannabidiol-moringin combination. Treatment with the transient receptor potential vanilloid receptor 1 antagonist was detrimental for the efficacy of cannabidiol, while no effect was elicited by cannabinoid receptor 1 and cannabinoid receptor 2 antagonists. None of these receptors was involved in the activity of moringin. Taken together, our in vitro results testify the anti -inflammatory, antioxidative, and anti-apoptotic effects of the combination of cannabidiol and moringin. [ABSTRACT FROM AUTHOR]

Wormwoods ( Artemisia species) from the génépi group are, along with Edelweiss, iconic plants of the Alpine region and true symbols of inaccessibility because of their rarity and their habitat, largely limited to moraines of glaciers and rock crevices. Infusions and liqueurs prepared from génépis have always enjoyed a panacea status in folk medicine, especially as thermogenic agents and remedies for fatigue, dyspepsia, and airway infections. In the wake of the successful cultivation of white génépi ( Artemisia umbelliformis Lam.) and the expansion of its supply chain, modern studies have evidenced the occurrence of unique constituents, whose chemistry, biological profile, and sensory properties are reviewed along with the ethnopharmacology, botany, cultivation and conservation strategies of their plant sources. [ABSTRACT FROM AUTHOR]

Abstract: Based on its capacity to inhibit in vitro HIV-1 replication in T cells and the release of pro-inflammatory cytokines in monocytes, the prenylated heterodimeric phloroglucinyl α-pyrone arzanol was identified as the major anti-inflammatory and anti-viral constituent from Helichrysum italicum. We have now investigated the activity of arzanol on the biosynthesis of pro-inflammatory eicosanoids, evaluating its anti-inflammatory efficacy in vitro and in vivo. Arzanol inhibited 5-lipoxygenase (EC 7.13.11.34) activity and related leukotriene formation in neutrophils, as well as the activity of cyclooxygenase (COX)-1 (EC 1.14.99.1) and the formation of COX-2-derived prostaglandin (PG)E2 in vitro (IC50 =2.3–9μM). Detailed studies revealed that arzanol primarily inhibits microsomal PGE2 synthase (mPGES)-1 (EC 5.3.99.3, IC50 =0.4μM) rather than COX-2. In fact, arzanol could block COX-2/mPGES-1-mediated PGE2 biosynthesis in lipopolysaccharide-stimulated human monocytes and human whole blood, but not the concomitant COX-2-derived biosynthesis of thromboxane B2 or of 6-keto PGF1α, and the expression of COX-2 or mPGES-1 protein was not affected. Arzanol potently suppressed the inflammatory response of the carrageenan-induced pleurisy in rats (3.6mg/kg, i.p.), with significantly reduced levels of PGE2 in the pleural exudates. Taken together, our data show that arzanol potently inhibits the biosynthesis of pro-inflammatory lipid mediators like PGE2 in vitro and in vivo, providing a mechanistic rationale for the anti-inflammatory activity of H. italicum, and a rationale for further pre-clinical evaluation of this novel anti-inflammatory lead. [ABSTRACT FROM AUTHOR]

The neutral fraction of a juniper (Juniperus communis L.) berries acetone extract could positively modulate the activity of type 1 - cannabinoid receptor (CB 1 R). Bioactivity-directed fractionation identified the labdane diterpenoid agathadiol (4) as a positive allosteric modulator of CB 1 R, while closely related analogues were inactive. Agathadiol (4) is a minor constituent of juniper, but could be more conveniently obtained by semisynthesis from agathic acid (8), a major constituent of Manila copal. [Display omitted] [ABSTRACT FROM AUTHOR]

Flavonoids are a huge class of polyphenolic compounds ubiquitous in higher plants, in most food and beverages of natural origin. They could be considered as dietary phenols, which exert many health-promoting effects on human and animal physiology with a wide range of biomedical and nutritional functions such as activation or inhibition of enzymes like lipoxygenase and cyclooxygenase, the detoxification of carcinogens and chemoprevention. From a chemical point of view, these aromatic compounds can be divided in six subgroups depending on the position of aromatic B ring on C ring, the degree of unsaturation and oxidation, the position of hydroxyl groups and their functionalization. Between flavonoids, the prenylated ones represent a unique class occurring in nature where the C -prenylation is the most common, whereas O -prenylation is rarely present. The presence of this lipophilic functional group in different positions on the scaffold of flavonoids can sometimes lead to relevant changes in their biological activity due to an increased bioavailability. Capitalizing on the restricted incidence in nature of prenylated flavonoids, we have assessed the synthesis of C - and O -prenylated derivatives starting from two flavonoids, quercetin and artemetin, aimed at the exploration of structure-activity relationships. Results showed that prenylation significantly increased the cytotoxic effect of flavonoids in cancer HeLa cells, also improving their capacity to affect cell phospholipid and fatty acid composition. A marked cell bioavailability increase was demonstrated for the artemetin C -prenylated derivative. [Display omitted] • Prenylated flavonoids represent a unique class occurring in nature. • The presence of prenyl-moiety on the scaffold of flavonoids lead to relevant changes in their biological activity. • Synthetic prenylation of quercetin and artemetin increased the cytotoxic effect of flavonoids in cancer HeLa cells. • Synthetic prenylation of quercetin and artemetin also affected cell phospholipid and fatty acid composition of HeLa cells. [ABSTRACT FROM AUTHOR]