Antidiabetic effect of the Chrysobalanus icaco L. aqueous extract in rats.

Chrysobalanus icaco L. is a medicinal plant popularly known in Brazil as "Grageru" or "Abageru." It is used in African and American continents as medicinal food in the treatment of several diseases, including diabetes. This study used phytochemical screening to determine the antioxidant and α-amylase inhibitor activities of the aqueous extract (AECI) of C. icaco, and evaluated its antidiabetic potential in rodents. Phytochemical screening was performed using colorimetric tests with specific reagents. The in vitro antioxidant activity was evaluated by the scavenging activity of 2,2-diphenyl-1-picril-hydrazyl. The lethality test and behavioral screening was performed using an oral administration of 5 g/kg of AECI. The antidiabetic potential of AECI was evaluated through the oral glucose tolerance test (OGTT) and chronic hypoglycemic test at the doses of 100, 200, and 400 mg/kg (orally). Metformin was used as a reference drug in all tests. Diabetes was induced by injection of alloxan (40 mg/kg; intravenously). Phytochemical screening showed the presence of various compounds, including tannins, flavones, triterpenoids, steroids, saponins, and alkaloids. The in vitro antioxidant test demonstrated that AECI presented potent antioxidant activity. The lethality test and behavioral screening did not show lethality signs. In the OGTT test, AECI administration was not able to inhibit the elevation of glycemia. However, chronically administrated, it was able to cause a significant (P<.05) reduction of glycemia from 335±27 up to 197±15 mg/dL. These results demonstrate that the AECI presents a potential beneficial effect for diabetes.

Massive, painful tumoral calcinosis in a long-term hemodialysis patient.

In chronic dialysis patients, ectopic, extraosseous calcifications can cause significant morbidity. Uremic tumoral calcinosis is an uncommon and severe complication of dialysis therapy. It is defined as deposition of dense nodular calcium-containing masses surrounding the large joints of the body, generally associated with the presence of high serum calcium-and-phosphorus product. We describe a 69-year-old woman submitted to long-term chronic hemodialysis that developed painful, bilateral hip tumors. Radiographic investigation showed extensive periarticular calcifications, and a bone biopsy was suggestive of adynamic bone disease and contained substantial amounts of aluminum. The lesions were surgically excised, and the histological analysis demonstrated amorphous, calcified material associated with densely collagenized connective tissue.

Cardiovascular effects induced by Cymbopogon winterianus essential oil in rats: involvement of calcium channels and vagal pathway.

OBJECTIVES: This study has investigated the cardiovascular effects of the Cymbopogon winterianus essential oil (EOCW) in rats. C. winterianus is a plant used in folk medicine for the treatment of hypertension. METHODS: For the measurement of haemodynamic and ECG parameters, male Wistar rats under anaesthesia were cannulated in the abdominal aorta and lower vena cava and electrodes were subcutaneously implanted in their paws. For an in-vitro approach, the rats were killed and the superior mesenteric artery was removed and cut into rings (1-2 mm). These rings were then mounted in organ baths containing Tyrode's solution at 37 degrees C and gassed with carbogen. KEY FINDINGS: In rats, EOCW (1-20 mg/kg, i.v.) induced dose-dependent hypotension and tachycardia. These effects were not affected by L-NAME or indometacin, but were partially reduced after atropine administration. EOCW (20 mg/kg only) also induced bradycardia-associated sinoatrial blockade, junctional rhythm, and first-degree atrioventricular block, which was abolished after atropine administration or vagotomy. In arterial rings, EOCW (0.1-3000 microg/ml) induced relaxation of phenylephrine tonus that was not affected by removal of the endothelium. These relaxations were similar to those observed in rings without endothelium precontracted with KCl 80 mm. EOCW was able to antagonize the CaCl(2) (30-300 mum) induced contractions in depolarizing solution (KCl 60 mm). CONCLUSIONS: These results demonstrated that EOCW induced hypotension and vasorelaxation. These effects appeared to be mainly mediated by Ca(+2)-channel blocking. Furthermore, the higher dose of EOCW induced transient bradycardia and arrhythmias due to a cardiac muscarinic activation secondary to a vagal discharge.