RESUMO
Although copper is an essential element for any organism's well-being, it becomes toxic if present in excess. In the present study, copper was provisioned at 25, 50, and 75 mg/kg in an artificial diet and fed to juvenile larvae of cotton bollworm, Helicoverpa armigera (Lepidoptera; Noctuidae), for 4 generations. The results of this investigation exhibited shortening of larval life in the first 2 generations, but extended duration was observed in third and fourth generations compared to controls, and dietary copper caused reduced total hemocyte counts in all treatments. The number of immunocytes (i.e., granulocytes and plasmatocytes) were also significantly reduced. The changes in activities of certain important enzymes, including catalase, superoxide dismutase, and peroxidases, were seen. Furthermore, after treatment, an increase in the activity of 2 detoxifying enzymes, glutathione s-transferase and acetylcholinesterase, was observed. It is clear that metallothioneins are important in maintaining essential and nonessential metal ion homeostasis. While copper is typically regarded as an important essential metal in an organism's life, excessive amounts can have deteriorating effects. This heavy metal is being used as a nano-based pesticide. Therefore, the present investigation aims to determine the fate of Cu in insects receiving them in new formulations.
RESUMO
Misuse of synthetic pesticides and antimicrobials in agriculture and the food industry has resulted in food contamination, promoting resistant pests and pathogen strains and hazards for humanity and the environment. Therefore, ever-increasing concern about synthetic chemicals has stimulated interest in eco-friendly compounds. Ferulago angulata (Schltdl.) Boiss. and Ferula assa-foetida L., as medicinal species with restricted natural distribution and unknown biological potential, aimed at investigation of their essential oil (EO) biological properties, were subjected. Z-ß-Ocimene and Z-1-Propenyl-sec-butyl disulfide molecules were identified as the major composition of the essential oil of the fruits of F. angulata and F. assa-foetida, respectively. In vitro antimicrobial activity and membrane destruction investigation by scanning electron microscopy imaging illustrated that F. angulata EO had potent antibacterial activity. Besides, the EOs of both plants exhibited significant anti-yeast activity against Candida albicans. In relation to insecticidal activity, both EOs indicated appropriate potential against Ephestia kuehniella; however, the F. assa-foetida EO had more toxicity on the studied pest. Among several insecticidal-related targets, acetylcholinesterase was identified as the main target of EO based on the molecular docking approach. Hence, in line with in vitro results, in silico evaluation determined that F. assa-foetida has a higher potential for inhibiting acetylcholinesterase and, consequently, better insecticide properties. Overall, in addition to the antioxidant properties of both EO, F. angulata EO could serve as an effective prevention against microbial spoilage and foodborne pathogens, and F. assa-foetida EO holds promise as a multi-purpose and natural biocide for yeast contamination and pest management particularly against E. kuehniella.
RESUMO
The rice weevil, Sitophilus oryzae L., is one of the most widespread and destructive stored-product pests and resistant to a wide range of chemical insecticides. In this research, Artemisia annua L. essential oil (EO) and its encapsulated form by chitosan/TPP (tripolyphosphate) and zeolite were tested against S. oryzae adults. The order of toxicity was chitosan/TPP (LC30: 30.83, LC50: 39.52, and LC90: 72.50 µL/L air) > pure EO (LC30: 35.75, LC50: 46.25, and LC90: 86.76 µL/L air) > EO loaded in the zeolite (LC30: 43.35, LC50: 55.07, and LC90: 98.80 µL/L air). These encapsulated samples were characterized by dynamic light scattering (DLS) and field emission scanning electron microscope (FE-SEM) which revealed the size and morphology of the droplets measuring 255.2 to 272 nm and 245 to 271.8 nm for EO loaded in chitosan and zeolite respectively. The encapsulation efficiency and loading percentages of A. annua EO in chitosan/TPP and zeolite were 40.16% and 6.01%, and 88% and 85%, respectively. Fumigant persistence was increased from 6 days for pure EO then, 20 and 22 days for encapsulated oil in zeolite and chitosan/TPP, respectively. Our results showed that A. annua EO contains (±)-camphor (29.29%), 1,8-cineole (12.56%), ß-caryophyllene (10.29%), α-pinene (8.68%), and artemisia ketone (8.48%) as its major composition. The activity level of glutathione S-transferase increased while general esterase and acetylcholinesterase activity were significantly inhibited in the treated group compared with the control. Antioxidant enzymes, including catalase, peroxidase, and superoxide dismutase were activated in treated adults compared to controls. The current results suggest that encapsulation of A. annua EO by chitosan/TPP and zeolite in addition to safety and environmentally friendly approach could increase its sustainability and therefore enhancing the efficiency in controlling S. oryzae in storage.
