ABSTRACT
Phytocannabinoids, such as the principal bioactive component of marijuana, delta9-tetrahydrocannabinol, have been used for thousands of years for medical and recreational purposes. delta9-Tetrahydrocannabinol and endogenous cannabinoids (e.g., anandamide) initiate their agonist properties by stimulating the cannabinoid family of G protein-coupled receptors (CB1 and CB2). The biosynthesis and physiology of anandamide is well understood, but its mechanism of uptake (resulting in signal termination by fatty acid amide hydrolase) has been elusive. Mounting evidence points to the existence of a specific anandamide transport protein; however, no direct evidence for this protein has been provided. Here, we use a potent, competitive small molecule inhibitor of anandamide uptake (LY2318912, IC50 7.27 +/- 0.510 nM) to identify a high-affinity, saturable anandamide transporter binding site (LY2318912; K(d) = 7.62 +/- 1.18 nM, B(max) = 31.6 +/- 1.80 fmol/mg protein) that is distinct from fatty acid amide hydrolase. Systemic administration of the inhibitor into rodents elevates anandamide levels 5-fold in the brain and demonstrates efficacy in the formalin paw-licking model of persistent pain with no obvious adverse effects on motor function. Identification of the anandamide transporter binding site resolves a missing mechanistic link in endocannabinoid signaling, and in vivo results suggest that endocannabinoid transporter antagonists may provide a strategy for positive modulation of cannabinoid receptors.
Subject(s)
Cannabinoids/metabolism , Animals , Binding Sites/drug effects , Biological Transport/drug effects , Cell Line , Humans , Molecular Structure , Rats , Tetrazoles/chemistry , Tetrazoles/pharmacologyABSTRACT
A diterpenoid, totarol (1), from Podocarpus nagi was evaluated as an antioxidant. This diterpenoid inhibited autoxidation of linoleic acid. Mitochondrial and microsomal lipid peroxidation induced by Fe(III)-ADP/NADH or Fe(III)-ADP/NADPH were also inhibited. Nagilactone E (2), a norditerpene lactone isolated from the same source, had no antioxidative activity. Furthermore, totarol protected red cells against oxidative hemolysis. This diterpene was shown to be effective in protecting biological systems against oxidative stresses.
Subject(s)
Antioxidants/pharmacology , Diterpenes/pharmacology , Lipid Peroxidation/drug effects , Abietanes , Adenosine Diphosphate/analogs & derivatives , Adenosine Diphosphate/pharmacology , Animals , Erythrocyte Membrane/metabolism , Humans , Linoleic Acid , Linoleic Acids/metabolism , Male , Membrane Lipids/blood , Microsomes, Liver/drug effects , Microsomes, Liver/metabolism , Mitochondria, Liver/drug effects , Mitochondria, Liver/metabolism , NAD/metabolism , NAD/pharmacology , NADP/metabolism , NADP/pharmacology , Oxidation-Reduction , Rats , Rats, WistarABSTRACT
A new steroid alkaloid, namely croomionidine (II), together with four known compounds pachysamine A(I), croomine (III), didehydrocroomine (IV) and beta-sitosterol were isolated from the roots of Croomia japonica Miq. Their structures were identified by IR, MS, 1H NMR, 13C NMR and chemical conversion.
Subject(s)
Drugs, Chinese Herbal/chemistry , Pregnanes/isolation & purification , Pyrrolidines/isolation & purification , Spiro Compounds/isolation & purification , Molecular Structure , Pregnanes/chemistry , Pyrrolidines/chemistry , Spiro Compounds/chemistryABSTRACT
Three novel diterpenoids, pseudolaric acids A, B and C, were isolated from the root bark of Pseudolarix kaempferi Gorden used as an antifungal agent in folk medicine in China. The structures of pseudolaric acids B and C were assigned as 1 and 6 by spectral and chemical evidence. Pseudolaric acids A, B and C possess antifungal activity and pseudolaric acid B possesses an antifertility effect.
