Antitumoral and Anticholinesterasic Activities of the Seven Species from Rubiaceae

Background: The genus Psychotria and Palicourea are reported as a source of alkaloids and iridoids, which exhibit biological activities. This study aimed to evaluate antiproliferative and anticholinesterase activities and quantification of the alkaloids of seven species among the genus found in Mato Grosso do Sul region in Brazil. Methods: Concentrations of alkaloids were measured spectrophotometrically. The extracts were submitted to antiproliferative activity against ten cell lines. The anticholinesterase activity of the extracts was developed using brain structures of male Wistar rats: cerebral cortex, hippocampus, hypothalamus and striatum by the Ellman method. Results: Alkaloids from Psychotria and Palicourea species were quantified which showed values of 47.6 to 21.9 µg/g. Regarding the antiproliferative potential, Palicourea crocea demonstrated selectivity against the 786-0 cell line (GI50: 22.87 µg/mL). Psychotria leiocarpa inhibited cell growth against OVCAR-3 (GI50: 3.28 µg/mL), K-562 (GI50: 5.26 µg/mL), HaCaT (GI50: 27.20 µg/mL), PC-3 (GI50: 34.92 µg/mL), MCF-7 (GI50: 35.80 µg/mL) and P. capillacea showed activity against OVCAR-3 (GI50: 2.33 µg/ml) and U251 (GI50: 16.66 µg/ml). The effect of acetylcholinesterase inhibition was more effective in the hippocampus, demonstrating inhibition for Paliourea crocea, Psychotria deflexa, P. brachybotrya and P. leiocarpa of 70%, 57%, 50% and 40%, respectively, followed by P. poeppigiana and P. capillacea, inhibiting 21%, compared to the control. Conclusion: Herein, the present work showed for the first time, anticholinesterasic and antiproliferative activities of extracts of Palicourea and Psychotria seem to be mainly associated with the levels of alkaloids in the leaves of these species.