Ethanolic extract of Casearia sylvestris Sw exhibits in vitro antioxidant and antimicrobial activities and in vivo hypolipidemic effect in rats / Extrato etanólico de Casearia sylvestris Sw apresenta atividade antioxidante e antimicrobiana in vitro e efeito hipolipemiante em ratos

ABSTRACT: The Casearia sylvestris Sw (Flacourtiaceae) is a shrub that occurs in forests of Southern Brazil; its leaves are widely used in folk medicine as a depurative, analgesic, anti-inflammatory and antiulcerogenic agent. The objective of this study was to perform the phytochemical description and to evaluate the pharmacological activities (antimicrobial, antifungal, antioxidant and toxicity) of the ethanolic extract (EE) of C. sylvestris Sw. In addition, we also evaluated the effect of the EE of C. sylvestris Sw on the glucose levels and lipid profile in blood serum of rats submitted to a model of streptozotocin-induced diabetes. Material and Methods: In vitro assay: the detection of chemical groups was done through chemical reactions with the development of color or precipitate and by chromatographic profile; the antioxidant activity was measured by the method of reduction of DPPH free radical (2,2-diphenyl-1-picrylhydrazyl); the Minimum Inhibitory Concentration was evaluated by the broth microdilution method, and the Minimum Bactericide Concentration and the Minimum Fungicide Concentration were performed in Petri dishes; the cytotoxic activity was measured by the Artemia salina test. In vivo assay: diabetic and non-diabetic rats were treated with EE of C. sylvestris Sw (300 mg/kg) for 45 days, and the glycaemia and lipid profile were analyzed. Results: The EE showed a Lethal Dose50 of 724.76 μg.mL-1 and important antioxidant, fungicide and fungistatic activities. The EE showed better antimicrobial activity regarding the microorganisms Staphylococcus aureus, Escherichia coli and Salmonella setubal. Conclusion: The EE of C. sylvestris Sw produces a significant decrease in triglycerides, total cholesterol and VLDL levels without any significant alteration in the glycaemia. The EE of C. sylvestris Sw presents antioxidant and antimicrobial activities and it exhibits a potent hypolipidemic effect.

RESUMO: Casearia sylvestris Sw (Flacourtiaceae) é uma planta comumente encontrada em florestas do sul do Brasil; suas folhas são amplamente utilizadas na medicina popular como depurativa, analgésica, anti-inflamatória e anti ulcerogênica. O objetivo deste estudo foi apresentar uma descrição fitoquímica e da atividade farmacológica (antimicrobiana, antifúngica, antioxidante e toxicidade) do extrato etanólico (EE) da C. Sylvestris Sw. Adicionalmente, procurou-se avaliar o efeito do EE da C. Sylvestris Sw sobre os níveis séricos de glicose e perfil lipídico de ratos submetidos a um modelo de diabetes induzida por estreptozotocina. A detecção de grupos químicos foi realizada por reações químicas de coloração ou precipitação, e também por cromatografia; a atividade antioxidante foi mensurada pelo método de redução do DPPH (2,2-difenil-1-picril-hidrazil); a concentração mínima inibitória foi realizada pela técnica de micro-diluição, e concentração mínima bactericida e concentração mínima fungicida foram realizadas em placa de Petri; enquanto a atividade citotóxica foi conduzida pelo teste da Artemia salina. Nos ensaios in vivo, ratos diabéticos e não-diabéticos foram tratado com EE da C. Sylvestris Sw (300mg/kg) por 45 dias, e os níveis glicêmico e perfil lipídico foram medidos. A dose Letal50 do EE foi de 724.76 μg.mL-1; mostrando importante atividades antioxidante, fungicida e fungistática e melhor atividade antimicrobiana contra Staphylococcus aureus, Escherichia coli e Salmonella setubal. O EE da C. Sylvestris Sw promoveu diminuição significativa nos níveis de triglicerídeos, colesterol total e VLDL; porém sem efeito significativo nos níveis glicêmicos. O EE da C. Sylvestris Sw, além de apresentar atividade antioxidante e antimicrobiana; possui também potente efeito hipolipidêmico.

[Homozygous and compound heterozygous RYR1 mutations. New findings on prevalence and penetrance of malignant hyperthermia]. / Homozygote und "compound"-heterozygote RYR1-Mutationen. Neue Erkenntnisse zu Prävalenz und Penetranz der malignen Hyperthermie.

BACKGROUND: Malignant hyperthermia (MH) is a life-threatening, acute pharmacogenetic disorder mostly due to heterozygous mutations in the ryanodin receptor 1 (RYR1) gene. Diagnosis is generally confirmed by the in vitro contracture test (IVCT). In this study the genotype-phenotype correlation was analyzed and the presumed prevalence of MH is discussed. PATIENTS AND METHODS: After the diagnosis of MH susceptibility by the IVCT DNA samples of 44 patients were analyzed for mutations in the RYR1 gene using the polymerase chain reaction and sequencing. For genotype-phenotype correlation, the mutation analysis data were compared with the IVCT data. RESULTS: Out of the 44 patients tested 13 were identified with a heterozygous mutation, 1 patient with a homozygous mutation (c.1840C>T) and 1 patient with compound heterozygous mutations (c.1840C>T and c.6487C>T). The two patients with two mutated alleles showed a stronger response in the IVCT compared to those with only one mutated allele. Patients with one RYR1 mutation displayed significantly higher contractures in the IVCT than patients without RYR1 mutations. CONCLUSION: In the two patients described the presence of two mutated RYR1 alleles seemed to have an additive effect on the functional restriction of the (RYR1 receptor and to lead to a stronger response both in the IVCT and with regard to clinical signs. The patients with no detected RYR1 mutations possibly have a RYR1 mutation with smaller effects outside the hot spot regions tested and/or false positive IVCT results. The data from a small patient group indicate a substantially higher prevalence of MH with a correspondingly lower penetrance in the German population than previously assumed.

Effects of phenylalanine and phenylpyruvate on ATP-ADP hydrolysis by rat blood serum.

The nucleotide (ATP-ADP)/nucleoside (adenosine) ratio in the circulation can modulate the processes of vasoconstriction, vasodilatation and platelet aggregation. The main objective of the present study with rat blood serum was to evaluate the possibility of changes in nucleotide hydrolysis by phenylalanine (Phe) and phenylpyruvate (PP), the levels of which could increase in the circulation of individuals with phenylketonuria. Results demonstrated that Phe in the range 1.0-5.0 mM inhibited the ADP hydrolysis by rat serum. The effect of inhibition by Phe on ATP hydrolysis appeared only at a concentration of 5.0 mM. PP had no significant effect upon nucleotide hydrolysis. Kinetic analysis indicated that the inhibition of ADP and ATP hydrolysis by Phe in rat blood serum is uncompetitive. Conversely, Phe and PP did not affect the hydrolysis of p-nitrophenyl-5'-TMP by rat serum.

Activation of chick tendon lysyl oxidase in response to dietary copper.

Lysyl oxidase (EC 1.4.3.13), a cuproenzyme, can account for 10-30% of the copper present in connective tissue. Herein, we assess the extent to which tissue copper concentrations and lysyl oxidase activity are related because the functional activity of lysyl oxidase and the copper content of chick tendon are both related to dietary copper intake. Chicks (1-d old) were fed diets (basal copper concentration, 0.4 microg/g diet) to which copper was added from 0 to 16 microg/g diet. Liver and plasma copper levels tended to normalize in chickens that consumed from 1 to 4 microg copper/g of diet, whereas tendon copper concentrations suggested an unusual accumulation of copper in chickens that consumed 16 microg copper/g diet. The molecular weight of lysyl oxidase was also estimated using matrix-assisted laser desorption ionization/time-of-flight/mass spectrometry (MALDI/TOF/MS). A novel aspect of these measurements was estimation of protein mass directly from the surface of chick tendons and aortae. Whether copper deficiency (0 added copper) or copper supplementation (16 microg copper/g of diet) caused changes in the molecular weight of protein(s) in tendon corresponding to lysyl oxidase was addressed. The average molecular weight of the peak corresponding to lysyl oxidase in tendon and aorta from copper-deficient birds was 28,386 Da +/- 86, whereas the average molecular weight of corresponding protein in tendon from copper-supplemented birds was 28,639 Da +/- 122. We propose that the shift in molecular weight is due in part to copper binding and the formation of lysyl tyrosyl quinone, the cofactor at the active site of lysyl oxidase.

Copper, lysyl oxidase, and extracellular matrix protein cross-linking.

Protein-lysine 6-oxidase (lysyl oxidase) is a cuproenzyme that is essential for stabilization of extracellular matrixes, specifically the enzymatic cross-linking of collagen and elastin. A hypothesis is proposed that links dietary copper levels to dynamic and proportional changes in lysyl oxidase activity in connective tissue. Although nutritional copper status does not influence the accumulation of lysyl oxidase as protein or lysyl oxidase steady state messenger RNA concentrations, the direct influence of dietary copper on the functional activity of lysyl oxidase is clear. The hypothesis is based on the possibility that copper efflux and lysyl oxidase secretion from cells may share a common pathway. The change in functional activity is most likely the result of posttranslational processing of lysyl oxidase. Copper is essential for organic cofactor formation in amine oxidases such as lysyl oxidase. Copper-containing amine oxidases have peptidyl 2,4,5 tri(oxo)phenylalanine (TOPA) at their active centers. TOPA is formed by copper-catalyzed oxidation of tyrosine, which takes place as part of Golgi or trans-Golgi processing. For lysyl oxidase, recent evidence (Science 1996;273:1078-84) indicates that as an additional step, a lysyl group at the active center of lysyl oxidase reacts with TOPA or its precursor to form lysyl tyrosylquinone.

Connecting with colleagues. Interview by Helen Griffiths.

How does a nurse go about maintaining her level of competence when she is one of the few local practitioners in her field? Vancouver sex therapist Bianca Rucker is doing it by cultivating a network of colleagues and mentors in related fields both at home and across the continent.

Ultraviolet light hardening in polymorphous light eruption--a controlled study comparing different emission spectra.

Polymorphous light eruption (PLE) is a common disorder characterized by a delayed, abnormal response to ultraviolet (UV) radiation, with a varied morphology of itching efflorescences on sun-exposed areas of the skin. Thirty-one PLE subjects were treated with either UVA (340-400 nm) or UVA and UVB (300-400 nm) phototherapy during spring 1987 (10 exposures to UV light). They were randomly allocated to these 2 groups. For subjects of the UVA group, the applied dose corresponded to their individual minimal tanning dose; for subjects of the UVA and UVB group it corresponded to approximately 3/4 of their individual minimal erythema dose. The sun protection effect was studied by a high dose of UVA (80-160 J/cm2; 340-440 nm) after the treatment period, by analysing the histidine content of the stratum corneum and the urocanic acid photoisomerization, and by evaluating the subjects' diaries. The patients were asked to expose their skin to sunlight at least 3 times after UV hardening in the following 2-10 weeks. The results of both the UVA provocation and of the natural sun exposure confirmed the success of UV hardening without the occurrence of severe side effects. The content of histidine and of its metabolite urocanic acid in stratum corneum was significantly increased during the treatment. These data are interpreted to be biochemical markers for improved sun protection.