Almir Gonçalves Wanderley

Acute and subacute toxicity of the Carapa guianensis Aublet (Meliaceae) seed oil.

Carapa guianensis (Meliaceae), known as Andiroba in Brazil, has been used by Amazon Rainforest indigenous communities for treatment of coughs, convulsions, skin diseases, arthritis, rheumatism, ear infections, to heal wounds and bruises and as an insect repellent. Carapa guianensis seed oil (SO) was evaluated for its acute and subacute toxicity (30 days) by the oral route in Wistar rats. In the acute toxicity test, SO (0.625-5.0g/kg, n=5/sex) did not produce any hazardous symptoms or deaths. The subacute treatment with SO (0.375, 0.75 and 1.5g/kg, n=10/group) failed to change body weight gain, food and water consumption. Hematological analysis showed no significant differences in any of the parameters examined. However, in the biochemical parameters, there was an increase in the alanine aminotransferase (ALT) serum level (29%) in the group SO 1.5g/kg. In addition, absolute and relative liver weights were increased at the doses of 0.75g/kg (23.4 and 19.1%) and 1.5g/kg (18.7 and 33.1%). In conclusion, acute and subacute administration of Carapa guianensis seed oil did not produce toxic effects in male Wistar rats. However, the increase in the ALT serum level and in both absolute and relative liver weights may indicate a possible hepatic toxicity.

Hypoglycaemic activity and molecular mechanisms of Caesalpinia ferrea Martius bark extract on streptozotocin-induced diabetes in Wistar rats

ETHNOPHARMACOLOGICAL RELEVANCE The tea from the stem bark of Caesalpinia ferrea Martius (Leguminosae) has been popularly used in the treatment of diabetes in Brazil. AIM OF THE STUDY To investigate the hypoglycaemic properties and to elucidate the mechanisms by which the aqueous extract of the stem bark of Caesalpinia ferrea reduces blood glucose levels in streptozotocin-induced diabetic rats via the enzymatic pathways of protein kinase B (PKB/Akt), AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC). MATERIALS AND METHODS The aqueous extract of the stem bark of Caesalpinia ferrea (300 and 450 mg/kg/day), vehicle and metformin (500 mg/kg/day) were administered orally to STZ-diabetic rats (n = 7/group) for 4 weeks. Changes in body weight, food and water intake, fasting glucose levels and oral glucose tolerance were evaluated. Phosphorylation (P) and the expression of Akt, AMPK and ACC in the liver and skeletal muscle were determined using Western blot. RESULTS The aqueous extract of the stem bark of Caesalpinia ferrea reduced blood glucose levels and improved the metabolic state of the animals. P-Akt was increased in the liver and skeletal muscle of the treated animals, P-AMPK was reduced only in the skeletal muscle of these animals and P-ACC was reduced in both when compared with untreated rats. CONCLUSION The results indicate that the aqueous extract of the stem bark of Caesalpinia ferrea has hypoglycaemic properties and possibly acts to regulate glucose uptake in liver and muscles by way of Akt activation, restoring the intracellular energy balance confirmed by inhibition of AMPK activation.

Acute and subacute toxicity of Cassia occidentalis L. stem and leaf in Wistar rats.

ETHNOPHARMACOLOGICAL RELEVANCE Cassia occidentalis L. (syn. Senna occidentalis; Leguminosae) has been used as natural medicine in rainforests and tropical regions as laxative, analgesic, febrifuge, diuretic, hepatoprotective, vermifuge and colagogo. Herein, we performed a pre-clinical safety evaluation of hydroalcoholic extract of Cassia occidentalis stem and leaf in male and female Wistar rats. MATERIALS AND METHODS In acute toxicity tests, four groups of rats (n=5/group/sex) were orally treated with doses of 0.625, 1.25, 2.5 and 5.0 g/kg and general behavior, adverse effects and mortality were recorded for up to 14 days. In subacute toxicity assays, animals received Cassia occidentalis by gavage at the doses of 0.10, 0.50 or 2.5 g/kg/day (n=10/group/sex) for 30 days and biochemical, hematological and morphological parameters were determined. RESULTS Cassia occidentalis did not produce any hazardous symptoms or death in the acute toxicity test, showing a LD(50) higher than 5 g/kg. Subacute treatment with Cassia occidentalis failed to change body weight gain, food and water consumption and hematological and biochemical profiles. In addition, no changes in macroscopical and microscopical aspect of organs were observed in the animals. CONCLUSIONS Our results showed that acute or subacute administration of Cassia occidentalis is not toxic in male and female Wistar rats, suggesting a safety use by humans.

Synthesis of 1,2,3-triazole derivatives and in vitro antifungal evaluation on Candida strains.

1,2,3-Triazoles have been extensively studied as compounds possessing important biological activities. In this work, we describe the synthesis of ten 2-(1-aryl-1H-1,2,3-triazol-4-yl)propan-2-ols via copper catalyzed azide alkyne cycloaddition (CuAAc or click chemistry). Next thein vitro antifungal activity of these ten compounds was evaluated using the microdilution broth method against 42 isolates of four different Candida species. Among all tested compounds, the halogen substituted triazole 2-[1-(4-chlorophenyl)-1H-(1,2,3)triazol-4-yl]propan-2-ol, revealed the best antifungal profile, showing that further modifications could be done in the structure to obtain a better drug candidate in the future.

Maternal low-protein diet induces changes in the cardiovascular autonomic modulation in male rat offspring

BACKGROUND AND AIMS Maternal undernutrition induces development of the arterial hypertension. We investigated the effects of a maternal low-protein diet on cardiovascular autonomic control in the offspring. METHODS AND RESULTS Male Wistar rats were divided into two groups according to the diets of their mothers during gestation and lactation: the control (normal protein, NP, 17% casein; n = 14) and low-protein (LP, 8% casein; n = 14) groups. Direct measurements of arterial pressure (AP) were recorded from wakeful 90-day-old male offspring. The LP offspring presented higher mean AP than did the NP rats (NP: 93 ± 4 vs. LP: 113 ± 2 mmHg; p < 0.05), whereas the heart rate (HR) was similar in the two groups. In the spectral analysis, the LP group showed higher power at low (NP: 1.98 ± 0.25 vs. LP: 3.7 ± 0.3 mmHg²; p < 0.05) and high (NP: 1.28 ± 0.18 vs. LP: 2.13 ± 0.42 mmHg²; p < 0.05) frequencies of systolic arterial pressure (SAP). In the pulse interval, the LP group presented an increase in the LF/HF ratio (NP: 0.32 vs. LP: 0.56; p < 0.05). After propranolol (4 mg/kg, intravenous (iv)), the bradycardia was higher in the LP group (NP: -36 ± 8 vs. LP: -94 ± 12 bpm; p < 0.05), after methylatropine (2 mg/kg, iv), the tachycardia was similar to NP group. After administration of the ganglionic blocker (hexamethonium; 25 mg/kg, iv), the LP animals showed larger delta variation in the AP (NP: -33.7 ± 5 vs. LP: -53.6 ± 4 mmHg; p < 0.05). CONCLUSION The rats subjected to protein malnutrition presented an increase in the cardiovascular sympathetic tone, which contributed to the elevated AP observed in these animals.

Anti-diabetic activity of extract from Persea americana Mill. leaf via the activation of protein kinase B (PKB/Akt) in streptozotocin-induced diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE The leaves of Persea americana Mill. (Lauraceae) have been popularly used in the treatment of diabetes in countries in Latin America and Africa. AIM OF THE STUDY To investigate the hypoglycaemic properties and to determine the molecular mechanism by which the hydroalcoholic extract of the leaves of Persea americana reduce blood glucose levels in streptozotocin (STZ)-induced diabetes in rats via the enzymatic pathway of protein kinase B (PKB/Akt). METHODS The hydroalcoholic extract of the leaves of Persea americana (0.15 and 0.3g/kg/day), vehicle and metformin (0.5g/kg/day) were administered orally to STZ-diabetic rats (n=7/group) for 4 weeks. Changes in body weight, food and water intake, fasting glucose levels and oral glucose tolerance were evaluated. Phosphorylation and the expression of PKB in the liver and soleus muscle were determined by Western blot. RESULTS The hydroalcoholic extract of the leaves of Persea americana reduced blood glucose levels and improved the metabolic state of the animals. Additionally, PKB activation was observed in the liver and skeletal muscle of treated rats when compared with untreated rats. CONCLUSION The results indicate that the hydroalcoholic extract of the leaves of Persea americana has anti-diabetic properties and possibly acts to regulate glucose uptake in liver and muscles by way of PKB/Akt activation, restoring the intracellular energy balance.

Acute and subacute toxicity of Schinus terebinthifolius bark extract.

ETHNOPHARMACOLOGICAL RELEVANCE Schinus terebinthifolius Raddi (Anacardiaceae) has long been used in traditional Brazilian medicine, especially to treat inflammatory and haemostatic diseases. AIM OF THE STUDY The objective of this study was to evaluate the acute and subacute toxicity (45 days) of Schinus terebinthifolius via the oral route in Wistar rats of both sexes. MATERIALS AND METHODS For the acute toxicity test, the dried extract of Schinus terebinthifolius bark was administered in doses from 0.625 to 5.0 g/kg (n=5/group/sex) and in the subacute toxicity test the following doses were used: 0.25, 0.625 and 1.5625 g/kg/day (n=13/group/sex), for 45 consecutive days. RESULTS In the acute toxicity test, Schinus terebinthifolius did not produce any toxic signs or deaths. The subacute treatment with Schinus terebinthifolius did not alter either the body weight gain or the food and water consumption. The hematological and biochemical analysis did not show significant differences in any of the parameters examined in female or male groups, except in two male groups, in which the treatment with Schinus terebinthifolius (0.25 and 0.625 g/kg) induced an increase of mean corpuscular volume values (2.9 and 2.6%, respectively). These variations are within the physiological limits described for the specie and does not have clinical relevance. CONCLUSION The acute and subacute administration of the dried extract of Schinus terebinthifolius bark did not produced toxic effects in Wistar rats.

Gastroprotective Mechanisms of the Monoterpene 1,8-Cineole (Eucalyptol).

Recently, our research group identified and reported 1,8-cineole (CIN), a monoterpene that naturally occur in many aromatic plants, as one of the major constituent of the essential oil from leaves of Hyptis martiusii (EOHM), as well as characterized the gastroprotective action of this oil. The aim of this study was to investigate the mechanisms of action involved in the antiulcer and healing activity of CIN, in order to confirm its correlation with the gastroprotective effect of EOHM. Wistar rats were exposed to different protocols (acute ulceration, gastrointestinal motility and antisecretory activity). In addition, were determinated the involvement of nitric oxide and sulphydryl groups; the levels of gastric mucus, lipid peroxidation, sulphydryl groups and myeloperoxidase activity. The healing ability was evaluated by acetic acid-induced chronic ulcer and histological and immunohistochemical analysis (PCNA, Ki-67 and BrdU). The treatment with CIN inhibited ethanol-, ethanol/HCl- and indomethacin-induced gastric lesions. The highest doses of CIN inhibited gastric emptying, but did not affect intestinal transit. CIN (100 mg/kg) reduced the volume of basal but not stimulated acid secretion. CIN increased levels of mucus (89.3%), prevented depletion of –SH groups (62.6%) and reduced the level of lipid peroxidation (55.3%) and myeloperoxidase activity (59.4%) in the gastric mucosa. In chronic ulcer model, CIN reduced in 43.1% the gastric area lesion, promoted significant regeneration and restoration of the levels of mucus in glandular cells as confirmed by histological analysis; and promoted increase in cell proliferation as evidenced by reactivity for PCNA, Ki-67 and BrdU. This findings demonstrate the role of 1,8-cineole as an important ulcer healing agent and indicate the involvement of antioxidant and cytoprotective mechanisms in the gastroprotective effect of compound. This study also provides evidence that 1,8-cineole is related to the gastroprotective effect of the essential oil of Hyptis martiusii.

Maternal Protein Restriction Increases Respiratory and Sympathetic Activities and Sensitizes Peripheral Chemoreflex in Male Rat Offspring

BACKGROUND Maternal protein restriction in rats increases the risk of adult offspring arterial hypertension through unknown mechanisms. OBJECTIVES The aims of the study were to evaluate the effects of a low-protein (LP) diet during pregnancy and lactation on baseline sympathetic and respiratory activities and peripheral chemoreflex sensitivity in the rat offspring. METHODS Wistar rat dams were fed a control [normal-protein (NP); 17% protein] or an LP (8% protein) diet during pregnancy and lactation, and their male offspring were studied at 30 d of age. Direct measurements of baseline arterial blood pressure (ABP), heart rate (HR), and respiratory frequency (Rf) as well as peripheral chemoreflex activation (potassium cyanide: 0.04%) were recorded in pups while they were awake. In addition, recordings of the phrenic nerve (PN) and thoracic sympathetic nerve (tSN) activities were obtained from the in situ preparations. Hypoxia-inducible factor 1α (HIF-1α) expression was also evaluated in carotid bifurcation through a Western blotting assay. RESULTS At 30 d of age, unanesthetized LP rats exhibited enhanced resting Rf (P = 0.001) and similar ABP and HR compared with the NP rats. Despite their similar baseline ABP values, LP rats exhibited augmented low-frequency variability (∼91%; P = 0.01). In addition, the unanesthetized LP rats showed enhanced pressor (P = 0.01) and tachypnoeic (P = 0.03) responses to peripheral chemoreflex activation. The LP rats displayed elevated baseline tSN activity (∼86%; P = 0.02) and PN burst frequency (45%; P = 0.01) and amplitude (53%; P = 0.001) as well as augmented sympathetic (P = 0.01) and phrenic (P = 0.04) excitatory responses to peripheral chemoreflex activation compared with the NP group. Furthermore, LP rats showed an increase of ∼100% in HIF-1α protein density in carotid bifurcation compared with NP rats. CONCLUSION Sympathetic-respiratory overactivity and amplified peripheral chemoreceptor responses, potentially through HIF-1α-dependent mechanisms, precede the onset of hypertension in juvenile rats exposed to protein undernutrition during gestation and lactation.

Toxicological reproductive study of Cassia occidentalis L. in female Wistar rats

ETHNOPHARMACOLOGICAL RELEVANCE Cassia occidentalis L. (Leguminosae) has long been used as natural medicine in rainforests and other tropical regions for the treatment of inflammation, fever, liver disorders, constipation, worms, fungal infections, ulcers, respiratory infections, snakebite and as a potent abortifacient. AIM OF THE STUDY This study has investigated the effects of oral sub-acute administration of Cassia occidentalis during pregnancy in female Wistar rats. MATERIALS AND METHODS Three groups of pregnant rats were treated orally from the 1st to the 6th day (pre-implantation period) and from the 7th to the 14th day (organogenic period) of pregnancy, with doses of 250 and 500 mg/kg. On the 20th day of pregnancy, the animals were euthanized and reproductive parameters evaluated. RESULTS The results revealed no statistically significant differences between the control and treated groups in terms of offspring/dam relationship; fetuses, placentae and ovaries weights; number of implantation and resorption sites; number of corpora lutea in the ovaries and pre- and post-implantation loss rates. However, the presence of dead fetuses was registered in both doses of 250 and 500 mg/kg of Cassia occidentalis. CONCLUSIONS Further studies should therefore be conducted to obtain more detailed characteristics of the toxic effects of this species, the use of which is not recommended during pregnancy.