Search of anti-allodynic compounds from Plantaginis Semen, a crude drug ingredient of Kampo formula “Goshajinkigan”

AbstractChemotherapy-induced peripheral neuropathy (CIPN) is one of the dose-limiting side effects of cancer chemotherapy. Although the control of CIPN is important, it is difficult to manage with currently available therapeutic drugs. Therefore, there is a need for novel therapeutic agents for treating CIPN. Goshajinkigan (GJG) is a Kampo formula composed of ten crude drugs. While GJG has been used for the treatment of CIPN, the active constituents of GJG and their underlying mechanisms of pharmacological effects are still unknown. Our previous study revealed that repetitive oral administration of the water extract of Plantaginis Semen, a crude drug ingredient of GJG, inhibited the mechanical allodynia induced by an intraperitoneal injection of paclitaxel in mice. To elucidate the active compounds of Plantaginis Semen, activity-guided separation of the water extract of Plantaginis Semen was performed. From the active fraction, four iridoids (1–4) were identified. Repetitive oral administration of aucubin (1) at 100 or 30  mg/kg and 100 mg/kg of the fractioncrude 3 [primarily comprised of pedicularis-lactone (3)], showed anti-allodynic activity, suggesting1 and3 could be some of the active compounds responsible for the anti-allodynic property of Plantaginis Semen and GJG. Our study establishes that oral administration of1 has potent anti-allodynic effect in addition to the activity of intraperitoneally administered1 reported previously. Identification of active anti-allod...
Source: Journal of Natural Medicines - Category: Drugs & Pharmacology Source Type: research