Nanostructured Lipid Carriers (NLC) for Biologically Active Green Tea and Fennel Natural Oils Delivery: Larvicidal and Adulticidal Activities against Culex pipiens

Abstract

(1) Background: The control of mosquitoes with essential oils is a growing demand. (2) Methods: This study evaluated the novel larvicidal and adulticidal activity of fennel and green tea oils and their nanostructured lipid carriers (NLC) against Culex pipiens (C. pipiens) in the laboratory, field conditions and evaluated their effect against non-target organisms. SLN type II nanoformulations were synthesized and characterized using dynamic light scattering (DLS), zeta potential and transmission electron microscope. (3) Results: The synthesized NLCs showed spherical shaped, homogenous, narrow, and monomodal particle size distribution. The mortality percent (MO%) post-treatment (PT) with 2000 ppm for 24 h with fennel oil and NLC fennel (NLC-F) reached 85% (LC50 = 643.81 ppm) and 100% (LC50 = 251.71), whereas MO% for green tea oil and NLC green tea (NLC-GT) were 80% (LC50 = 746.52 ppm) and 100% (LC50 = 278.63 ppm), respectively. Field trial data showed that the larval reduction percent of fennel oil and NLC-F reached 89.8% and 97.4%, 24 h PT and the reduction percent of green tea oil and NLC-GT reached 89% and 93%, 24 h PT with persistence reached 8 and 7 days, for NLC-F and NLC-GT, respectively. The adulticidal effects showed that NLC-F and NLC-GT (100% mortality) were more effective than fennel and green tea oils (90.0% and 83.33%), with 24 h PT, respectively. Moreover, their reduction of adult density after spraying with LC95 X2 for 15 min, with fennel oil, NLC-F, and green tea oil, NLC-GT were 83.6%, 100%, 79.1%, and 100%, respectively, with persistence (>50%) lasting for three days. The predation rate of the mosquitofish, Gambusia affinis, and the bug, Sphaerodema urinator, was not affected in both oil and its NLC, while the predation rate of the beetle, Cybister tripunctatus increased (66% and 68.3%) by green tea oil and NLC-GT, respectively. (4) Conclusions: NLCs nanoformulation encapsulated essential oils was prepared successfully with unique properties of size, morphology, and stability. In vitro larvicidal and adulticidal effects against C. pipiens supported with field evaluations have been performed using essential oils and their nanoformulations. The biological evaluation of nanoformulations manifested potential results toward both larvicidal and adulticidal compared to the essential oils themselves, especially NLC encapsulated fennel oil which had promising larvicidal and adulticidal activity.

Novel Pesticidal Efficacy of Araucaria heterophylla and Commiphora molmol Extracts against Camel and Cattle Blood-Sucking Ectoparasites

“…Botanicals have been well-known for their medicinal properties [24] since ancient times [25] and induce anthelmintic, antiprotozoal, antiviral, antifungal, and antibacterial [26][27][28][29][30][31][32] and pesticidal effects [14,15] such as ovicidal [33,34], larvicidal and insect growth regulating effects [19,[35][36][37][38][39][40][41][42][43][44][45][46][47][48] as well as adulticidal and repellent properties [8,33,34,39,45,46,[49][50][51][52][53]. Botanicals are characterized by high efficiency against pests and prevention of their associated diseases, safety to non-target organisms [5,10,44], and biodegradation [5,11].…”

Progress of nanopreparation technology applied to volatile oil drug delivery systems

“…Since SLN suffers from drug efflux defects and low hydrophilic drug loading capacity during storage, NLC is further designed to address these drawbacks, resulting in an ideal loading capacity and greater drug accumulation capacity of NLC, where the drug is essentially undischarged during storage. Many herbal volatile oils or major components have been co-incorporated into NLC to enhance therapeutic efficacy, including pepper oil [ 98 ], fennel oil [ 99 ], cinnamon oil [ 100 ], thyme oil [ 101 ], clove oil [ 102 ], cardamom oil [ 103 ], peppermint oil [ 104 ], and others. Notably, the drug-carrying capacity of NLC is higher than that of LS and SLN because NLC is able to contain three different volatile oils (lavender, peppermint, and rosemary) at the same time and achieve enhanced therapeutic effects for the treatment of neurodegenerative diseases [ 105 ].…”

“… Industrial production is difficult, and research on NLC is not very thorough. Pepper [ 98 ], Fennel [ 99 ], Cinnamon [ 100 ], Thyme [ 101 ], Clove [ 102 ], Cardamom [ 103 ], Peppermint oil [ 104 ] Self-emulsifying drug delivery system (SEDDS) Does not involve any heating or solvent evaporation steps to improve oral bioavailability. There is still little research in this direction.…”

Novel Acaricidal and Insect Growth Regulating Activity of Olive oil against Hyalomma dromedarii (Acari: Ixodida)

“…Because of the development of resistance against acaricides, searching for natural alternative control strategies is very important. Plant-based parasiticides are highly effective [18][19][20][21] Essential oils and plant extracts were used since ancient Egyptian civilizations [18,22] because of their high efficacy and low toxicity, safety to non-target organisms [15,19,[23][24][25][26][27][28][29]. Development of resistance against oils is less likely to occur due to various mechanisms of actions [30][31][32].…”

“…Development of resistance against oils is less likely to occur due to various mechanisms of actions [30][31][32]. Botanicals induce ovicidal, larvicidal, adulticidal, and insect growth regulating (IGRs) effects [26,28,[33][34][35][36][37][38][39][40][41][42][43][44][45].…”