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Biomedical subjects

R Niero

Publications and source records attributed to R Niero.

14 recordsLinked to original sources
PubMed2004

Pharmacological and phytochemical investigations of different parts of Calophyllum brasiliense (Clusiaceae).

Continuing our search for antinociceptive agents from natural sources, this study analyzed the antinociceptive effects of some fractions obtained from different parts (roots, flowers and fruits) of Calophyllum brasiliense, a Brazilian medicinal plant used to treat several diseases, including inflammation and pain. For this purpose, the writhing and formalin induced-pain models in mice were used. We also analyzed the chemical composition of these different parts and tested two pure compounds isolated from chloroform fraction (roots) identified as friedelin (1) and 1,5-dihydroxyxanthone (3), by direct comparison with authentic samples. The results showed that some fractions and both compounds exhibited considerable antinociception properties, particularly against the writhing test, and that these are more potent than acetyl salicylic acid and acetaminophen, two reference drugs used here for comparison.

Acetaminophen↗
PubMed2002

Phytochemical analysis and analgesic properties of Curcuma zedoaria grown in Brazil.

The present study describes the phytochemical analysis and analgesic activity of Curcuma zedoaria rhizomes grown in Brazil. The results showed that the hydroalcoholic extract, fractions, specially dichloromethane, and a pure compound, denoted as curcumenol (1), exhibited potent and dose-related analgesic activity when evaluated in several models of pain in mice, including writhing, formalin and capsaicin. Compound (1), which seems to be the main active principle from this plant, presented promising analgesic effects, being several times more potent than different reference drugs evaluated in the same experimental models. The calculated ID50 values (micromol/kg, i.p) were 22 and 12 when evaluated in writhing and capsaicin tests, respectively, and 29 micromol/kg in relation to the second phase of the formalin model. The lack of effect in the hot plate test suggests that (1) act by a mechanism which do not involves the participation of the opioid system. The phytochemical analysis indicated that the chemical composition of the plant grown in Brazil is similar to that grown in other countries. The results confirm and justify the popular use of this plant for the treatment of dolorous processes.

Analgesics↗
PubMed2000

Antinociceptive activity of a hydroalcoholic extract obtained from aerial parts of Sebastiania schottiana (Euphorbiaceae).

This study analyzed the antinociceptive effects of a hydroalcoholic extract obtained from the aerial parts of Sebastiania schottiana, a Brazilian medicinal plant used to treat various painful diseases. For this purpose, the writhing test, capsaicin and formalin induced-pain in mice were used. The results showed that the hydroalcoholic extract exhibited considerable antinociception in all the models studied, being more potent than aspirin.

Acetates↗
PubMed1999

Analgesic triterpenes from Sebastiania schottiana roots.

The present study was conducted in order to isolate and identify the phytochemical constituents responsible for analgesic effects shown by a methanolic extract obtained from Sebastiania schottiana roots. Conventional chromatographic procedures led to the isolation of moretenone, glutinol, beta-sitosterol and stigmasterol. The structural elucidation of these compounds was done on the basis of spectral data (IR, 1H- and 13C-NMR) and comparison with authentic samples. Either glutinol or moretenone exhibited marked analgesic action against acetic acid induced abdominal constrictions in mice by intraperitoneal route, indicating 16 to 26-fold higher efficacy than aspirin and paracetamol. When analyzed in a formal-in test, both compounds and standard drugs inhibited only the second phase (inflammatory pain). Our results suggest that the roots of S. schottiana contain analgesic compounds which justify, at least partially, the popular use of this plant for the treatment of urinary problems.

Acetates↗
PubMed1999

Antinociceptive activity of niga-ichigoside F1 from Rubus imperialis.

This work describes the antinociceptive effect of a triterpene glycoside, niga-ichigoside F1 (1), obtained from an EtOAc extract of the aerial parts of Rubus imperialis. When evaluated against an HOAc-induced writhing model, it exhibited an ID(50) value of 3.1 mg/kg (ip). Moreover, in a formalin-induced pain model, both phases of pain were inhibited by compound 1, with ID(50) values of 2.6 (first phase) and 2.7 (second phase) mg/kg, (ip), respectively.

Acetic Acid↗
PubMed1995

Evaluation of the polarographic technique for assay of the viability of freeze-dried BCG vaccine: I. The polarographic technique.

In this paper, a new assay based on oxygen uptake assessed by polarography was evaluated with the aim of establishing the viability of freeze-dried BCG vaccine. An oxygen electrode possessing a temperature sensor was designed for this purpose. The polarographic method used had several advantages, particularly its rapidity and use of small amounts of biological material. These advantages are ideal for quality control of BCG vaccine.

BCG Vaccine↗
PubMed1995

Evaluation of the polarographic technique for assay of the viability of freeze-dried BCG vaccine: II. Viability of the vaccine assessed by polarography, Warburg respirometry and colony counting.

A comparative study of the viability of 34 lots of freeze-dried BCG vaccine has been carried out using an oxygen electrode polarographic technique, Warburg respirometry and colony counting. There were no statistical differences between the results obtained with the polarographic and Warburg techniques. Both methods gave reliable and similar results and showed a positive correlation (r = 0.8615). Comparison between the polarographic and colony-counting methods showed a positive correlation (r = 0.6530); for comparison between the Warburg and colony-counting methods, the correlation value was r = 0.6868. All the tests were significant at the level of alpha = 0.05. The advantages of the polarographic technique are that it is much less time- and material-consuming than other methods. It is a reliable, inexpensive and convenient method for BCG vaccine quality control.

BCG Vaccine↗
PubMed1995

Antinociceptive properties of steroids isolated from Phyllanthus corcovadensis in mice.

The antinociceptive actions of the steroid compounds isolated from the leaves, stems, and roots of P. corcovadensis have been investigated in mice. Stigmasterol, stigmasterol acetate, beta-sitosterol, and aspirin (3-100 mk/kg, i.p.) inhibited, in a dose-related manner, acetic acid-induced abdominal constriction in mice with ID50s of 16, 11, 9, and 24 mg/kg, respectively. In the formalin test, stigmasterol and stigmasterol acetate (10-100 mg/kg, i.p.) caused graded inhibition of both the neurogenic (first phase) and inflammatory phases (second phase) of formalin-induced pain. However, both compounds were more effective in relation of the second phase of the formalin test with ID50 values of 26 and 41 mg/kg, respectively. Furthermore, both steroids failed to affect the edematogenic response of the formalin test. Given orally, stigmasterol and stigmasterol acetate (50-200 mg/kg) also exhibited significant though less potent analgesic action against both acetic acid- and formalin-induced nociception in mice. In addition, stigmasterol (up to 100 mg/kg, i.p.), in contrast to morphine (10 mg/kg, s.c.), had no analgesic effect in either tail-flick or hot-plate models. These findings suggest that stigmasterol and beta-sitosterol may account, at least in part, for the antinociceptive actions reported previously for the hydroalcoholic extract of Phyllanthus corcovadensis.

Analgesics↗
PubMed1994

Analgesic effects of callus culture extracts from selected species of Phyllanthus in mice.

The aim of this study was to evaluate the analgesic effect of the methanolic extract from callus culture of Phyllanthus tenellus, P. corcovadensis and P. niruri in several models of pain in mice. The extracts (medium containing 2,4-dichlorophenoxyacetic acid) of P. corcovadensis, P. niruri and P. tenellus (3-90 mg kg-1, i.p.) caused graded inhibition of abdominal constrictions induced by acetic acid (0.6%), with ID50 (i.e. dose that reduced response of control by 50%) values of about 30, 19 and > 30 mg kg-1, respectively. The extract of callus of Phyllanthus obtained in indole-3-butyric acid and indole-3-acetic acid media (3-90 mg kg-1, i.p.) caused a similar analgesic effect. In the formalin test, the extract of P. tenellus obtained in indole butyric acid medium (3-100 mg kg-1, i.p.) inhibited only the second phase of formalin-induced pain with an ID50 value of about 100 mg kg-1. Both the indole acetic acid and indole butyric acid methanolic extracts of P. tenellus and P. corcovadensis (10-100 mg kg-1, i.p.) dose-dependently inhibited both phases of formalin-induced pain (ID50 values for the second phase were approx. 100 and 52 mg kg-1, respectively). However, the extract of callus from Phyllanthus failed to affect formalin-induced paw oedema, as well as the response to radiant heat in the tail-flick test. In addition, the analgesic effect of morphine, but not the analgesic effects caused by Phyllanthus callus extract, was fully antagonized by naloxone.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdominal Muscles↗
PubMedDate not supplied

A comparative chemical study of Maytenus ilicifolia mart. reiss and Maytenus robusta reiss (Celastraceae).

This work describes a comparative qualitative and quantitative chemical analysis of Maytenus ilicifolia and Maytenus robusta (Celastraceae), extracts by high-resolution gas chromatography (HRGC), using external standards as the method of determination and thin layer chromatographic (TLC). The results show that both plants have a similar chromatographic profile. However, M. robusta exhibited about three times higher concentration of triterpene friedelin than M. ilicifolia.

Brazil↗
PubMedDate not supplied

Preliminary evaluation of the hypoglycemic effect of some Brazilian medicinal plants.

The hypoglycemic effect of five Brazilian medicinal plants (Epidendrum monsenii, Marrubium vulgare, Rheedia gardneriana, Rubus imperialis and Wedelia paludosa) was studied on alloxan-induced diabetic rats. The extract of these plants was intragastrically administered to diabetic rats. The results showed that all plants studied (except R. gardneriana) significantly lowered the blood glucose. These results suggest that these four medicinal plants could be an adjuvant agent in the treatment of diabetes mellitus.

Alloxan↗
PubMedDate not supplied

Antinociceptive action of extracts and fractions from Rubus imperialis (Rosaceae).

Rubus imperialis is a Brasilian medicinal plant which previously exhibited therapeutical perspectives. This work describes the antinociceptive action of methanolic extracts obtained from different parts of the plant (roots and branches) as well as hexane, chloroform and ethyl acetate fractions obtained from branches. Such extracts or fractions caused significative inhibition in the writhing test in mice at 10 mg/kg, given intraperitoneally. They were more active than two reference drugs, aspirin and paracetamol. The fractions also exhibited antinociceptive activity in the writhing test when administered orally at 200 mg/kg. When analyzed in the formalin test, the chloroform fraction was the most active, causing considerable inhibition against both neurogenic and inflammatory phases of pain.

Acetic Acid↗