Effects of concomitant administration of Processed Shilajit (PS, 0.1 and 1
mg/kg, i.p.), in Swiss mice were evaluated on the development of tolerance
to morphine induced analgesia in the hot plate test. Chronic administration
of morphine (10 mg/kg, i.p,, b.i.d.) to mice over a duration of 10 days re
sulted in the development of tolerance to the analgesic effect of morphine.
Concomitant administration of PS with morphine, from day 6 to day 10, resu
lted in a significant inhibition of the development of tolerance to morphin
e (10 mg/kg, i.p.) induced analgesia. Processed Shilajit per se, in the dos
es used, did not elicit any significant analgesia in mice; nor did the chro
nic concomitant administration of Processed Shilajit alter the morphine-ind
uced analgesia, These findings with Processed Shilajit indicate its potenti
al as a prospective modifier of analgesic tolerance to morphine. Copyright
(C) 2001 John Wiley & Sons, Ltd.