Abstract:
In Sri Lankan folk medicine, seeds of Mucuna
prurita (Hook) (Family: Leguminosae) are recommended to
be consumed as a curry ingredient to relieve aches and
pains. The seeds contain large quantities of dopa and nicotine.
Thus it is possible that they have antinociceptive and
perhaps also sedative activities. The aim of this study was to
investigate these possibilities. A powdered seed suspension
(PSS) of the seeds was made in 1% methyl cellulose.
Different doses (750, 1,500 or 3,000 mg/kg) or vehicle were
administered orally to male rats and the mid dose to female
rats. 3 h later, analgesic potential (using hot plate and tail
flick tests) and sedative potential (only with mid dose, and
male rats, using the rat hole-board technique) were determined.
A l l three doses were well tolerated and significantly
{P < 0.05) increased both the reaction time and % maximum
possible effect in hot plate test, indicating potent antinociception
mediated supraspinally. In contrast, no analgesic
activity was evident in the tail flick test. These effects were
dose-reiated and not blocked by naloxone, an opioid receptor
blocker. The mid dose caused only mild sedation.
Further, in the females, the mid dose exhibited potent analgesia,
as in males. This was not affected by the stage of the
oestrous cycle. In addition, the treatment did not alter
intestinal transit, muscle strength (as judged by a bar holding
test) or muscle co-ordination (evaluated by bridge test).
We conclude that antinociception of M. prurita seeds is not
mediated by the opioid mechanism but possibly via
dopamine and nicotine.
