title: Histological studies of neuroprotective effects of Curcuma longa Linn. on neuronal loss induced by dexamethasone treatment in the rat hippocampus.
abstract: Long term exposure to dexamethasone (Dx) is associated with brain damage especially in the hippocampus via the oxidative stress pathway. Previously, an ethanolic extract from Curcuma longa Linn. (CL) containing the curcumin constituent has been reported to produce antioxidant effects. However, its neuroprotective property on brain histology has remained unexplored. This study has examined the effects of a CL extract on the densities of cresyl violet positive neurons and glial fibrillary acidic protein immunoreactive (GFAP-ir) astrocytes in the hippocampus of Dx treated male rats. It showed that 21 days of Dx treatment (0.5mg/kg, i.p. once daily) significantly reduced the densities of cresyl violet positive neurons in the sub-areas CA1, CA3 and the dentate gyrus, but not in the CA2 area. However, CL pretreatment (100mg/kg, p.o.) was found to significantly restore neuronal densities in the CA1 and dentate gyrus. In addition, Dx treatment also significantly decreased the densities of the GFAP-ir astrocytes in the sub-areas CA1, CA3 and the dentate gyrus. However, CL pretreatment (100mg/kg, p.o.) failed to protect the loss of astrocytes in these sub-areas. These findings confirm the neuroprotective effects of the CL extract and indicate that the cause of astrocyte loss might be partially reduced by a non-oxidative mechanism. Moreover, the detection of neuronal and glial densities was suitable method to study brain damage and the effects of treatment.
authors.affiliation: Department of Physiology, Faculty of Science, Prince of Songkla University, Songkhla, Thailand.
authors.forename: Acharaporn
authors.initials: A
authors.lastname: Issuriya
authors.affiliation: Department of Physiology, Faculty of Science, Prince of Songkla University, Songkhla, Thailand; Natural Product Research Center of Excellence, Faculty of Science, Prince of Songkla University, Songkhla, Thailand.
authors.forename: Ekkasit
authors.initials: E
authors.lastname: Kumarnsit
authors.affiliation: Department of Pharmacognosy and Pharmaceutical Botany, Faculty of Pharmaceutical Science, Prince of Songkla University, Songkhla, Thailand.
authors.forename: Chatchai
authors.initials: C
authors.lastname: Wattanapiromsakul
authors.affiliation: Department of Anatomy, Faculty of Science, Prince of Songkla University, Hat-Yai, Songkhla, Thailand. Electronic address: uraporn.v@psu.ac.th.
authors.forename: Uraporn
authors.initials: U
authors.lastname: Vongvatcharanon
mesh_terms: D000818:Animals; D030024:Curcuma / Q000737:chemistry*; D003907:Dexamethasone / Q000494:pharmacology*; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D007150:Immunohistochemistry; D008297:Male; D018696:Neuroprotective Agents / Q000737:chemistry* / Q000494:pharmacology*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D018696:Neuroprotective Agents; D010936:Plant Extracts; D003907:Dexamethasone
keywords: Chronic stress; Cresyl violet; Curcuma longa; Dexamethasone; Glial fibrillary acidic protein; Hippocampus; Rats