Hydroalcoholic extract of Urtica circularis: a neuropharmacological profile

Neuropharmacological Effects in Animal Models and HPLC-Phytochemical Profiling of Byrsonima crassifolia (L.) Kunth Bark Extracts

B. crassifolia is a species that grows in various areas of Latin America. It was known to be useful for the treatment of different human ailments. The present work evaluated the neuropharmacological and analgesic effects of hydroalcoholic and dichloromethane extracts of B. crassifolia. The effect on the central nervous system (CNS) of both extracts obtained from bark, administered by the intraperitoneal route in mice, was evaluated by different tests: spontaneous motor activity, hole-board, motor coordination, pentobarbital induced hypnosis, and rectal temperature. Analgesic activity was evaluated using a hot plate test. Phytochemical analysis was performed by high-performance liquid chromatography (HPLC) using reversed-phase and gradient of elution. The hydroalcoholic extract (dose 0.5 g dry plant/kg weigh) administration caused an important reduction of the head-dipping response in the hole board test. A decrease in spontaneous motor activity test and a disturbance of motor coordination in the rotarod test was observed. The hydroalcoholic extract produced a significant prolongation of pentobarbital induced sleeping time. This extract prevented hot plate test induced nociception. The phytochemical analysis revealed the presence of catechin, epicatechin, and procyanidin B12. Therefore, this study revealed that the hydroalcoholic extract of B. crassifolia possesses analgesic and sedative CNS activity.

Antinociceptive and sedative activity of Vernonia patula and predictive interactions of its phenolic compounds with the cannabinoid type 1 receptor

When tested in the acetic acid-induced writhing and formalin-induced paw-licking tests, the ethanol extract of Vernonia patula (VP) aerial parts showed significant antinociceptive activity. In neuropharmacological tests, it also significantly delayed the onset of sleep, increased the duration of sleeping time, and significantly reduced the locomotor activity and exploratory behaviour of mice. Five phenolic compounds, namely gallic acid, vanillic acid, caffeic acid, quercetin and kaempferol, were detected in VP following HPLC-DAD analysis. The presence of these phenolic compounds in VP provides some support for the observed antinociceptive and sedative effects. A computational study was performed to predict the binding affinity of gallic acid, vanillic acid, caffeic acid, quercetin and kaempferol towards the cannabinoid type 1 (CB1) receptor. Caffeic and vanillic acid showed the highest probable ligand efficiency indices towards the CB1 target. Vanillic acid displayed the best blood-brain barrier penetration prediction score. These findings provide some evidence for the traditional use of VP to treat pain.

Hydroalcoholic extract of leaf of Arachis hypogaea L. (Fabaceae) did not induce toxic effects in the repeated-dose toxicity study in rats

Arachis hypogaea L. (peanut) leaf is traditionally used for the treatment of insomnia in Asia. However, studies describing the safety and toxicity profile for this plant preparation are limited. Thus, the goal of this study was to investigate the toxicity of peanut leaf hydroalcoholic extract (PLHE) repeated treatment. The extract was administered orally (100, 300 or 1000 mg/kg) in male and female Wistar rats for 28 days (OECD guideline 407). PLHE treatment did not cause mortality or weight variation in the animals. Also, there was no alteration on locomotor activity (open field test), motor coordination (rotarod test), or anxiety behaviour (elevated plus-maze test). Male rats had a reduction in relative liver weight (100 mg/kg) and an increase in total kidney weight (1000 mg/kg), but there was no change in biochemical and haematological parameters after PLHE treatment. Free extracellular double-stranded DNA (dsDNA) levels was also evaluated, but PLHE treatment did not increase this parameter in rat organs. Also, the dose of 1000 mg/kg of PLHE significantly increased the total thiols in the liver of females compared with the control animals. Thus, PLHE did not induce toxicity after repeated exposure for 28 days in rats.

Analgesic and Anxiolytic Activities of Achillea Biebersteinii: Evidence for the Involvement of GABAergic Systems

Achillea biebersteinii (Asteraceae) is used in traditional medicine for treating abdominal pain, menstrual pain and headache. The analgesic, antidepressant and anxiolytic activities of this plant were studied. Moreover, molecular docking technique was used for plant constituents to determine their energy of binding against GABAA and GABAB receptors. A. biebersteinii decreased flinching in early and late phases of formalin test and increased the time in hot plate test. In forced swimming test, no difference in immobility time was found. In open field test, high doses decreased the crossed lines number and rearing behavior. A. biebersteinii increased the time that the animals spent in the open arm side of elevated plus maze apparatus. Both bicuculline and SCH 50911 reversed A. biebersteinii action. Lavndulyl-2-methylbutanoate and sesquisabinene hydrate, showed the lowest binding energies for both GABAA and GABAB receptors. In conclusion, A. biebersteinii exerted analgesic, anxiolytic but no antidepressant activity. Its effect involved interaction with GABAA and GABAB systems.