|
|
|
|
|
Kerchove,C.M.; Markus,R.P.; Freitas,J.C.; Costa-Lotufo,L.V.. |
Trimethylsulfonium, a compound present in the midgut gland of the sea hare Aplysia brasiliana, negatively modulates vagal response, indicating a probable ability to inhibit cholinergic responses. In the present study, the pharmacological profile of trimethylsulfonium was characterized on muscarinic and nicotinic acetylcholine receptors. In rat jejunum the contractile response induced by trimethylsulfonium (pD2 = 2.46 ± 0.12 and maximal response = 2.14 ± 0.32 g) was not antagonized competitively by atropine. The maximal response (Emax) to trimethylsulfonium was diminished in the presence of increasing doses of atropine (P<0.05), suggesting that trimethylsulfonium-induced contraction was not related to muscarinic stimulation, but might be caused by... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aplysia brasiliana; Trimethylsulfonium; Cholinergic systems; Muscarinic acetylcholine receptors; Nicotinic acetylcholine receptors. |
Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2002000400013 |
| |
|
|
Bezerra,D.P.; Castro,F.O.; Alves,A.P.N.N.; Pessoa,C.; Moraes,M.O.; Silveira,E.R.; Lima,M.A.S.; Elmiro,F.J.M.; Costa-Lotufo,L.V.. |
Piplartine {5,6-dihydro-1-[1-oxo-3-(3,4,5-trimethoxyphenyl)-2-propenyl]-2(1H)pyridinone} and piperine {1-5-(1,3)-benzodioxol-5-yl)-1-oxo-2,4-pentadienyl]piperidine} are alkaloid amides isolated from Piper. Both have been reported to show cytotoxic activity towards several tumor cell lines. In the present study, the in vivo antitumor activity of these compounds was evaluated in 60 female Swiss mice (N = 10 per group) transplanted with Sarcoma 180. Histopathological and morphological analyses of the tumor and the organs, including liver, spleen, and kidney, were performed in order to evaluate the toxicological aspects of the treatment with these amides. Administration of piplartine or piperine (50 or 100 mg kg-1 day-1 intraperitoneally for 7 days starting 1... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Piplartine; Piperine; Antitumor activity; Toxicity. |
Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2006000600014 |
| |
|
|
Costa-Lotufo,L.V.; Ferreira,M.A.D.; Lemos,T.L.G.; Pessoa,O.D.L.; Viana,G.S.B.; Cunha,G.M.A.. |
Auxemma oncocalyx Taub. belongs to the Boraginaceae family and is native to the Brazilian northeast where it is known as "pau-branco". We investigated the ability of the water soluble fraction isolated from the heartwood of A. oncocalyx to inhibit sea urchin egg development. This fraction contains about 80% oncocalyxone A (quinone fraction), a compound known to possess strong cytotoxic and antitumor activities. In fact, the quinone fraction inhibited cleavage in a dose-dependent manner [IC50 of 18.4 (12.4-27.2) µg/ml, N = 6], and destroyed the embryos in the blastula stage [IC50 of 16.2 (13.7-19.2) µg/ml, N = 6]. We suggest that this activity is due to the presence of oncocalyxone A. In fact, these quinones present in A. oncocalyx extract have strong... |
Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Auxemma oncocalyx; Quinones; Sea urchin eggs; Oncocalyxone A. |
Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2002000800010 |
| |
|
|
|