Browsing by Author "Watchueng, J."
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Omisore, N.; Adewunmi, C.; Iwalewa, E.; Ngadjui, B.; Watchueng, J.; Abegaz, B.; Ojewole, J. (Elsevier Ltd. www.elsevier.com/locate/jethpharm, NaN, 2004)[more][less]
Abstract: The present studywas undertaken to investigate the antinociceptive and anti-inflammatory activities of the leaf and twig extracts of Dorstenia barteri (Moraceae) in mice. Both the leaf and twig extracts of Dorstenia barteri at 50, 100 and 200 mg/kg showed significant (P < 0.05-0.01) antinociceptive activities in chemical-, mechanical- and thermal-induced pain test models. Intraperitoneal administration of the plant extracts at 50, 100 and 200 mg/kg significantly (P < 0.05-0.01) inhibited carrageenin-induced acute inflammation in oedema paw weight, pulmonary oedema and number of pleural leucocytes in a dose-dependent way. The twig extract was found to be more active than the leaf extract in all the experimental models used. The inhibitory effects of the plant extracts were comparable to those of the reference drugs acetylsalicyclic acid (ASA) and phenylbutazone (PBZ) at 100 mg/kg i.p. The significant reduction in acetic acid-induced abdominal contractions, the decrease in oedema paw weight as well as in the number of leucocytes in the pleural cavity exudates, and the significant increase in the reaction time and pain threshold of mice observed in this study suggest that Dorstenia barteri extracts possess both anti-inflammatory and antinociceptive activities. The present study, therefore, lend pharmacological support to the folkloric uses of Dorstenia barteri extracts in the treatment, control and/or management of arthritis, rheumatism, gout, headache and other forms of body pains in some parts of Africa. URI: http://hdl.handle.net/10311/256 Files in this item: 2
license.txt (1.998Kb) -
Omisore, N.O.A.; Adewunmi, C.O.; Iwalewa, E.O.; Ngadjui, B.T.; Adenowo, T.K.; Abegaz, B.M.; Ojewole, J.A.; Watchueng, J. (Brazilian Journal of Medical and Biological Research. http://www.scielo.br/scielo.php?pid=0100-879X&script=sci_serial, NaN, 2005)[more][less]
Abstract: Dorstenia barteri and D. convexa extracts and some isolated components of the former were investigated for effectiveness against Trichomonas gallinarum and compared with quercetin and quercitrin. The antioxidant activity of the extracts/compounds was also determined. The minimum lethal concentrations (MLCs) for the extract of D. barteri leaves and twigs at 24 h were found to be 15.625 and 15.625 μg/ml, respectively. However, the MLCs of the leaf and twig extract of D. convexa were 125 and 437.5 μg/ml, respectively. The prenylated and geranylated chalcones were as active as the prenylated flavones, 6- prenylapigenin and the diprenylated derivative 6,8-diprenyleridictyol. The order of the antitrichomonal activity of the compounds at 24 h was: quercetin (0.121 μg/ml) > quercitrin (0.244 μg/ml) ≥ bartericin B (0.244 μg/ml) > bartericin A (0.73 μg/ml) > stigmasterol (0.98 μg/ml) > 6,8-diprenyleridictyol = isobavachalcone = dorsmanin F (31.25 μg/ ml). D. barteri extracts, quercitrin, and bartericin A, and the prenylated flavonoids had potent antioxidant properties. The twig extract of D. barteri was more potent than the leaf extract. Moderate (EC50 >50 μg/ ml) and high (EC50 <50 μg/ml) antioxidant activities were detected in the leaf and twig extracts of D. barteri and the prenylated flavonoids. Prenylated flavonoids and the isolated compounds with antioxidant properties described here may account for the anti-inflammatory action of these extracts. The antitrichomonal and antioxidant activities shown by the extracts and compounds in this study are consistent with the ethnomedicinal and local use of the Dorstenia species studied. URI: http://hdl.handle.net/10311/284 Files in this item: 1
Antitrichomonal and antioxidant.pdf (2.508Mb) -
Ngameni, B.; Ngadjui, B.; Folefoc, G.; Watchueng, J.; Abegaz, B. (Elsevier Ltd; www.elsevier.com/locate/phytochem, NaN, 2003)[more][less]
Abstract: The twigs of Dorstenia barteri var. subtriangularis yielded three diprenylated chalcones: ( )-3-(3,3-dimethylallyl)-50-(2-hydroxy-3- methylbut-3-enyl)-4,20,40-trihydroxychalcone, (+)-3-(3,3-dimethylallyl)-40,50-[2000-(1-hydroxy-1-methylethyl)-dihydrofurano]-4,20- dihydroxychalcone and 3,4-(600,600-dimethyldihydropyrano)-40,50-[2000,-(1-hydroxy-1-methylethyl)-dihydrofurano]-20-hydroxychalcone for which the names bartericins A, B and C, respectively, are proposed. Stipulin, b-sitosterol and its 3-b-D-glucopyranosyl derivative were also isolated. The structures of these secondary metabolites were determined on the basis of spectroscopic analysis, especially, NMR spectra in conjunction with 2D experiments, COSY, HMQC and HMBC. The structural relationship of bartericins B and C was further established by the chemical cyclization of one to the other. URI: http://hdl.handle.net/10311/258 Files in this item: 2
Diprenylated chalcones and other.pdf (3.479Mb)license.txt (1.998Kb) -
Ngadjui, B.; Watchueng, J.; Keumedjio, F.; Ngameni, B.; Simo, I.; Abegaz, B. (Elsevier Ltd. www.elsevier.com/locate/phytochem, NaN, 2004)[more][less]
Abstract: The twigs of Dorstenia angusticornis and Dorstenia barteri var. subtriangularis yielded 16 compounds. Two novel diprenylated chalcones: 3,50-di-(2-hydroxy-3-methylbut-3-enyl)-4,20,40-trihydroxychalcone, 3, 4-(2,2-dimethylpyrano)-30-(2-hydroxy-3-methylbut- 3-enyl)-20,40-dihydroxychalcone and the known stipulin were isolated from both species. 3-(2-Hydroxy-3-methylbut-3-enyl)- 50-(3,3-dimethylallyl)-4,20,40-trihydroxychalcone and the known compounds: 4-hydroxylonchocarpin, kanzonol B, bartericins A, B, C and 30-(2-hydroxy -3-methylbut-3-enyl)-4,20,40-trihydroxychalcone were isolated from D. barteri while the known compounds: gancaonin Q, paratocarpins C, F, and lupeol were obtained from Dorstenia angusticornis. b-Sitosterol and its b-D-glucopyranoside were isolated from both species. Structures of these secondary metabolites were established using spectroscopic analysis, especially, NMR spectra in conjunction with 2D experiments, COSY, HMQC and HMBC. URI: http://hdl.handle.net/10311/253 Files in this item: 2
license.txt (1.998Kb)Prenylated chalcones, flavone.pdf (3.563Mb)
Now showing items 1-4 of 4