Gastrointestinal activity of Justicia spicigera Schltdl. in experimental models.

Justicia spicigera Schltdl. (Acanthaceae) is used for treatment of gastrointestinal illnesses therapy in traditional medicine. The objective of this study was to give evidence of the antinociceptive and spasmolytic effects of the J. spicigera ethanol extract (JS EtOH) using in in vivo and/or in vitro assays. The JS EtOH exerted regulatory effect on the motility and a partial relaxing response on the intestinal tissue. Furthermore, a significant abdominal antinociceptive response was obtained in mice, which was totally abolished in the presence of 5-HT1A receptor antagonist (WAY100635, 0.1 mg/kg, s.c.) and partially by blocking opioid receptors (NX, 1 mg/kg, i.p.), whereas the inhibition of the NO synthesis (L-NAME, 30 mg/kg, i.p.) facilitated antinociception of this extract. Kaempferitrin was isolated and identified as major secondary metabolite. These results support the analgesic and spasmolytic-like activity of J. spicigera aerial parts involving inhibitory neurotransmission reinforcing the potential of this medicinal plant for alleviating pain.

Tagetes lucida Cav.: Ethnobotany, phytochemistry and pharmacology of its tranquilizing properties.

ETHNOPHARMACOLOGICAL RELEVANCE: Morelos State is one of the most important regions of Mexico where several plant species are used in traditional medicine to influence central nervous system (CNS) activity; for example Tagetes lucida Cav. AIM OF THE STUDY: To investigate the ethnobotany, phytochemistry and pharmacology of the tranquilizing properties of T. lucida aerial parts. MATERIAL AND METHODS: Data on the medicinal uses of T. lucida were explored by interviewing healers and merchants of local markets in different regions of Morelos State by using a questionnaire. Anxiolytic and/or sedative-like responses of the T. lucida were investigated in experimental models in mice such as: open-field, exploration cylinder, hole-board, plus-maze, and the barbituric-induced hypnosis potentiation. The possible mechanism of action was explored in the presence of WAY100635 (0.32mg/kg, i.p.) and flumazenil (10mg/kg, i.p.) antagonists. A feasible active compound was isolated and identified by using conventional chromatography, including UHPLC and MS (DART) [M+H]+ techniques. RESULTS: Interviews of healers and merchants from ten local regions of Morelos State showed that they recommended T. lucida as infusion and as tincture for several culture-bound syndromes associated with the CNS. Anxiolytic and sedative-like activities of polar extracts were corroborated in the experimental models; these effects were inhibited in the presence of 5-HT1A and GABA/BDZ receptor antagonists. Dimethylfraxetin was identified as one possible active compound. CONCLUSIONS: The results support the anxiolytic and sedative-like properties of T. lucida in traditional medicine by involving serotonergic and GABAergic neurotransmission and coumarinic constituents.

Postprandial glycaemia and inhibition of α-glucosidase activity by aqueous extract from Coriandrum sativum.

The antihyperglycaemic properties of the aqueous extract from the leaves and stems of Coriandrum sativum L. were evaluated in normoglycaemic rats, and on α-glucosidase activity from Saccharomyces cerevisiae, in order to validate its use in folk medicine. In in vivo experiments rats were administered with the aqueous extract of the plant at 100, 300 and 500 mg/kg, to observe the effect on oral sucrose tolerance test. The aqueous extract exhibited significant antihyperglycaemic activity at the three tested doses. In vitro experiments with α-glucosidase exhibited a competitive-type inhibition. These results confirm the antidiabetic properties of the extract of C. sativum L., probably by the inhibition of α-glucosidase in the gastrointestinal tract.

Aqueous extract of Annona macroprophyllata: a potential α-glucosidase inhibitor.

Annona genus contains plants used in folk medicine for the treatment of diabetes. In the present study, an aqueous extract prepared from Annona macroprophyllata (Annonaceae, also known as A. diversifolia) leaves was evaluated on both the activity of yeast α -glucosidase (an in vitro assay) and sucrose tolerance in Wistar rats. The results have shown that the aqueous extract from A. macroprophyllata inhibits the yeast α -glucosidase with an IC50 = 1.18 mg/mL, in a competitive manner with a K(i) = 0.97 mg/mL, a similar value to that of acarbose (K(i) = 0.79 mg/mL). The inhibitory activity of A. macroprophyllata was reinforced by its antihyperglycemic effect, at doses of 100, 300, and 500 mg/kg in rats. Chromatographic analysis identified the flavonoids rutin and isoquercitrin in the most polar fractions of A. macroprophyllata crude extract, suggesting that these flavonoids are part of the active constituents in the plant. Our results support the use of A. macroprophyllata in Mexican folk medicine to control postprandial glycemia in people with diabetes mellitus, involving active constituents of flavonoid nature.