Acute/Chronic Pain Relief: Is Althaea officinalis Essential Oil Effective?

Background: The Althaea officinalis (marshmallow) plant is traditionally used to treat skin burns and constipation and to reduce inflammation. Objectives: The aim of this study was to evaluate the acute and chronic analgesic effects of the essential oil of Althaea officinalis leaves (EOAO) in adult male mice. Materials and Methods: This experimental study used thirty-six adult male mice, which were randomly divided into six groups: a control, three groups treated with EOAO (18, 38, or 80 mg/kg, i.p.), a morphine group (1 mg/kg, i.p.), and a group treated with a combination of naloxone (1 mg/kg, i.p.) and 80 mg/kg EOAO. The analgesic effects of EOAO were evaluated by writhing, tail-flick, and formalin tests. The essential oil of the plant was prepared by the steady distillation method and its composition was analyzed by GC/MS. Results: Significant antinociceptive effects were noted with doses of 38 and 80 mg/kg EOAO in the chronic phase response of the formalin test (P < 0.05 versus control). Doses of 38 and 80 mg/kg EOAO had a significant analgesic effect in the writhing test (P < 0.05 and P < 0.01, respectively, versus control). The 80 mg/kg dose of EOAO caused an enhancement in reaction time in the tail-flick test (P < 0.01 versus control). Conclusions: EOAO showed an analgesic effect that may involve both the central and peripheral nervous systems.