A group of flavonoids isolated from medicinal plants and which are selective inhibitors of lipoxygenase activity in vitro: sideritoflavone, cirsiliol, hypolaetin-8-O-beta-D-glucoside, hypolaetin, oroxindin, quercetagetin-7-O-beta-D-glucoside, gossypin, hibifolin and gossypetin, besides leucocyanidol, have been studied for their effects on acute responses induced by carrageenin in mice. The oral administration of flavonoids to mice inhibited dose-dependently the development of paw oedema at 1, 3 and 5 h after carrageenin injection. A similar administration of flavonoids induced a dose-dependent inhibition of leukocyte accumulation in inflammatory exudates following intraperitoneal injection of carrageenin into mice. Some of the flavonoids exhibited a potency against leukocyte infiltration similar to that seen for inhibition of carrageenin oedema at 3 h of induction. In agreement with data reported in rats, indomethacin was much more effective on inhibition of prostaglandin E2 (PGE2) formation than on leukocyte infiltration in mice. The selectivity of flavonoids towards lipoxygenase is not retained in vivo since they behave as dual inhibitors of PGE2 and leukotriene B4 (LTB4) formation in peritoneal exudates. Our data support the inhibition of arachidonic acid metabolism as one of the mechanisms by which flavonoids exert their anti-inflammatory effects.
Many in vitro studies have used cell cultures to focus on the relationships between cyclo-oxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) isoforms. We have investigated the time-course of regulation and the role of COX-2 and iNOS in a model of experimental inflammation in mice, the air pouch injected with zymosan. This study demonstrates that there is an early acute phase (4 h) mediated mainly by eicosanoids, with high levels of prostaglandin E2 (PGE2) produced by cyclo-oxygenase-1. In addition, in the later phase (from 12 h) there is a participation of nitric oxide (NO) and PGE2 accompanied by co-induction of both iNOS and COX-2. These enzymes were detected in migrating leukocytes as well as in macrophages lining the air pouch. Administration of NS398 or indomethacin inhibited PGE2 levels and COX activity, but also nitrite levels and iNOS activity, which was accompanied by a reduction in iNOS expression. Aminoguanidine inhibited nitrite levels and iNOS activity in addition to exerting inhibitory effects on the COX pathway. Treatment of animals with dexamethasone reduced nitrite and PGE2 concentrations in air pouch exudates, as well as iNOS and COX-2 expression in migrating cells. Our results indicate that PGE2 and NO may play in vivo mutual modulatory roles in the inflammatory response caused by zymosan injection into the mouse air pouch, a suitable model to study drugs acting on those pathways.
1. A series of flavonoids isolated from Indian medicinal plants: kaempferol-3-O-galactoside, hispidulin, nepetin, scutellarein, scutellarein-7-O-glucuronide, hibifolin and morelloflavone were studied for their activity as inhibitors of microsomal lipid peroxidation and scavengers of oxygen free radicals in vitro as well as in a model of xenobiotic toxicity in mouse. 2. All compounds inhibited lipid peroxidation in vitro. The most potent compounds were nepetin (non-enzymic lipid peroxidation) and morelloflavone (enzymic lipid peroxidation) with IC50's in the micromolar range. Some of the compounds behaved as scavengers of hydroxyl radical in the deoxyribose degradation assay, with a calculated rate constant for kaempferol-3-O-galactoside of 1.55 x 10(10) M-1 s-1. 3. Scutellarein and nepetin were found to be inhibitors of xanthine oxidase activity, whereas morelloflavone acted as a scavenger of superoxide generated by hypoxanthine/xanthine oxidase. 4. Treatment of mice with scutellarein, hispidulin, nepetin and kaempferol-3-O-galactoside after bromobenzene intoxication decreased serum glumate-pyruvate transaminase activity, although only the last flavonoid was able to significantly reduce hepatic lipid peroxidation products and to increase the reduced glutathione level. In contrast, morelloflavone increased bromobenzene toxicity.
*Objective: The aims of this study were to identify potentially inappropriate prescribing using the Beers and STOPP criteria. The START criteria were applied to detect prescription omission in the geriatric population. We compared the utility of these criteria in institutionalised older people. Methods: Descriptive study reviewing the medication and clinical records of 81 residents (aged 65 years and more) by pharmacists in a nursing home in the Lleida region (Spain). Results: The mean patients' age was 84 (SD=8) years, with an average of 5 drugs per resident (total prescriptions: 416 medicines). The Beers criteria identified potentially inappropriate medication use in 25% of patients and 48% of patients used at least 1 inappropriate medication according to STOPP criteria. The most frequent potentially inappropriate medications for both criteria were long-acting benzodiazepines and NSAIDs. START detected 58 potential prescribing omissions in 44% of patients. Calcium-vitamin D supplementation in osteoporosis was the most frequent rule (15%), but omissions corresponding to the cardiovascular system implied 23% of patients. Conclusion:The STOPP-START criteria reveal that potentially inappropriate prescribing (PIP) is a highly prevalent problem among Spanish nursing home residents, and a statistically significant positive correlation was found between the number of medicines prescribed and the number of PIP detected in this study. The STOPP criteria detect a larger number of PI medications in this geriatric population than the Beers criteria. PRESCRIPCIÓN POTENCIALMENTE INAPROPIADA EN ANCIANOS INSTITUCIONALIZADOS EN ESPAÑA: LOS CRITERIOS STOPP-START COMPARADOS CON LOS CRITERIOS DE BEERS RESUMENObjetivo: Este estudio está orientado a identificar la prescripción potencialmente inapropiada usando los criterios de Beers y STOPP. Las omisiones de prescripciones se detectan en esta población geriátrica aplicando los criterios START. Se compara la utilidad de estos criterios en ancianos institucionalizados. Métodos: Estudio descriptivo de revisión de la medicación y las historias clínicas por farmacéuticos, de 81 pacientes (con 65 o más años) ingresados en una residencia en la provincia de Lleida (España). Resultados: La media de edad de los pacientes fue de 84 años (DE=8), con cinco medicamentos de promedio de tratamiento por residente (prescripciones totales: 416 medicamentos). Los criterios de Beers detectaron el uso de medicación potencialmente inapropiada en el 25% de los pacientes. Los criterios STOPP identificaron una posible medicación inapropiada en el 48% de los pacientes. La mayor frecuencia de uso de medicamentos potencialmente inapropiados para ambos criterios correspondió a las benzodiacepinas de larga duración y los AINE. Los criterios START detectaron 58 prescripciones potencialmente omitidas en el 44% de los pacientes. Entre ellas, la ausencia de suplementos de Calcio-vitamina D en osteoporosis fue la regla más frecuentemente implicada (15% de los pacientes); sin embargo, las omisiones relacionad...
Objective. Redox imbalance contributes to bone fragility. We have evaluated the in vivo role of nuclear factor erythroid derived 2-related factor-2 (Nrf2), an important regulator of cellular responses to oxidative stress, in bone metabolism using a model of postmenopausal osteoporosis. Methods. Ovariectomy was performed in both wild-type and mice deficient in Nrf2 (Nrf2−/−). Bone microarchitecture was analyzed by μCT. Serum markers of bone metabolism were also measured. Reactive oxygen species production was determined using dihydrorhodamine 123. Results. Sham-operated or ovariectomized Nrf2−/− mice exhibit a loss in trabecular bone mineral density in femur, accompanied by a reduction in cortical area in vertebrae. Nrf2 deficiency tended to increase osteoblastic markers and significantly enhanced osteoclastic markers in sham-operated animals indicating an increased bone turnover with a main effect on bone resorption. We have also shown an increased production of oxidative stress in bone marrow-derived cells from sham-operated or ovariectomized Nrf2−/− mice and a higher responsiveness of bone marrow-derived cells to osteoclastogenic stimuli in vitro. Conclusion. We have demonstrated in vivo a key role of Nrf2 in the maintenance of bone microarchitecture.
Objective. Heme oxygenase 1 (HO-1) can be induced by inflammatory mediators as an adaptive response. The objective of the present study was to determine the consequences of HO-1 modulation in the murine collagen-induced arthritis (CIA) model.Methods. DBA/1J mice were treated with an inhibitor of HO-1, tin protoporphyrin IX (SnPP), or with an inducer of HO-1, cobalt protoporphyrin IX (CoPP), from day 22 to day 29 after CIA induction. The clinical evolution of disease was monitored visually. At the end of the experiment, joints were examined for histopathologic changes. Cytokine levels in paws were measured by enzyme-linked immunosorbent assay. Levels of HO-1, cyclooxygenase 2 (COX-2), and prostaglandin E 2 (PGE 2 ) were determined. Effects of treatments on the early phase of disease and after prophylactic administration were also assessed.Results. CoPP strongly induced HO-1, resulting in the inhibition of cartilage erosion accompanied by extensive fibrosis in the joint. Levels of tumor necrosis factor ␣ (TNF␣), interleukin-2 (IL-2), and IL-10 were inhibited by CoPP, whereas levels of vascular endothelial growth factor were increased. Treatment with SnPP significantly reduced the severity of CIA, with inhibition of joint inflammation and cartilage destruction. The levels of PGE 2 , IL-1, and TNF␣ were also significantly reduced by SnPP treatment, which did not modify COX-2 protein expression. SnPP was more effective than CoPP in preventing the development of CIA (prophylactic administration).Conclusion. HO-1 is induced during CIA. Although overexpression of this protein causes some beneficial effects, strategies aimed at HO-1 overexpression cannot slow the progression of the chronic inflammatory disease, whereas treatment with SnPP, which inhibits HO-1, exerts prophylactic and therapeutic effects.
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