ABSTRACT
Although the cultivation of transgenic plants expressing toxins of Bacillus thuringiensis (Bt) represents a successful pest management strategy, the rapid evolution of resistance to Bt plants in several lepidopteran pests has threatened the sustainability of this practice. By exhibiting a favorable safety profile and allowing integration with pest management initiatives, plant essential oils have become relevant pest control alternatives. Here, we assessed the potential of essential oils extracted from a Neotropical plant, Siparuna guianensis Aublet, for improving the control and resistance management of key lepidopteran pests (i.e., Spodoptera frugiperda and Anticarsia gemmatalis). The essential oil exhibited high toxicity against both lepidopteran pest species (including an S. frugiperda strain resistant to Cry1A.105 and Cry2Ab Bt toxins). This high insecticidal activity was associated with necrotic and apoptotic effects revealed by in vitro assays with lepidopteran (but not human) cell lines. Furthermore, deficits in reproduction (e.g., egg-laying deterrence and decreased egg viability), larval development (e.g., feeding inhibition) and locomotion (e.g., individual and grouped larvae walking activities) were recorded for lepidopterans sublethally exposed to the essential oil. Thus, by similarly and efficiently controlling lepidopteran strains susceptible and resistant to Bt toxins, the S. guianensis essential oil represents a promising management tool against key lepidopteran pests.
Subject(s)
Insecticide Resistance/drug effects , Insecticides/pharmacology , Laurales/chemistry , Moths/drug effects , Oils, Volatile/pharmacology , Spodoptera/drug effects , Animals , Bacillus thuringiensis/chemistry , Bacillus thuringiensis Toxins , Bacterial Proteins/isolation & purification , Bacterial Proteins/pharmacology , Cell Line , Endotoxins/isolation & purification , Endotoxins/pharmacology , Hemolysin Proteins/isolation & purification , Hemolysin Proteins/pharmacology , Insecticides/isolation & purification , Larva/drug effects , Larva/physiology , Locomotion/drug effects , Locomotion/physiology , Moths/physiology , Oils, Volatile/isolation & purification , Pest Control, Biological/methods , Spodoptera/physiology , Zygote/drug effects , Zygote/physiologyABSTRACT
AIM: To identify linear peptide homing to non-small cell lung cancer (NSCLC) tumor cells using ex vivo phage display method. MATERIALS AND METHODS: Twenty-six clinical patient samples were used to identify linear homing peptide, which was exposed to NSCLC cell cultures and control cell lines to determine cell binding affinity and cell localization. Also, ex vivo biodistribution was analyzed using tumor-bearing mice. RESULTS: The panning yielded peptide enrichment with a core motif (A)/SRXPXXX. Based on this, an amino acid sequence, ARRPKLD, was selected for characterization and named Thx-peptide. The in vitro binding properties of Thx-peptide demonstrated selectivity toward NSCLC. Internalization assays showed that Thx-Alexa and fluorescein conjugates were located in a subset of perinuclearly located lysosomes of tumor cells. Thx-peptide appeared with fluorescein-labeled peptide and peptide-DTPA-chelator complex in adenocarcinoma xenografts in mice. CONCLUSION: Thx shows promise for targeted imaging and drug delivery.