Total Western Diet Alters Mechanical and Thermal Sensitivity and Prolongs Hypersensitivity Following Complete Freund's Adjuvant in Mice

Abstract: The main objectives of the present work are to determine the clinical effect of niranthin on visceral or somatic inflammatory pain. The study was performed to determine the effects of niranthin on visceral or somatic inflammatory hypersensitivity of adult Swiss albino mice by using complete Freund’s adjuvant (CFA) induced pain model. The effect of CFA injection was determined after 24 hours of injection by using an aesthesiometer such as Von Frey filaments to evaluate tactile acetone-evoked cooling and thermal sensitivity. We used a digital Plethysmometer to measure paw edema. Single dose of niranthin intraperitoneal injection (5 & 10 mg/kg) was injected into mice having CFA-induced mechanical hypersensitivity and after 30 minutes of administration, reduced mechanical hypersensitivity was observed. In addition, niranthin also reduced acetone-evoked hypersensitivity within 4 hours. Compared to DMSO, niranthin was most highly active to reduce CFA-induced paw edema. To reduce mechanical hypersensitivity, multiple doses of niranthin (bis in die (b.i.d.)) from 1st - 5th day and b.i.d. day 9th and 10th) were given and remarkable results were observed such as did not cause tolerance in multiple dosing and significantly reduced in CFA induced hypersensitivity. This work reported niranthin having antinociceptive activity and indicated that niranthin is conventionally active in the management of persistent pain.

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Electroacupuncture Confers Antinociceptive Effects via Inhibition of Glutamate Transporter Downregulation in Complete Freund's Adjuvant-Injected Rats

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2012/643973 ◽

2012 ◽

Vol 2012 ◽

pp. 1-11 ◽

Cited By ~ 7

Author(s):

Ha-Neui Kim ◽

Yu-Ri Kim ◽

Ji-Yeon Jang ◽

Hwa-Kyoung Shin ◽

Byung-Tae Choi

Keyword(s):

Thermal Sensitivity ◽

Antinociceptive Effect ◽

Glutamate Transporter ◽

Complete Freund’S Adjuvant ◽

Double Labeling ◽

Mrna Content ◽

Freund’S Adjuvant ◽

Complete Freund's Adjuvant ◽

Freund's Adjuvant ◽

Glutamate Transporter 1

When we evaluated changes of glial fibrillary acidic protein (GFAP) and two glutamate transporter (GTs) by immunohistochemistry, expression of GFAP showed a significant increase in complete Freund's adjuvant (CFA)-injected rats; however, this expression was strongly inhibited by electroacupuncture (EA) stimulation. Robust downregulation of glutamate-aspartate transporter (GLAST) and glutamate transporter-1 (GLT-1) was observed in CFA-injected rats; however, EA stimulation resulted in recovery of this expression. Double-labeling staining showed co-localization of a large proportion of GLAST or GLT-1 with GFAP. Using Western blot, we confirmed protein expression of two GTs, but no differences in the mRNA content of these GTs were observed. Because EA treatment resulted in strong inhibition of CFA-induced proteasome activities, we examined the question of whether thermal sensitivities and GTs expression could be regulated by proteasome inhibitor MG132. CFA-injected rats co-treated with EA and MG132 showed a significantly longer thermal sensitivity, compared with CFA-injected rats with or without MG132. Both EA and MG132 blocked CFA-induced GLAST and GLT-1 downregulation within the spinal cord. These results provide evidence for involvement of GLAST and GLT-1 in response to activation of spinal astrocytes in an EA antinociceptive effect. Antinociceptive effect of EA may be induced via proteasome-mediated regulation of spinal GTs.

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