Abstract
The dried aqueous extract of Harpagophytum procumbens (Pedaliaceae) and its main iridoid glycoside, harpagoside, have been evaluated for
anti-inflammatory and analgesic effects in mice and rats, in order to validate or
invalidate the involvement of this compound in such properties. This extract exerted
significant and dose-dependent anti-inflammatory and analgesic effects, from the dose
100 mg of dried secondary roots/kg, the first being obtained on an acute inflammatory
process (carrageenan-induced edema test in rats) and the second being obtained against
a chemical stimulus (writhing test in mice). Harpagoside does not appear to be involved
in anti-inflammatory properties, since this iridoid glycoside did not protect against
carrageenan inflammatory effects when it was used at 5 and 10 mg/kg; 5 mg corresponding
to the quantity contained in 400 mg of dried secondary roots. The main iridoid glycoside
of H. procumbens appears to be implicated in the peripheral analgesic properties of this species,
but other compounds have to be involved, since the dose of 10 mg/kg exerted a significant
protective effect.
The absence of the activity of H. procumbens after an acid treatment (0.1 N hydrochloric acid), similar to the physio-chemical
conditions found in the stomach, suggests the use of a suitable galenic preparation
in order to protect the active principles from the action of the acid released in
the stomach.
Key words
Harpagophytum procumbens
- harpagoside - anti-inflammatory activity - analgesic activity
