OPEN Foundation

Z. Oreščanin-Dušić

The Effects of Ibogaine on Uterine Smooth Muscle Contractions: Relation to the Activity of Antioxidant Enzymes

Abstract

Ibogaine is an indole alkaloid originally extracted from the root bark of the African rainforest shrub Tabernanthe iboga. It has been explored as a treatment for substance abuse because it interrupts drug addiction and relieves withdrawal symptoms. However, it has been shown that ibogaine treatment leads to a sharp and transient fall in cellular ATP level followed by an increase of cellular respiration and ROS production. Since contractile tissues are sensitive to changes in the levels of ATP and ROS, here we investigated an ibogaine-mediated link between altered redox homeostasis and uterine contractile activity. We found that low concentrations of ibogaine stimulated contractile activity in spontaneously active uteri, but incremental increase of doses inhibited it. Inhibitory concentrations of ibogaine led to decreased SOD1 and elevated GSH-Px activity, but doses that completely inhibited contractions increased CAT activity. Western blot analyses showed that changes in enzyme activities were not due to elevated enzyme protein concentrations but posttranslational modifications. Changes in antioxidant enzyme activities point to a vast concentration-dependent increase in H2O2 level. Knowing that extracellular ATP stimulates isolated uterus contractility, while H2O2 has an inhibitory effect, this concentration-dependent stimulation/inhibition could be linked to ibogaine-related alterations in ATP level and redox homeostasis.
Oreščanin-Dušić, Z., Tatalović, N., Vidonja-Uzelac, T., Nestorov, J., Nikolić-Kokić, A., Mijušković, A., … & Blagojević, D. (2018). The Effects of Ibogaine on Uterine Smooth Muscle Contractions: Relation to the Activity of Antioxidant Enzymes. Oxidative medicine and cellular longevity2018. 10.1155/2018/5969486
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Ex vivo effects of ibogaine on the activity of antioxidative enzymes in human erythrocytes

Abstract

Ethnopharmacological relevance

Ibogaine is a naturally occurring alkaloid with psychotropic and metabotropic effects, derived from the bark of the root of the West African Tabernanthe iboga plant. The tribes of Kongo basin have been using iboga as a stimulant, for medicinal purposes, and in rite of passage ceremonies, for centuries. Besides, it has been found that this drug has anti-addictive effects.

Aim of the study

Previous studies have demonstrated that ibogaine changed the quantity of ATP and energy related enzymes as well as the activity of antioxidant enzymes in cells thus altering redox equilibrium in a time manner. In this work, the mechanism of its action was further studied by measuring the effects of ibogaine in human erythrocytes in vitro on ATP liberation, membrane fluidity and antioxidant enzymes activity.

Materials and methods

Heparinized human blood samples were incubated with ibogaine (10 and 20 μM) at 37°C for 1 h. Blood plasma was separated by centrifugation and the levels of ATP and uric acid were measured 10 min after the addition of ibogaine using standard kits. The activity of copper–zinc superoxide dismutase (SOD1), catalase (CAT), glutathione peroxidase (GSH-Px) and glutathione reductase (GR) were measured in erythrocytes after incubation period. The stability of SOD1 activity was further tested through in vitro incubation with H2O2 and scanning of its electrophoretic profiles. Membrane fluidity was determined using an electron paramagnetic resonance spin-labelling method.

Results

Results showed that ibogaine treatment of erythrocytes in vitro increased ATP concentration in the blood plasma without changes in neither erythrocytes membrane fluidity nor uric acid concentration. Ibogaine also increased SOD1 activity in erythrocytes at both doses applied here. Treatment with 20 μM also elevated GR activity after in vitro incubation at 37 °C. Electrophoretic profiles revealed that incubation with ibogaine mitigates H2O2 mediated suppression of SOD1 activity.

Conclusion

Some of the effects of ibogaine seem to be mediated through its influence on energy metabolism, redox active processes and the effects of discrete fluctuations of individual reactive oxygen species on different levels of enzyme activities. Overall, ibogaine acts as a pro-antioxidant by increasing activity of antioxidative enzymes and as an adaptagene in oxidative distress.

Nikolić-Kokić, A., Oreščanin-Dušić, Z., Spasojević, I., Slavić, M., Mijušković, A., Paškulin, R., … & Blagojević, D. P. (2015). Ex vivo effects of ibogaine on the activity of antioxidative enzymes in human erythrocytes. Journal of ethnopharmacology, 164, 64-70. http://dx.doi.org/10.1016/j.jep.2015.01.037
Link to full text

Ex vivo effects of ibogaine on the activity of antioxidative enzymes in human erythrocytes

Abstract

Ethnopharmacological relevance

Ibogaine is a naturally occurring alkaloid with psychotropic and metabotropic effects, derived from the bark of the root of the West African Tabernanthe iboga plant. The tribes of Kongo basin have been using iboga as a stimulant, for medicinal purposes, and in rite of passage ceremonies, for centuries. Besides, it has been found that this drug has anti-addictive effects.

Aim of the study

Previous studies have demonstrated that ibogaine changed the quantity of ATP and energy related enzymes as well as the activity of antioxidant enzymes in cells thus altering redox equilibrium in a time manner. In this work, the mechanism of its action was further studied by measuring the effects of ibogaine in human erythrocytes in vitro on ATP liberation, membrane fluidity and antioxidant enzymes activity.

Materials and methods

Heparinized human blood samples were incubated with ibogaine (10 and 20 μM) at 37°C for 1 h. Blood plasma was separated by centrifugation and the levels of ATP and uric acid were measured 10 min after the addition of ibogaine using standard kits. The activity of copper–zinc superoxide dismutase (SOD1), catalase (CAT), glutathione peroxidase (GSH-Px) and glutathione reductase (GR) were measured in erythrocytes after incubation period. The stability of SOD1 activity was further tested through in vitro incubation with H2O2 and scanning of its electrophoretic profiles. Membrane fluidity was determined using an electron paramagnetic resonance spin-labelling method.

Results

Results showed that ibogaine treatment of erythrocytes in vitro increased ATP concentration in the blood plasma without changes in neither erythrocytes membrane fluidity nor uric acid concentration. Ibogaine also increased SOD1 activity in erythrocytes at both doses applied here. Treatment with 20 μM also elevated GR activity after in vitro incubation at 37 °C. Electrophoretic profiles revealed that incubation with ibogaine mitigates H2O2 mediated suppression of SOD1 activity.

Conclusion

Some of the effects of ibogaine seem to be mediated through its influence on energy metabolism, redox active processes and the effects of discrete fluctuations of individual reactive oxygen species on different levels of enzyme activities. Overall, ibogaine acts as a pro-antioxidant by increasing activity of antioxidative enzymes and as an adaptagene in oxidative distress.

Nikolić-Kokić, A., Oreščanin-Dušić, Z., Spasojević, I., Slavić, M., Mijušković, A., Paškulin, R., … & Blagojević, D. P. (2015). Ex vivo effects of ibogaine on the activity of antioxidative enzymes in Human erythrocytes. Journal of ethnopharmacology. http://dx.doi.org/10.1016/j.jep.2015.01.037
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30 April - Q&A with Rick Strassman

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