Chen-Hwan Cherng1, Kwong-Chiu Lee2, Chih-Cheng Chien3, Kuang-Yi Chou4, Yu-Che Cheng5, Shih-Tai Hsin6, Sing-Ong Lee3, Ching-Hui Shen7, Ru-Yin Tsai8, Chih-Shung Wong9. 1. Department of Anesthesiology, Tri-Service General Hospital and National Defense Medical Center, Taipei, Taiwan. 2. Department of Anesthesiology, Changhua Christian Hospital, Changhua, Taiwan. 3. Department of Anesthesiology, Cathay General Hospital, Taipei, Taiwan. 4. General Education Center, National Taipei University of Nursing and Health Sciences, Taipei, Taiwan. 5. Department of Medical Research, Cathay General Hospital, Taipei, Taiwan; Institute of Biomedical Engineering, National Central University, Jhongli, Taiwan. 6. Graduate Institute of Medical Science, National Defense Medical Center, Taipei, Taiwan. 7. Department of Anesthesiology, Veterans General Hospital, Taichung, Taiwan. 8. Department of Anesthesiology, Cathay General Hospital, Taipei, Taiwan; Department of Health Care Management, National Taipei University of Nursing and Health Sciences, Taipei, Taiwan. Electronic address: iris8084@gmail.com. 9. Department of Anesthesiology, Cathay General Hospital, Taipei, Taiwan; Department of Medical Research, Cathay General Hospital, Taipei, Taiwan; Graduate Institute of Medical Science, National Defense Medical Center, Taipei, Taiwan; School of Medicine, Fu-Jen Catholic University, New Taipei, Taiwan. Electronic address: w82556@gmail.com.
Abstract
BACKGROUND/ PURPOSE: In a recent study, we found that baicalin exhibited a potent analgesic effect on carrageenan-evoked thermal hyperalgesia. The underlining mechanisms may be associated with inhibition of inflammatory mediator overproduction, including proinflammatory cytokines, nitric oxide (NO), and prostaglandin E2 (PGE2). In the present study, we examined the effect of baicalin on the antinociceptive effect of morphine and histone deacetylase 1 (HDAC1) expression in the spinal cord dorsal horn in neuropathic pain rats. METHODS: Neuropathic pain was induced by tight ligation of the left L5 spinal nerve of the rats. An intrathecal catheter was implanted for drug administration. Nociception was assessed by using the plantar test with the Hargreaves radiant heat apparatus, and the von Frey test with the dynamic plantar anesthesiometer. Spinal cords were removed for histone acetyl-H3 and HDAC1 western blot analysis at the end of the nociceptive assessment. RESULTS: The results showed that hyperalgesia and allodynia were observed in the spinal nerve ligated (SNL) left hindlimb; it was companied by histone-H3 deacetylation and HDAC1 overexpression on the ipsilateral side of the spinal cord dorsal horn. Intrathecal injection of baicalin (10 μg) significantly attenuated the allodynia and hyperalgesia, and enhanced the antinociceptive effect of morphine (15 μg). Moreover, baicalin reversed the histone-H3 acetylation and suppressed HDAC1 expression on the ipsilateral side of the spinal cord dorsal horn of SNL rats. CONCLUSION: The present findings suggest that baicalin can ameliorate neuropathic pain by suppressing HDAC1 expression and preventing histone-H3 acetylation in the spinal cord dorsal horn of SNL rats.
BACKGROUND/ PURPOSE: In a recent study, we found that baicalin exhibited a potent analgesic effect on carrageenan-evoked thermal hyperalgesia. The underlining mechanisms may be associated with inhibition of inflammatory mediator overproduction, including proinflammatory cytokines, nitric oxide (NO), and prostaglandin E2 (PGE2). In the present study, we examined the effect of baicalin on the antinociceptive effect of morphine and histone deacetylase 1 (HDAC1) expression in the spinal cord dorsal horn in neuropathic painrats. METHODS:Neuropathic pain was induced by tight ligation of the left L5 spinal nerve of the rats. An intrathecal catheter was implanted for drug administration. Nociception was assessed by using the plantar test with the Hargreaves radiant heat apparatus, and the von Frey test with the dynamic plantar anesthesiometer. Spinal cords were removed for histone acetyl-H3 and HDAC1 western blot analysis at the end of the nociceptive assessment. RESULTS: The results showed that hyperalgesia and allodynia were observed in the spinal nerve ligated (SNL) left hindlimb; it was companied by histone-H3 deacetylation and HDAC1 overexpression on the ipsilateral side of the spinal cord dorsal horn. Intrathecal injection of baicalin (10 μg) significantly attenuated the allodynia and hyperalgesia, and enhanced the antinociceptive effect of morphine (15 μg). Moreover, baicalin reversed the histone-H3 acetylation and suppressed HDAC1 expression on the ipsilateral side of the spinal cord dorsal horn of SNL rats. CONCLUSION: The present findings suggest that baicalin can ameliorate neuropathic pain by suppressing HDAC1 expression and preventing histone-H3 acetylation in the spinal cord dorsal horn of SNL rats.