Antimycobacterial activity and alkaloid prospection of Psychotria species (Rubiaceae) from the Brazilian Atlantic Rainforest.
Ten Psychotria species were collected in two fragments of Atlantic Forest in Rio de Janeiro: Psychotria pubigera (P1A and B), P. ruelliifolia (P2), P. suterela (P3), P. stachyoides (P4), P. capitata (P5), P. glaziovii (P6), P. leiocarpa (P7), P. nuda (P8), P. racemosa (P9) and P. vellosiana (P10). Ethanol extracts 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 tuberculosis, 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 production 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 expression. In addition, cytotoxicity was tested in the macrophages (the host cells of the Mycobacterium) and it was verified that the extracts selectively 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 detected 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.
Laboratório de Biologia Celular e Tecidual, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, RJ, Brazil.
Tarsila Maria da Silva
TM
Moraes
Marlon Heggdorne
MH
de Araújo
Natália R
NR
Bernardes
Daniela B
DB
de Oliveira
Elena B
EB
Lasunskaia
Michelle Frazão
MF
Muzitano
Maura
M
Da Cunha
D000470:Alkaloids / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D000893:Anti-Inflammatory Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D000995:Antitubercular Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D001938:Brazil; D045744:Cell Line, Tumor; D007211:Indoles / Q000737:chemistry; D020128:Inhibitory Concentration 50; D008264:Macrophages / Q000187:drug effects; D051379:Mice; D009161:Mycobacterium / Q000187:drug effects; D009569:Nitric Oxide / Q000378:metabolism; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry; D032069:Psychotria / Q000737:chemistry*; D014376:Tuberculosis
D000470:Alkaloids; D000900:Anti-Bacterial Agents; D000893:Anti-Inflammatory Agents; D000975:Antioxidants; D000995:Antitubercular Agents; D007211:Indoles; D010936:Plant Extracts; D009569:Nitric Oxide