The effect of Cratylia floribunda lectin on renal hemodynamics and ion transport

Lectins have been described as glycoproteins that reversibly and specifically bind to carbohydrates. Legume lectins isolated from the subtribe Diocleinae (Canavalia, Dioclea andCratylia) are structurally homologous with respect to their primary structures. The Diocleinae lectins of Canavalia brasiliensis, Dioclea guianensis andCanavalia ensiformis have been shown to distinctly alter physiological parameters in isolated rat kidneys. Thus, the aim of this study was to investigate the effect of Cratylia floribunda lectin (CFL) on renal hemodynamics and ion transport in rats. In isolated perfused kidneys, CFL (10 mg/mL, n=5) increased RPP, RVR and decreased %TK+, but did not change urinary flow, glomerular filtration rate, sodium or chloride tubular transport. In isolated perfused mesenteric bed, CFL (3 and 10 mg/mL/min; n=4) did not alter tissue basal tonus or tissue contraction by phenylephrine (1 mM/mL/min). In conclusion, the seed lectin of Cratylia floribunda increased renal hemodynamic parameters showing a kaliuretic effect. This effect could be of tubular origin, rather than a result from haemodynamic alterations.

As lectinas são descritas como (glico)proteínas que se ligam, especificamente e reversivelmente, a carboidratos. Lectinas de leguminosas isoladas da subtribo Diocleinae (Canavalia, Dioclea eCratylia) são estruturalmente homólogas em relação às suas estruturas primárias. Demonstrou-se que as lectinas de DiocleinaeCanavalia brasiliensis, Dioclea guianensis eCanavalia ensiformis alteram diferentemente parâmetros fisiológicos em rins isolados de ratos. Dessa maneira, o objetivo deste estudo foi investigar o papel da lectina de Cratylia floribunda (CFL) na hemodinâmica renal e no transporte de íons em ratos. Em rins isolados perfundidos, CFL (10 mg/mL, n=5) aumentou a pressão de perfusão renal, a resistência vascular renal e reduziu o percentual do transporte tubular de K+, mas não alterou o fluxo urinário, a taxa de filtração glomerular e o percentual de transporte tubular dos íons sódio e cloreto. No leito mesentérico isolado perfundido, CFL (3 e 10 mg/mL/min, n=4) não alterou o tônus basal ou a contração do tecido induzida por fenilefrina (1 mM/mL/min). Em conclusão, a lectina de sementes de Cratylia floribunda altera parâmetros hemodinâmicos renais, provavelmente de origem tubular, e não por alterações hemodinâmicas.

Central nervous system effects of Dioclea grandiflora pods on mice / Efectos en el sistema nervioso central de la vaina de Dioclea grandiflora en camundongos

Many plant substances are known for their interference with the central nervous system (CNS). Dioclea grandiflora Mart. Ex. Benth (Fabaceae) is a plant used in folk medicine to treat prostate disorders and kidney stones whose extracts from its seeds and root barks were reported to have a significant activity on the CNS and analgesic effect in rodents. In this study, the psychopharmacological activities of D. grandiflora were investigated, using the pods of this plant. Swiss mice were submitted to acute treatments with ethanol extract from the pods of D. grandiflora (EDgP) at doses of 75, 150 and 300 mg/kg by intraperitoneal administration followed by the evaluation of anxiety, depressant and anticonvulsant-related responses. The treatment with EDgP produced a depressant activity on the CNS and a sedative effect in mice. These findings suggest that EDgP has a central activity in mice, indicating an anxiogenic effect.

Varias sustancias de plantas son conocidas por su acción en el sistema nervioso central (SNC). La Dioclea grandiflora Mart. Ex. Benth (Fabaceae) es una planta utilizada en la medicina popular para tratar enfermedades en la próstata y piedras en los riñones, cuyos extractos de sus semillas y de las cáscaras de sus raíces presentan una actividad significativa sobre el SNC y efecto analgésico en roedores. En este estudio, las actividades psicofarmacológicas de D. grandiflora fueron investigadas, utilizando la vaina de la planta. Camudongos Swiss fueron sometidos a tratamientos agudos por la administración intraperitoneal del extracto etanólico de la vaina de D. grandiflora (EDgP) en dosis de 75, 150 y 300 mg/kg administrados intraperitonealmente seguida por la evaluación de respuestas relacionadas con la ansiedad, depresión y anticonvulsivo. El tratamiento con EDgP produjo una actividad depresora sobre el sistema nervioso central y un efecto sedante en camundongos. Estos resultados sugieren que EDgP tiene una actividad central en camundongos, indicando un efecto ansiogénico.

Comparison of the Amino Acid Sequences of Lectins from the Seeds of Dioclea Reflexa and Canavalia Ensiformis

The amino acid sequence of a glucose/mannose specific lectin from the seeds of Dioclea reflexa (Dioclea reflexa agglutinin II; DRA-II) was determined by sequential Edman analyses of the intact subunit; and of the peptides derived from the protein by enzymatic digestion with trypsin. This sequence was found to be very similar to those of the lectins from other Dioclea species; Dioclea grandiflora and Dioclea lehmanii; and also the lectin from Canavalia ensiformis (Con A). Comparison of these amino acid sequences showed that a high degree of homology exists among these proteins