HPLC-Based Activity Profiling for Antiprotozoal Compounds in Croton gratissimus and Cuscuta hyalina

Abstract

In a screening of Sudanese medicinal plants for antiprotozoal activity, the chloroform fractions obtained by liquid-liquid partitioning from ethanolic extracts of fruits of Croton gratissimus var. gratissimus and stems of Cuscuta hyalina Roth ex Schult. exhibited in vitro activity against axenically grown Leishmania donovani amastigotes. This antileishmanial activity was localized by HPLC-based activity profiling. Targeted preparative isolation afforded flavonoids 1-6, 3methoxy-4-hydroxybenzoic acid (7), and benzyltetrahydroisoquinoline alkaloids laudanine (8) and laudanosine (9) from C. gratissimus, and pinoresinol (10), isorhamnetin (11), (-)-pseudosemiglabrin (12), and kaempferol (13) from C. hyalina. The antiprotozoal activity of 1-13 against L. donovani (axenic and intracellular amastigotes), Trypanosoma brucei rhodesiense (bloodstream forms), and Plasmodium falciparum (erythrocytic stages), and the cytotoxicity in L6 murine myoblast cells were determined in vitro. Quercetin-3,7-dimethylether (6) showed the highest activity against axenic L.

Critical Antileishmanial in vitro Effects of Highly Examined Gold Nanoparticles

“… 50 Furthermore, the IC 50 values for intramacrophagic amastigotes have been reported to be much higher than those for the axenic amastigotes. 34 , 35 …”

“…50 Furthermore, the IC 50 values for intramacrophagic amastigotes have been reported to be much higher than those for the axenic amastigotes. 34,35 In this study, we synthesized and characterized citratestabilized GNP and assessed its potential as an antileishmanial agent in vitro against L. donovani. The GNP showed a strong surface plasmon band at 520 nm that falls in the visible range, thus confirming the synthesis of nanoparticles.…”

“…Macrophage-infected amastigotes are a more elaborate and physiologic model for drug testing compared to axenic amastigotes. 34 , 35 Moreover, activity against axenic amastigotes does not always correlate with efficacy against the parasite in its intracellular niche. 34 …”

“…Macrophage-infected amastigotes are a more elaborate and physiologic model for drug testing compared to axenic amastigotes. 34,35 Moreover, activity against axenic amastigotes does not always correlate with efficacy against the parasite in its intracellular niche. 34 Furthermore, in earlier studies, side effects were observed against peritoneal macrophages harvested from Swiss outbred mice after induction of thioglycollate.…”

Boswellic Acids Show In Vitro Activity against Leishmania donovani

“…In total, 200 mg of fraction Bs-20 was purified with a Jasco HPLC system on a Reprosil 100 C-18 column (5 µm, 250 × 20 mm) using a methanol:water gradient (start-70:30; 8-25 min-100:0; 9 mL/min: t R = 17-18 min) to yield 6. In vitro tests for determination of activity against axenic amastigotes of Leishmania donovani (MHOM-ET-67/L82 strain) and cytotoxicity against mammalian cells (L6-cell-line from rat skeletal myoblasts) as well as against intramacrophage amastigotes of L. donovani were conducted at Swiss TPH according to an established protocol as reported before [14,15]. For a repetition of these methods, see Supplementary File.…”