In Vitro Cercaricidal and Schistosomicidal Activities of the Raffia Wine and Hydroethanolic Extracts of Pedilanthus tithymaloides Linn (Poit). Stem Barks.

Schistosomiasis control remains a public health concern, and there is a need to evaluate new strategies for targeting larval and adult stages of the parasite. As Pedilanthus tithymaloides is empirically used to treat schistosomiasis, it becomes essential to know its effective action scientifically. This study assessed the cercaricidal and schistosomicidal activity of P. tithymaloides stem barks raffia wine extract (RwPt) and hydroethanolic extract (HePt). Different concentrations of these extracts were tested against cercariae (31.25-1000 µg/mL) and adult worms (62.5-2000 µg/mL) of Schistosoma mansoni. Niclosamide-olamine 5% (1 µg/mL) and praziquantel (10 µg/mL) were used as pharmacological controls. Cercariae viability was determined every 30 min for 180 min, and adult worms' motor activity and viability after 24 and 48 h incubation. In addition, cytotoxicity and phytochemical analysis were performed. HePt was lethal to cercariae and adult worms with LC50 of 73.91 µg/mL after 60 min of incubation and 731.17 µg/mL after 48 h of incubation, respectively. Furthermore, a significant reduction of 94.44% in motor activity was observed in surviving worms at the concentration of 2000 µg/mL. RwPt was less effective on S. mansoni cercariae with an LC50 of 617.86 µg/mL after 180 min and on adult worms with a mortality rate of 9.83% at 2000 µg/mL for 48 h incubation. Both extracts showed a weak cytotoxicity profile with an IC50 of 983.50 µg/mL for HePt and more than 1000 µg/mL for RwPt. The LC-MS analysis of HePt allowed the detection of two annotated diterpenoids. Based on the selectivity index, the hydroethanolic extract of P. tithymaloides stem barks disclosed an intense cercaricidal activity and a moderate schistosomicidal effect with low cytotoxicity. These findings may support the potential use of Pedilanthus tithymaloides as a natural product or a source of natural-derived compounds for interrupting schistosomiasis transmission.

Four new neo-clerodane diterpenes from the stem bark of Croton oligandrus.

Four new neo-clerodanes, crotonolins C-F (3-6), were isolated from the stem bark of Croton oligandrus together with the known clerodane crotonzambefuran A, the abietanes 7-ß-hydroxydehydroabietic acid and 7-oxodehydroabietic acid, and ferulic acid. Their structures were elucidated by spectroscopic analyses including 1D and 2D NMR and HRESIMS and by comparison with previously reported data. The cytotoxicity of the isolated compounds against A549, MCF7, PC3 and PNT2 cells was evaluated using the MTT assay. Only 7-ß-hydroxydehydroabietic acid showed a moderate level of activity against PC3 cells with an IC50 value of 68.9 ± 6.6 µM.