Search

Urera aurantiaca Wedd. (Urticaceae) is a medicinal plant commonly used in traditional medicine to relieve pain in inflammatory processes. In the present study, the in vivo anti-inflammatory and antinociceptive effects of U. aurantiaca methanolic extract and its possible mechanisms of action were investigated. The extract showed anti-inflammatory activity in the ear edema in mice test (34.3% inhibition), myeloperoxidase (MPO) activity was markedly reduced in animals administered with the extract: within 49.6% and 68.5%. In the histological analysis, intense dermal edema and intense cellular infiltration of inflammatory cells were markedly reduced in the ear tissue of the animals treated with the extract. In the carrageenan-induced hind paw edema in rats assay the extract provoked a significant inhibition of the inflammation (45.5%, 5 h after the treatment) and the MPO activity was markedly reduced (maximum inhibition 71.7%), The extract also exhibited significant and dose-dependent inhibitory effect on the increased vascular permeability induced by acetic acid. The extract presented antioxidant activity in both 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azinobis 3-ethylbenzothiazoline 6-sulfonic acid tests and its total phenol content was 35.4 ± 0.06 mg GAE/g of extract. Also, the extract produced significant inhibition on nociception induced by acetic acid (ED50 : 8.7 mg/kg, i.p.) administered intraperitoneally and orally. Naloxone significantly prevented this activity., (Copyright © 2014 John Wiley & Sons, Ltd.)

Context: The genus Urtica has been known since ancient times. It has known to be useful for the treatment of different human ailments., Objective: The present work evaluated the neuropharmacological effects of a hydroalcoholic extract of Urtica circularis (Hicken) Sorarú (Urticaceae). materials and method: The effect on central nervous system of U. circularis hydroalcoholic extract (from leaves and stems) administered by the intraperitoneal route in mice was evaluated by several tests: Pentobarbital- and midazolam-induced hypnosis, open field, hole board, elevated plus-maze and forced swimming. Phytochemical analysis was performed by high-performance liquid chromatography., Results: A total of 300 mg/kg i.p. of the extract produced a significant prolongation of pentobarbital- (40 mg/kg i.p.; 60.1 min versus 25.4 min) and midazolam- (50 mg/kg i.v.; 53.4 min versus 25.1 min) induced sleeping time. The extract's administration caused a marked reduction of the head-dipping response (DE50: 373 mg/kg i.p.) in the hole-board test. Urtica circularis extract (DE50: 46 mg/kg i.p.) reduced the spontaneous locomotor activity in the open field test. Flumazenil and atropine significantly antagonized the extract's effect on the locomotor activity. No motor coordination disturbance was observed in the rota rod test at any doses. In the forced swimming test, the extract did not produce any change in the immobility time and it had no significant effects in elevated plus maze test. The phytochemical analysis revealed the presence of chlorogenic acid, vanillic acid, caffeic acid, vicenin-2, p-cumaric acid, ferulic acid, vitexin and isovitexin., Conclusion: This study revealed that U. circularis hydroalcoholic extract possesses sedative activity, facilitating GABAergic and cholinergic transmission.

Vicenin-2 (1), a flavonoid glycoside, was isolated and identified from an ethanol extract of the aerial parts of Urtica circularis. This crude extract was found to possess significant anti-inflammatory activity in a carrageenan-induced rat hind paw edema model (41.5% inhibition at a dose of 300 mg/kg; ip). The effects of 1 on several inflammatory mediators were investigated. In cultured murine macrophages, this compound modified LPS-induced total nitrite and TNF-α production, in addition to the LPS-induced translocation of the nuclear factor NF-κB.

Ethnopharmacological Relevance: Urtica circularis (Hicken) Sorarú is a medicinal plant commonly used in traditional medicine to relieve pain in inflammatory processes., Aim of the Study: In the present study, the in vivo antinociceptive effect of Urtica circularis ethanolic extract and its isolated compounds has been investigated., Materials and Methods: Antinociceptive activity was evaluated through writhing, formalin and hot plate tests in mice. The phytochemical analysis was performed., Results: The extract produced significant inhibition on nociception induced by acetic acid (ED50: 72.2mg/kg, i.p.) and formalin (ED50: 15.8 mg/kg, i.p.) administered intraperitoneally and also orally. Atropine diminished the activity of the extract in the acetic acid test. In this model, at dose of 10mg/kg i.p., vitexin was the most active of the isolated compounds (inhibition of 91%), and chlorogenic acid, caffeic acid and vicenin-2 (6,8-di-C-glucosyl apigenin) produced an inhibition of 72%, 41% and 41%, respectively, whereas apigenin did not show any activity., Conclusions: These results suggest that Urtica circularis extract produced antinociception possibly related to the presence of vitexin, chlorogenic, caffeic acid and vicenin-2. The activation of cholinergic systems seems to be involved in the mechanism of antinociception of the extract., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

The antinociceptive and antiinflammatory activities of the ethanol extract of the aerial part of Urtica urens were determined by experimental animal models. U. urens extract was found to possess significant antinociceptive activity in chemically induced mouse pain models (ED₅₀ 39.3 mg/kg: 17.2-74.5 mg/kg) in the writhing test and 62.8% inhibition of the licking time in the late phase of the formalin test at a dose of 500 mg/kg p.o. and antiinflammatory activity on carrageenan-induced rat hind paw edema (41.5% inhibition at a dose of 300 mg/kg i.p.). The extract displayed activity neither in the thermal model of pain nor in the topical inflammation model. The major component of the extract was determined as chlorogenic acid (670 mg/1000 g dry weight) and could be partly responsible for this activity., (Copyright © 2010 John Wiley & Sons, Ltd.)