Brain research
March 28, 1997
H N Bhargava, Y J Cao, G M Zhao
19 citations
Ibogaine, a compound from the African shrub Tabernanthe iboga, did not alter pain relief (antinociception) produced by morphine, U-50,488H, or DPDPE in male Swiss-Webster mice when given 10 minutes before these opioids. Ibogaine alone had no effect on pain sensitivity. However, its metabolite noribogaine enhanced morphine's pain-relieving effect at doses of 40 and 80 mg/kg, particularly with a lower morphine dose (5 mg/kg). Noribogaine did not affect pain relief from U-50,488H or DPDPE. The authors conclude that ibogaine's reported ability to reduce drug self-administration likely does not involve direct interaction with multiple opioid receptors, but its metabolite noribogaine may interact with mu-opioid receptors to enhance morphine's effects.
Brain research
March 28, 1997
Y J Cao, H N Bhargava
18 citations
Ibogaine, a compound from the African shrub Tabernanthe iboga, selectively blocks the development of tolerance to morphine's pain-relieving effect in male Swiss-Webster mice. Mice given morphine, U-50,488H, or DPDPE (agonists for mu-, kappa-, and delta-opioid receptors, respectively) twice daily for four days became tolerant to these drugs' antinociceptive effects. Ibogaine at 40 or 80 mg/kg, given before each morphine injection, prevented tolerance to morphine, but 20 mg/kg did not. Ibogaine did not affect tolerance to kappa- or delta-receptor agonists at any dose. The results suggest ibogaine specifically inhibits tolerance to mu-opioid receptor agonists.
Pharmacology
November 1, 1998
S Sunder Sharma, H N Bhargava
17 citations
In male Swiss-Webster mice, ibogaine and its metabolite noribogaine enhanced morphine's pain-relieving effect in animals that had developed tolerance to morphine, but not in those that had never received morphine. Tolerance was induced by implanting a 25 mg morphine pellet for three days. Both compounds dose-dependently increased morphine antinociception only in morphine-tolerant mice, suggesting they may help restore opioid effectiveness in tolerant states.
Pharmacology
June 1, 1995
R V House, P T Thomas, H N Bhargava
12 citations
Indole alkaloids ibogaine and harmaline suppress several immune functions in a dose-dependent manner in laboratory tests. At high concentrations (10–100 μmol/L), both compounds reduced T-cell regulatory and effector activity, B-cell function, and natural killer-cell function. Macrophage function was not affected. The suppression was observed across multiple assays, suggesting a broad immunomodulatory effect at elevated doses.