In Guadeloupe, epidemiological data have linked atypical parkinsonism with fruit and herbal teas from plants of the Annonaceae family, particularly Annona muricata. These plants contain a class of powerful, lipophilic complex I inhibitors, the annonaceous acetogenins. To determine the neurotoxic potential of these substances, we administered annonacin, the major acetogenin of A. muricata, to rats intravenously with Azlet osmotic minipumps (3.8 and 7.6 mg per kg per day for 28 days). Annonacin inhibited complex I in brain homogenates in a concentration-dependent manner, and, when administered systemically, entered the brain parenchyma, where it was detected by matrix-associated laser desorption ionization -time of flight mass spectrometry, and decreased brain ATP levels by 44%. In the absence of evident systemic toxicity, we observed neuropathological abnormalities in the basal ganglia and brainstem nuclei. Stereological cell counts showed significant loss of dopaminergic neurones in the substantia nigra () 31.7%), and cholinergic () 37.9%) and dopamine and cyclic AMP-regulated phosphoprotein (DARPP-32)-immunoreactive GABAergic neurones () 39.3%) in the striatum, accompanied by a significant increase in the number of astrocytes (35.4%) and microglial cells (73.4%). The distribution of the lesions was similar to that in patients with atypical parkinsonism. These data are compatible with the theory that annonaceous acetogenins, such as annonacin, might be implicated in the aetiology of Guadeloupean parkinsonism and support the hypothesis that some forms of parkinsonism might be induced by environmental toxins.

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Atypical parkinsonism in Guadeloupe has been associated with the consumption of fruit and infusions or decoctions prepared from leaves of Annona muricata L. (Annonaceae), which contains annonaceous acetogenins, lipophilic inhibitors of complex I of the mitochondrial respiratory chain. We have determined the concentrations of annonacin, the major acetogenin in A. muricata, in extracts of fruit and leaves by matrix-assisted laser desorption-ionization mass spectrometry. An average fruit is estimated to contain about 15 mg of annonacin, a can of commercial nectar 36 mg, and a cup of infusion or decoction 140 microg. As an indication of its potential toxicity, an adult who consumes one fruit or can of nectar a day is estimated to ingest over 1 year the amount of annonacin that induced brain lesions in rats receiving purified annonacin by intravenous infusion.

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Summary :The active compounds obtained from some medicinal plants used traditionally worldwide for the treatment of leishmaniasis are reviewed. Among these active molecules described in recent literature are quinoline alkaloids such as alkyl-2 quinoline and aryl-2 quinoline from Galipea longiflora, isoquinoline alkaloids such as isoguattouregidine from Guatteria foliosa, indole alkaloids such as conodurine and gabunine from Pescheiera van heurkii, terpenes such as jatrogrossidione from Jatropha grossidentata, acetogenins such as senegalene from Annona senegalensis and lignans such as (+)nyasol from Asparagus africanus. Other natural compounds with antileishmanial activity are coumarins, chalcones, lactones, tetralones and saponins. Some of them are known antiprotozoal natural products. These compounds could be used as templates to discover new and effective drugs against leishmaniasis.KEY WORDS : antileishmanial, leishmaniasis, natural products, alkaloids, terpenes, quinones, coumarins, chalcones, acetogenins, lactone, lignan. Résumé : DONNÉES RÉCENTES SUR LES COMPOSÉS ACTIFS DE PLANTES MÉDICINALES UTILISÉES DANS LE TRAITEMENT DE LA LEISHMANIOSE

Phytochemical investigation of roots of Annona muricata led to the identification of seven mono-tetrahydrofuran (mono-THF) acetogenins. Six new acetogenins having the unusual cis-configuration of the THF ring, cis-solamin (1), cis-panatellin (2), cis-uvariamicin IV (3), cis-uvariamicin I (4), cis-reticulatacin (5), and cis-reticulatacin-10-one (6) were identified, in addition to a known compound, solamin.

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