Microanatomy, lipid peroxidation and antioxidant system of the visual cortex of rats following withdrawal from prolonged lead nitrate administration.

Exposure to lead (Pb) has been shown to alter the function of central nervous system and affect cholinergic neurons of the visual cortex in animal models. This study sought to investigate the withdrawal symptoms and oxidative stress on the visual cortex after lead exposure. A total of 20 healthy male Wistar rats were randomly divided into two groups (n=10): group A, control, received 10 ml/kg of distilled water for 30 days orally; group B, lead treated group, received 10 mg/kg of lead nitrate solution for 30 days orally. Group B was divided into two subgroups, group B1 serves as non-recovery while B2 serves as recovery (withdrawal). Five rats from each group were sacrificed under ether anesthesia 24 hours after the last oral administration of lead, while the remaining 5 rats (withdrawal subgroup) were sacrificed 30 days after the last oral administration of lead. The visual cortex was grossed from the brain tissue and processed for histology. Blood/serum samples were obtained and markers of oxidative stress (superoxide dismutase [SOD], catalase [CAT], glutathione peroxidase [GPX]), and lipid peroxidation (malondialdehyde [MDA]) were analyzed. Lead-exposed rats display a significant reduction in the SOD, CAT, and GPX level as well as increased in MDA level. However, following a recovery period, a non-significant improvement was seen in the histoarchitecture of the visual cortex.

Anti-hepatotoxic activities of Hibiscus sabdariffa L. in animal model of streptozotocin diabetes-induced liver damage.

BACKGROUND: Flavonoid-rich aqueous fraction of methanolic extract of Hibiscus sabdariffa calyx was evaluated for its anti-hepatotoxic activities in streptozotocin-induced diabetic Wistar rats. METHODS: Diabetes Mellitus was induced in Wistar rats by a single i.p injection of 80 mg/kg b.w. streptozotocin (STZ) dissolved in 0.1 M citrate buffer (pH 6.3). RESULTS: The ameliorative effects of the extract on STZ-diabetes induced liver damage was evident from the histopathological analysis and the biochemical parameters evaluated in the serum and liver homogenates. Reduced levels of glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) (3.76 ± 0.38 µM, 0.42 ± 0.04 U/L, 41.08 ± 3.04 U/ml, 0.82 ± 0.04 U/L respectively) in the liver of diabetic rats were restored to a near normal level in the Hibiscus sabdariffa-treated rats (6.87 ± 0.51 µM, 0.72 ± 0.06 U/L, 87.92 ± 5.26 U/ml, 1.37 ± 0.06 U/L respectively). Elevated levels of aspartate amino transferase (AST), alanine amino transferase (ALT) and alkaline phosphatase (ALP) in the serum of diabetic rats were also restored in Hibiscus sabdariffa -treated rats. Examination of stained liver sections revealed hepatic fibrosis and excessive glycogen deposition in the diabetic rats. These pathological changes were ameliorated in the extract-treated rats. CONCLUSION: The anti-hepatotoxic activity of Hibiscus sabdariffa extract in STZ diabetic rats could be partly related to its antioxidant activity and the presence of flavonnoids.

Hypoglycaemic and hypotensive effects of Ficus exasperata vahl. (Moraceae) leaf aqueous extract in rats.

The hypotensive and hypoglycaemic effects of Ficus exasperata (Vahl) (family: Moraceae) leaf aqueous extract (FEE) were investigated in experimental rat models. In this study, spontaneously-hypertensive rats (SHR) (type 1 diabetes), obese Zucker (type 2 diabetes) and Wistar rats were used. Three (A, B and C) groups of rats, each group consisting of 10 rats, were used. Group A Wistar rats received distilled water in quantities equivalent to the volume of streptozotocin (STZ) and FEE administered intraperitoneally to treated rats. Diabetes mellitus was induced in the SHR group B rats by multiple low-dose (MLD) intraperitoneal injections of STZ (40 mg/kg body weight) to induce type 1 diabetes. The animals in group C were the obese Zucker rats with non-insulin-independent diabetes mellitus (NDDM) (type 2 diabetes) on genetic basis. F. exasperata leaf aqueous extract (FEE, 100 mg/kg/day p.o.) was administered orally by orogastric intubation to fasted Groups B and C rats. In groups B and C rats, administration of FEE commenced 4 weeks post STZ injection, and continued for the next 4 consecutive weeks. Group A rats gave normal biochemical and morphological findings. Group B rats exhibited pronounced polyuria, hypoinsulinaemia, hyperlipidaemia and hyperglycaemia. These findings were also observed in group C rats, except that there was hyperinsilinaemia. Histopathological study of the aortic blood vessels showed extensive collagen fiber formation as well as perivascular fibrosis in both groups B and C rats. Four weeks of oral administration of F. exasperata leaf aqueous extract to diabetic groups of rats decreased blood glucose, blood pressure and lipid profiles. Administration of FEE (100 mg/kg p.o.) also restored the microanatomy of the blood vessels to almost normal levels. The findings of this study suggest that F. exasperata leaf aqueous extract possesses hypoglycaemic, hypotensive and hypolipidaemic properties. These findings lend biomedical and pharmacological support to the folkloric, ethnomedical uses of the plant in the management and/or control of diabetes and hypertension among the Yoruba-speaking people of Western Nigeria.

Mixture of kerosene and xylene: a contribution to clearing agents / Mezcla de kerosene y xileno: una contribución a agentes de aclaramiento

The aim of this study was to substitute costly and hazardous compound- xylene, used as clearing agent, with less costly compounds (mixture of xylene and kerosene) having less toxicity and without compromising the cellular integrity and staining characteristics of the sections. Tissues (liver and kidney) obtained from a presumable healthy adult Wistar rat, were fixed in 10 percent formol saline, separated in to five groups (A, B, C, D and E) and processed for light microscopic study adopting H & E staining procedure. During the clearing section, groups A, B, C, D and E were respectively cleared in solvent 1 (xylene only), solvent 2 (70ml xylene : 30ml kerosene), solvent 3 (50ml xylene : 50ml kerosene), solvent 4 (30ml xylene : 70ml kerosene) and solvent 5 (kerosene only). Our result revealed that tissues in groups A, B and C were properly cleared without any morphological impairment. The staining characteristics were also observed to be very bright. Groups D and E however presented poor staining intensity with reduced cellular details. Semi-stained transparent patches were also noticed. It is inferred from the present investigation that a mixture of xylene and kerosene could be employed in the clearing of tissues only at the prescribed ratio i.e. solvent 2 and solvent 3 without posing any health risk or compromising the cellular integrity.

El objetivo de este estudio fue el de sustituir el costoso y peligroso compuesto xileno, utilizado como agente de aclaramiento, por un compuesto menos costoso (mezcla de kerosene y xileno), con menor toxicidad y sin comprometer la integridad celular ni las características de tinción de las secciones. Los tejidos (hígado y riñon) fueron obtenidos a partir de una rata Wistar adulta presumiblemente sana, los que fueron fijados en solución de formalina salina al 10 por ciento, y separadas en cinco grupos (A, B, C, D y E) y tratadas para estudio con microscópico de luz, con tinción H & E. Durante el aclaramiento de las secciones histológicas, los grupos A, B, C, D y E, fueron, respectivamente, aclarados con el disolvente 1 (sólo xileno), solvente 2 (70ml de xileno: 30ml Kerosene), solvente 3 (50ml de xileno: 50ml Kerosene), solvente 4 (30ml xileno: 70ml kerosene) y solvente 5 (sólo el kerosene). Los resultados revelaron que los tejidos de los grupos A, B y C fueron aclarados correctamente sin alteraciones morfológicas. En la tinción también se observó como característica, ser muy brillante. Los grupos D y E, sin embargo presentaron una tinción de pobre intensidad con la reducción de los detalles celulares. Zonas con manchas semitransparentes también fueron observadas. Se infiere que una mezcla de xileno y kerosene podría ser empleado en el aclaramiento de los tejidos, sólo prescrito en la proporción del solvente 2 y 3, sin suponer ningún riesgo para la salud o comprometer la integridad celular.

Hypoglycaemic effect of mollic acid glucoside, a 1alpha-hydroxycycloartenoid saponin extractive from Combretum molle R. Br. ex G. Don (Combretaceae) leaf, in rodents.

In this study, we investigated the hypoglycaemic and antidiabetic properties of mollic acid glucoside (MAG), a 1alpha-hydroxycycloartenoid extractive from Combretum molle leaf, in rodents. Stepwise, escalated doses of MAG (5-80 mg/kg p.o.) produced dose-dependent and significant (P < 0.05-0.01) hypoglycaemic and antidiabetic effects in normal (normoglycaemic) and streptozotocin-treated diabetic rats. Experimental evidence obtained from this laboratory animal study indicates that MAG, an extractive from C. molle leaf, possesses hypoglycaemic and antidiabetic properties. These findings lend pharmacological credence to the folkloric, ethnomedical uses of the plant's leaf in the management and/or control of diabetes mellitus in some rural communities of southern Africa.

Protective effects of Annona muricata Linn. (Annonaceae) leaf aqueous extract on serum lipid profiles and oxidative stress in hepatocytes of streptozotocin-treated diabetic rats.

Extracts from various morphological parts of Annona muricata Linn. (Annonaceae) are widely used medicinally in many parts of the world for the management, control and/or treatment of a plethora of human ailments, including diabetes mellitus (DM). The present study was undertaken to investigate the possible protective effects of A. muricata leaf aqueous extract (AME) in rat experimental paradigms of DM. The animals used were broadly divided into four (A, B, C and D) experimental groups. Group A rats served as 'control' animals and received distilled water in quantities equivalent to the administered volumes of AME and reference drugs' solutions intraperitoneally. Diabetes mellitus was induced in Groups B and C rats by intraperitoneal injections of streptozotocin (STZ, 70 mg kg(-1)). Group C rats were additionally treated with AME (100 mg kg(-1) day(-1), p.o.) as from day 3 post STZ injection, for four consecutive weeks. Group D rats received AME (100 mg kg(-1) day(-1) p.o.) only for four weeks. Post-euthanization, hepatic tissues were excised and processed biochemically for antioxidant enzymes and lipid profiles, such as catalase (CAT), reactive oxygen species (ROS), glutathione (GSH), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), thiobarbituric acid reactive substances (TBARS), triglycerides (TG), total cholesterol (TC), high density lipoprotein (HDL) and low density lipoprotein (LDL), respectively. Treatment of Groups B and C rats with STZ (70 mg kg(-1) i. p.) resulted in hyperglycaemia, hypoinsulinaemia, and increased TBARS, ROS, TC, TG and LDL levels. STZ treatment also significantly decreased (p<0.05) CAT, GSH, SOD, GSH-Px activities, and HDL levels. AME-treated Groups C and D rats showed significant decrease (p<0.05) in elevated blood glucose, ROS, TBARS, TC, TG and LDL. Furthermore, AME treatment significantly increased (p<0.05) antioxidant enzymes' activities, as well as serum insulin levels. The findings of this laboratory animal study suggest that A. muricata extract has a protective, beneficial effect on hepatic tissues subjected to STZ-induced oxidative stress, possibly by decreasing lipid peroxidation and indirectly enhancing production of insulin and endogenous antioxidants.

Artocarpus communis Forst. root-bark aqueous extract- and streptozotocin-induced ultrastructural and metabolic changes in hepatic tissues of Wistar rats.

Decoctions and infusions of Artocarpus communis (Forst.) (family: Moraceae) root-bark are commonly used traditionally among the Yoruba-speaking people of Western Nigeria as folk remedies for the management, control and/or treatment of an array of human diseases, including type 2, adult-onset diabetes mellitus. Although numerous bioactive flavonoids have been isolated from the roots, stem-bark and leaves of A. communis, to the best of our knowledge, the effects of the plant's root-bark extract on animal model of diabetes mellitus and on liver tissues have hitherto, not been reported in the biomedical literature. In view of this, the present study was undertaken to investigate the glycaemic effect of, and hepatic tissue ultrastructural, morphological and metabolic changes induced by A. communis root-bark aqueous extract (ACE) in Wistar rats. The ultrastructural, morphological and metabolic effects of ACE have been compared with those induced by streptozotocin (STZ) in rat experimental paradigms. Four groups (A, B, C and D) of Wistar rats, each group containing 10 rats, were used. Diabetes mellitus was induced in the diabetic groups B and C animals by intraperitoneal injections of STZ (75 mg/kg body weight), while group A rats received A. communis root-bark aqueous extract (ACE, 100 mg/kg body weight, i.p.) alone. Control group D rats received distilled water in quantities equivalent to the volume of ACE administered intraperitoneally. The rats in group C were additionally treated with ACE (100 mg/kg body weight i. p.) daily from day 3 to day 10 after STZ treatment. Hepatic glucokinase, hexokinase, glutamate dehydrogenase, succinate dehydrogenase, beta-hydroxybutyrate dehydrogenase, serum insulin and blood glucose levels of the animals were measured and recorded before and after ACE, STZ and STZ+ACE treatments. Hepatic tissues were also processed for transmission electron microscopy. Electron microscopic examinations showed toxic, deleterious alterations in the ultrastructures of groups A, B and C hepatic cells, the most prominent deleterious effects being on the hepatocytes. Ultrastructural changes observed within the hepatocytes of groups A, B and C rats include disrupted mitochondria with increase in lipid droplets, extensive hepatocellular vacuolation, scanty rough endoplasmic reticulum (RER) and ribosomes. Large glycogen clusters were also noticed displacing the mitochondria and RER in group A rats. Group A rats also developed significant hyperglycemia (p<0.05) immediately after ACE administration, while groups B and C rats developed hyperglycemia 24 hours after STZ treatment. When compared with the control group D rats, the activities of all the three subsystems were disrupted, leading to overall inhibition of oxidative phosphorylation of the liver mitochondria in groups A, B and C rats, but remain normal in the untreated group D control rats. The findings of the present study indicate that A. communis root-bark aqueous extract induces hyperglycaemia in the experimental animal model used, and that the plant's extract disrupts the ultrastructural characteristics and architecture of hepatocytes as well as oxidative energy metabolism.

Hypoglycaemic and hypotensive effects of Momordica charantia Linn (Cucurbitaceae) whole-plant aqueous extract in rats.

Various morphological parts (roots, stems, leaves and fruits) of Momordica charantia Linn (family: Cucurbitaceae) are used traditionally in African folk medicine to manage, control and/or treat a plethora of human ailments, including diabetes mellitus and hypertension. In order to scientifically appraise some of the folkloric, anecdotal and ethnomedical uses of M charantia, the present study was undertaken to investigate the hypoglycaemic and hypotensive effects of M charantia whole-plant aqueous extract (MCE) in rat experimental paradigms. The hypoglycaemic effect of the plant extract was examined in normal and diabetic rats, using streptozotocin (STZ)- induced diabetes mellitus models. Normotensive (normal), and hypertensive Dahl salt-sensitive rats were used to probe the hypotensive (antihypertensive) effect of the plant extract. Chlorpropamide was used as reference hypoglycaemic agent for comparison. Acute oral administrations of the plant extract caused dose-related, significant hypoglycaemia in normal (normoglycaemic) and STZ-treated, diabetic rats. Furthermore, acute intravenous administrations of MCE produced dose-dependent, significant reductions in systemic arterial blood pressure and heart rates of normal, and hypertensive Dahl salt-sensitive rats. Although the exact hypoglycaemic and hypotensive mechanisms of action of the plant extract remain speculative at the moment, it is unlikely that the herb causes hypotension in the mammalian experimental animal model used via cholinergic mechanisms, since its cardiovascular effects are resistant to atropine pretreatment. However, the findings of this experimental animal study indicate that the plant extract possesses hypoglycaemic and hypotensive properties, and therefore, lend pharmacological credence to folkloric, ethnomedical uses of the plant in the management and/or control of diabetes mellitus and hypertension in some rural African communities.

Protective effect of quercetin on the morphology of pancreatic beta-cells of streptozotocin-treated diabetic rats.

This study was undertaken to investigate the protective effects of quercetin (QCT) on the morphology of pancreatic beta-cells against diabetes mellitus and oxidative stress experimentally-induced by streptozotocin (STZ) treatment in Wistar rats. Fifty male and female Wistar rats (200-250 g) were randomly divided into three experimental groups (i. e., control, STZ-treated, and STZ + Quercetin-treated groups). Diabetes was induced in the diabetic groups (B and C) of animals, by a single intraperitoneal injection of STZ (75 mg/kg), while each of the rats in the 'control' group received equal volume of citrate buffer (pH 6.3) solution intraperitoneally. In group C rats, quercetin (QCT, 25 mg/kg/day i.p.) was injected daily for 3 days prior to STZ treatment, and QCT administration continued until the end of the study period (30 days). Diabetes mellitus was confirmed by using Bayer's Glucometer Elite and compatible blood glucose test strips. The rats were sacrificed serially until the end of the study period (after 30 days). The pancreases of the sacrificed rats were excised and randomly processed for histological staining and biochemical assays for antioxidant enzymes [such as glutathione peroxidase (GSHPx), superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA) and serum nitric oxide (NO)]. In the diabetic state, pancreatic beta-cells of STZ-treated group B rats histologically demonstrated an early chromatin aggregation, cytoplasmic vesiculation in the central beta-cells, nuclear shrinkage, and lysis of beta-cells with distortion of granules. The morphology of QCT-treated rats' pancreases showed viable cellularity with distinct beta-cell mass. STZ treatment significantly decreased (p<0.05) GSHPx, SOD, CAT and pancreatic insulin content. However, STZ treatment increased blood glucose concentrations, MDA and serum NO. The QCT-treated group of animals showed a significant decrease (p<0.05) in elevated blood glucose, MDA and NO. Furthermore, QCT treatment significantly increased (p<0.05) antioxidant enzymes' activities, as well as pancreatic insulin contents. Quercetin (QCT) treatment protected and preserved pancreatic beta-cell architecture and integrity. In conclusion, the findings of the present experimental animal study indicate that QCT treatment has beneficial effects on pancreatic tissues subjected to STZ-induced oxidative stress by directly quenching lipid peroxides and indirectly enhancing production of endogenous antioxidants.