Protective effect of vitamin B complex in diabetic peripheral neuropathy - Histopathological study

Vitamin B complex has been used for peripheral neuropathy for a long time and continues to be part of current practice despite lack of strong evidence for its use and its non-inclusion in treatment guidelines. So this study was carried out to verify the neuroprotective effect of vitamin B complex from morphological changes of the diabetic rat sciatic nerve. A total number of 30 adult male albino rats were used and divided into three groups. Group I: normal vehicle control (N=10). Group II: streptozotocin-induced diabetic rats (N=20), which is equally divided into two subgroups; IIa (diabetic vehicle control) and IIb (diabetic vitamin B complex-treated, at a dose of 1mg/kg/day for 6 weeks).Diabetes was induced by a single intraperitoneal injection of streptozotocin (STZ) at a dose of 80mg/kg. Specimens from sciatic nerve were processed for light, electron microscopy and immunohistochemistry investigations. Morphological indices including the average myelin sheath thickness, the average myelinated nerve fiber area, endoneurial capillary density and perineurial index were measured and statistically analysed. Vitamin B complex treatment for six weeks markedly protected the sciatic nerve from the deleterious effect of hyperglycemia and preserved normal structural features of the perineurium, Schwann cells and their myelin sheath, nerve fibers, blood capillaries and the interstitium. The results were verified by immunohistochemistry (using CD 31, CD 68 and anti caspase-3 antibodies) and the morphological indices including the myelin sheath thickness, perineurial index and endoneurial capillary density. In conclusion, vitamin B complex supplementation might provide a long-term, drug approach for protection from diabetic peripheral neuropathy

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Effect of All-Trans Retinoic Acid on the Pancreas of Streptozotocin-Induced Diabetic Rat.

All-trans Retinoic acid (atRA) is instructive for the development of endocrine pancreas and is an integral component of ß-cell induction protocols. We showed that atRA induces glucose-responsive endocrine transdifferentiation of pleomorphic pancreatic ductal adenocarcinoma cells in vitro. This study aimed to detect the role of atRA in improving the histological changes of the pancreas in diabetic rats. Forty young male Wistar rats were used and divided into three groups. Group I: normal vehicle control (N = 5). Group II: streptozotocin-induced diabetic rats (N = 20) were followed up at 0.0, 1, 2, and 4 weeks. Group III: streptozotocin-induced diabetic rats (N = 15) treated with atRA (2.5 mg/kg/day), were followed up at 1, 2, and 4 weeks. Specimens from the pancreas were processed for light, electron microscopy and pancreatic insulin mRNA expression. Blood samples were assayed for the levels of glucose, insulin, and total peroxides. In the atRA-treated group, the number of the islets and the islet area significantly increased. Strong insulin-immunoreactive endocrine-like cells were observed nearby the pancreatic acini and the interlobular ducts. Interestingly, insulin-positive cells seemed to arise from pancreatic acinar and ductal epithelium. Ultrastructurally, ß-cells, acinar, and ductal cells restored their normal appearance. Pancreatic insulin mRNA and blood indices were almost normalized. AtRA improved the histological changes of the pancreas and the blood indices in diabetic rats.

Histological study on effect of Nigella sativa on aged olfactory system of female albino rat.

Nigella sativa (NS) has wide-ranging healing properties, neuroprotective and antioxidant effects. Aging process is commonly associated with a decline in the chemical senses including smell. To detect a possible improvement effect of NS on the aging of the olfactory system we used 15 female albino rats that equally divided into three groups: group I (control adult), group II (control aged), group III (treated aged) received 40 mg/kg/day NS orally for two months. Specimens from the olfactory epithelium (OE), main olfactory bulb (MOB) and piriform cortex (PC) were processed for light and electron microscopy. Aging in OE revealed reduction in thickness, vacuolations, an increase in PAS reaction and lipofuscin autofluorescence. Aged MOB and PC exhibited a reduction in basophilia and accumulation of neurofibrillary tangles (NFTs) in mitral and pyramidal cells respectively. NS treatment improved the structure and the thickness of the OE and reduced the lipofuscin autofluorescence. It also attenuated the reduction in cytoplasmic basophilia and the accumulation of lipofuscin pigment and the NFTs in both mitral and pyramidal cells and the lipofuscin autofluorescence. These observations indicate that use of NS, could be of value in improving the structural changes of the peripheral and central main olfactory organs, which occurred in association with aging.