Ginseng total saponin potentiates acute U-50,488H-induced analgesia and inhibits tolerance to U-50,488H-induced analgesia in mice.
In the present study, an attempt has been made to investigate whether the potentiating effect of U-50,488H (U50)-induced analgesia by ginseng total saponin (GTS) is playing a role in inhibiting the tolerance to U50-induced analgesia as measured using the tail-flick test in mice. GTS (100 and 200 mg/kg i.p.), on acute administration, potentiated the U50 (40 mg/kg i.p.)-induced analgesia in U50-naive mice. Twice daily administration of U50 (40 mg/kg i.p.) for 6 days resulted in tolerance to U50-induced analgesia in mice. Chronic administration (Days 4-6) of GTS (50, 100, and 200 mg/kg i.p.) to U50-tolerant mice dose-dependently inhibited the tolerance to U50-induced analgesia. On the other hand, chronic administration of GTS (50, 100, and 200 mg/kg i.p.) dose-dependently potentiated the U50-induced analgesia in U50-naive mice. The dose-response curve to U50-induced analgesia in U50-tolerant mice was shifted rightward (2.6-fold) as compared to U50-naive mice, indicating the development of tolerance to U50-induced analgesia. GTS (100 mg/kg i.p. o.d.), on chronic administration, prevented the rightward shift of dose-response curve to U50-induced analgesia in U50-tolerant mice, whereas in U50-naive mice it resulted in leftward shift (0.6-fold). It can be concluded that acute and chronic administration of GTS potentiates the U50-induced analgesia in U50-naive mice. The potentiating effect of GTS on U50-induced analgesia may be partially responsible in the inhibition of tolerance to U50-induced analgesia in mice.
Nemmani
Kumar V S
KV
Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research, Phase-X, Sector 67, SAS Nagar, Mohali 160 062 Pb, India.
Ramarao
Poduri
P
D019900:3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer / Q000494:pharmacology*; D018712:Analgesics, Non-Narcotic / Q000037:antagonists & inhibitors* / Q000494:pharmacology*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D004361:Drug Tolerance / Q000502:physiology; D008297:Male; D051379:Mice; D010147:Pain Measurement / Q000187:drug effects / Q000379:methods; D005894:Panax; D012503:Saponins / Q000494:pharmacology*
D018712:Analgesics, Non-Narcotic; D012503:Saponins; D019900:3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer