RESUMEN
Rheumatoid arthritis (RA) is an autoimmune disease of knee joints involving pain and inflammation. Rhoifolin is a plant flavonoid known to have antioxidant and anti-inflammatory properties. This study was taken to identify the effect of rhoifolin on complete Freund's adjuvant (CFA)-induced arthritis in the rat model. Treatment with rhoifolin (10 and 20 mg/kg) showed a significant improvement in the overall health parameters such as paw edema and weight loss. This improvement in morphological parameters corroborated the findings with gross morphological changes observed in the histopathological analysis. Rhoifolin treatment also caused a significant decrease in oxidative stress, evident from changes in intracellular levels of glutathione, glutathione peroxidase, malondialdehyde, and superoxide dismutase in the articular cartilage tissue. Moreover, proinflammatory cytokines, tumor necrosis factor (TNF)-α, interleukin(IL)-1ß, and IL-6 showed a significant downregulation of gene expression and intracellular protein concentration levels. The NF-κB pathway showed a significant attenuation as evident in the significant reduction in the levels of NF-κB p65 and p-IκB-α. These results indicated that rhoifolin can be a natural therapeutic alternative to the extant regimens, which include non-steroidal anti-inflammatory drugs and immunosuppressants. Additionally, the antioxidant and anti-inflammatory action of rhoifolin was probably mediated by the NF-κB pathway. However, the exact target molecules of this pathway need to be determined in further studies.
Asunto(s)
Artritis Experimental/tratamiento farmacológico , Artritis Reumatoide/tratamiento farmacológico , Citocinas/sangre , Disacáridos/administración & dosificación , Flavonoides/administración & dosificación , Adyuvante de Freund/administración & dosificación , Glicósidos/administración & dosificación , FN-kappa B/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Animales , Artritis Experimental/metabolismo , Artritis Reumatoide/metabolismo , Biomarcadores/sangre , Interleucina-1beta/sangre , Interleucina-6/sangre , Masculino , FN-kappa B/metabolismo , Ratas , Factor de Necrosis Tumoral alfa/sangreRESUMEN
Establishing new animal models for the study of inflammation is very important in the process of discovering new drugs, since the inflammatory event is the basis of many pathological processes. Whereas rodent models have been the primary focus of inflammation research, we defend the zebrafish (Danio rerio) test as a feasible alternative for preclinical studies. Moreover, despite all the technological development already achieved by humanity, nature can still be considered a relevant source of new medicines. In this context, the aim of this work was to evaluate the anti-inflammatory effect of a substance isolated from the medicinal plant Annona crassilfora Mart, the peltatoside, in an inflammatory model of zebrafish. It was determined: (i) total leukocyte count in the coelomate exudate; (ii) N-acetyl-ß-d-glucuronidase (NAG); (iii) myeloperoxidase (MPO); (iv) and the histology of liver, intestine and mesentery. Peltotoside (25, 50 and 100 µg) and dexamethasone (25 µg) were administered intracelomatically (i.c.) 30 min before carrageenan (i.c.). Pretreatment with peltatoside at three doses significantly inhibited leukocyte recruitment in the coelomic cavity, and inhibited NAG and MPO activity against the action of Cg, in a similar manner as dexamethasone. However, some microlesions in the evaluated organs were detected. The dose of 25 µg showed an anti-inflammatory effect with lower undesirable effects in the tissues. Our results suggest that the zebrafish test was satisfactory in performing our analyzes and that the peltotoside has a modulatory action in reducing leukocyte migration.
Asunto(s)
Annona/química , Antiinflamatorios/farmacología , Modelos Animales de Enfermedad , Glicósidos/farmacología , Inflamación/tratamiento farmacológico , Extractos Vegetales/farmacología , Quercetina/análogos & derivados , Pez Cebra , Animales , Antiinflamatorios/administración & dosificación , Antiinflamatorios/química , Glicósidos/administración & dosificación , Glicósidos/química , Extractos Vegetales/administración & dosificación , Extractos Vegetales/química , Hojas de la Planta/química , Plantas Medicinales/química , Quercetina/administración & dosificación , Quercetina/química , Quercetina/farmacologíaRESUMEN
Rheumatoid arthritis (RA) is an autoimmune disease of knee joints involving pain and inflammation. Rhoifolin is a plant flavonoid known to have antioxidant and anti-inflammatory properties. This study was taken to identify the effect of rhoifolin on complete Freund's adjuvant (CFA)-induced arthritis in the rat model. Treatment with rhoifolin (10 and 20 mg/kg) showed a significant improvement in the overall health parameters such as paw edema and weight loss. This improvement in morphological parameters corroborated the findings with gross morphological changes observed in the histopathological analysis. Rhoifolin treatment also caused a significant decrease in oxidative stress, evident from changes in intracellular levels of glutathione, glutathione peroxidase, malondialdehyde, and superoxide dismutase in the articular cartilage tissue. Moreover, proinflammatory cytokines, tumor necrosis factor (TNF)-α, interleukin(IL)-1β, and IL-6 showed a significant downregulation of gene expression and intracellular protein concentration levels. The NF-κB pathway showed a significant attenuation as evident in the significant reduction in the levels of NF-κB p65 and p-IκB-α. These results indicated that rhoifolin can be a natural therapeutic alternative to the extant regimens, which include non-steroidal anti-inflammatory drugs and immunosuppressants. Additionally, the antioxidant and anti-inflammatory action of rhoifolin was probably mediated by the NF-κB pathway. However, the exact target molecules of this pathway need to be determined in further studies.
Asunto(s)
Animales , Masculino , Ratas , Artritis Experimental/tratamiento farmacológico , Artritis Reumatoide/tratamiento farmacológico , Flavonoides/administración & dosificación , Adyuvante de Freund/administración & dosificación , Citocinas/sangre , Estrés Oxidativo/efectos de los fármacos , Disacáridos/administración & dosificación , Artritis Experimental/metabolismo , Artritis Reumatoide/metabolismo , Biomarcadores/sangre , FN-kappa B/efectos de los fármacos , FN-kappa B/metabolismo , Interleucina-6/sangre , Factor de Necrosis Tumoral alfa/sangre , Interleucina-1beta/sangre , Glicósidos/administración & dosificaciónRESUMEN
BACKGROUND: The sand fly Lutzomyia longipalpis is the main vector of American visceral leishmaniasis, a disease caused by parasites of the genus Leishmania. Adults of this insect feed on blood (females only) or sugar from plant sources, but their digestion of carbohydrates is poorly studied. Beta-glycosides as esculin and amygdalin are plant compounds and release toxic compounds as esculetin and mandelonitrile when hydrolyzed. Beta-glucosidase and trehalase are essential enzymes in sand fly metabolism and participate in sugar digestion. It is therefore possible that the toxic portions of these glycosides, released during digestion, affect sand fly physiology and the development of Leishmania. RESULTS: We tested the oral administration to sand flies of amygdalin, esculin, mandelonitrile, and esculetin in the sugar meal. These compounds significantly decreased the longevity of Lutzomyia longipalpis females and males. Lutzomyia longipalpis adults have significant hydrolytic activities against esculin and feeding on this compound cause changes in trehalase and ß-glucosidase activities. Female trehalase activity is inhibited in vitro by esculin. Esculin is naturally fluorescent, so its ingestion may be detected and quantified in whole insects or tissue samples stored in methanol. Mandelonitrile neither affected the amount of sugar ingested by sand flies nor showed repellent activity. Our results show that mandelonitrile significantly reduces the viability of L. amazonensis, L. braziliensis, L. infantum and L. mexicana, in a concentration-dependent manner. Esculetin caused a similar effect, reducing the number of L. infantum and L. mexicana. Female L. longipalpis fed on mandelonitrile had a reduction in the number of parasites and prevalence of infection after seven days of infection with L. mexicana, either by counting in a Neubauer chamber or by qPCR assays. CONCLUSIONS: Glycosides have significant effects on L. longipalpis longevity and metabolism and also affect the development of parasites in culture and inside the insect. These observations might help to conceptualize new vector control strategies using transmission blocking sugar baits.
Asunto(s)
Glicósidos/toxicidad , Control de Insectos/métodos , Insectos Vectores/enzimología , Insectos Vectores/parasitología , Leishmania/crecimiento & desarrollo , Psychodidae/enzimología , Psychodidae/parasitología , Acetonitrilos/toxicidad , Amigdalina/toxicidad , Animales , Esculina/toxicidad , Femenino , Glicósidos/administración & dosificación , Leishmaniasis/prevención & control , Leishmaniasis/transmisión , Masculino , Trehalasa/efectos de los fármacos , Umbeliferonas/administración & dosificación , Umbeliferonas/toxicidad , beta-Glucosidasa/efectos de los fármacosRESUMEN
An experiment was performed to evaluate the effect of decreased levels of vitamin D3 in the premix and 1,25-dyhydroxyvitamin D3-glycoside (1,25(OH)2D3-glycoside) supplementation on performance, carcass yield and bone quality in 42d old broilers. Seven-d-old male chickens Cobb500® were distributed in a randomized design with six treatments: a control diet with inclusion of vitamin D3 in the premix, without supplementation of 1,25(OH)2D3-glycoside, and five diets with decreased levels of vitamin D3 (100%, 75%, 50%, 25% and 0% about the control) plus the addition of 1,25(OH)2D3-glycoside, 50g ton-1 of diet. The main results were to reduce the tenor of Vitamin D3 in the premix when the addition of 1,25(OH)2D3-glycoside did not affect (P>0.05) the performance, carcass yield and bone quality variables. However, performance (feed intake, gain weight, feed conversion), yield (warm carcass weight) and bone quality (dry weight, length, mineral matter and breaking strength) of broilers fed with diets without vitamin D3 in the premix and with addition of 1,25(OH)2D3-glycoside, which was the single source of vitamin D, had as a result very low (P 0.05) values comparing to the control. For the purposes of the present research, it was concluded that is possible the reduction of vitamin D3 tenor in the premix up to 75% when the diet of male broilers is supplemented with 1,25(OH)2D3-glycoside. However, the use of 1,25(OH)2D3-glycoside as a single source of vitamin D, as tested here, is not recommended for broilers diets.
Um experimento foi realizado para avaliar o efeito da diminuição dos níveis de vitamina D3 no premix e a suplementação de 1,25-dihidroxivitamina D3-glicosídeo (1,25(OH)2D3-glicosídeo) sobre o desempenho, rendimento de carcaça e qualidade óssea em frangos de corte de 42 dias. Machos Cobb500® de sete dias de idade foram distribuídos em delineamento inteiramente casualizado com seis tratamentos: uma dieta controle com inclusão de vitamina D3 no premix, sem suplementação de 1,25(OH)2D3-glicosídeo, e cinco dietas com níveis decrescentes de vitamina D3 (100%, 75%, 50%, 25% e 0% em relação ao controle) mais a adição de 1,25(OH)2D3-glicosídeo (50g ton-1 de dieta). Entre os principais resultados, foi observado que a redução do teor de vitamina D3 no premix quando adicionado 1,25(OH)2D3-glicosídeo não afetou (P>0,05) o desempenho, o rendimento da carcaça e as variáveis da qualidade óssea. No entanto, as variáveis do desempenho e o rendimento (consumo de ração, ganho de peso, conversão alimentar, peso da carcaça quente) e da qualidade dos ossos (peso seco, comprimento, matéria mineral e resistência à ruptura) de frangos alimentados com dietas sem vitamina D3 no premix, com a adição de 1,25(OH)2D3-glicosídeo como a única fonte de vitamina D, teve como resultado valores muito baixos (P 0,05) em comparação ao controle. Para os propósitos da presente pesquisa, concluiu-se que é possível a redução do teor de vitamina D3 no premix até 75% quando a dieta de frangos de corte machos é suplementada com 1,25(OH)2D3-glicosídeo. No entanto, o uso de 1,25(OH)2D3-glicosídeo como única fonte de vitamina D, conforme testado aqui, não é recomendado para dietas de frangos de corte.(AU)
Asunto(s)
Animales , Pollos , Colecalciferol/administración & dosificación , Glicósidos/administración & dosificación , Suplementos Dietéticos , Solanum glaucophyllum , Desarrollo ÓseoRESUMEN
In this study, we examined the effects of Tripterygium wilfordii glycosides (TWGs) on Th17 and regulatory T cells (Tregs) in an immunoglobulin A nephropathy (IgAN) rat model. IgAN model rats were randomly divided into the model group, TWG treatment group, and prednisone group. Normal rats were included as controls. There were 6 rats in each group. The urine protein levels and the number of red blood cells in urine were analyzed at 24 h. IgA deposition in renal tissue was detected by fluorescence microscopy. The concentration of interleukin-17 in serum was detected by an enzyme-linked immunosorbent assay and the number of Tregs in blood was analyzed by flow cytometry. TWGs and prednisone significantly reduced urine protein levels and urine red blood cells at 24 h in IgAN model rats (P < 0.01), but prednisone had a greater effect than did TWGs (P < 0.05). TWGs and prednisone reduced IgA deposition in renal tissue, but prednisone had a greater effect than TWGs. T. wilfordii glycosides and prednisone significantly decreased the serum IL-17 level in an IgAN rat model and increased the number of Tregs in the blood (P < 0.01). There was no significant difference between prednisone and TWGs (P > 0.05). In conclusion, TWGs had therapeutic effects on IgAN model rats and may regulate the immune balance of Th17 and Tregs.
Asunto(s)
Glomerulonefritis por IGA/tratamiento farmacológico , Glicósidos/administración & dosificación , Linfocitos T Reguladores/inmunología , Células Th17/inmunología , Animales , Modelos Animales de Enfermedad , Glomerulonefritis por IGA/inmunología , Glomerulonefritis por IGA/patología , Glicósidos/química , Humanos , Prednisona/administración & dosificación , Ratas , Linfocitos T Reguladores/efectos de los fármacos , Células Th17/efectos de los fármacos , Tripterygium/químicaRESUMEN
Opuntia ficus-indica (OFI) has been widely used in Mexico as a food and for the treatment of different health disorders such as inflammation and skin aging. Its biological properties have been attributed to different phytochemicals such as the isorhamnetin glycosides which are the most abundant flavonoids. Moreover, these compounds are considered a chemotaxonomic characteristic of OFI species. The aim of this study was to evaluate the effect of OFI extract and its isorhamnetin glycosides on different inflammatory markers in vitro and in vivo. OFI extract was obtained by alkaline hydrolysis of OFI cladodes powder and pure compounds were obtained by preparative chromatography. Nitric oxide (NO), cyclooxygenase-2 (COX-2), tumor necrosis factor- (TNF-) α, and interleukin- (IL-) 6 production were measured. NO production was tested in lipopolysaccharide-stimulated RAW 264.7 cells while in vivo studies were carried on croton oil-induced ear edema model. OFI extract and diglycoside isorhamnetin-glucosyl-rhamnoside (IGR) at 125 ng/mL suppressed the NO production in vitro (73.5 ± 4.8% and 68.7 ± 5.0%, resp.) without affecting cell viability. Likewise, IGR inhibited the ear edema (77.4 ± 5.7%) equating the indomethacin effects (69.5 ± 5.3%). Both IGR and OFI extract significantly inhibited the COX-2, TNF-α, and IL-6 production. IGR seems to be a suitable natural compound for development of new anti-inflammatory ingredient.
Asunto(s)
Glicósidos/administración & dosificación , Opuntia/química , Otitis Externa/tratamiento farmacológico , Otitis Externa/inmunología , Extractos Vegetales/administración & dosificación , Quercetina/análogos & derivados , Animales , Antiinflamatorios/administración & dosificación , Antiinflamatorios/química , Citocinas/inmunología , Relación Dosis-Respuesta a Droga , Glicósidos/química , Masculino , Extractos Vegetales/química , Quercetina/administración & dosificación , Quercetina/química , Ratas , Ratas Wistar , Resultado del TratamientoRESUMEN
Psychotria is a complex genus whose neotropical species are known by the presence of glucosidic monoterpene indole alkaloids. These compounds are able to display a large range of effects on the central nervous system, such as anxiolytic, antidepressant, analgesic, and impairment of learning and memory acquisition. The aims of this study were to investigate the effects displayed by strictosidinic acid, isolated from Psychotria myriantha Mull. Arg. (Rubiaceae) leaves, on monoamine levels in rat hippocampus and on monoamine oxidase activity. A significance (p<0.01) of 83.5% reduction in 5-HT levels was observed after intra-hippocampal injection (20 µg/µl). After treatment by intraperitoneal route (10 mg/kg), a 63.4% reduction in 5-HT levels and a 67.4% reduction in DOPAC values were observed. The results indicate that strictosidinic acid seems to act on 5-HT system in rat hippocampus, possibly inhibiting precursor enzymes of 5-HT biosynthesis. The decrease verified in DOPAC levels suggests a role of strictosidinic acid in the dopaminergic transmission, probably due to an inhibition of monoamine oxidase activity, confirmed by the enzymatic assay, which demonstrated an inhibitory effect on MAO A in rat brain mitochondria.
Asunto(s)
Ácido 3,4-Dihidroxifenilacético/metabolismo , Carbolinas/farmacología , Glicósidos/farmacología , Hipocampo/metabolismo , Monoaminooxidasa/metabolismo , Extractos Vegetales/farmacología , Psychotria/química , Serotonina/metabolismo , Animales , Carbolinas/administración & dosificación , Carbolinas/aislamiento & purificación , Glicósidos/administración & dosificación , Glicósidos/aislamiento & purificación , Masculino , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Inhibidores de la Monoaminooxidasa/administración & dosificación , Inhibidores de la Monoaminooxidasa/aislamiento & purificación , Inhibidores de la Monoaminooxidasa/farmacología , Extractos Vegetales/administración & dosificación , Extractos Vegetales/química , Hojas de la Planta , Ratas , Ratas Wistar , Serotonina/biosíntesis , Antagonistas de la Serotonina/administración & dosificación , Antagonistas de la Serotonina/aislamiento & purificación , Antagonistas de la Serotonina/farmacologíaRESUMEN
To expand the potential of pseudopterosins and seco-pseudopterosins isolated from the octocoral Pseudopterogorgia elisabethae of San Andrés and Providencia islands (southwest Caribbean Sea), we report the anti-microbial profile against four pathogenic microorganisms (Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa and Candida albicans) and report a more complete cytotoxic profile against five human cells lines (HeLa, PC-3, HCT116, MCF-7 and BJ) for the compounds PsG, PsP, PsQ, PsS, PsT, PsU, 3-O-acetyl-PsU, seco-PsJ, seco-PsK and IMNGD. For the cytotoxic profiles, all compounds evaluated showed moderate and non-selective activity against both tumor and normal cell lines, where PsQ and PsG were the most active compounds (GI50 values between 5.8 µM to 12.0 µM). With respect to their anti-microbial activity the compounds showed good and selective activity against the Gram-positive bacteria, while they did not show activity against the Gram-negative bacterium or yeast. PsU, PsQ, PsS, seco-PsK and PsG were the most active compounds (IC50 2.9-4.5 µM) against S. aureus and PsG, PsU and seco-PsK showed good activity (IC50 3.1-3.8 µM) against E. faecalis, comparable to the reference drug vancomycin (4.2 µM).
Asunto(s)
Antozoos/química , Antiinfecciosos/farmacología , Antineoplásicos/farmacología , Diterpenos/farmacología , Glicósidos/farmacología , Animales , Antiinfecciosos/administración & dosificación , Antiinfecciosos/aislamiento & purificación , Antineoplásicos/administración & dosificación , Antineoplásicos/aislamiento & purificación , Candida albicans/efectos de los fármacos , Región del Caribe , Línea Celular Tumoral , Diterpenos/administración & dosificación , Diterpenos/aislamiento & purificación , Glicósidos/administración & dosificación , Glicósidos/aislamiento & purificación , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Humanos , Concentración 50 Inhibidora , Pruebas de Sensibilidad Microbiana , Vancomicina/farmacologíaRESUMEN
Asthma is a chronic respiratory disease characterized by airway inflammation and airway hyperresponsiveness (AHR). One strategy to treat allergic diseases is the development of new drugs. Flavonoids are compounds derived from plants and are known to have antiallergic, anti-inflammatory, and antioxidant properties. To investigate whether the flavonoid kaempferol glycoside 3-O-[beta-d-glycopiranosil-(1-->6)-alpha-l-ramnopiranosil]-7-O-alpha-l-ramnopiranosil-kaempferol (GRRK) would be capable of modulating allergic airway disease (AAD) either as a preventive (GRRK P) or curative (GRRK C) treatment in an experimental model of asthma. At weekly intervals, BALB/c mice were subcutaneously (sc) sensitized twice with ovalbumin (OVA)/alum and challenged twice with OVA administered intranasally. To evaluate any preventive effect, GRRK was administered 1h (hour) before each OVA-sensitization and challenge, while to analyze the curative effect, mice were first sensitized with OVA, followed by GRRK given at day 18 through 21. The onset of AAD was evaluated 24h after the last OVA challenge. Both treatments resulted in a dose-dependent reduction in total leukocyte and eosinophil counts in the bronchoalveolar lavage fluid (BAL). GRRK also decreased CD4(+), B220(+), MHC class II and CD40 molecule expressions in BAL cells. Histology and lung mechanic showed that GRRK suppressed mucus production and ameliorated the AHR induced by OVA challenge. Furthermore, GRRK impaired Th2 cytokine production (IL-5 and IL-13) and did not induce a Th1 pattern of inflammation. These findings demonstrate that GRRK treatment before or after established allergic lung disease down-regulates key asthmatic features. Therefore, GRRK has a potential clinical use for the treatment of allergic asthma.
Asunto(s)
Asma/tratamiento farmacológico , Disacáridos/administración & dosificación , Eosinófilos/efectos de los fármacos , Glicósidos/administración & dosificación , Quempferoles/administración & dosificación , Leucocitos/efectos de los fármacos , Pulmón/efectos de los fármacos , Animales , Antígenos CD/biosíntesis , Antígenos CD/genética , Líquido del Lavado Bronquioalveolar/citología , Recuento de Células , Disacáridos/química , Disacáridos/aislamiento & purificación , Eosinófilos/patología , Femenino , Glicósidos/química , Glicósidos/aislamiento & purificación , Antígenos de Histocompatibilidad Clase II/biosíntesis , Antígenos de Histocompatibilidad Clase II/genética , Interleucina-13/metabolismo , Interleucina-5/metabolismo , Quempferoles/química , Quempferoles/aislamiento & purificación , Leucocitos/patología , Pulmón/inmunología , Pulmón/metabolismo , Pulmón/patología , Ratones , Ratones Endogámicos BALB C , Moco/metabolismo , Ovalbúmina/inmunología , Células Th2/inmunologíaRESUMEN
Investigation of the stem bark of the unique Amazonian herbal plant Potalia amara yielded two new phenolic glycosides, potalioside A (1) and B (2), along with di-O-methylcrenatin (3), 2,6-dimethoxy-4-hydroxyphenol 1-glucoside and sweroside. The structures of potalioside A and B were established by interpretation of spectral data as 4-hydroxymethyl-2,6-dimethoxyphenyl 1-O-beta-D-glucopyranosyl(1-->6)-beta-D-glucopyranoside and 4-hydroxymethyl-2,6-dimethoxyphenyl 1-O-beta- D-xylopyranosyl(1-->6)- beta-D-glucopyranoside, respectively.
Asunto(s)
Gentianaceae , Fitoterapia , Extractos Vegetales/farmacología , Antibacterianos/administración & dosificación , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Bacterias/efectos de los fármacos , Brasil , Candida albicans/efectos de los fármacos , Glicósidos/administración & dosificación , Glicósidos/farmacología , Glicósidos/uso terapéutico , Humanos , Medicina Tradicional , Pruebas de Sensibilidad Microbiana , Fenoles/administración & dosificación , Fenoles/farmacología , Fenoles/uso terapéutico , Corteza de la Planta , Extractos Vegetales/administración & dosificación , Extractos Vegetales/uso terapéuticoRESUMEN
TLC autographic assay revealed, in the EtOAc extract obtained from leaves and root bark of Maytenus aquifolium (Celastraceae), the presence of fi ve compounds exhibiting antioxidant properties towards beta-carotene. They were isolated and identified as epigallocatechin (1), (+) ouratea-catechin (2), proanthocyanidin (3), kaempferol 3-O-alpha-L-rhamnopyranosyl (1-->6)-O-[beta-D-glucopyranosyl (1-->3)-O-alpha-L-rhamnopyranosyl-(1-->2)]-O-beta-D-glucopyranosyl (4) and quercetin 3-O-alpha-L-rhamnopyranosyl (1-->6)-O-[beta-D-glucopyranosyl (1-->3)-O-alpha-L-rhamnopyranosyl-(1-->2)]-O-beta-D-glucopyranosyl (5). The isolates were investigated for their redox properties using cyclic voltammetry and for their radical scavenging abilities through spectrophotometric assay on the reduction of 2,2-diphenyl-pycryl hydrazyl (DPPH). These results were correlated to the inhibition of beta-carotene bleaching on TLC autographic assay and to structural features of the flavonoids.
Asunto(s)
Antioxidantes/farmacología , Flavonoides/farmacología , Flavonoles/farmacología , Glicósidos/farmacología , Maytenus , Fitoterapia , Antioxidantes/administración & dosificación , Antioxidantes/uso terapéutico , Compuestos de Bifenilo , Electroquímica , Flavonoides/administración & dosificación , Flavonoides/uso terapéutico , Flavonoles/administración & dosificación , Flavonoles/uso terapéutico , Glicósidos/administración & dosificación , Glicósidos/uso terapéutico , Humanos , Picratos , Extractos Vegetales/administración & dosificación , Extractos Vegetales/farmacología , Extractos Vegetales/uso terapéutico , Hojas de la Planta , Raíces de Plantas , beta Caroteno/químicaRESUMEN
The pregnane compound MV8612 isolated from the rhizome of the plant Mandevilla velutina administered by intraperitoneal (i.p.), intrathecal (i.t.) or by intracerebroventricular (i.c.v.) routes caused graded and complete inhibition of the thermal hyperalgesia caused by i.t. injection of bradykinin (BK) in mice with mean ID(50) values of 7.8 micromol/kg, 33.6 and 4.6 nmol/site, respectively. Compound MV8612 (i.p.) also inhibited both the neurogenic and inflammatory pain responses to formalin with mean ID(50) values of 5.6 and 10.6 micromol/kg, respectively. Given i.t., MV8612 produced significant inhibition of both phases of the formalin-induced licking (inhibition of 34+/-5 and 36+/-4%, respectively). Given by i.c.v. route MV8612 inhibited both phases of formalin-induced pain (32+/-6 and 63+/-5%) with mean ID(50) of 8.4 nmol/site against the late phase. MV8612, given by i.p., i.c.v. or i.t. routes, also inhibited capsaicin-induced pain (51+/-4, 25+/-8 and 39+/-6%, respectively). The i.t. injection of potassium (K(+)) channel blockers, apamin and charybdotoxin given 15 min before, markedly prevented the antinociception of MV8612 against both phases of formalin-induced nociception. In contrast, tetraethylammonium (TEA) or glibenclamide had no effect. The i.c.v. treatment with pertussis toxin resulted in a significant inhibition of both MV8612- and morphine-induced antinociception against both phases of formalin-induced pain. Taken together these results confirm and also extend our previous data by demonstrating that the greater part of the antinociception caused by MV8612 seems to be associated with its ability to interfere with BK action. Finally, both the low and high conductance calcium (Ca(2+))-activated K(+) channels and the activation of G(i/o) pertussis sensitive G-proteins take part in the mechanism by which compound MV8612 produces antinociception.