| dc.description.abstract | Ethnopharmacological relevance: In silico data revealed that the active compound of ginger (Zingiber officinale
Roscoe), 6-shogaol, has strong affinity toward transient receptor potential vanilloid-1 (TRPV-1). TRPV-1 is expressed
in nervous tissue and pancreatic β-cells. Prolonged induction of TRPV-1 is related to the expression of Nmethyl-D-aspartate
receptor subunit 2B (NMDAR2B). However, there are no data on TRPV-1 and NMDAR2B
expressions in nervous tissue after 6-shogaol or ginger extract treatment nor pancreatic islet morphology and
insulin expression in mice model of painful diabetic neuropathy (PDN).
Aim of the study: This study aimed to investigate the mechanism of action of ginger extract and its compound, 6shogaol,
on pancreatic islets as well as on expressions of TRPV-1 and NMDAR2B in the spinal cord of streptozotocin
(STZ)-induced mice model of PDN.
Materials and methods: Sixty-four 5–6 weeks old male-Balb/C mice were induced with 110 mg/kgBW STZ i.p.,
while eight mice were used as control group. Mice with blood glucose level ≥200 mg/d, that suffered hyperalgesia
and allodynia were classified as PDN mice. Hot plate and von Frey filament tests were performed once a
week until termination. At day 28 after considered as PDN, ginger extracts, 6-shogaol or gabapentin as control
treatment were given once daily for 21 days until day 49, except for the diabetic control group. Upon termination,
mice’ pancreas were fixed, processed as paraffin sections and stained with hematoxylin eosin. Total
volume of pancreatic islets was estimated using Cavalieri methods. Immunohistochemistry on pancreatic sections
were performed to observe insulin expression. mRNA was extracted from lumbar segments of the spinal
cord, followed by cDNA preparation and quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) to
measure the expressions of TRPV1 and NMDAR2B. The mean differences between groups were analyzed using
one-way analysis of variance (ANOVA) with p < 0.05 considered statistically significant.
Results: Ginger extracts and 6-shogaol alleviated hyperalgesia and allodynia. The groups that received ginger
extract 400 mg/kgBW or 6-shogaol 15 mg/kgBW had significantly lower TRPV1 and NMDAR2B expressions in
the spinal cord compared to the diabetic control group (p < 0.001;p < 0.05). However, no differences in
volume of pancreatic islets (p > 0.05) nor insulin expression were observed in all PDN groups.
Conclusion: Ginger extracts and its compound, 6-shogaol, reduced pain symptoms in PDN via its effect on decreasing
TRPV1 and NMDAR2B expressions in the spinal cord, with very limited effect on pancreatic islets. | en_US |
