Aims:In the present study, the objective was to estimate the toxicity of an insect growth regulator with juvenile hormone-like activity, kinoprene, on Culex pipiens, the most abundant and investigated mosquito species. Effects of this compound on growth and development were also evaluated. Methodology: A commercial formulation (Enstar 65% EC) was tested at different concentrations ranging between 162.5 and 650µg/L on newly molted fourth-instar larvae that were exposed for 24 h under standard laboratory conditions according to World Health Organization recommendations. Results: Kinoprene exhibited insecticidal activity by direct action on the treated fourthinstar larvae but also by differed action on the other following stages of development. Mortality occurred after earlier inhibition of their development or by their inability to complete their ecdysis. The LC 50 values were 1287.4µg/L for the direct action on fourth instar larvae, and 246.8µg/L for the differed action until adult emergence. Moreover, the compound disturbed growth and development since several morphological types and an increase in the duration of larval and pupal stages were recorded. In a second series of experiments, the effects of kinoprene were examined on morphometric measurements of 2264 larvae, pupae and adults, respectively. The compound affected body volume. Conclusion: The overall results are discussed in relation to previous reports and suggested that kinoprene have potential as a biorational insecticide for controlling of mosquitoes in an environmentally-friendly manner to the aquatic ecosystem.

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Warionia saharae Benth. & Coss. (Asteraceae) is an endemic species of North Africa naturally grown in the southwest of the Algerian Sahara. In the present study, this species’ hydromethanolic leaf extract was investigated for its phenolic profile characterized by ultra-high-performance liquid chromatography coupled with a diode array detector and an electrospray mass spectrometer (UHPLC-DAD-ESI/MS). Additionally, the chemical composition of W. saharae was analyzed by gas chromatography–mass spectrometry, and its antioxidant potential was assessed through five in vitro tests: DPPH● scavenging activity, ABTS●+ scavenging assay, galvinoxyl scavenging activity, ferric reducing power (FRP), and cupric reducing antioxidant capacity. The UHPLC-DAD-ESI/MS analysis allowed the detection and quantification of 22 compounds, with taxifolin as the dominant compound. The GC–MS analysis allowed the identification of 37 compounds, and the antioxidant activity data indicate that W. saharae extract has a very high capacity to capture radicals due to its richness in compounds with antioxidant capacity. The extract also showed potent α-glucosidase inhibition as well as a good anti-inflammatory activity. However, weak anti-α-amylase and anticholinesterase activities were recorded. Moreover, an in silico docking study was performed to highlight possible interactions between three significant compounds identified in W. saharae extract and α-glucosidase enzyme.

The present study shows the chemical profile and cytotoxic properties of the ethanolic extracts of Inula viscosa from Northeast Algeria. The extract was obtained by maceration using ethanol. Its phenolic profile was determined using ultra-high-performance liquid chromatography coupled with a diode array detector and an electrospray mass spectrometer (UHPLC-DAD-ESI/MS), which allowed the identification and quantification of 17 compounds, 1,5-O-caffeoylquinic acid being the most abundant. The cytotoxic activity was assessed against human gastric cancer (AGS) and human non-small-cell lung cancer (A549) cell lines, whereas ethanolic extract elicited nearly 60 % and 40 % viability loss toward AGS and A549 cancer cells, respectively. Results also showed that cell death is caspase-independent and confirmed the involvement of RIPK1 and the necroptosis pathway in the toxicity induced by the I. viscosa extract. In addition, the ethanolic extract would not provoke morphological traits in the cancer cells. These findings suggest that I. viscosa can be a source of new antiproliferative drugs or used in preparation plant-derived pharmaceuticals.

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Methoxyfenozide is an insect growth disruptor belonging to the class of nonsteroidal ecdysone agonists. In the present study, methoxyfenozide (23% emulsifiable concentrate) is evaluated against newly molted fourth‐instar larvae of Culex pipiens L. and Culiseta longiareolata Macquart (Diptera: Culicidae), aiming to investigate its possible effects on growth and development. Larvae are exposed for 24 h under standard laboratory conditions in accordance with World Health Organization recommendations. The product is found to exhibit insecticidal activity against the two tested mosquito species with a concentration–response relationship. Moreover, based on the lethal concentrations determined, methoxyfenozide is slightly more toxic against C. pipiens than C. longiareolata. Furthermore, fourth‐instar larva of the two mosquito species are treated using two lethal concentrations (LC50 and LC90) of methoxyfenozide, and then individual survivals (larvae, pupae and adults) from larval treatment are subjected to a biometrical and biochemical study. The compound is found to interfere with growth by reducing the larval and pupal development duration. Moreover, the body volume and the main biochemical contents (proteins, carbohydrates and lipids) from different stages are affected. The overall results suggest that the ecdysone agonist under investigation interferes with the development process and has potential for mosquito control.

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To select potential plant‐based insecticides, Tecoma stans (Bignoniaceae) leaf extract was screened for its larvicidal and delayed effects against a medically important mosquito species Culex pipiens L. (Diptera: Culicidae). First, gas chromatography–mass spectrometry (GC–MS) was conducted on T. stans extract, collected in ethanol for its chemical characterization and detection of active constituents. Second, insecticidal bioassays were made with several concentrations on earlier fourth instar larvae (L4) of Cx. pipiens for 24 h as recommended by WHO, in order to determine the lethality parameters of the tested extract. For that, two concentrations (LC30 and LC50) were applied on L4 for 24 h, and emerged adults were observed for their reproductive performance success like fecundity, percentage of hatching (fertility), body and gonads' volume. The biochemical composition of whole bodies of adults was investigated. Also, the specific activities of acetylcholinesterase (AChE) and glutathion S‐transferase (GST), biomarkers of neurotoxicity and detoxification, respectively, were also determined in L4 at different time intervals. Qualitative and quantitative phytochemical analysis (GC–MS) of the extract unveiled nine phytoconstituents with 2‐[4‐cyclohexylbutanoylamino]‐3‐chloro‐1,4‐naphthoquinone (36.24%) and 1,2‐Benzenedicarboxylic acid, mono(2‐ethylhexyl) ester (22.65%) as major components. The early L4 of Cx. pipiens were exposed to LC30 and LC50, and after 24 h, surviving individuals have been further reared until adult emergence. All over, T. stans leaves ethanolic extract impairs adults reproductive traits; it adversely affected gonad's size, fecundity and fertility, which negatively affected the survival of their offspring. Lipids contents were found to increase in both male and female adults. T. stans ethanolic extract increased GST activity and slightly inhibited AChE activity in L4. In conclusion, the ethanolic extract of T. stans could be a potential candidate used as a sustainable botanical insecticide for controlling mosquito.