Chemical constituents and evaluation of antiproliferative and anti-inflammatory activities from Psychotria schlechtendaliana (Rubiaceae)

Phytochemical study of Psychotria schlechtendaliana (Rubiaceae) aerial parts resulted in the isolation of alkaloids 4-N-oxide harmane (1) and strictosidinic acid (2), and the terpenoids sitosterol, estigmasterol, α-amyrin, β-amyrin and betulinic acid. The crude extract (CE), its fractions (hexane FH, chloroform FC, ethyl acetate FEA, hydromethanolic FHM, alkaloidal chloroform FCOH, alkaloidal aqueous FAq) and majority alkaloid (1) were investigated for their antiproliferative potential against nine human tumor cells lines and one non-tumoral human cell line (HaCat). CE, FH and FEA fractions exhibited strong growth inhibition for ovary cells (OVCAR-3, GI₅₀ = 5.89; 1.36 and 6.59 μg mL^-1, respectively) and FC, FH and FAq fractions showed potent activity on the growth of leukemia cell lines (K562, GI₅₀ = 1.92; 7.23 and 8.81 μg mL^-1, respectively). Compound 1 exhibited selective antiproliferative activity to breast cancer (MCF-7, GI₅₀ = 32.7 μg mL^-1) and was non-toxic to HaCat cells. To evaluate the anti-inflammatory effect, models of ear edema induced by croton oil and the enzyme myeloperoxidase (MPO) were used. FH and FC fractions exhibited antiinflammatory effect and reduce ear edema compared to the control group. These fractions showed results superior to those exhibited by indomethacin (75.1%), FH (97.5%) and FC (95.5%) fractions. (author)