Carla Marrassini

Evaluation of antinociceptive, antinflammatory activities and phytochemical analysis of aerial parts of Urtica urens L.

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

Vicenin-2, a potential anti-inflammatory constituent of Urtica circularis.

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.

Anti‐Inflammatory and Antinociceptive Activity of Urera aurantiaca

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

In vivo immunomodulatory effect of Tilia x viridis extracts on normal lymphocyte proliferation: a direct and an indirect action.

The flowers of Tilia species have been used in Europe for many years to treat colds, bronchitis, fever, inflammations and influenza. It is well known that lymphocytes play a role in acquired immunity related to pathogens and tumor cells attachment. The aim of this study was to determine the effect of an aqueous (AE) and a dichloromethane extract (DM) from Tilia x viridis which is widely used and distributed in Argentina, on normal murine lymphocyte proliferation after being administered to mice. Both extracts presented a stimulatory effect on normal murine lymphocyte proliferation. The effect exerted by DM was principally related to macrophage activation, meanwhile AE exerted an important direct effect on lymphocytes related to the rutin presence. The stimulating effect, exerted on normal lymphocytes was due to a protective effect of apoptosis and also to cell IL2 production. Copyright

Beneficial properties of Passiflora caerulea on experimental colitis

ETHNOPHARMACOLOGICAL RELEVANCE Passiflora caerulea L. (Passifloraceae) is a medicinal plant commonly used in traditional medicine in South America for different pathologies associated with the gastrointestinal tract. AIM OF THE STUDY In the present study, the activity of the ethanolic extract of P. caerulea on an experimental colitis model related to inflammatory bowel disease has been investigated. MATERIALS AND METHODS Colitis was induced by intracolonic instillation of a 2mL of 4% (v/v) acetic acid solution. Macroscopic scoring, myeloperoxidase activity and thiobarbituric acid reactive substances levels were evaluated on isolated colon mucosae. The histopathological studies of colon mucosae were performed by hematoxylin and eosin and Alcian blue staining. Diarrhoea was induced by the administration of castor oil (0.3mL/mouse). The first watery defecation time, the total amount of solid, semi-solid and watery stools and the amount of watery stools were determined. The effect of the extract on a cumulative concentration-response curve of acetylcholine and CaCl2 on isolated rat jejunum was also evaluated. The phytochemical analysis was performed. RESULTS The extract (250mg/kg, p.o.) induced a significant reduction in the weight/length ratio, the macroscopic lesion score, TBARS levels and the microscopic tissue damage when compared with the acetic acid-treated group of animals. P. caerulea (125mg/kg, p.o.) decreased significantly the amount of watery stools in the castor oil-induced-diarrhoea model. Moreover, the P. caerulea extract antagonized the jejunum contractions induced by Ach (Emax for 0.3mg/mL: 76.25%; Emax for 1mg/mL: 63.47%; Emax for 3mg/mL: 42.01%) and CaCl2 (Emax for 0.3mg/mL: 75.69%; Emax for1 mg/mL: 56.1%; Emax for 3mg/mL: 53.4%). Isoorientin, vitexin, isovitexin, and vicenin-2 were identified in the extract. CONCLUSION P. caerulea showed anti-inflammatory, anti-diarrhoeal and spasmolityc activities on preclinical models.

Modulatory Effect of an Urera Aurantiaca Extract on Immune and Tumoral Cells During Inflammation

There is a well known link between inflammation and cancer during initiation, propagation and metastasis. Urera aurantiaca (UA) Wedd. (Urticaceae) is a medicinal plant used in traditional medicine to treat inflammatory processes with proven in vivo antiinflammatory and antinociceptive effects. The effects of a methanolic extract (UA) and a purified fraction (PF) on the proliferation of normal and tumoral lymphocytes under the effect of prostaglandin E2 (PGE2) and on nitric oxide production by lipopolysaccharide‐stimulated macrophages was evaluated. Both UA and PF stimulated normal lymphocytes but, in presence of PGE2, a modulatory effect was observed. The normal lymphocyte proliferation induced by PGE2 was driven by pathways involving both PKC and H2O2. In macrophages, UA and PF did not modify cell viability and abrogated the synthesis of nitric oxide induced by lipopolysaccharide. In tumoral lymphocytes, the UA exerted a biphasic effect: at low concentrations it increased cell proliferation, while at high concentrations, it displayed an antiproliferative effect. UA and PF were capable of reverting the proliferative action of PGE2. The tumoral cell proliferation induced by PGE2 is related to PKC, ERK 1/2 and MAP Kinase P38 pathways. The observed effects could be attributed to polyphenols, flavonoids and tannins. This work demonstrates the modulatory effects of the UA on different cell types during inflammatory conditions, which reinforces its antiinflammatory action. Copyright

Hydroalcoholic extract of Urtica circularis: A neuropharmacological profile

Abstract 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.

Food preservation by Larrea divaricata extract: participation of polyphenols

Abstract The aim of this study was to evaluate the antioxidant and protease inhibitor capacities on eggs and milk protein of a nor‐dihydroguaiaretic (NDGA)‐standardized aqueous extract of Larrea divaricata (AE) and to analyze the participation of polyphenols as NDGA in these actions. NDGA was determined by high‐performance liquid chromatography; flavonoids and polyphenols were quantified by spectrophotometric methods as well as inhibition of lipid peroxidation, proteinase inhibitor capacity, advanced glycation end products (AGES) formation, and inhibition of albumin denaturation. The extract protected food for oxidative damage by preventing malondialdehyde formation in egg yolk and by preventing AGE formation in completely cooked eggs, also impeded albumin denaturation, and casein hydrolysis induced by trypsin and heat. Polyphenols, especially flavonoids and NDGA, were involved in these actions.

Comparative study of the polyphenol content-related anti-inflammatory and antioxidant activities of two Urera aurantiaca specimens from different geographical areas

BackgroundUrera aurantiaca is an Argentinean species that has been traditionally used to treat symptoms of inflammation. The aim of this study was to determine and compare the anti-inflammatory and antioxidant effects of two specimens of Urera aurantiaca obtained in the provinces of Salta and Misiones, which are two different geographical areas of Argentina.MethodsThe anti-inflammatory activity of the extracts was tested in LPS-stimulated macrophages through the DPPH radical scavenging activity, the SOD-like activity, the reducing power and the inhibition of lipid peroxidation. The anti-inflammatory activity was also evaluated by the inhibition of albumin denaturation and proteinase inhibitory action tests. The total polyphenols, flavonoids and tannins content were quantified.ResultsBoth extracts were able to reduce the augmented NO release in LPS-activated macrophages and showed antioxidant and in vitro anti-inflammatory activities. The polyphenols content was higher in the extract obtained from the specimen from Salta than in that obtained in Misiones. This finding accounts for the higher anti-inflammatory and antioxidant properties obtained with the former.ConclusionThe differences in chemical composition and the biological activities observed between the extracts are probably related to the different environmental conditions found in both provinces.