TY - JOUR
T1 - Neuroprotective effect of L-theanine in a rat model of chronic constriction injury of sciatic nerve-induced neuropathic pain
AU - Chen, Shu Mei
AU - Wang, Mao Hsien
AU - Soung, Hung Sheng
AU - Tseng, Hsiang Chien
AU - Fang, Chih Hsiang
AU - Lin, Yi Wen
AU - Yang, Chih Chuan
AU - Tsai, Cheng Chia
N1 - Funding Information:
This study was supported by the Mackay Memorial Hospital ( MMH-107-89 ). The authors thank Persistent BioMed Editing services located in Philadelphia, U.S.A. for their valuable editing and proof-reading of the current manuscript.
Publisher Copyright:
© 2021 Formosan Medical Association
PY - 2022/4
Y1 - 2022/4
N2 - Background/purpose: We investigated the protective efficacy of L-theanine (LT), the major amino acid components of green tea, on chronic constriction injury (CCI) of sciatic nerve-induced neuropathic pain (NP) development and neuronal functional changes in rats. Methods: Rats with NP induced by CCI of the left sciatic nerve and sham-operated rats received LT or saline solution, with pain sensitive tests of thermal hyperalgesia and mechanical allodynia. Motor and sensory nerve conduction velocities were measured after surgery. Subsequently, the rats were sacrificed; the sciatic nerve was excised, homogenized, prepared and subjected for estimation of nitric oxide (NO), malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), myeloperoxidase (MPO), and caspase-3. Results: CCI produced a significant increase in hyperalgesia and allodynia, an increase in SFI, a decrease in nerve conduction velocity, increases in NO, MDA, TNF-α, IL-1β, IL-6, MPO, and caspase-3 levels, as well as reduction of GSH, SOD, and CAT in the rat sciatic nerve. LT treatment significantly and dose-dependently alleviated CCI-induced nociceptive pain thresholds and ameliorated abnormal nerve conduction and functional loss in rats with CCI. Moreover, LT treatment reduced NO and MDA levels, increased antioxidative strength, and markedly suppressed the levels of neuroinflammatory and apoptotic markers in injured sciatic nerves. Conclusion: This is the first report on the ameliorative effect of LT in CCI-induced NP in rats. This effect might be attributed to its anti-oxidative, anti-inflammatory, anti-apoptotic, and neuroprotective, thus making it potentially useful as an adjuvant to conventional treatment.
AB - Background/purpose: We investigated the protective efficacy of L-theanine (LT), the major amino acid components of green tea, on chronic constriction injury (CCI) of sciatic nerve-induced neuropathic pain (NP) development and neuronal functional changes in rats. Methods: Rats with NP induced by CCI of the left sciatic nerve and sham-operated rats received LT or saline solution, with pain sensitive tests of thermal hyperalgesia and mechanical allodynia. Motor and sensory nerve conduction velocities were measured after surgery. Subsequently, the rats were sacrificed; the sciatic nerve was excised, homogenized, prepared and subjected for estimation of nitric oxide (NO), malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), myeloperoxidase (MPO), and caspase-3. Results: CCI produced a significant increase in hyperalgesia and allodynia, an increase in SFI, a decrease in nerve conduction velocity, increases in NO, MDA, TNF-α, IL-1β, IL-6, MPO, and caspase-3 levels, as well as reduction of GSH, SOD, and CAT in the rat sciatic nerve. LT treatment significantly and dose-dependently alleviated CCI-induced nociceptive pain thresholds and ameliorated abnormal nerve conduction and functional loss in rats with CCI. Moreover, LT treatment reduced NO and MDA levels, increased antioxidative strength, and markedly suppressed the levels of neuroinflammatory and apoptotic markers in injured sciatic nerves. Conclusion: This is the first report on the ameliorative effect of LT in CCI-induced NP in rats. This effect might be attributed to its anti-oxidative, anti-inflammatory, anti-apoptotic, and neuroprotective, thus making it potentially useful as an adjuvant to conventional treatment.
KW - -theanine
KW - Apoptosis
KW - Chronic constriction injury
KW - Inflammation
KW - Neuropathic pain
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U2 - 10.1016/j.jfma.2021.08.023
DO - 10.1016/j.jfma.2021.08.023
M3 - Article
C2 - 34531102
AN - SCOPUS:85114917587
SN - 0929-6646
VL - 121
SP - 802
EP - 814
JO - Journal of the Formosan Medical Association
JF - Journal of the Formosan Medical Association
IS - 4
ER -