Ameliorating the antitumor activity of lenalidomide using PLGA nanoparticles for the treatment of multiple myeloma

Abstract Lenalidomide (LND) is an anti-cancer drug and an effective derivative of thalidomide used for multiple myeloma therapy. Because of its poor solubility in water, LND is known to cause low oral bioavailability (below 33%), and as a direct consequence of this, the dosing frequency is extended thus increasing risk of toxicity. To improve its bioavailability and sustained release, the present study aims to formulate polymeric nanoparticles (NPs) for LND using [Poly (lactic-co-glycolic acid)] (PLGA) as a polymer. The polymeric NPs were evaluated for particle size, SEM, XRD, drug content, entrapment efficiency (EE), in vitro release studies and in vivo bioavailability studies in rats. The formulated NPs possessed a size of 179±0.9 nm and a zeta potential of -24.4 ± 0.2 mV. The drug loading and EE of the optimized formulation was 32 ± 0.37 % and 78 ± 0.92% respectively. After oral administration of LND PLGA-NPs, the relative bioavailability was enhanced about 3.67-fold compared to LND. This study demonstrates the novel drug delivery for LND with PLGA-NPs as effective drug delivery system for sustained delivery of LND.

Alkaloid-rich fraction of Himatanthus lancifolius contains anti-tumor agents against leukemic cells

The effects of the alkaloid-rich fraction of Himatanthus lancifolius (Müll. Arg) Woodson on normal marrow cells and leukemic cell lines were investigated. After 48 h exposure, the proliferation assay showed significant cell growth inhibition for Daudi (0.1-10 µg/mL), K-562 (1-10 µg/mL), and REH cells (10-100 µg/mL), yet was inert for normal marrow cells. A similar inhibition profile was observed in clonogenic assays. This alkaloid-rich fraction, in which uleine is the main compound, showed no signs of toxicity to any cells up to 10 µg/mL. Cell feature analyses after induction of differentiation showed maintenance of the initial phenotype. Flow cytometric expression of Annexin-V and 7-AAD in K-562 and Daudi cells has indicated that the cells were not undergoing apoptosis or necrosis, suggesting cytostatic activity for tumor cells.

Os efeitos da fração rica em alcalóides indólicos de Himatanthus lancifolius (Müll. Arg) Woodson sobre células normais de medula óssea e linhagens celulares leucêmicas foram investigados. Após 48 horas de exposição, os ensaios de proliferação demonstraram efeitos inibitórios significativos para as linhagens Daudi (0,1-10 µg/mL), K-562 (1-10 µg/mL) e REH (10-100 µg/mL), enquanto mostrou-se inerte sobre células normais de medula óssea. Os perfis de inibição se repetiram nos ensaios clonogênicos. A fração rica em alcalóides, na qual a uleína é a substância majoritária, não demonstrou toxicidade até a dose de 10 µg/mL para nenhuma das células incluídas no estudo. Da mesma forma, não se observou influência dessa fração sobre a diferenciação celular dessas linhagens, mas manutenção de seu estado maturacional inicial. O conjunto de dados descritos associado à baixa co-expressão de anexina-V e 7-AAD sugerem que esta fração exerce atividade citostática para células tumorais.