Morphological, agronomical and pharmacological characterization of Hyptis pectinata (L.) Poit germplasm

Several species of the genus Hyptis have presented medicinal characteristics and are frequently indicated to treat gastro intestinal infections, gramps and pain, as well as for skin infections. Three harvests were carried out using six H. pectinata accessions, and the following characteristics were evaluated: plant height, canopy diameter, leave length (L) and width (W), L/W relation and dry weight of leaves and stem. The accession SAM006 have presented highest leave dry matter yield when the three harvests were summed. The aqueous leaf extracts of the same six H. pectinata accessions were tested for anti-edematogenic effect using the carrageenin-induced rat paw edema at doses of 200, 400 and 600 mg/kg. The extracts administered orally had a significant anti-edematogenic effect. The dose of 200 mg/kg of accessions SAM004 and SAM005 had a stronger effect reducing the edema by 19.6 percent and 15.4 percent, respectively. Similar results were obtained using higher dosages of the aqueous extract of the accessions SAM002, SAM003 and SAM006. It can be concluded that the accessions SAM004, SAM005 and SAM006 are promising genotypes for a plant breeding program that aims the development of a cultivar with highest leave yielding and anti-edematogenic effect.

Differential effects of lead and zinc on inhibitory avoidance learning in mice

We studied the effects of chronic intoxication with the heavy metals lead (Pb2+) and zinc (Zn2+) on memory formation in mice. Animals were intoxicated through drinking water during the pre- and postnatal periods and then tested in the step-through inhibitory avoidance memory task. Chronic postnatal intoxication with Pb2+ did not change the step-through latency values recorded during the 4 weeks of the test (ANOVA, P>0.05). In contrast, mice intoxicated during the prenatal period showed significantly reduced latency values when compared to the control group (day 1: q = 4.62, P<0.05; day 7: q = 4.42, P<0.05; day 14: q = 5.65, P<0.05; day 21: q = 3.96, P<0.05, and day 28: q = 6.09, P<0.05). Although chronic postnatal intoxication with Zn2+ did not alter a memory retention test performed 24 h after training, we noticed a gradual decrease in latency at subsequent 4-week intervals (F = 3.07, P<0.05), an effect that was not observed in the control or in the Pb2+-treated groups. These results suggest an impairment of memory formation by Pb2+ when the animals are exposed during the critical period of neurogenesis, while Zn2+ appears to facilitate learning extinction

Efeitos do extrato aquoso da hyptis pectinata sobre a regeneraçäo hepática após hepatectomia parcial de 70 por cento: resultados preliminares / Effects of the aqueous extract of hyptis pectinata on liver regeneration after 70 percent partial hepatectomy: preliminary results

O uso de plantas medicinais tem aumentado bastante na populaçäo mundial. O objetivo desta pesquisa é avaliar os efeitos do extrato aquoso das folhas da Hyptis pectinata, popularmente conhecida como "sambacaitá" ou "canudinho", sobre a regeneraçäo hepática após hepatectomia parcial de 70 por cento. Foram utilizados 24 ratos, divididos em 4 grupos: grupo OS, em que se realizou operaçäo simulada e aplicaçäo oral de água destilada por 4 dias; grupo OSD200, também submetido à laparotomia com manipulaçäo do fígado e aplicaçäo de 200 mg de extrato/Kg de animal durante o mesmo período; grupo HP, hepatectomizado a 70 por cento após 4 dias de aplicaçäo por via oral de água destilada; e grupo HPD200, hepatectomizado a 70 por cento após 4 dias de administraçäo de 200 mg extrato/Kg de animal. Foram dosadas fosfatase alcalina, bilirrubina total e as aminotransferases e estudou-se o estado III da funçäo mitocondrial. O grupo OSD200, quando comparado ao OS, apresentou reduçäo significativa da fosfatase alcalina. O grupo HPD200, em comparaçäo ao HP, teve reduçäo estatisticamente significativa no nível da AST e do estado III da funçäo mitocondrial.

Evidence for the involvement of nitric oxide in the electrically induced relaxations of human lower esophageal sphincter and distal pylorus

The aim of the present study was to investigate in vitro the effect of Ng-nitro-L-arginine methyl ester (L-NAME), a nitric oxide (NO) synthase inhibitor, on neurogenic relaxation of human lower esophageal sphincter (LES) and distal pylorus (DP) circular muscle strips induced by electr4ical field stimulation (EFS). Muscle strips obtained from 5 patients who underwent total gastrectomy were suspended in 10-ml organ baths containing Krebs solution for recording isometric tension. L-NAME(30 uM) reduced the amplitude of the EFS-induced relaxation by 85 ñ 9% (N=3) in the LES and by 52 ñ 16% (N=3) in the DP but did not affect sodium nitroprusside-induced relaxation. L-Arginine (300 uM) partially reversed the L-NAME inhibition in the LES and totally in the DP. These findings suggest a role for L-arginine-derived NO in the nerve-mediated NANC relaxation of the human LES and DP