Intestinal anti-inflammatory activity of morin on chronic experimental colitis in the rat.

BACKGROUND: Morin, a bioflavonoid with antioxidant properties, shows intestinal anti-inflammatory activity in the acute phase of the trinitrobenzenesulphonic acid model of rat colitis. AIM: To assess the anti-inflammatory activity of morin in the chronic stages of trinitrobenzenesulphonic acid-induced rat colitis. METHODS: Rats were rendered colitic by a single colonic instillation of 30 mg of the hapten trinitrobenzenesulphonic acid dissolved in 0.25 mL of 50% ethanol. A group of colitic animals was given morin orally at doses of 25 mg/kg daily. Animals were sacrificed every week for 4 weeks. Colonic damage was evaluated macroscopically and microscopically. Different biochemical markers of colonic inflammation were also assayed, including myeloperoxidase activity, leukotriene B4 and interleukin-1beta synthesis, glutathione and malonyldialdehyde levels and nitric oxide synthase activity. RESULTS: The administration of morin facilitated tissue recovery during the 4 weeks following colonic insult with trinitrobenzenesulphonic acid, as demonstrated macroscopically and microscopically, as well as biochemically by a reduction in myeloperoxidase activity. The intestinal anti-inflammatory effect of morin was accompanied by a significant reduction in colonic leukotriene B4 and interleukin-1beta levels, improvement in colonic oxidative stress and inhibition of colonic nitric oxide synthase activity. CONCLUSIONS: Morin exerts a beneficial anti-inflammatory effect in the chronic phase of trinitrobenzenesulphonic acid-induced rat colitis through the down-regulation of some of the mediators involved in the intestinal inflammatory response, including free radicals, cytokines, leukotriene B4 and nitric oxide.

Acid phosphatase, genetic polymorphism and cardiovascular risk factors in a pediatric population.

BACKGROUND: Although the clinical expression of cardiovascular disease usually occurs in adulthood, it is unanimously accepted that atherosclerosis begins in the pediatric age. Because of the early onset of the disease, it is of great importance to screen for major risk factors since pre-school age, especially in risk families. Recent investigations have shown a great interest not only in studying the classic risk factors, but also in the evaluation of oxidative stress and the main antioxidant defense systems. The major cause of this interest is the knowledge of the deleterious effect of reactive oxygen species on lipids, the endothelial membrane of arteries and, finally, on the occurrence of cardiovascular disease. POPULATION AND METHODS: 51 children of both genders, aged 9-12 years, randomly selected from a rural community, were observed. A possible association between low molecular acid phosphatase genetic polymorphism of the erythrocyte and the prooxidant status markers (epinephrine oxidase and low molecular protein phosphotyrosine phosphatase from the erythrocyte), some enzymatic systems of the body antioxidant defense (transmembranar reductase of ferricyanide and metahemoglobin reductase) and finally some intermediate phenotypes of cardiovascular disease (lipid profile and blood pressure) were studied. RESULTS: The study of prooxidant status markers and antioxidant enzymes shows significant differences for acid phosphatase and epinephrine oxidase activities in relation to low molecular acid phosphatase genetic polymorphism, the highest values observed being in those homozygous to the B allele (p < 0.05). The inter-relation study between variables showed, among other things, a significant inverse correlation between acid phosphatase and transmembrane reductase and a direct correlation between apolipoprotein B, acid phosphatase and metahemoglobin reductase. A positive family history for cardiovascular disease also showed a direct and significant correlation to total cholesterol, LDL-cholesterol and apolipoprotein B. CONCLUSIONS: The polymorphic variants of low molecular acid phosphatase and protein phosphotyrosine phosphatase with greater activity are strongly associated, not with the classic parameters of cardiovascular risk factors, but with oxidative stress indicators, such as low molecular protein phosphotyrosine phosphatase and epinephrine oxidase. Family history indicators of cardiovascular risk are clearly associated, since early ages, to some conventional risk factors, such as lipid profile and blood pressure.

Insulin and high glucose modulation of phosphatase and reductase enzymes in the human erythrocytes: a comparative analysis in normal and diabetic states.

The ability of insulin to influence activities of various protein kinases and protein phosphatases, that are thought to mediate insulin action, are limited in patients with insulin resistance. Because numerous responses to insulin are affected, we undertook studies to determine whether protein tyrosine phosphatases (PTPs) activities are altered in patients with diabetes syndrome. In order to evaluate abnormal PTP activities, we done a comparative study using erythrocytes from normal and diabetic patients. We determined the activity of the cytosolic acid PTP in basal and insulin-dependent states. Mean basal PTP activities, were found to be significantly higher in diabetics than in normal subjects (type 1 diabetics: 0.36 +/- 0.01 vs 0.28 +/- 0.01 mmol p-nitrophenolate/h per g hemoglobin (Hb), P < 0.001; type 2 diabetics: 0.35 +/- 0.01 vs 0.28 +/- 0.01 mmol p-nitrophenolate/h per g Hb, P < 0.001). Insulin, at concentrations above physiological levels (1 mIU/ml), inhibited the PTP activities in erythrocytes from normal subjects (-15 +/- 4.1%, P < 0.01). Insulin could also modulate glycolysis, probably as a consequence of receptor tyrosine kinase activation, inducing phosphorylation of protein band 3 and hence the release of glycolytic enzymes. We have previously reported that a reductase enzyme in human erythrocytes is dependent on glycolysis being significantly activated (+28 +/- 3.1%, P < 0.001) by high insulin levels (1 mIU/ml). Mean basal reductase activities were found to be significantly lower in diabetics than in normal subjects (type 1 diabetics: 0.77 +/- 0.03 vs 0.97 +/- 0.02 mmol ferrocyanide/20 min per l cells, P < 0.001; type 2 diabetics: 0.77 +/- 0.04 vs 0.97 +/- 0.02 mmol ferrocyanide/20 min per l cells, P < 0.001), indicating altered erythrocyte metabolism in the diabetic patients. High glucose levels were used to mimic hyperglycemia condition, using erythrocytes from normal subjects. At 30 mM glucose, erythrocytic phosphatase activity was stimulated (+32 +/- 4.2%, P < 0.0001), although no effect was observed on the reductase enzyme at the same glucose levels. Results indicated that diabetic disorders appear to be associated with quantitative alterations of erythrocyte acid phosphatase activity and other enzymes that depend on the glycolytic rate (reductase). The overall data suggest that erythrocyte acid phosphatase may have a role in the modulation of glycolytic rates through the control of insulin receptor phosphorylation.

Anti-inflammatory activity of diosmin and hesperidin in rat colitis induced by TNBS.

The intestinal anti-inflammatory activity of two flavonoids, hesperidin and diosmin, was evaluated in the acute stage of the trinitrobenzenesulfonic acid (TNBS) model of rat colitis. The results obtained showed that pretreatment with diosmin (10 mg/kg) or hesperidin (10 and 25 mg/kg) reduced colonic damage compared to TNBS control rats. This effect was confirmed biochemically by a reduction in colonic myeloperoxidase activity compared to non-treated colitic animals. Colonic glutathione levels in colitic animals were significantly increased after hesperidin or diosmin treatment. Diosmin decreased colonic MDA production and inhibited LTB4 synthesis, whereas hesperidin failed to do so. Conversely, only hesperidin improved colonic fluid absorption, which was impaired in colitic animals. In conclusion, both diosmin and hesperidin were able to prevent colonic inflammation, acting via a mechanism in which protection against oxidative insult may play a role.

Effects of morin on an experimental model of acute colitis in rats.

The flavonoid morin was tested for anti-inflammatory activity in trinitrobenzenesulfonic acid (TNBS)-induced rat colitis. Rats were pretreated orally with several doses of the flavonoid (5, 10, 25, 100 and 200 mg/kg) 48, 24 and 1 h before and 24 h after colitis induction and examined for colonic damage 48 h after colitis induction. Colonic inflammation was characterized by diffuse hemorrhagic necrosis of the mucosa, bowel wall thickening, impairment of fluid absorption, increase in myeloperoxidase (MPO) activity, enhanced leukotriene B4 (LTB4) synthesis, glutathione depletion and increased levels of malonyldialdehyde (MDA). Morin treatment, at doses ranging from 10 to 200 mg/kg, significantly reduced colonic macroscopic damage. This beneficial effect was also confirmed by inhibition of colonic MPO activity. Several mechanisms may contribute to the protective effect exerted by morin. First, inhibition of colonic LTB4 synthesis is a common feature for all the active doses of the flavonoid. Second, the antioxidant properties of morin, which partially prevented colonic glutathione depletion (at doses of 10 and 25 mg/kg) or inhibited colonic MDA production (at doses of 100 and 200 mg/kg), can collaborate in preventing TNBS-induced inflammation.

Oral administration of rutoside can ameliorate inflammatory bowel disease in rats.

Rutoside, a flavonoid with antioxidant properties, was tested for acute and chronic antiinflammatory activity in trinitrobenzenesulfonic acid-induced rat colitis. Pretreatment with 10 or 25 mg/kg of rutoside by the oral route reduced colonic damage at 2 days. Several mechanisms can be involved in this activity, and one of these may be related to its ability in preventing glutathione depletion of colitic animals, and this could result in mucosal protection against oxidative insult. When rutoside was tested for 1 and 2 weeks after colitis induction, it was able to promote colonic healing. The chronic effect of the flavonoid was also related with its ability to increase colonic glutathione levels and thus reduce the tissue damage derived from intestinal oxidative stress which characterizes inflammatory colitis.

Insulin activation of NADH ferricyanide reductase in human erythrocytes is mediated by the insulin receptor tyrosine kinase: a comparative study in normal and diabetic states.

We have previously reported that NADH ferricyanide reductase in human erythrocytes is stimulated by insulin. Hormone-stimulated activities are attenuated in the presence of glycolytic inhibitors like vanadate, indicating the involvement of glycolysis in the mechanism by which insulin stimulates ferricyanide reduction. Activation of erythrocyte metabolism in response to insulin could be a result of hormone binding to its receptor, inducing phosphorylation of band 3 (at a site for reversible association of glycolytic enzymes) and/or other membrane proteins like the Na(+)/H(+) antiport. Activation of the antiporter protein by insulin can stimulate glycolysis by an increase in intracellular pH, an effect which is prevented by amiloride. Evidence for a role for tyrosine phosphorylation in triggering the reductase activation came from studies with protein kinase inhibitors. Genistein, sphingosine and acridine orange have been shown to prevent insulin-stimulated ferricyanide reduction, implicating tyrosine phosphorylation as an important signal for activation of the enzyme by insulin. To evaluate activation of the enzyme by insulin stimulated phosphorylation, a comparative study was done using erythrocytes from healthy and diabetic humans. We measured ferricyanide reductase activities in basal and insulin stimulated states. Basal activities were lower in diabetics than in normal humans. Nevertheless, hormone stimulated activities were similar, despite earlier reports of decreased receptor phosphorylation of exogenous substrates in type 2 diabetics. These observations, together with previous ones, suggest that insulin-receptor kinase interaction may mediate the action of insulin on human erythrocytes by phosphorylation of cellular proteins like band 3 and/or the Na(+)/H(+) antiport.

Membrane-mediated effects of catecholamines on the DNA of human leukocytes: the role of reactive oxygen species.

The effects of epinephrine and two other beta 2-adrenergic agonists, ritodrine and isoxsuprine, on the induction of damage to the DNA (production of strand breaks) in human leukocytes were studied by fluorescence analyses of unwinding DNA. Epinephrine stimulated the development of DNA strand breaks. Ritodrine and isoxsuprine inhibited this effect of epinephrine on the human leukocytes by competition for binding to receptors, but they were not oxidized to the same extent as epinephrine. Metoprolol, which acts predominantly as a beta 1-antagonist, demonstrated a beta 2-antagonism, as compared with epinephrine. Since the o-oxidation of epinephrine involves the production of damaging oxygen species such as O2-. and H2O2, we studied the effects on DNA of extracellular H2O2 in the presence and absence of epinephrine. Extracellular H2O2 induced significant damage to the DNA, but it had a smaller effect when applied with epinephrine. The results obtained with 3-amino-1,2,4-triazole, an inhibitor of endogenous catalase, were not significantly different from control results, under our experimental conditions. Nevertheless, this compound had a mitigating effect when applied with epinephrine. We also investigated the action of nicotinamide in the presence and absence of epinephrine. The results demonstrated the importance of nicotinamide in cellular oxidative stress. Two antioxidant enzymes, superoxide dismutase and catalase, inhibited the epinephrine-induced damage to DNA.

Control of NADH ferricyanide reductase activity in the human erythrocyte by somatotrophin and insulin.

Reduction of external ferricyanide by the human erythrocyte is significantly stimulated by insulin and somatotrophin at concentrations above physiological levels. Basal (in absence of hormones) and hormone-stimulated activities are attenuated in the presence of glycolytic inhibitors iodoacetate and vanadate indicating the requirement of glycolytic substrates for the reduction process and for the activation of cellular metabolism in response to the hormones. Sulfhydryl reagents like N-ethylmaleimide also attenuate the basal and hormone-stimulated activities and this effect was rationalized on the basis of action at SH sites which trigger responses to hormones. Stimulation of ferricyanide reduction by insulin and somatotrophin may be also the result of Na(+)/H(+) antiport activation which may be prevented by amiloride. This suggests that Na(+)/H(+) antiport is part of the membrane transduction system for insulin and somatotrophin in the human erythrocyte. These observations are a contribution to the study of plasma membrane oxidoreductase systems involved in physiological and metabolic functions of the cell.

Antidiarrhoeic activity of Euphorbia hirta extract and isolation of an active flavonoid constituent.

The antidiarrhoeic activity of the Euphorbia hirta whole plant was investigated. The lyophilized decoction demonstrated antidiarrhoeic activity in experimental models of diarrhoea induced by castor oil, arachidonic acid, and prostaglandin E2. It showed no activity when magnesium sulphate was used to provoke the diarrhoea. The lyophilized decoction delayed small intestinal transit when this was accelerated by castor oil but not in normal conditions. A flavonoid, quercitrin, with antidiarrhoeic activity was isolated from this crude drug.

Antidiarrhoeic activity of quercitrin in mice and rats.

Quercitrin, a flavonoid isolated from Euphorbia hirta, shows antidiarrhoeic activity at doses of 50 mg kg-1, against castor oil- and PGE2-induced diarrhoea in mice, but not when magnesium sulphate is used as a cathartic agent. It also delays rat small intestinal transit if this is accelerated with castor oil. However, the flavonoid does not modify the fluid transport across the colonic mucosa when it is administered intraluminally, either in normal conditions or when this transport is altered by PGE2 or sodium picosulphate. However, quercetin, the aglycone of quercitrin, increases the colonic fluid absorption only in the presence of secretagogue compounds, such as PGE2 and sodium picosulphate. It is concluded that the antidiarrhoeic activity of quercitrin is due to its aglycone, quercetin, which is released by the glycoside in the intestine.

[Pubic hair in children and late onset congenital adrenal hyperplasia]. / Pilosidade púbica na criança e hiperplasia congénita supra-renal não clássica.

Before the age of 8 in females and 9 in males, the presence of pubic hair can be the first sign of a gonadal or adrenal disease. In order to identify the late onset type of congenital adrenal hyperplasia in premature pubescence, we did the adrenal short stimulation test with Synacthen, on 30 children. Five girls and one boy showed a 21-hydroxylase deficiency, in which the seric 17-OH Progesterone at 60 minutes is 28.8 +/- 15.2 ng/ml, being in a control group 2.30 +/- 0.8 ng/ml [p less than 0.01]. The 20% incidence we have found, justifies the testing of every premature pubescent child.

Antibacterial activity of the essential oil of Thymus serpylloides subspecies gadorensis.

The in vitro antibacterial activity of the essential oil obtained from the flowering apex of Thymus serpylloides ssp. gadorensis against various micro-organisms is reported. Moreover, the main chemical groups found in this essential oil are described.

The Essential Oil of Thymus serpylloides ssp. gadorensis.

THYMUS SERPYLLOIDES ssp. GADORENSIS is endemic in the Betic region (Spain). Gas chromatography and GC/mass spectrometry studies of its essential oil showed its major components to be carvacrol and its biosynthetic precursors (gamma-terpinene and P-cymene).

Seasonal Variation of Essential Oil Yield and Composition of Thymus hyemalis.

The aerial parts of THYMUS HYEMALIS Lange were collected throughout its complete vegetative cycle (April 1981 to March 1982) from the same locality. The yield and composition of essential oil have been determined in eleven samples with special reference to the content of 1,8-cineole, camphor, thymol, and carvacrol. It was found that the yield and composition of the oil changed from month to month. On the basis of the results obtained, July might be proposed as the most suitable month for harvesting T. HYEMALIS, giving the maximum yield in essential oil, which is especially rich in terpenic hydrocarbons at this time. Maximum levels of 1,8-cineole in August, however, might warrent harvesting during this month as well.

The Essential Oil of Salvia lavandulifolia Subspecies Oxyodon. A Study of its Vegetative Cycle.

The qualitative and quantitative variations in the essential oil of the OXYODON subspecies of SALVIA LAVANDULIFOLIA Vahl were studied - throughout its complete vegetative cycle (March 1983 to February 1984). Spasmolytic activity of the essential oil was selected as a characteristic warrenting more in depth study. Major components of the essential oil were found to be camphor and 1, 8-cineole, whereas only trace quantities of thujones could be detected at any time in the plant's vegetative cycle. Spasmolytic activity was most intense in May (the flowering period) and lowest in July.