Zaluzania montagnifolia: essential oil composition and biological properties / Zaluzania montagnifolia: composición del aceite esencial y actividades biológicas

The chemical composition of the seasonal essential oils (2015-2016) from the leaves and flowers of Zaluzania montagnifolia is presented. The chemical content of those oils showed quantitative and qualitative differences. Germacrene D (19.9-29.8%), camphor (12.4- 19.4%) and ß-caryophyllene (13.7-18.5%) were the most abundant volatiles in the leaves. The essential oils from the flowers contained high amounts of camphor (32.7-37.2%) limonene (19.8-24.9%) and germacrene D (3.2-7.3%). All the seasonal essential oils showed a potent in vitro inhibition against HMG-CoA reductase. The essential oils from flowers (IC50, 40.5-55.1 µg mL-1) showed better inhibition properties than those of leaves (IC50, 84.4-123.5 µg mL-1). Camphor (IC50, 72.5 µg mL-1) and borneol (IC50, 84.4 µg mL-1) exerted a non-competitive inhibition on the enzyme. Additionally, the hydrodistillates exhibited antibacterial activity against the phytopathogenic Pseudomonas syringae pv. tabaci TBR2004 (MIC, 62.7-76.5 µg mL-1) P. syringae pv. tomato DC3000 (MIC, 45.4-50.4 µg mL-1) and P. syringae pv. phaseolicola NPS3121 (MIC, 26.7-31.9 µg mL-1). Germacrene D (MIC, 35.4-66.2 µg mL-1) and ß-caryophyllene (MIC, 36.5-54.2 µg mL-1) were the strongest anti-Pseudomonas syringae agents.

Se presenta la composición química de los aceites esenciales estacionales (2015-2016) provenientes de hojas y flores de Zaluzania montagnifolia. El contenido químico de los aceites esenciales mostró diferencias cualitativas y cuantitativas. El germacreno D (19.9-29.8%), alcanfor (12.4-19.4%) y ß-cariofileno (13.7-18.5%) fueron los volátiles más abundantes en las hojas. Los aceites esenciales de las flores contuvieron altas concentraciones de alcanfor (32.7-37.2%), limoneno (19.8-24.9%) y germacreno D (3.2-7.3%). Todos los aceites esenciales estacionales mostraron una potente inhibición in vitro contra la HMG-CoA reductasa. Los aceites esenciales de las flores (IC50, 40.5-55.1 µg mL-1) mostraron mejores propiedades inhibitorias que aquellos de las hojas (IC50, 84.4-123.5 µg mL-1). El alcanfor (IC50, 72.5 µg mL-1) y el borneol (IC50, 84.4 µg mL-1) ejercieron una inhibición no competitiva sobre la enzima. Adicionalmente, los hidrodestilados exhibieron una actividad antibacterial contra los fitopatógenos Pseudomonas syringae pv. tabaci TBR2004 (MIC, 62.7-76.5 µg mL-1) P. syringae pv. tomato DC3000 (MIC, 45.4-50.4 µg mL-1) y P. syringae pv. phaseolicola NPS3121 (MIC, 26.7-31.9 µg mL-1). El germacreno D (MIC, 35.4-66.2 µg mL-1) y ß-cariofileno (MIC, 36.5-54.2 µg mL-1) fueron los agentes más fuertes contra los patovares de Pseudomonas syringae.

The methyl ester of rosuvastatin elicited an endothelium-independent and 3-hydroxy-3-methylglutaryl coenzyme A reductase-independent relaxant effect in rat aorta

The relaxant effect of the methyl ester of rosuvastatin was evaluated on aortic rings from male Wistar rats (250-300 g, 6 rats for each experimental group) with and without endothelium precontracted with 1.0 µM phenylephrine. The methyl ester presented a slightly greater potency than rosuvastatin in relaxing aortic rings, with log IC50 values of -6.88 and -6.07 M, respectively. Unlike rosuvastatin, the effect of its methyl ester was endothelium-independent. Pretreatment with 10 µM indomethacin did not inhibit, and pretreatment with 1 mM mevalonate only modestly inhibited the relaxant effect of the methyl ester. Nω-nitro-L-arginine methyl ester (L-NAME, 10 µM), the selective nitric oxide-2 (NO-2) inhibitor 1400 W (10 µM), tetraethylammonium (TEA, 10 mM), and cycloheximide (10 µM) partially inhibited the relaxant effect of the methyl ester on endothelium-denuded aortic rings. However, the combination of TEA plus either L-NAME or cycloheximide completely inhibited the relaxant effect. Inducible NO synthase (NOS-2) was only present in endothelium-denuded aortic rings, as demonstrated by immunoblot with methyl ester-treated rings. In conclusion, whereas rosuvastatin was associated with a relaxant effect dependent on endothelium and hydroxymethylglutaryl coenzyme A reductase in rat aorta, the methyl ester of rosuvastatin exhibited an endothelium-independent and only slightly hydroxymethylglutaryl coenzyme A reductase-dependent relaxant effect. Both NO produced by NOS-2 and K+ channels are involved in the relaxant effect of the methyl ester of rosuvastatin.

Recombinant Schistosoma mansoni 3-hydroxymethylglutaryl-coenzyme-A reductase has different inhibitor kinetics compared to the mammalian host enzyme.

Previous publications have clearly demonstrated that hydroxymethylglutaryl coenzyme A [HMG-CoA] reductase activity of Schistosoma mansoni is vital for parasite reproductive activity and that drugs which inhibit this enzyme have been found to be effective antischistosomal agents. In this report we describe the expression and purification of enzymatically active schistosome HMG-CoA reductase enzyme. The recombinant protein was tested, in parallel with the mammalian enzyme, against well-known mammalian HMG-CoA reductase inhibitors obtained from various pharmaceutical companies. We demonstrated that there were significant differences in the response of the two proteins to an array of HMG-CoA reductase inhibitors. The difference in the characteristics between mammalian and schistosome enzyme could be exploited for rational drug design.

Effect of policosanol on the hepatic cholesterol biosynthesis of normocholesterolemic rats

We have suggested previously, measuring 14C-acetate incorporation into free cholesterol, that oral administration of policosanol inhibits hepatic cholesterol biosynthesis in rats. Nevertheless, since acetate has limitations to study cholesterol synthesis in vivo, we now investigate rates of incorporation of labeled water into hepatic sterol after policosanol treatment. Absolute rates of incorporation of 3H-water in sterols were depressed by policosanol by about 20 percent, giving a more accurate degree of cholesterol biosynthesis inhibition in this species. Since policosanol did not inhibit labeled mevalonate incorporation into cholesterol in rat liver, we also studied the effect of policosanol on hydroxy-methylglutaryl-coenzyme A (HMG-CoA) reductase. Reductase activity assayed in microsomes treated with policosanol remained unchanged, suggesting that cholesterol synthesis is not inhibited by a direct action of policosanol on this enzyme

Estatinas no tratamento da hipercolesterolemia / Statins in the hypercholesterolemia treatment

Estatinas säo drogas derivadas de microorganismos e que eficientemente interferem na síntese celular de colesterol por inibiçäo competitiva da enzima HMG-CoA-redutase. Näo obstante, as estatinas reduzem a colesterolemia por induzirem formaçäo de receptores que captam as LDL do plasma e por diminuirem a síntese de VLDL no fígado. Esta última explica o efeito parcial na queda da trigliceridemia. A eficiência das estatinas na diminuiçäo da colesterolemia é comparável à das resinas seqüestradoras de ácidos biliares, porém superios à dos fibrates e ácido nicotínico. Estatinas säo melhor toleradas do que estas últimas duas drogas, mas inferiores quanto à capacidade de diminuirem os triglicérides e de aumentarem o HDL-colesterol. Seletividade tissular varia entre as diversas estatinas, mas esta é uma questäo irrelevante tendo em vista a raridade dos efeitos colaterais. Conseqüentemente, estas drogas devem ser prescritas em razäo da potência farmacológica e do fator custo. Cinecoronarioangiografia seqüencial em pacientes com coronariopatia tratados com placebo em comparaçäo a estatinas isoladamente, indica que a doença arterial regride por métodos farmacológicos.

As açöes dos inibidores da HMG CoA redutase säo influenciadas por variaçöes do peso corpóreo? Estudo com a pravastatina / The actions of reductase HMG CoA inhibitors were influenced with body weight variations? Study with pravastatin

Dispondo dos resultados do estudo multicêntrico que avaliou a eficácia da pravastatina em pacientes com hipercolesterolemia primária, os AA investigaram se a intensidade das respostas guardava ligaçäo com a variaçäo do peso corpóreo, ocorrida em 12 semanas de observaçäo. Foi analisado o comportamento das variáveis lipídicas (CT, TG, HDL-C, VLDL-C e LDL-C em tres grupos de pacientes: G1 - 308 pacientes que tiveram elevaçäo do peso corpóreo superior a 5 por cento: G2 - 1.250 pacientes com oscilaçöes entre - 5 e + 5 por cento: G3 - 162 pacientes que tiveram reduçäo do peso superior a 5 por cento. A análise comparativa entre os grupos mostrou que o G3 teve reduçöes significativamente maiores de CT,LDL-C E TG e nesse mesmo grupo houve freqüência de indivíduos que atingiram valores desejáveis de LDL-C e CT. Entre os G1 e G2 näo foram observadas diferenças significativas, embora açäo da pravastatina se mostrasse eficaz em ambos. Portanto, reduçäo do peso corpóreo pareceu potencializar a açäo da pravastatina sendo recomendáveis estudos controlados para confirmar a hipótese