Introduction ! Psychotria L. is comprised of approximately 2000 species that are found in tropical and subtropical rain forests [1]. The genus, which belongs to the Rubiaceae family, is taxonomically complex. Based on morphology and biogeography, it is di- vided into three subgenera: Psychotria (pantropi- cal), Tetramerae (some species from Africa and Madagascar), and Heteropsychotria (neotropical species) [2]. However, morphological, phyto- chemical, and molecular similarities between species of the subgenus Heteropsychotria and of the genera Palicourea and Rudgea suggest that these taxa should be placed in a new genus [3]. Studies about the chemistry of Psychotria have helped establish new limits for the genus, which is known for its synthesis of bioactive alkaloids. The main metabolites found in pantropical spe- cies of Psychotria (subgenus Psychotria) are poly- indole alkaloids [4]. Monoterpenoid indole alka- loids have been found in the neotropical species, and most of these alkaloids contain a glucoside residue that is unique compared to other mono- terpene alkaloids (e.g., [5, 6]). Several species of Psychotria show biological ac- tivity by presenting different types of secondary metabolites, especially alkaloids. Psychotria ipe- cacuanha is a medicinal plant of the understory of forests that is a powerful emetic and amebicide [7]. Psychotria viridis is used in religious rituals, where it is an ingredient in the hallucinogenic drink called ayahuasca [8]. Some species, such as P. beccarioides, P. forsteriana, and P. olenoides, bio- synthesize highly cytotoxic alkaloids [9, 10]. Other pharmacological effects have also been reported for some species, such as the following: anti-in- flammatory and antipyretic efficacies, and anal- gesic activity [11, 12]; inhibition of platelet aggre- gation [13]; antidepressant, anxiolytic, and anti- psychotic activities [14]; antioxidant and anti- Abstract ! Ten Psychotria species were collected in two frag- ments of Atlantic Forest in Rio de Janeiro: Psycho- tria pubigera (P1A and B), P. ruelliifolia (P2), P. su- terela (P3), P. stachyoides (P4), P. capitata (P5), P. glaziovii (P6), P. leiocarpa (P7), P. nuda (P8), P. racemosa (P9) and P. vellosiana (P10). Ethanol ex- tracts of these species were evaluated for their antimycobacterial activity, in an attempt to find new antituberculosis agents. Psychotria pubigera (P1A), P. ruelliifolia (P2) and P. stachyoides (P4) were the most active against Mycobacterium. The anti-inflammatory potential of these extracts was also evaluated in vitro to learn if they inhibit nitric oxide (NO) production in macrophages and if they have free-radical scavenging properties, because inflammation is a severe problem caused by tu- berculosis, especially when the infection is from M. bovis or M. tuberculosis. Psychotria suterela (P3), P. stachyoides (P4) and P. capitata (P5) were the most active in inhibiting macrophage NO pro- duction but they were not the most antioxidant species. This suggests that NO inhibitory activity is not due to the scavenging of NO generated but due to a specific inhibition of iNOS activity or ex- pression. In addition, cytotoxicity was tested in the macrophages (the host cells of the Mycobacte- rium) and it was verified that the extracts selec- tively killed the bacteria and not the host cells. When analyzing antimycobacterial, cytotoxicity and NO inhibitory activities in combination, P. stachyoides (P4) was the most promising anti-TB extract tested. Further, indol alkaloids were de- tected in P. suterela and P. nuda, and 5,6-dihydro- β-carboline alkaloids in all of the species studied, with the highest amounts found in P. capitata and P. racemosa. Antimycobacterial Activity and Alkaloid Prospection of Psychotria Species (Rubiaceae) from the Brazilian Atlantic Rainforest Authors Tarsila Maria da Silva Moraes 1 , Marlon Heggdorne de Araújo 2,3 , Natália R. Bernardes 2 , Daniela B. de Oliveira 3 , Elena B. Lasunskaia 2 , Michelle Frazão Muzitano 2, 4 , Maura Da Cunha 1 Affiliations The affiliations are listed at the end of the article Key words l " Psychotria (Rubiaceae) l " alkaloids l " Mycobacterium bovis l " anti‑inflammatory l " antioxidant l " tuberculosis received August 23, 2010 revised Dec. 1, 2010 accepted Dec. 3, 2010 Bibliography DOI http://dx.doi.org/ 10.1055/s-0030-1250656 Published online January 17, 2011 Planta Med 2011; 77: 964–970 © Georg Thieme Verlag KG Stuttgart · New York · ISSN 0032‑0943 Correspondence Prof. Dr. Maura Da Cunha Laboratório de Biologia Celular e Tecidual Centro de Biociências e Biotecnologia Universidade Estadual do Norte Fluminense Av. Alberto Lamego, 2000 CEP 28013-602 Campos dos Goytacazes Brazil Phone: + 55 22 27 39 72 63 Fax: + 55 22 27 39 71 78 maurauenf@gmail.com Correspondence Prof. Dr. Michelle Frazão Muzitano Faculdade de Farmácia, Campus Macaé Universidade Federal do Rio de Janeiro R. Aluísio da Silva Gomes, 50 CEP 27930-560 Macaé, RJ Brazil Phone: + 55 22 27 96 25 39 Fax: + 55 22 27 96 25 39 mfmuzitano@yahoo.com.br 964 Moraes TMS et al. Antimycobacterial Activity and … Planta Med 2011; 77: 964–970 Original Papers