title: The protective effects of DA-9801 (Dioscorea extract) on the peripheral nerves in streptozotocin-induced diabetic rats.
abstract: It has been reported that DA-9801, an extract mixture of Dioscorea japonica Thunb and Dioscorea nipponica Makino, produces a neurotrophic activity. Therefore, this study was conducted to examine the neuroprotective effects of DA-9801 in streptozotocin-induced diabetic rats. The experimental rats were divided into six groups: the control group, Group I (non-diabetic rats treated with DA-9801), Group II (diabetic, non-treated rats) and Groups III, IV, and V (diabetic rats treated with DA-9801 at doses of 10, 50 or 100 mg/kg/d). Following a 16-wk course of oral treatment with DA-9801, functional parameters (von Frey filament test, hot plate test), biochemical parameters (nerve growth factor (NGF), tumor necrosis factor (TNF)-α, interleukin (IL)-6) were measured. An immunohistochemical staining was done to assess the neuroprotective effects of DA-9081 in the skin, sciatic nerve, gastric mucosa and renal cortex. In Week 8, pain was evoked by either tactile or thermal stimuli, whose threshold was significantly higher in Group III, IV and V than Group II. Western blot analysis showed a more significant increase in NGF and decrease in TNF-α and IL-6 in Group III, IV and V than in Group II (p<0.05). Moreover, following the treatment with DA-9801, a loss of intraepidermal nerve fibers (IENFs) was inhibited to a significant level in the skin, myelinated axonal fibers of the sciatic nerve and small nerve fibers innervating the gastric mucosa or renal cortex (p<0.05). Our results demonstrated that DA-9801 is a beneficial agent that protects the peripheral nerves in diabetic rats.
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Research Institute of Clinical Medicine of Chonbuk National University-Biomedical Research Institute of Chonbuk National University Hospital.
authors.forename: Kyung Ae
authors.initials: KA
authors.lastname: Lee
authors.forename: Heung Yong
authors.initials: HY
authors.lastname: Jin
authors.forename: Hong Sun
authors.initials: HS
authors.lastname: Baek
authors.forename: Tae Sun
authors.initials: TS
authors.lastname: Park
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000009:adverse effects / Q000378:metabolism / Q000627:therapeutic use*; D016207:Cytokines / Q000037:antagonists & inhibitors / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000150:complications; D003929:Diabetic Neuropathies / Q000276:immunology / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D019587:Dietary Supplements; D005753:Gastric Mucosa / Q000276:immunology / Q000294:innervation / Q000378:metabolism / Q000473:pathology; D007672:Kidney Cortex / Q000276:immunology / Q000294:innervation / Q000378:metabolism / Q000473:pathology; D008297:Male; D020932:Nerve Growth Factor / Q000819:agonists* / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism; D018696:Neuroprotective Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000378:metabolism / Q000627:therapeutic use*; D017288:Pain Threshold; D017933:Peripheral Nervous System / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D010936:Plant Extracts / Q000008:administration & dosage / Q000009:adverse effects / Q000378:metabolism / Q000627:therapeutic use*; D028321:Plant Preparations / Q000008:administration & dosage / Q000009:adverse effects / Q000378:metabolism / Q000627:therapeutic use; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012584:Sciatic Nerve / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D012867:Skin / Q000276:immunology / Q000294:innervation / Q000378:metabolism / Q000473:pathology; D013311:Streptozocin
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D016207:Cytokines; C562027:DA-9801; D009419:Nerve Tissue Proteins; D018696:Neuroprotective Agents; D010936:Plant Extracts; D028321:Plant Preparations; D013311:Streptozocin; D020932:Nerve Growth Factor