Morinda lucida stem bark reversed the pattern and extent of lead nitrate-induced liver injury in Wistar rats.

Lead toxicity remains one of the most important occupational and environmental health problems with characteristic features that are incompatible with life. Considering the foregoing, we investigated the ameliorative potentials of Morinda lucida stem bark (MLSB) extract on lead nitrate-induced hepatic injury with particular emphasis on its effects on the pattern and extent of lead nitrate toxicity. Thirty-six adult Wistar rats were randomly assigned into six groups (n=6). Normal control group received 2.2mL/kg distilled water only for 4 weeks while hepatic injury was induced by 2-week oral administration of 30mg/kg lead nitrate to experimental rats in the remaining five groups. Following induction, test groups were treated with MLSB for another 2 weeks at 100, 250, and 500mg/kg concentrations respectively while silymarin was administered orally for 2 weeks to positive control group. At the end of the study, serum activities of liver function enzymes and tissue levels of malondialdehyde were determined. Patterns and extent of injury were determined in hematoxylin and eosin-stained section. The result revealed a significant reduction in sera levels of liver function enzymes and tissue level of malondialdehyde (MDA) in extract treated groups. Lead nitrate-induced necrotic changes and other deranged features observed in histological sections were multifocal and they span through multiple zones of hepatic acini (panacinar), MLSB at 250mg/kg concentration reversed by some of these effects. The study concluded that ameliorative property of MLSB could be due to the antioxidant and membrane stabilizing properties of its phenolic compounds.

Hibiscus sabdariffa renews pancreatic ß-cells in experimental type 1 diabetic model rats.

This study evaluated the antidiabetic potentials of flavonoid-rich aqueous fraction of methanolic extract of Hibiscus sabdariffa calyx (HSCE) on the pancreatic ß-cells of experimental type I diabetic model rats. Type 1 diabetes mellitus was induced in Wistar rats by a single intraperitoneal injection of 80mg/kg b/w streptozotocin (STZ) dissolved in 0.1M citrate buffer (pH 6.3). The rats were divided into five groups (n=12) including normal control group, test group I, diabetic negative control, test group II, and diabetic positive control. The test groups received 1.75g/kg b/w of HSCE by gavage for 15 days. Animals were sacrificed; the splenic portion of their pancreas and serum were evaluated for histopathological and biochemical parameters respectively. The regenerative effects of the extract on STZ-diabetes ß-cells damage was evident from the results of the histopathological analysis and the biochemical parameters evaluated in the serum. Reduced levels of glutathione, catalase and superoxide dismutase in the serum of diabetic rats were significantly improved in the H. sabdariffa-treated rats (P<0.05). Histological examination of pancreatic islet sections revealed degenerative and necrotic changes (D) in the pancreatic islet of Langerhans, ß-cell degranulation, pyknotic ß-cell nuclei, decreased islet cellular density, and severe vacuolation (V) in the islet of STZ-diabetic negative control group. The morphology of the pancreas of HSCE-treated diabetic rats (test group II) revealed remarkable improvements in the islet of Langerhans. Stereological studies also revealed that HSCE-treatment remarkably improved volume of the pancreatic islets and the numerical density of ß-cell (number of ß-cells per unit area of islet) depleted by STZ diabetes. The study concluded that possible antidiabetic mechanism of Hibiscus sabdariffa in STZ diabetes is through induction of ß-cell regeneration and its strong antioxidant potential.

Ethanol extract of Curcuma longa rhizome mitigates potassium bromate-induced liver changes in the Wistar rat: Histological, histochemical and immunohistochemical assessments.

The effects of Curcuma longa rhizome on hepatic cells, glycogen, connective tissue fibres and filamentous cytoskeleton were evaluated following KBrO3-induced liver injury in Wistar rats. Thirty-five male rats were randomly divided into seven groups (n=5). Group 1 were normal saline treated rats. Hepatic injury was induced in groups 2 to 7 by oral administration of 100mg/kg KBrO3 for 2 weeks. Following induction, rats in group 2 were sacrificed while groups 3, 4, 5 were given oral dose of EECLOR at 100, 200, 400mg/kg respectively. Group 6 rats were treated with silymarine while group 7 rats were left untreated. The rats were sacrificed and the liver sections were stained with H&E, Masson trichrome, Gordon and Sweets, PAS, Feulgen reaction, anti-vimentin antibody for demonstration of general histoarchitecture, elastic fibre, collagen fibre; glycogen, nuclear DNA and filamentous cytoskeleton respectively. Groups 2, 3, 7 developed intranuclear vacuolation, plasma coagulation, plamolysis, karyopyknosis, karyorrhexis and karyolysis, hyperchromatism, DNA fading and pleomorphism. Immunohistochemical study revealed near negative immunoreaction for vimentin. These pathological changes were ameliorated in EECLOR-treated groups in a manner comparable to silymarine-treated group. The study concluded that ameliorative effects of EECLOR in KBrO3-induced liver injury could be due to its vimentin stabilization property.

ISOLATION, CHARACTERIZATION AND IMMUNOCHEMICAL STUDIES ON FIBROUS PROTEINS FROM COWRY SHELL (CYPRAEA MONETA, LINNAEUS).

BACKGROUND: Biomaterials are non-drug substances used to treat, enhance or replace functions of body tissues or organs. Natural sources of biomaterials have recently become the focus of several research activities. Cowry shell constitutes one of the most promising natural sources of biomaterials because of its chemical stability, biodegradability and biocompatibility in the body. However, its applications may be limited due to immunogenic and toxic responses that may occur following implantation, hence this study. MATERIALS AND METHODS: Crude fibrous protein extracted with citrate buffer from pulverised cowry shells (Cypraea moneta (L)), was resolved into two components (CSP1 and CSP2) by gel filtration. Immunological studies were performed with antisera obtained from rabbits by double immunodiffusion and immunoelectrophoresis techniques. Mice treated with the proteins were observed for signs of toxicity and their liver, kidney, lungs and spleen were processed histologically. RESULTS: The native molecular weight of CSP1 and CSP2 determined by gel filtration were 91kDa and 33kDa respectively. CSP1 and CSP2 displayed single bands on SDS-PAGE with subunit molecular weight values of 19kDa and 19.5kDa respectively. Antisera obtained from rabbits immunised with the crude citrate buffer extracts precipitated the antigen in double immunodiffusion tests. Histopathological examinations revealed a dose-dependent damaging effect of the shell proteins on liver, kidney, lung and spleen tissues of the treated mice. CONCLUSION: This study showed that cowry shells contain fibrous proteins which are immunogenic and toxic in mice at relatively high concentrations, causing visible organ damage without concurrent physical manifestations.

Histomorphological and morphometric studies of the pancreatic islet cells of diabetic rats treated with extracts of Annona muricata.

Microanatomical changes in the pancreatic islet cells of streptozotocin induced diabetic Wistar rats were studied after treatment with methanolic extracts of Annona muricata leaves. Thirty adult Wistar rats were randomly assigned into three groups (control, untreated diabetic group, and A. muricata-treated diabetic group) of ten rats each. Diabetes mellitus was experimentally induced in groups B and C by a single intra-peritoneal injection of 80 mg/kg streptozotocin dissolved in 0.1 M citrate buffer. The control rats were intraperitoneally injected with an equivalent volume of citrate buffer. Daily intra peritoneal injections of 100 mg/kg A. muricata were administered to group C rats for two weeks. Post sacrifice the pancreases of the rats were excised and fixed in Bouin's fluid. The tissues were processed for paraffin embedding and sections of 5 mum thickness were produced and stained with H & E, Gomori aldehyde fuchsin, and chrome alum haematoxylin-phloxine for demonstration of the beta-cells of islets of pancreatic islets. Histomorphological and morphometric examination of the stained pancreatic sections showed a significant increase in the number, diameter, and volume of the beta-cells of pancreatic islets of the A. muricata-treated group (5.67 +/- 0.184 N/1000 mum(2), 5.38 +/- 0.093 mum and 85.12 +/- 4.24 mum(3), respectively) when compared to that of the untreated diabetic group of rats (2.85 +/- 0.361 N/1000 mum(2), 2.85 +/- 0.362 mum and 69.56 +/- 5.216 mum(3), respectively). The results revealed regeneration of the beta-cells of islets of pancreatic islet of rats treated with extract of A. muricata.

Morphological and morphometric studies of the aorta, pulmonary trunk, and heart of streptozotocin-induced diabetic Wistar rats.

Micro-anatomical changes in the aorta, pulmonary trunk, and left ventricle of Wistar rats were studied after the administration of streptozotocin. Twenty adult Rattus norvegicus were randomly assigned into two groups (control and diabetic) of ten rats each. Diabetes mellitus was experimentally induced in the diabetic group of rats by daily intra-peritoneal administration of multiple doses of 40 mg/kg streptozotocin dissolved in 0.1 M sodium citrate buffer for five consecutive days. The control group was given the equivalent volume of citrate buffer. The animals were monitored for four weeks after streptozotocin administration. Post sacrifice, the left ventricle, aorta, and pulmonary trunk were excised, weighed, and fixed by immersion in 10% formol saline. The tissues were processed for paraffin embedding, and sections of 6 mum thickness were produced and stained with H & E for general histological observations, and Verhoeff-van Gieson elastic fibre stain to demonstrate elastic fibres in these cardiovascular structures. The data obtained were analyzed with descriptive and inferential statistics. Histopathological and morphometric examinations of the stained sections showed a significant increase in the thickness of the tunica intima of aorta (t = -7.49; df = 9; p < 0.05) and pulmonary trunk (t = -10.81; df = 9; p < 0.05) in diabetic rats (14.59 + or - 1.189 mm and 11.307 + or - 0.863 mm, respectively) when compared to that of the control group (3.62 + or - 0.353 mm and 3.22 + or - 0.244 mm, respectively). In addition, the distribution of elastic and collagen fibres was sparse in the hearts of the diabetic group when compared to that of the control group. The findings of this study demonstrated that diabetes mellitus might cause some alterations in the microanatomy of cardiovascular structures.