Mosquitocidal Activity of the Methanolic Extract of Annickia chlorantha and Its Isolated Compounds against Culex pipiens, and Their Impact on the Non-Target Organism Zebrafish, Danio rerio

Abstract

In this study, the crude extract and its isolated compounds from the stem bark of Annickiachlorantha were tested for their larvicidal, developmental, and repellent activity against the mosquito vector, Culex pipiens, besides their toxicity to the non-target aquatic organism, the zebrafish (Danio rerio). The acute larvicidal activity of isolated compounds; namely, palmatine, jatrorrhizine, columbamine, β-sitosterol, and Annickiachlorantha methanolic extract (AC), was observed. Developmentally, the larval duration was significantly prolonged when palmatine and β-sitosterol were applied, whereas the pupal duration was significantly prolonged for almost all treatments except palmatine and jatrorrhizine, where it shortened from those in the control. Acetylcholinesterase (AChE) enzyme showed different activity patterns, where it significantly increased in columbamine and β-sitosterol, and decreased in (AC), palmatine, and jatrorrhizine treatments, whereas glutathione S-transferase (GST) enzyme was significantly increased when AC methanolic extract/isolated compounds were applied, compared to the control. The adult emergence percentages were significantly decreased in all treatments, whereas tested compounds revealed non-significant (p > 0.05) changes in the sex ratio percentages, with a slight female-to-male preference presented in the AC-treated group. Additionally, the tested materials revealed repellence action; interestingly, palmatine and jatrorrhizine recorded higher levels of protection, followed by AC, columbamine, and β-sitosterol for 7 consecutive hours compared to the negative and positive control groups. The non-target assay confirms that the tested materials have very low toxic activity compared to the reported toxicity against mosquito larvae. A docking simulation was employed to better understand the interaction of the isolated compounds with the enzymes, AChE and GST. Additionally, DFT calculations revealed that the reported larvicidal activity may be due to the differing electron distributions among tested compounds. Overall, this study highlights the potential of A. chlorantha extract and its isolated compounds as effective mosquitocidal agents with a very low toxic effect on non-target organisms.

Extraction and assessment of Rudbeckia hirta extracts’ larvicidal activity on lackey moth (Malacosoma neustria Testacea): toxicity, nutritional effects and enzyme activities

“…Using insecticides to control agricultural pests may lead to important risks for non-target aquatic organisms (Ba et al, 2018). Previous studies have shown that the methanolic extract of Annickia chlorantha had mosquitocidal activity, and a very low toxic effect on on the non-target organism D. Rerio (Selim et al, 2022). Our research aligns with these ndings, the RHE was practically nontoxic to D. rerio compared to the toxicity of M. neustria testacea larvae reported here.…”

Surf Redfish-Based ZnO-NPs and Their Biological Activity with Reference to Their Non-Target Toxicity

“…Zetasizer software (V7.12, Malvern Instruments, Malvern, UK) was used to collect and evaluate data. The mosquito Culex pipiens larvae were colonized as previously described by Selim et al [51]; they were provided ad libitum with fish food as a diet and maintained at laboratory conditions of 27 ± 2 • C, 70 ± 5% relative humidity (RH), with a 14-10 h photoperiod. The housefly Musca domestica (L.) adults were fed on a mixture of sugar and milk powder (1:1).…”