Yoshihiko Nakatani1, Kanako Negoro2, Miki Yamauchi3, Maki Katasho4, Kei-Ichiro Ishikura5, Anna Iwaki6, Kazuyo Tsukada7, Marina Yamaguchi8, Arata Uehara9, Masato Yoshida10, Kan'ichiro Ishiuchi11, Toshiaki Makino12, Masaki Kitajima13, Masahiro Ohsawa14, Taku Amano15. 1. Department of Pharmacotherapeutics, School of Pharmacy, International University of Health and Welfare, 2600-1 Kitakanemaru, Ohtawara, Tochigi, 324-8501, Japan; Advanced Education and Research Center for Kampo Medicine, International University of Health and Welfare, 2600-1 Kitakanemaru, Ohtawara, Tochigi, 324-8501, Japan. Electronic address: ynakatani@iuhw.ac. 2. Department of Pharmacotherapeutics, School of Pharmacy, International University of Health and Welfare, 2600-1 Kitakanemaru, Ohtawara, Tochigi, 324-8501, Japan. Electronic address: goronekanako@gmail.com. 3. Department of Pharmacotherapeutics, School of Pharmacy, International University of Health and Welfare, 2600-1 Kitakanemaru, Ohtawara, Tochigi, 324-8501, Japan. Electronic address: sw_clover_en@icloud.com. 4. Department of Pharmacotherapeutics, School of Pharmacy, International University of Health and Welfare, 2600-1 Kitakanemaru, Ohtawara, Tochigi, 324-8501, Japan. Electronic address: prism_ksgh@icloud.com. 5. Department of Neuropharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, 467-8603, Japan. Electronic address: c162703@ed.phar.nagoya-cu.ac.jp. 6. Department of Neuropharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, 467-8603, Japan. Electronic address: c182704@ed.phar.nagoya-cu.ac.jp. 7. Department of Pharmacotherapeutics, School of Pharmacy, International University of Health and Welfare, 2600-1 Kitakanemaru, Ohtawara, Tochigi, 324-8501, Japan. Electronic address: 1031145@g.iuhw.ac.jp. 8. Department of Pharmacotherapeutics, School of Pharmacy, International University of Health and Welfare, 2600-1 Kitakanemaru, Ohtawara, Tochigi, 324-8501, Japan. Electronic address: 1231179@g.iuhw.ac.jp. 9. Department of Neuropharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, 467-8603, Japan. Electronic address: 1331023@g.iuhw.ac.jp. 10. Department of Pharmacognosy, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, 467-8603, Japan. Electronic address: vxv.be3al2si6o18.licht@gmail.com. 11. Department of Pharmacognosy, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, 467-8603, Japan. Electronic address: ishiuchi@phar.nagoya-cu.ac.jp. 12. Department of Pharmacognosy, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, 467-8603, Japan. Electronic address: makino@phar.nagoya-cu.ac.jp. 13. International University of Health and Welfare, Tokyo Office, Amity-Nogizaka-BIdg 1-24-1 Minamiaoyama, Minato-ku, Tokyo, 107-0062, Japan. 14. Department of Neuropharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, 467-8603, Japan. Electronic address: ohsawa@phar.nagoya-cu.ac.jp. 15. Department of Pharmacotherapeutics, School of Pharmacy, International University of Health and Welfare, 2600-1 Kitakanemaru, Ohtawara, Tochigi, 324-8501, Japan; Advanced Education and Research Center for Kampo Medicine, International University of Health and Welfare, 2600-1 Kitakanemaru, Ohtawara, Tochigi, 324-8501, Japan. Electronic address: amano-pharmacothera@iuhw.ac.jp.
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE: Goshajinkigan (GJG), a traditional Japanese Kampo formula, has been shown to exhibit several pharmacological actions, including antinociceptive effects. Processed aconite root (PA), which is considered to be an active ingredient of GJG, has also been demonstrated to have an ameliorative effect on pain, such as diabetic peripheral neuropathic pain. We recently identified neoline as the active ingredient of both GJG and PA that is responsible for its effects against oxaliplatin-induced neuropathic pain in mice. AIM OF THE STUDY: In the present study, we investigated whether GJG, PA, and neoline could inhibit Nav1.7 voltage-gated sodium channel (VGSC) current and whether neoline could ameliorate mechanical hyperalgesia in diabetic mice. MATERIALS AND METHODS: To assess the electrophysiological properties of GJG extract formulation, powdered PA, and neoline on Nav1.7 VGSCs, whole-cell patch clamp recording was performed using human HEK293 cells expressing Nav1.7 VGSCs. In addition, the ameliorative effects of neoline on diabetic peripheral neuropathic pain were evaluated using the von Frey test in streptozotocin (STZ)-induced diabetic model mice. RESULTS: GJG extract formulation significantly inhibited Nav1.7 VGSC peak current. Powdered PA also inhibited Nav1.7 VGSC peak current. Like GJG and PA, neoline could inhibit Nav1.7 VGSC current. When diabetic mice were treated with neoline by intraperitoneal acute administration, the mechanical threshold was increased in diabetic mice, but not in non-diabetic mice, in a behavioral study. CONCLUSION: These results suggest that neoline might be a novel active ingredient of GJG and PA that is one of responsible ingredients for ameliorating mechanical hyperalgesia in diabetes via the inhibition of Nav1.7 VGSC current at least.
ETHNOPHARMACOLOGICAL RELEVANCE: Goshajinkigan (GJG), a traditional Japanese Kampo formula, has been shown to exhibit several pharmacological actions, including antinociceptive effects. Processed aconite root (PA), which is considered to be an active ingredient of GJG, has also been demonstrated to have an ameliorative effect on pain, such as diabetic peripheral neuropathic pain. We recently identified neoline as the active ingredient of both GJG and PA that is responsible for its effects against oxaliplatin-induced neuropathic pain in mice. AIM OF THE STUDY: In the present study, we investigated whether GJG, PA, and neoline could inhibit Nav1.7voltage-gated sodium channel (VGSC) current and whether neoline could ameliorate mechanical hyperalgesia in diabeticmice. MATERIALS AND METHODS: To assess the electrophysiological properties of GJG extract formulation, powdered PA, and neoline on Nav1.7 VGSCs, whole-cell patch clamp recording was performed using humanHEK293 cells expressing Nav1.7 VGSCs. In addition, the ameliorative effects of neoline on diabetic peripheral neuropathic pain were evaluated using the von Frey test in streptozotocin (STZ)-induced diabetic model mice. RESULTS:GJG extract formulation significantly inhibited Nav1.7 VGSC peak current. Powdered PA also inhibited Nav1.7 VGSC peak current. Like GJG and PA, neoline could inhibit Nav1.7 VGSC current. When diabeticmice were treated with neoline by intraperitoneal acute administration, the mechanical threshold was increased in diabeticmice, but not in non-diabeticmice, in a behavioral study. CONCLUSION: These results suggest that neoline might be a novel active ingredient of GJG and PA that is one of responsible ingredients for ameliorating mechanical hyperalgesia in diabetes via the inhibition of Nav1.7 VGSC current at least.