Boric acid-induced effects on protein profiles of Galleria mellonella hemolymph and fat body

Boron compounds are effective on Tribolium castaneum (Coleoptera: Tenebrionidae): Reduced lipogenesis and induced body weight loss

In the current study, we investigated the insecticidal efficacy of two borates, disodium octaborate tetrahydrate (Etidot-67) and calcium metaborate (CMB) via surface application or diet delivery on the red flour beetle, Tribolium castaneum (Herbst, 1797) (Coleoptera: Tenebrionidae). The application method did not change the boron-related mortality, but CMB was more effective than Etidot-67. At the highest dose, it took around 13 days to reach the highest mortality (≥98.1%) for CMB, while it was 19 days for Etidot-67 (≥95.8%). Both boron compounds led to a significant reduction in triglyceride levels in parallel to the downregulation of acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS), the two primary genes involved in de novo lipogenesis, while they also induced body weight loss. In conclusion, the current study indicated the insecticidal potential of boron compounds but CMB is more promising and more effective in controlling T. castaneum, while lipogenesis is inhibited and weight loss is induced by boron compounds.

Molluscicidal activity of calcium borate nanoparticles with kodom ball-flower structure on hematological, histological and biochemical parameters of Eobania vermiculata snails

Land snails are the most harmful pests in agricultural fields. Eobania vermiculata is a widespread snail species that causes massive damage to all agricultural crops. Thus, the molluscicidal activity of calcium borate nanoparticles (CB-NPs) against Eobania vermiculata was evaluated and compared with metaldehyde (Gastrotox® E 5% G). The amorphous phase of CB-NPs was obtained after thermal treatment at a low temperature (500 °C) which conformed by X-ray diffraction (XRD) analysis. CB-NPs are composed of aggregated nano-sheets with an average thickness of 54 nm which enhanced their molluscicidal activity. These nano-sheets displayed meso-porous network architecture with pore diameters of 13.65 nm, and a 9.46 m2/g specific surface area. CB-NPs and metaldehyde (Gastrotox® E 5% G) exhibited molluscicidal effects on Eobania vermiculata snails with median lethal concentrations LC50 of 175.3 and 60.5 mg/l, respectively, after 72 h of exposure. The results also showed significant reductions of Eobania vermiculata snails hemocytes' mean total number, the levels of Testosterone (T) and Estrogen (E), alkaline phosphatase, acid phosphatase, albumin, and protein concentrations, succinate dehydrogenase, glucose, triglycerides and phospholipids levels, while significant increases in the phagocytic index and mortality index, both transaminases (ALT and AST) and glycogen phosphorylase concentration were observed after the exposure to LC50 of CB-NPs or metaldehyde (Gastrotox® E 5% G) compared to the control group. Therefore, CB-NPs could be used as an alternative molluscicide for controlling Eobania vermiculata, but further studies are needed to assess their effects on non-target organisms.

Boric acid-induced immunotoxicity and genotoxicity in model insect Galleria mellonella L. (Lepidoptera: Pyralidae)

Boric acid (BA) is widely used in various industrial process and can be accessed to nontarget organisms. This study aimed to investigate the insecticidal effects of BA and its toxic activities with respect to immunologic and genotoxic effects using Galleria mellonella larvae as a model. BA concentrations (78.125-10,000 ppm) were administrated to the larvae using the feeding method. Concentration-dependent mortality was observed in all larval groups. Probit analysis revealed LC₃₀ , LC₅₀ , and LC₇₀ values to be 112.4, 320.1, and 911.4 ppm, respectively. These concentrations were used in all bioassays. Drastic reductions in total hemocyte counts along with changes in differential hemocyte counts were observed following BA treatment. Cell viability assays showed dose-dependent reductions in viable cells and an increase in the necrotic and apoptotic ratios after BA treatment. However, mitotic indices of larval hemocytes did not change at all BA concentrations. The cytotoxic effect of BA led to a significant reduction in cellular immune responses such as encapsulation, melanization, and nodulation activities of treated larvae. While BA increased micronucleus ratios at the highest concentration, comet parameters indicating DNA damage increased in G. mellonella larval hemocytes at all concentrations. These report that BA suppresses the immune system of G. mellonella and also poses risks of genotoxicity at high concentrations.

Oxidative Effects of Gemifloxacin on Some Biological Traits of Drosophila melanogaster (Diptera: Drosophilidae)

In recent times, several studies have been undertaken on the artificial mass-rearing of insects in which clinical antibacterial antibiotics, including gemifloxacin, which is a DNA gyrase and topoisomerases inhibitor, are amended into the diet to control microbial contamination and preserve diet. The findings of these studies have suggested the possibility that these antibiotics influence the biological traits of insects in relation to their oxidative effects. This study investigated the effects of gemifloxacin on Drosophila melanogaster (Meigen) survival rates, development times, and male-female adult longevity. And we also determined the effects of gemifloxacin on lipid peroxidation product, malondialdehyde, protein carbonyl levels, and glutathione S-transferase activity of fruit fly eggs. First instars were fed on artificial diets containing 150, 300, 600, and 900 mg/liter concentrations of gemifloxacin until adult emergence. Our results indicate that sublethal effects of gemifloxacin are likely to significantly impair adult fitness and life-history parameters in D. melanogaster, probably because of its oxidative effects.

Effect of boric acid on antioxidant enzyme activity, lipid peroxidation, and ultrastructure of midgut and fat body of Galleria mellonella

Boric acid is widely used as an insecticide, acaricide, herbicide, and fungicide and also during various industrial processings. Hence, numerous populations are subjects to this toxic compound. Its action on animals is still not fully known and understood. We examined the effect of boric acid on larvae of greater wax moth (Galleria mellonella). The chemical appeared to be toxic for larvae, usually in a concentration-dependent manner. Exposed groups revealed increased lipid peroxidation and altered activity of catalase, superoxide dismutase, glutathione S-transferase, and glutathione peroxidase. We also observed changes of ultrastructure, which were in tune with biochemical assays. We suggest that boric acid has a broad mode of action, which may affect exposed larvae, and even if sublethal, they may lead to disturbances within exposed populations.