The effect of Bromelia pinguin extract on the pregnant rat uterus

A non proteinaceous extract of Bromelia pinguin fruit was examined for activity on the rat uterus in vivo and in vitro. The in vivo experiments involved pregnant rats given the extract intraperitoneally. These rats did not abort nor were any foetal deformities observed. The extract inhibited spontaneous activity of the pregnant rat uterus in vitro. The extract of Bromelia pinguin fruit may have some utero-active compound which inhibits uterine motility.(AU)

Streptozotocin alters pancreatic beta-cell responsiveness to glucose within six hours of injection into rats

A 24-hour glycaemic profile following streptozotocin (80 mg/kg. ip) injection was investigated in fasted rats. The most prominent changes in blood glucose were hyperglycaemia associated with low levels of plasma insulin after two hours followed by hypoglycaemia associated with high levels of plasma insulin after six hours; subsequently hyperglycaemia progressively developed and this was associated with decreasing levels of plasma insulin. Further probing revealed that at two hours after streptozotocin injection, the pancreatic ß-cells could not respond to an oral glucose load while, at six hours after, there was an apparent return of ß-cell responsiveness, but subsequently ß-cell responsiveness was progressively lost and histological examination revealed cellular damage. From these results, it is concluded that within six hours of injection, stretozotocin initiates pancreatic ß-cell damage which leads to the development of diabetes mellitus.

Streptozotocin alters pancreatic beta-cell responsiveness to glucose within six hours of injection into rats

A 24-hour glycaemic profile following streptozotocin (80 mg/kg. ip) injection was investigated in fasted rats. The most prominent changes in blood glucose were hyperglycaemia associated with low levels of plasma insulin after two hours followed by hypoglycaemia associated with high levels of plasma insulin after six hours; subsequently hyperglycaemia progressively developed and this was associated with decreasing levels of plasma insulin. Further probing revealed that at two hours after streptozotocin injection, the pancreatic á-cells could not respond to an oral glucose load while, at six hours after, there was an apparent return of á-cell responsiveness, but subsequently á-cell responsiveness was progressively lost and histological examination revealed cellular damage. From these results, it is concluded that within six hours of injection, stretozotocin initiates pancreatic á-cell damage which leads to the development of diabetes mellitus. (AU)

An overview of current research on the biological effects of extracts from the unripe ackee (Blighia sapida L.) - abstract

It has been demonstrated that subacute intraperitoneal administration of high doses of the lipid fraction of the unripe ackee resulted in marked neutropaenia, pulmonary toxicity and changes in the blood chemistry in rats. This study has been carried out to further isolate the neutropaenic principle by testing both aqueous and lipid fractions and to see if this effect could be demonstrated in a different animal species. In mice, intraperitoneal administration of aqueous and lipid extracts of the ackee at a dose regimen of 300mg/kg thrice weekly for six weeks showed an initial rise, followed by a lowering of the neutrophil count, red blood cell count, haemoglobin, platelet count, serum albumin and alkaline phosphatase also decreased. It is concluded that in addition to it's hypoglycaemic principle, both aqueous and lipid extracts of unripe ackee, when adminstered separately, have neutropaenic activity. Further research involving characterization and testing is in progress. (AU)

Unstable diabetic state produced by a small dose of streptozotocin in rats

A diabetic state was induced with a single intraperitoneal dose (45 mg/kg) of streptozotocin in rats. Their fasting blood glucose concentrations oscillated between 12.7 ñ 1.9 mmol/l and 4.6 ñ 0.6 mmol/l during 35 days of monitoring. Their body weights were also reduced, while controls gained weight, although food consumption was not significantly different. Also, within the first «-hour of the oral glucose tolerance test, blood glucose concentration increased in the diabetic and the control rats, but only in the control rats was there a simultaneous increase in serus IRI concentration (7.2 ñ 8 x 10 to the 2nd power pmol/l to 27.0 ñ 5.2 x 10 to the 2nd power pmol/l) which, like the blood glucose concentration, subsequently fell to fasting level in the control rats. In the diabetic rats, however, it was not until the following hour of the tolerance test that serum IRI concentration increased (3.4 ñ 0.3 x 10 to the 2nd power pmol/l to 65.0 ñ 12.5 x 10 to the 2nd power pmol/l) and blood glucose concentration began to fall. By the end of the test in the diabetic rats, blood glucose concentration fell but remained significantly higher than the control value. Additionally, no pancreatic tumours were identified in these diabetic rats. The results therefore suggest that an unstable diabetic state was produced by streptozotocin because the treshold for insulin secretion by glucose was increased, while the production of insulin by the pancreas was not significantly affected (AU)

The hypoglycaemic effect of annatto (bixa orellana) - abstract

In West Indian folklore, a number of plant extracts are utilised for medicinal purposes. One common malady so treated is diabetes mellitus. Some twenty (20) folk medicines (bush tea) were investigated as to their efficacy in lowering blood sugar levels in the anaesthetised dog model. The annatto (bixa orellana) when prepared as an oil suspension of the red seed coat was found to be quite a potent hypoglycaemic agent. It was further studied in order to purify the crude extract and possibly identify the pharmacologically active agent(s). The annatto seeds were percolated with chloroform until the bright red colour of the seed coat was removed. This extract was concentrated in vacua and the residue extracted selectively with 60 percent ethanol/water and petroleum ether. A final wine-red to orange viscous extract was used in the biological experiments. This partially purified petroleum ether extract was dissolved in corn oil (80 mg/kg body weight animal) and given to anaesthetized dogs via a stomach tube. After a residence time of one (1) hour, oral glucose tolerance tests were performed. The results showed hypoglycaemia in both the normal and streptozotocin diabetic dogs when compared to controls. Its effect is to delay the peaking of glucose after a meal and to increase the release of insulin in relation to blood glucose levels. The possibility of an effective hypoglycaemic principle in this extract increases pharmacological curiosity into this form of 'lay' treatment of diabetes mellitus. Detailed studies are continuing to identify and isolate the active component(s) (AU)

Extraction of an hyperglycaemic principle from the annatto (Bixa orellana)

The red powdery extract from the seeds of the annatto, Bixa orellana, is a well known food colouring. In an oil suspension it is used as a folk remedy (bush tea) in the West Indies, for diabetes mellitus. Detailed investigations on this extract, yielded a methyl ester, trans-bixin, molecular weight 394 and molecular formula C24 H30 O4. This purified substance was demonstrated, in anaaesthetised mongrel dogs, to cause hyperglycaemia. Concomitant electron microscopy of tissues biopsies, revealed damage to mitochrondria and endoplasmic reticulum mainly in liver and pancreas. When dogs were fed on a diet fortified with riboflavin, there was neither demonstratable tissue damage nor associated hyperglycaemia. These findings point to: (i) the potential dangers of informal medications such as 'bush teas'; (ii) the possible role of plant extracts/food additives in the development of diabetes mellitus especially in the undernourished state. (AU)

Isolation, purification and identification of the hyperglycaemic principle of the annatto (Bixa orellana) - abstract

The crude extract eluted from the seed of Bixa orellana was seen to cause hyperglycaemia in anaesthetized dogs. Further investigation was carried out to find the biologically active component. Column chromatography, PLC and recrystallizations yielded a pure residue with m.p. 220. The experimental dogs in quantities below one gram, it caused sustained hyperglycaemia and severe damage to tissues of the liver, kidney and pancreas. The level of toxicity associated with this plant is of interest, since its extract is widley used in various goods (AU)

Toxicity of the hyperglycaemic-inducing extract of the Annatto (Bixa orellana) in the dog

The Annatto seed coat extract, which is commonly used in folklore in treating diabetes mellitus, has been investigated for its effects on blood sugar levels in the dog. An alkali-soluble hyperglycaemia-inducing fraction was detected, and detailed studies revealed toxic effects in the pancreas and liver accompanied by hyperglycaemia and apparent tendency to increased insulin levels. The toxicity was diminished by feeding riboflavin. The relevance of this finding points to a possible aetiological role in the development of malnutrition-related diabetes mellitus and also to the potential toxicity inherent in the widespread use of folklore medicines (AU)

Long-term effects of marihuana smoke on uterine contractility and tumour development in rats

The present investigation considered the role of acute and chronic marihuana smoking, as well as crude extracts of marihuana (ME), on uterine contractions and tumour development. The contractions and the electrical activity were recorded on isolated superfused rats' uteri. Enhanced spontaneous activity and contractile responses were observed following exposure to marihuana smoke. Atropine failed to block contractile responses with ME following chronic smoke exposure. It is suggested that ME contains both contractile and relaxing properties. Chronic exposure to marihuana smoke resulted in appearance of various tumours in 50 percent of experimental animals. This study suggested far-reaching consequences on reproductive activity following chronic use of marihuana (AU)

The effect of bixa orellana (annatto) on blood sugar levels in the anaesthetized dog

The fruit of Bixa has red-coated seeds. This red coat was extracted with chloroform and the solution evaporated to dryness. The dried product was sparingly soluble in oil, and a saturated solution (4 gm per 100 ml) produced non-insulin mediated hypoglycaemia and insulinopenia. A 13.4 gm per 100 ml absolute alcohol solution produced hyperglycaemia. The potential therapuetic value of this extract supports its detailed investigation (AU)

A preliminary study of the effects of some West Indian medicinal plants on blood sugar levels in the dog

Many plant extracts used in folklore for lowering the blood sugar level, especially in diabetic patients, seem to have some effect though to a variable extent. Significant data has accumulated to support the concept that annatto seed, bird pepper and peri-winkle extracts are effective hypoglycaemic agents which are capable of sustained action in the anaesthetised dog (AU)

Effects of interruption of pallidal function on striatal-mediated motor activity: relevance to concepts in neurology and psychiatry

This work was conducted to evaluate the effects of bilateral lesion of the globus pallidus on spontaneous motor behaviour and drug-induced stereotypy. The evidence suggests that the pallidus is necessary for the expression of normal motor behaviour. Bilateral lesioned rats manifested hypoactivity. This hypoactivity or response depression was counteracted by low and high doses of amphetamine. Apomorphime (1.0 mg/kg) induced a normalizing effect on spontaneous motor activity in lesioned rats. However this higher dose of apomorphine induced marked stereotypic activity in lesioned rats. The results of this work raise important implications for certain motor disorders and the psychoses. (AU)