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1.
J Dairy Sci ; 99(7): 5808-5819, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27157583

RESUMEN

Maternal metabolic pressure due to a cow's negative energy balance (NEB) has a negative effect on oocyte quality as a result of increased oxidative stress. In this study, we hypothesized that a NEB status may negatively affect the availability of ß-carotene (bC, an antioxidant) in the micro-environment of the oocyte or follicular fluid (FF) and that daily bC supplementation can increase bC availability. We aimed to (1) determine the effect of a nutritionally induced NEB on bC concentrations in serum and FF as well as on the presence of bC metabolites, oxidative stress levels, and follicular growth in a nonlactating dairy cow model, and (2) investigate how this effect could be altered by dietary bC supplementation. Six multiparous nonlactating Holstein Friesian cows were subjected to 4 consecutive dietary treatments, 28 d each: (1) 1.2 × maintenance (M) or positive energy balance (PEB) without bC supplement (PEB-bC), (2) 1.2 × M with daily supplement of 2,000mg of bC comparable to the level of bC intake at grazing (PEB+bC), (3) 0.6 × M with 2,000mg of bC (NEB+bC), and (4) 0.6 × M (NEB-bC). At the end of each treatment, estrous cycles were synchronized and blood and FF of the largest follicle were sampled and analyzed for bC, retinol, α-tocopherol, free fatty acids, estradiol, and progesterone. Serum cholesterol, triglycerides, urea, insulin growth factor 1, growth hormone, total antioxidant status (TAS), and red blood cell glutathione (GSH) concentrations were determined as well. All cows lost body weight during both energy restriction periods and showed increased serum free fatty acid concentrations, illustrating a NEB. A dietary induced NEB reduced FF bC, but not plasma bC or plasma and FF retinol concentrations. However, bC and retinol concentrations drastically increased in both fluid compartments after bC supplementation. Follicular diameter was increased in supplemented PEB cows. Energy restriction reduced the TAS and red blood cell GSH, whereas daily bC supplementation could restore GSH concentrations, but not the TAS, to levels present in healthy PEB cows. In conclusion, daily bC supplementation can substantially improve bC and retinol availability in the oocyte's micro-environment, irrespective of the energy balance, which may affect follicular development and oocyte quality in the presence of maternal metabolic stress. This knowledge can be of importance to optimize nutritional strategies in the dairy industry to feed for optimal oocyte quality and fertility.


Asunto(s)
Líquido Folicular , beta Caroteno/metabolismo , Animales , Bovinos , Metabolismo Energético , Ácidos Grasos no Esterificados/sangre , Femenino , Lactancia/metabolismo , Folículo Ovárico/metabolismo
2.
Curr Med Chem ; 14(4): 417-30, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17305543

RESUMEN

Over the last decade, much research has focused on the potential health benefits of antioxidants and indeed many synthetic and natural compounds have been evaluated for their antioxidant profile. However, in several studies only a limited number of assays, often poorly validated, are used and the techniques available frequently lack specificity. These limitations may incorrectly influence the results. This review will therefore focus on several pitfalls that may emerge in vitro and in vivo antioxidant research. First, different in vitro techniques to determine antioxidant potential are discussed, including radical scavenging assays and fingerprinting methods. As a rule, a panel of different assays is indispensable to characterize and establish in vitro antioxidant activity. Furthermore, as problems of absorption, distribution, metabolism and excretion are only accounted for by in vivo studies, the need for in vivo antioxidant research is pointed out. Several methods to characterize the in vivo activity of antioxidants, including major drawbacks and pitfalls of some assays, have been discussed. The availability of both a representative "oxidative stress" animal model and a battery of well-validated assays to assess the broad diversity of oxidative damage and antioxidative defence parameters, are crucial for antioxidant research in vivo.


Asunto(s)
Antioxidantes/uso terapéutico , Investigación Biomédica , Evaluación Preclínica de Medicamentos/métodos , Animales , Antioxidantes/farmacocinética , Antioxidantes/farmacología , Humanos , Estrés Oxidativo/efectos de los fármacos
3.
J Ethnopharmacol ; 107(1): 83-90, 2006 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-16603327

RESUMEN

An aqueous decotion (dried extract), an 80% MeOH extract from Morinda morindoides leaves, and 10 flavonoids and 4 iridoids isolated from the 80% MeOH extract were evaluated in vitro for their potential antiamoebic activity and their cytotoxic effect against MT-4 cells. Results indicated that the aqueous decoction and the 80% MeOH extract exhibited an interesting antiamoebic activity with IC(50) values of 3.1 +/- 1.7 and 1.7 +/- 0.6 microg/ml, respectively. Apigenin-7-O-glucoside and luteolin-7-O-glucoside exhibited a moderate antiamoebic activity with IC(50) values of 22.3 +/- 3.2 and 37.4 +/- 2.7 microg/ml, respectively. Kaempferol (IC(50) = 10.3 +/- 2.3 microg/ml), apigenin (IC(50) = 12.7 +/- 4.3 microg/ml), and luteolin (IC(50) = 17.8 +/- 4.3 microg/ml) showed a more pronounced activity than their corresponding glycosides. All tested iridoids displayed a very good activity with IC(50) values less than 10 microg/ml. The most active iridoids were epoxygaertneroside (IC(50) = 1.3 +/- 0.4 microg/ml) and methoxygaertneroside (IC(50) = 2.3. +/- 0.7), followed by gaertneroside and gaertneric acid with IC(50) values of 4.3 +/- 1.8 and 7.1 +/- 1.4 microg/ml, respectively. Except quercetin and quercetin-7,4'-dimethylether which have shown a cytotoxic effect with IC(50) ranging from 14 to 22 microg/ml. No correlation could be deduced between the observed antiamoebic and cytotoxic activity of these tested samples. A structure-activity relationship for isolated compounds is discussed. These findings support the medicinal report for the traditional use of Morinda morindoides leaves for the treatment of amoebiasis.


Asunto(s)
Amebicidas/farmacología , Entamoeba histolytica/efectos de los fármacos , Morinda/química , Extractos Vegetales/farmacología , Hojas de la Planta/química , Animales
4.
J Ethnopharmacol ; 95(2-3): 399-404, 2004 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-15507366

RESUMEN

The ethanolic extracts from fresh apical stems of Phyllanthus niruri L. (Euphorbiaceae) cultured on Murashige and Skoog (MS) medium supplemented with IBA/BAP/Coco nucifera L. milk for 1, 2, 4 and 6 months were phytochemically and biologically investigated and compared with intact plant part and whole plant extracts. Results from the in vitro antiplasmodial testing indicated that the EtOH extract of a 1-month-old callus culture (IC(50) = 16.3 +/- 2.5 microg/ml) exhibited a higher activity than the ethanolic extracts of the fresh apical stem (IC(50) = 18.2 +/- 2.4 microg/ml) and callus cultures of 2-, 4- and 6-months-old (25 microg/ml < IC(50) < 40 microg/ml). These activities were however lower than that displayed by the ethanolic extract of the whole plant (IC(50) < 3 microg/ml). The EtOH extract of 1-month-old callus culture (the most active) was fractionated with solvents of different polarities. Its CH(2)Cl(2) fraction rich in terpenic constituents (IC(50) = 9.2 +/- 3.4 microg/ml) exhibited a higher antiplasmodial activity than its isoamylic alcohol fraction obtained at pH 2-3 (IC(50) = 25.6 +/- 2.3 microg/ml) rich in flavonoids. The activity of these two fractions was lower than that displayed by the same fractions from the whole plant (2 microg/ml < IC(50) < 3 microg/ml). Alkaloidic fractions from the whole plant and 1-month-old callus culture of fresh apical stem were considered as inactive (IC(50) > 100 microg/ml).


Asunto(s)
Antimaláricos/farmacología , Phyllanthus , Plasmodium falciparum/efectos de los fármacos , Animales , Antimaláricos/aislamiento & purificación , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/farmacología , Tallos de la Planta , Plasmodium falciparum/fisiología
5.
Phytomedicine ; 9(1): 56-61, 2002 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11924765

RESUMEN

Forty-two ethanolic extracts of thirty-six Rwandan medicinal plants were investigated for their influence on complement-mediated hemolysis. The plants were selected on the base of their ethnomedicinal use in infections and autoimmune diseases. Eight plant extracts showed an inhibitory activity against the classical pathway of the complement system and ten plant extracts against the alternative pathway. Three plant extracts exhibited an interesting activity against both pathways, i.e. Aspilia pluriseta, Coleus kilimandschari, and Macaranga kilimandscharica (leaves and stem). Further study indicated that the complement inhibitory activity was not caused by chelation of bivalent cations or by direct action on the target erythrocytes.


Asunto(s)
Activación de Complemento , Eritrocitos/efectos de los fármacos , Hemólisis/efectos de los fármacos , Medicinas Tradicionales Africanas , Fitoterapia , Extractos Vegetales/farmacología , Humanos , Concentración 50 Inhibidora , Estructuras de las Plantas , Rwanda
6.
Phytomedicine ; 9(1): 62-8, 2002 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11924766

RESUMEN

Selected plants used in Rwandan traditional medicine for the treatment of infections and/or rheumatoid diseases were investigated for antiviral activity in vitro against human immunodeficiency virus type-1 (HIV-1). Of the 38 tested 80% ethanolic extracts, belonging to plants of 21 different families only the extracts from the leaves of Aspilia pluriseta (Asteraceae) and Rumex bequaertii (Polygonaceae) had interesting selectivity indices (SI = ratio of the 50% cytotoxic concentration to the 50% effective antiviral concentration) higher than 1. Further fractionation of the initially antivirally inactive ethanolic extract of Tithonia diversifolia, however, led to an aqueous fraction with a high anti-HIV-1 activity (SI > 461), indicating that the cytotoxicity of some plant components may mask the antiviral properties of the active plant substances in total plant extracts.


Asunto(s)
Fármacos Anti-VIH/farmacología , VIH-1/efectos de los fármacos , Medicinas Tradicionales Africanas , Fitoterapia , Extractos Vegetales/farmacología , Fármacos Anti-VIH/uso terapéutico , Línea Celular/efectos de los fármacos , Infecciones por VIH/tratamiento farmacológico , Humanos , Extractos Vegetales/uso terapéutico , Estructuras de las Plantas , Rwanda
7.
J Ethnopharmacol ; 79(2): 155-63, 2002 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11801376

RESUMEN

A total of 45 Rwandan plant extracts, belonging to 37 different plant species out of 21 families, were investigated for their antibacterial, antifungal, and antiviral properties. The plants were selected on the base of their ethnomedicinal use against infections and autoimmune diseases. From all the plant extracts tested, only Clematis hirsuta (leaves) showed a pronounced antifungal activity against Candida albicans and the dermatophytes Trichophyton rubrum, Epidermophyton floccosum, and Microsporum canis. Seven plant extracts showed a high antiviral activity against the DNA-virus Herpes simplex type 1, while five and three plant extracts were highly active against the RNA-viruses Coxsackie and Polio, respectively. Only Macaranga kilimandscharica (leaves) showed an interesting anti-measles activity, whereas Eriosema montanum (leaves) and Entada abyssinica (leaves) were highly active against Semliki forest virus. Some plant extracts showed an antibacterial activity against Gram-positive bacteria and Mycobacterium fortuitum, but none of them were active against the Gram-negative bacteria tested.


Asunto(s)
Antiinfecciosos/farmacología , Antivirales/farmacología , Evaluación Preclínica de Medicamentos/métodos , Medicinas Tradicionales Africanas , Extractos Vegetales/farmacología , Antibacterianos , Antiinfecciosos/uso terapéutico , Antifúngicos/farmacología , Antifúngicos/uso terapéutico , Antivirales/uso terapéutico , Evaluación Preclínica de Medicamentos/estadística & datos numéricos , Fitoterapia/métodos , Fitoterapia/estadística & datos numéricos , Extractos Vegetales/uso terapéutico , Hojas de la Planta/química , Rwanda
8.
J Ethnopharmacol ; 79(2): 213-20, 2002 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11801384

RESUMEN

The chemical composition of essential oils from 15 aromatic medicinal plant species growing in the Democratic Republic of Congo have been studied. More than 15 constituents in an amount higher than 0.1% were identified in each essential oil. 1,8-cineole, alpha and beta-pinene, p-cymene, myrcene, gamma-terpinene, alpha-terpineol and limonene were prevalent constituents in almost more than 10 selected plant species. Results from the antibacterial testing by the diffusion method indicate that all essential oils (5 microl per disc) inhibited the growth of selected bacteria at different extents. The most active antibacterial essential oils were those of the leaves of Eucalyptus camadulensis and Eucalyptus terticornis (12-30 mm zone diameter of inhibition). They showed particularly a most potent inhibition of Pseudomonas aeruginosa growth (15-16 mm), followed by Eucalyptus robusta (12 mm). Essential oils from the leaves of Eucalyptus alba, Eucalyptus citriodora, Eucalyptus deglupta, Eucalyptus globulus, Eucalyptus saligna, Eucalyptus robusta, Aframomum stipulatum, Cymbopogon citratus, Ocimum americanum and that of the seeds of Monodora myristica showed also a good antibacterial activity (10-18 mm). Eucalyptus propinqua, Eucalyptus urophylla and Ocimum gratissimum essential oils were the less active samples against the selected bacteria. No correlation between the amount of major constituents such as 1,8-cineol, alpha-pinene, p-cymene, cryptone or thymol and the antibacterial activity was observed.


Asunto(s)
Antibacterianos/química , Antibacterianos/farmacología , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Medicinas Tradicionales Africanas , Aceites Volátiles/química , Aceites Volátiles/farmacología , Antibacterianos/uso terapéutico , República Democrática del Congo , Evaluación Preclínica de Medicamentos/métodos , Evaluación Preclínica de Medicamentos/estadística & datos numéricos , Bacterias Gramnegativas/crecimiento & desarrollo , Bacterias Grampositivas/crecimiento & desarrollo , Aceites Volátiles/uso terapéutico , Fitoterapia/métodos , Fitoterapia/estadística & datos numéricos , Semillas/química
9.
J Pharm Pharmacol ; 53(5): 757-61, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11370716

RESUMEN

Bridelia ferruginea Benth. (Euphorbiaceae) is a subtropical medicinal plant widely used in traditional African medicine against various diseases, including rheumatic pains. Seven of its constituents (3-O-methylquercetin (1), 3,7,3',4'-tetra-O-methylquercetin (rutisin, 2), myricetin (3), 3',4',5'-tri-O-methylmyricetin (ferrugin, 4), 3,3',4',5'-tetra-O-methylmyricetin (5), quercetin 3-O-glucoside (6), and a biflavanol gallocatechin-[4'-O-7]-epigallocatechin (7)) have been evaluated in-vitro in the xanthine-xanthine oxidase enzymatic system for inhibition of xanthine oxidase and radical scavenging activity. Results indicated that compounds 1, 3, 4 and 6 exhibited, at different levels, xanthine oxidase inhibiting and superoxide scavenging activity at micromolar concentrations, whereas compound 7 showed scavenging activity only. Compounds 2 and 5 were inactive in both cases. Study of the structure-activity relationship demonstrated that for flavonoids the xanthine oxidase inhibitory activity was reduced by methylation of the hydroxyl functionality at C-3 and in rings A and B. These results may partly explain and support the use of B. ferruginea stem bark for the treatment of rheumatic pains in traditional medicine.


Asunto(s)
Depuradores de Radicales Libres/farmacología , Fenoles/farmacología , Xantina Oxidasa/metabolismo , Artritis Reumatoide/tratamiento farmacológico , Humanos , Medicinas Tradicionales Africanas , Fenoles/aislamiento & purificación , Extractos Vegetales , Plantas Medicinales , Xantina Oxidasa/efectos de los fármacos
10.
Ann Trop Med Parasitol ; 95(1): 47-57, 2001 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11235553

RESUMEN

The ethanolic, dichloromethane and lyophilized aqueous extracts of Cassia occidentalis root bark, Morinda morindoides leaves and whole plants of Phyllanthus niruri were evaluated for their antimalarial actvity in vivo, in 4-day, suppressive assays against Plasmodium berghei ANKA in mice. No toxic effect or mortality was observed in mice treated, orally, with any of the extracts as a single dose, of 500 mg/kg body weight, or as the same dose given twice weekly for 4 weeks (to give a total dose of 4 g/kg). No significant lesions were observed, by eye or during histopathological examinations, in the hearts, lungs, spleens, kidneys, livers, large intestines or brains of any mouse. At doses of 200 mg/kg, all the ethanolic and dichloromethane extracts produced significant chemosuppressions of parasitaemia (of > 60% for C. occidentalis root bark and Ph. niruri whole plant, and of 30% for M. morindoides leaves) when administered orally. The most active ethanolic extract, that of Ph. niruri, reduced parasitaemia by 73%. The dichloromethane extracts of M. morindoides and Ph. niruri produced similar reductions (74% and 72% chemosuppression, respectively), whereas that of C. occidentalis was slightly less active (60% chemosuppression). Each lyophilized aqueous extract was less active than the corresponding ethanolic extract.


Asunto(s)
Cassia/uso terapéutico , Euphorbiaceae/uso terapéutico , Malaria/tratamiento farmacológico , Fitoterapia , Plantas Medicinales , Plasmodium berghei/efectos de los fármacos , Rubiaceae/uso terapéutico , Administración Oral , Animales , Ratones , Extractos Vegetales/uso terapéutico , Hojas de la Planta , Raíces de Plantas , Resultado del Tratamiento
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