Antidiarrheal, vasorelaxant, and neuropharmacological actions of the diterpene tilifodiolide

Neuropharmacological Effects of the Dichloromethane Extract from the Stems of Argemone ochroleuca Sweet (Papaveraceae) and Its Active Compound Dihydrosanguinarine

Argemone ochroleuca Sweet (Papaveraceae) is used in folk medicine as a sedative and hypnotic agent. This study aimed to evaluate the anxiolytic-like, sedative, antidepressant-like, and anticonvulsant activities of a dichloromethane extract of A. ochroleuca stems (AOE), chemically standardized using gas chromatography-mass spectrometry (GC-MS), and its active compound dihydrosanguinarine (DHS). The anxiolytic-like, sedative, antidepressant-like, and anticonvulsant activities of the AOE (0.1-50 mg/kg p.o.) and DHS (0.1-10 mg/kg p.o.) were evaluated using murine models. A possible mechanism for the neurological actions induced by the AOE or DHS was assessed using inhibitors of neurotransmission pathways and molecular docking. Effective dose 50 (ED50) values were calculated by a linear regression analysis. The AOE showed anxiolytic-like activity in the cylinder exploratory test (ED50 = 33 mg/kg), and antidepressant-like effects in the forced swimming test (ED50 = 3 mg/kg) and the tail suspension test (ED50 = 23 mg/kg), whereas DHS showed anxiolytic-like activity (ED50 = 2 mg/kg) in the hole board test. The AOE (1-50 mg/kg) showed no locomotive affectations or sedation in mice. A docking study revealed the affinity of DHS for α2-adrenoreceptors and GABAA receptors. The anxiolytic-like and anticonvulsant effects of the AOE are due to GABAergic participation, whereas the antidepressant-like effects of the AOE are due to the noradrenergic system. The noradrenergic and GABAergic systems are involved in the anxiolytic-like actions of DHS.

In Vivo Neuropharmacological Effects of Neophytadiene

Neophytadiene (NPT) is a diterpene found in the methanolic extracts of Crataeva nurvala and Blumea lacera, plants reported with anxiolytic-like activity, sedative properties, and antidepressant-like actions; however, the contribution of neophytadiene to these effects is unknown. This study determined the neuropharmacological (anxiolytic-like, antidepressant-like, anticonvulsant, and sedative) effects of neophytadiene (0.1-10 mg/kg p.o.) and determined the mechanisms of action involved in the neuropharmacological actions using inhibitors such as flumazenil and analyzing the possible interaction of neophytadiene with GABA receptors using a molecular docking study. The behavioral tests were evaluated using the light-dark box, elevated plus-maze, open field, hole-board, convulsion, tail suspension, pentobarbital-induced sleeping, and rotarod. The results showed that neophytadiene exhibited anxiolytic-like activity only to the high dose (10 mg/kg) in the elevated plus-maze and hole-board tests, and anticonvulsant actions in the 4-aminopyridine and pentylenetetrazole-induced seizures test. The anxiolytic-like and anticonvulsant effects of neophytadiene were abolished with the pre-treatment with 2 mg/kg flumazenil. In addition, neophytadiene showed low antidepressant effects (about 3-fold lower) compared to fluoxetine. On other hand, neophytadiene had no sedative or locomotor effects. In conclusion, neophytadiene exerts anxiolytic-like and anticonvulsant activities with the probable participation of the GABAergic system.

A Review on the Ethnopharmacology and Phytochemistry of the Neotropical Sages (Salvia Subgenus Calosphace; Lamiaceae) Emphasizing Mexican Species

Salvia is the most diverse genus within the mint family (Lamiaceae), many of its species are well-known due to their medicinal and culinary uses. Most of the ethnopharmacological and phytochemical studies on Salvia are centred on species from the European and Asian clades. However, studies about the most diverse clade, the Neotropical sages (Salvia subgenus Calosphace; 587 spp.), are relatively scarce. This review aims to compile the information on the traditional medicinal uses, pharmacological and phytochemistry properties of the Neotropical sages. To do so, we carried out a comprehensive review of the articles available in different online databases published from the past to 2022 (i.e., PubMed, Scopus, and Web of Science, among others) and summarized the information in tables. To uncover phylogenetic patterns in the distribution of four different groups of metabolites (mono-, sesqui-, di-, and triterpenes), we generated presence-absence matrices and plotted the tip states over a dated phylogeny of Salvia. We found several studies involving Mexican species of Salvia, but only a few about taxa from other diversity centres. The main traditional uses of the Mexican species of Calosphace are medicinal and ceremonial. In traditional medicine 56 species are used to treat diseases from 17 categories according to the WHO, plus cultural-bound syndromes. Pharmacological studies reveal a wide range of biological properties (e.g., antinociceptive, anti-inflammatory, anxiolytic, cytotoxic, and antidiabetic, etc.) found in extracts and isolated compounds of 38 Neotropical sages. From extracts of these species, at least 109 compounds have been isolated, identified and evaluated pharmacologically; 73 of these compounds are clerodanes, 21 abietanes, six flavonoids, five sesquiterpenoids, and four triterpenoids. The most characteristic metabolites found in the Neotropical sages are the diterpenes, particularly clerodanes (e.g., Amarisolide A, Tilifodiolide), that are found almost exclusively in this group. The Neotropical sages are a promising resource in the production of herbal medication, but studies that corroborate the properties that have been attributed to them in traditional medicine are scarce. Research of these metabolites guided by the phylogenies is recommended, since closely related species tend to share the presence of similar compounds and thus similar medicinal properties.