HORSETAIL (equisetum arvense)
Cognitive enhancement in aged rats after chronic administration of Equisetum arvense L. with demonstrated antioxidant properties in vitro
1: Pharmacol Biochem Behav. 2005 Jul;81(3):593-600.
Cognitive enhancement in aged rats after chronic administration of Equisetum arvense L. with demonstrated antioxidant properties in vitro.
- Guilherme dos Santos J Jr, Hoffmann Martins do Monte F, Marcela Blanco M, Maria do Nascimento Bispo Lanziotti V, Damasseno Maia F, Kalyne de Almeida Leal L.
Department of Physiology, Federal University of Sao Paulo, Laboratorio de Neurofisiologia, R. Botucatu, 862, Ed. Ciencias Biomedicas, 5o andar, Sao Paulo, SP, Brazil. guistos@mailcity.com
The aim of this work was to verify if chronic administration of the hydroalcoholic extract of stems from Equisetum arvense (HAE) reverses the cognitive impairment in aged rats, as well as, evaluates it in vitro antioxidant properties. Chronic administration of HAE at dose of 50 mg/kg, i.p., improved both short- and long-term retention of inhibitory avoidance task and ameliorated the cognitive performance in reference and working memory version of the Morris Water Maze. No differences were found between all three groups of young controls, aged controls and EHA-treated animals with regard to the open field and elevated plus maze tests. Indeed, no toxicity manifestations were observed during treatment. In vitro assays revealed that HAE diminished the thiobarbituric acid reactive substances as well as nitrite formation, but did not alter catalase activity. Thus, the cognitive enhancement effects of the HAE may be attributed, at least in part, to it antioxidant action.
PMID: 15972233 [PubMed - indexed for MEDLINE]
Hepatoprotective and free radical scavenging activities of phenolic petrosins and flavonoids isolated from Equisetum arvense
1: J Ethnopharmacol. 2004 Dec;95(2-3):421-4
Hepatoprotective and free radical scavenging activities of phenolic petrosins and flavonoids isolated from Equisetum arvense.
Laboratory of Cell Signaling Regulation, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-333, South Korea.
Hepatoprotective activity-guided fractionation of the MeOH extract of Equisetum arvense L. (Equisetaceae) resulted in the isolation of two phenolic petrosins, onitin (1) and onitin-9-O-glucoside (2), along with four flavonoids, apigenin (3), luteolin (4), kaempferol-3-O-glucoside (5), and quercetin-3-O-glucoside (6). Among these, compounds 1 and 4 exhibited hepatoprotective activities on tacrine-induced cytotoxicity in human liver-derived Hep G2 cells, displaying EC(50) values of 85.8 +/ -9.3 microM and 20.2 +/- 1.4 microM, respectively. Silybin, used as a positive control, showed the EC(50) value of 69.0 +/- 3.3 microM. Compounds 1 and 4 also showed superoxide scavenging effects (IC(50) = 35.3 +/- 0.2 microM and 5.9 +/- 0.3 microM, respectively) and DPPH free radical scavenging effect (IC(50) of 35.8 +/- 0.4 microM and 22.7 +/- 2.8 microM, respectively). These results support the use of this plant for the treatment of hepatitis in oriental traditional medicine.
PMID: 15507369 [PubMed - indexed for MEDLINE]
Antinociceptive and anti-inflammatory properties of the hydroalcoholic extract of stems from Equisetum arvense L. in mice
1: Pharmacol Res. 2004 Mar;49(3):239-43.
Antinociceptive and anti-inflammatory properties of the hydroalcoholic extract of stems from Equisetum arvense L. in mice.
Department of Morphophysiology, State University of Santa Catarina, Rua Cel. Nunes de Melo, 1127, 60430-270, Fortaleza, Brazil,
In this study, antinociceptive and anti-inflammatory effects of hydroalcoholic extract of stem from Equisetum arvense in mice were evaluated. The extract (10, 25, 50 and 100mgkg(-1), i.p.), reduced the writhing induced by acetic acid in 49, 57, 93 and 98%, respectively. In the formalin test, 50 and 100mgkg(-1) (i.p.) extract, reduced in 80 and 95% the licking activity in the first phase, but in the second phase only the latter dose diminished the licking time (35%). In both phases, naloxone failed to revert the analgesic effect of the extract. In the hot-plate test, the extract at 100 and 200mgkg(-1) does not change the latency to licking or jumping. In the carrageenan-induced paw oedema, the extract at 50mgkg(-1), reduced the paw oedema 2h (25%) and 4h (30%) after carrageenan administration. The dose of 100mgkg(-1) caused reduction of the paw oedema (29%) only 4h after carrageenan administration. These results indicate that this extract exhibits an antinociceptive effect in chemical models of nociception which is not related to the opioid system, as well as anti-inflammatory properties.
PMID: 14726218 [PubMed - indexed for MEDLINE]
Structure of silica in Equisetum arvense
Authors: G. Holzhüter, K. Narayanan, T. Gerber
Abstract
Silicified regions in the stem and leaf of the horsetail Equisetum arvense were studied by scanning and transmission electron microscopy. The silica was present as a thin layer on the outer surface with variation in the size of this layer depending on the part investigated. There was a dense arrangement of silica spheres with some density fluctuations. A loose arrangement of silica particles with variation in their size was found beneath this dense arrangement suggesting the agglomeration of silica. An electron diffraction pattern showed the presence of amorphous silica, with the short range order being comparable to that of silica from other chemical sources. The medium range order shows the presence of silica with a high inner surface. SAXS measurements correlate with the particle size observed in TEM, and provide values for surface fractals. A new method of plasma ashing to remove the organics is also described.
http://www.springerlink.com/content/qpnbp3mh8qy47qgn/
Sterols from Equisetum arvense
1: Boll Soc Ital Biol Sper. 1984 Dec 30;60(12):2241-5.
Sterols from Equisetum arvense.
The sterol fraction of Equisetum arvense L. contains, essentially, the following sterols: beta-sitosterol (60.0%), campesterol (32.9%), isofucosterol (5.9%) and cholesterol (trace amounts). The identification of the compounds has been carried out through NMR and MS, while the corresponding percentage have been desumed from the GLC and HPLC data.
PMID: 6529502 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retriev
e&dopt=AbstractPlus&list_uids=6529502&query_hl=16&itool=pubmed_DocSum
