Distribution of ibogaine and noribogaine in a man following a poisoning involving root bark of the Tabernanthe iboga shrub.
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In the present paper, we report for the first time the tissue distribution of ibogaine and noribogaine, the main metabolite of ibogaine, in a 48-year-old Caucasian male, with a history of drug abuse, found dead at his home after a poisoning involving the ingestion of root bark from the shrub Tabernanthe iboga. Ibogaine and noribogaine were quantified in tissues and fluids using a fully validated liquid chromatography-electrospray mass spectrometry method. Apart from cardiac tissue, ibogaine and noribogaine were identified in all matrices investigated. The highest concentrations were found in spleen, liver, brain, and lung. The tissue/subclavian blood concentration ratios averaged 1.78, 3.75, 1.16, and 4.64 for ibogaine and 0.83, 2.43, 0.90, and 2.69 for noribogaine for spleen, liver, brain, and lung, respectively. Very low concentrations of the two drugs were found in the prostatic tissue. Both ibogaine and noribogaine are secreted in the bile and cross the blood-brain barrier. Four other compounds were detected in most of the studied matrices. One of them was identified as ibogamine. Unfortunately, we were not able to positively identify the other three compounds because of the unavailability of reference substances. Two of them could possibly be attributed to the following oxidation products: iboluteine and desmethoxyiboluteine. The third compound could be ibogaline. (+info)
Two fast screening methods (GC-MS and TLC-ChEI assay) for rapid evaluation of potential anticholinesterasic indole alkaloids in complex mixtures.
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Antibacterial activity of Tabernaemontana stapfiana britten (Apocynaceae) extracts.
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Antibacterial and phytochemical screening of methanolic, sequential extracts (hexane, dichloromethane, ethyl acetate and methanol) and alkaloid rich fractions of Tabernaemontana stapfiana Britten was carried out. The phytochemical screening showed the presence of alkaloids, flavonoids, coumarins, tannins and saponins that have been associated with antimicrobial activity. The stem and root bark methanolic extracts showed good activity against the bacterial strains used including the multiple drug resistant Staphylococcus aureus strain with minimum inhibitory concentrations ranging from 15.6 to 500 microg/ml and minimum bactericidal concentrations ranging from 31.25 to 500 microg/ml. The sequential extracts of the root and stem bark had high antimicrobial activity with minimum inhibitory concentrations (MICs) ranging between 3.9 and 250 microg/ml and minimum bactericidal concentrations (MBCs) ranging between 7.8 and 500 microg/ml against the tested microorganisms. The dichloromethane extract of the alkaloid rich fractions however exhibited reduced antibacterial activities as compared to methanol and sequential extracts but the dichloromethane:methanol (4:1) mixture showed high activity with MICs ranging between 15.6 and 250 microg/ml. These antibacterial efficacy studies suggest that Tabernaemontana stapfiana Britten could be a source of antibacterial agents. (+info)
Reversible acetylcholinesterase inhibitory effect of Tabernaemontana divaricata extract on synaptic transmission in rat CA1 hippocampus.
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BACKGROUND & OBJECTIVES: Acetylcholinesterase inhibitors (AChE-Is) are used for the treatment of Alzheimer's disease (AD). These drugs including galanthamine have been shown to modulate synaptic activity in hippocampus and improve memory processes. Although Tabernaemontana divaricata extract (TDE) has been used as traditional medicine for various pharmacological effects, its effect in enhancing cholinergic activity provides additional benefit to its known effects. We investigated whether TDE can modulate the synaptic function in hippocampus and compared its effects to those of galanthamine. METHODS: Hippocampal slices were prepared from male wistar rats, functional effects of TDE were characterized by using pharmacological tools and extracellular recordings of field excitatory postsynaptic potentials (fEPSPs). RESULTS: TDE significantly reduced fEPSPs. The fEPSPs reduction was prevented by atropine, but not pancuronium. These TDE effects were similar to those of galanthamine. INTERPRETATION & CONCLUSIONS: Our findings indicate that TDE can effectively modulate synaptic responses in the hippocampus similar to galanthamine, suggesting that this traditional medicine could be beneficial in ageing with ACh deprivation in the brain. (+info)
Application of preparative high-speed counter-current chromatography for the separation of two alkaloids from the roots of Tabernaemontana catharinensis (Apocynaceae).
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Prostaglandin analogous and antioxidant activity mediated gastroprotective action of Tabernaemontana divaricata (L.) R. Br. flower methanolic extract against chemically induced gastric ulcers in rats.
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