Transcriptomics and proteomic studies reveal acaricidal mechanism of octadecanoic acid-3, 4 - tetrahydrofuran diester against Sarcoptes scabiei var. cuniculi

Natural Products as Mite Control Agents in Animals: A Review

Mites have been a persistent infectious disease affecting both humans and animals since ancient times. In veterinary clinics, the primary approach for treating and managing mite infestations has long been the use of chemical acaricides. However, the widespread use of these chemicals has resulted in significant problems, including drug resistance, drug residues, and environmental pollution, limiting their effectiveness. To address these challenges, researchers have shifted their focus towards natural products that have shown promise both in the laboratory and real-world settings against mite infestations. Natural products have a wide variety of chemical structures and biological activities, including acaricidal properties. This article offers a comprehensive review of the acaricidal capabilities and mechanisms of action of natural products like plant extracts, natural compounds, algae, and microbial metabolites against common animal mites.

iTRAQ-Based Quantitative Proteomic Analysis of Arthrobacter simplex in Response to Cortisone Acetate and Its Mutants with Improved Δ1-Dehydrogenation Efficiency

Arthrobacter simplex is extensively used for cortisone acetate (CA) biotransformation in industry, but the Δ¹-dehydrogenation molecular fundamental remains unclear. Herein, the comparative proteome revealed several proteins with the potential role in this reaction, which were mainly involved in lipid or amino acid transport and metabolism, energy production and conversion, steroid degradation, and transporter. The influences of six proteins were further confirmed, where pps, MceG_A, yrbE4A_A, yrbE4B_A, and hyp2 showed positive impacts, while hyp1 exhibited a negative effect. Additionally, KsdD5 behaved as the best catalytic enzyme. By the combined manipulation in multiple genes under the control of a stronger promoter, an optimal strain with better catalytic enzyme activity, substrate transportation, and cell stress tolerance was created. After biotechnology optimization, the production peak and productivity were, respectively, boosted by 4.1- and 4.0-fold relative to the initial level. Our work broadens the understanding of the Δ¹-dehydrogenation mechanism, also providing effective strategies for excellent steroid-transforming strains.

Essential Oils against Sarcoptes scabiei

Herbal remedia are widely employed in folk medicine, and have been more and more often studied and considered in the treatment of several infections. Sarcoptic mange (scabies, when referring to human patients) is a highly contagious skin disease caused by Sarcoptes scabiei (sarcoptiformes, Sarcoptinae), an astigmatid mite which burrows into the epidermis, actively penetrating the stratum corneum. This parasitosis negatively affects livestock productions and represents a constraint on animal and human health. The treatment relies on permethrine and ivermectine but, since these molecules do not have ovicidal action, more than a single dose should be administered. Toxicity, the possible onset of parasite resistance, the presence of residues in meat and other animal products and environmental contamination are the major constraints. These shortcomings could be reduced by the use of plant extracts that have been in vitro or in vivo checked against these mites, sometimes with promising results. The aim of the present study was to review the literature dealing with the treatment of both scabies and sarcoptic mange by plant-derived agents, notably essential oils.

A Combined Differential Proteome and Transcriptome Profiling of Fast- and Slow-Twitch Skeletal Muscle in Pigs

Skeletal muscle fiber types can contribute in part to affecting pork quality parameters. Biceps femoris (Bf) (fast muscle or white muscle) and Soleus (Sol) (slow muscle or red muscle) are two typical skeletal muscles characterized by obvious muscle fiber type differences in pigs. However, the critical proteins and potential regulatory mechanisms regulating porcine skeletal muscle fibers have yet to be clearly defined. In this study, the isobaric Tag for Relative and Absolute Quantification (iTRAQ)-based proteome was used to identify the key proteins affecting the skeletal muscle fiber types with Bf and Sol, by integrating the previous transcriptome data, while function enrichment analysis and a protein–protein interaction (PPI) network were utilized to explore the potential regulatory mechanisms of skeletal muscle fibers. A total of 126 differentially abundant proteins (DAPs) between the Bf and Sol were identified, and 12 genes were found to be overlapping between differentially expressed genes (DEGs) and DAPs, which are the critical proteins regulating the formation of skeletal muscle fibers. Functional enrichment and PPI analysis showed that the DAPs were mainly involved in the skeletal-muscle-associated structural proteins, mitochondria and energy metabolism, tricarboxylic acid cycle, fatty acid metabolism, and kinase activity, suggesting that PPI networks including DAPs are the main regulatory network affecting muscle fiber formation. Overall, these data provide valuable information for understanding the molecular mechanism underlying the formation and conversion of muscle fiber types, and provide potential markers for the evaluation of meat quality.

Structural modification of octadecanoic acid-3,4-tetrahydrofuran diester and the acaricidal activity and mechanism of its derivatives against Sarcoptesscabiei var. Cuniculi

Octadecanoic acid-3,4-tetrahydrofuran diester is a compound with acaricidal activity isolated and extracted from neem oil. In this study, a series of derivatives were obtained by structural modification of octadecanoic acid-3,4-tetrahydrofuran diester. The acaricidal activity of these derivatives indicated that introduction of benzyloxy substitution at the 2-position of the furan ring and the formation of a benzoate at the 3,4-position of the furan ring (benzoic acid-2-benzyloxy-3,4-tetrahydrofuran diester) could enhance the acaricidal activity. At concentration of 20, 10, and 5 mg/ml, the median lethal time (LT₅₀) values of benzoic acid-2-benzyloxy-3,4-tetrahydrofuran diester were 16.138, 47.274, and 108.122 min, respectively. The LC₅₀ value of benzoic acid-2-benzyloxy-3,4-tetrahydrofuran diester at 60 min was 5.342 mg/ml. Transmission electron microscopy showed that after treatment with benzoic acid-2-benzyloxy-3,4-tetrahydrofuran diester, the body structure of mites was destroyed; dermal organelles were dissolved; nuclear chromatin was ablated. Further, transcriptome sequencing analysis was used to get insight into the acaricidal mechanism of benzoic acid-2-benzyloxy-3,4-tetrahydrofuran diester. The results showed that its acaricidal mechanism is related to interfering “energy metabolism” in S. scabiei, including processes such as citric acid cycle, oxidative phosphorylation pathway and fatty acid metabolism. Additionally, through the activity detection of the mitochondrial complexes of S. scabiei, it was further verified that the acaricidal mechanism of benzoic acid-2-benzyloxy-3,4-tetrahydrofuran diester was related to the energy metabolism system of S. scabiei.

Quercetin Mitigates Methamphetamine-Induced Anxiety-Like Behavior Through Ameliorating Mitochondrial Dysfunction and Neuroinflammation

Methamphetamine (MA) abuse results in neurotoxic outcomes, including increased anxiety and depression. Studies have reported an association between MA exposure and anxiety, nonetheless, the underlying mechanism remains elusive. In the present study, we developed a mouse model of anxiety-like behavior induced by MA administration. RNA-seq was then performed to profile the gene expression patterns of hippocampus (HIPP), and the differentially expressed genes (DEGs) were significantly enriched in signaling pathways related to psychiatric disorders and mitochondrial function. Based on these, mitochondria was hypothesized to be involved in MA-induced anxiety. Quercetin, as a mitochondrial protector, was used to investigate whether to be a potential treatment for MA-induced anxiety; accordingly, it alleviated anxiety-like behavior and improved mitochondrial impairment in vivo. Further experiments in vitro suggested that quercetin alleviated the dysfunction and morphological abnormalities of mitochondria induced by MA, via decreasing the levels of reactive oxygen species (ROS), mitochondrial membrane potential (MMP), and increasing the oxygen consumption rate (OCR) and ATP production. Moreover, the study examined the effect of quercetin on astrocytes activation and neuroinflammation, and the results indicated that it significantly attenuated the activation of astrocytes and reduced the levels of IL-1β, TNFα but not IL-6. In light of these findings, quantitative evidence is presented in the study supporting the view that MA can evoke anxiety-like behavior via the induction of mitochondrial dysfunction. Quercetin exerted antipsychotic activity through modulation of mitochondrial function and neuroinflammation, suggesting its potential for further therapeutic development in MA-induced anxiety.

Acaricidal activity of strophanthidin derivatives against Psoroptes cuniculi and their inhibitory effect on Na+-K+-ATPase

In our previous studies, we found that as the active gradients of Adonis coerulea, cardenolides and cardiac glycosides presented toxicity against mites by inhibiting Na⁺-K⁺-ATPase. In this paper, after evaluating the acaricidal activity of the commercial cardiac aglycones/glycosides, serials of novel strophanthidin derivatives were designed and synthesized with an efficient and simple route under mild conditions, and their toxicity against mites, the cytotoxicity and inhibitory effect on Na⁺-K⁺-ATP enzyme in PC12 cells were investigated. Results showed among of all compounds, including 9 commercial agent and 32 synthesized strophanthidin derivatives, QXG-1 presented the strongest toxicity against mites with the LC₅₀ value of 320.0 μg/mL. C-19 group of strophanthidin substituted with glycinemethylester would increase the toxicity against mites, and the hydroxyl group at C-5 play the vital role in terms of the toxicity. At the given concentration, QXG-1 displayed the safety against PC12 (10.0 μg/mL) in vitro and mice (3.2 mg/kg) in acute toxicity test, and strong inhibitory effect on Na⁺-K⁺-ATPase. It could be used as a promising acaricidal agent. This study lays the foundation to develop of QXG-1 as a relatively safe and alternative acaricidal agent.

A value-added application of eugenol as acaricidal agent: The mechanism of action and the safety evaluation

Introduction

Eugenol is a major component of essential oils of several plants, it exhibits significant antiparasitic and acaricidal activities, yet its molecular targets remain unknown.

Objectives

We aimed to systematically investigate the mechanism of action and the potential targets of eugenol against P. cuniculi, and evaluate the safety for laying the theoretical foundation for clinical application as an acaricide.

Methods

Using RNA-Seq analysis, surface plasmon resonance analysis and RNA interference assay, the mode of action of eugenol against Psoroptes cuniculi was investigated. The effect on the mitochondrial membrane potential and complex I of PC12 cells and C6/36 cells was assayed to investigate the species specificity of eugenol in insects and mammals. Finally, a safety evaluation of eugenol in vivo was performed.

Results

Eugenol inhibited complex I activity of the mitochondrial respiratory chain in the oxidative phosphorylation pathway by binding to NADH dehydrogenase chain 2 and resulted in the death of mites. The inhibition rates were 37.89% for 50 μg/mL and 60.26% for 100 μg/mL, respectively. Further experiments indicated that the difference in the complex I sequence between insects and mammals led to the different affinity of eugenol to specific peptide, resulting in species specificity. Eugenol exhibited significant inhibitory effects against the mitochondrial membrane potential and complex I in Aedes albopictus C6/36 cells but was not active in rat PC12 cells. Insect cells were particularly sensitive to eugenol. In contrast to the known inhibitor rotenone, eugenol had better safety and did not result in Parkinson's disease or other diseases in rats.

Conclusion

This is the first report on acaricidal eugenol targeting complex I of the mitochondrial respiratory chain. This work lays the foundation for the development of eugenol as an environmentally alternative acaricidal agent.

Gegen Qinlian Decoction abates nonalcoholic steatohepatitis associated liver injuries via anti-oxidative stress and anti-inflammatory response involved inhibition of toll-like receptor 4 signaling pathways

Gegen Qilian Decoction (GGQLD) is a well-established classic Chinese medicine prescription in treating nonalcoholic steatohepatitis (NASH). However, the molecular mechanism of GGQLD action on NASH is still not clear. This study aimed to assess the anti-NASH effect of GGQLD, and to explore its molecular mechanisms in vivo and in vitro. In HFD-fed rats, GGQLD decreased significantly serum triglyceride (TG), cholesterol (CHO), total bile acid (TBA), low-density lipoprotein (LDL), free fatty acid (FFA) and lipopolysaccharide (LPS) levels, increased levels of differentially expressed proteins (DEPs) Ahcy, Gpx1, Mat1a, GNMT, and reduced the expression of ALDOB. In RAW264.7 macrophages, GGQLD reduced the expression levels of inflammatory factors TNF-α and IL-6 mRNA, and diminished NASH by increasing differentially expressed genes (DEGs) CBS, Mat1a, Hnf4α and Pparα to reduce oxidative stress or lipid metabolism. The results of DEGs verification also showed that GGQLD up-regulated expressions of Hnf4α, Pparα and Cbs genes. In HepG2 cells, GGQLD decreased IL-6 levels and intracellular TG content, and inhibited FFA-induced expression of toll-like receptor 4 (TLR4). In summary, GGQLD abates NASH associated liver injuries via anti-oxidative stress and anti-inflammatory response involved inhibition of TLR4 signal pathways. These findings provide new insights into the anti-NASH therapy by GGQLD.

Integrated Transcriptome and Proteome Studies Reveal the Underlying Mechanisms for Sterol Catabolism and Steroid Production in Mycobacterium neoaurum

Integrated transcriptome and proteome studies were performed to investigate sterol biotransformation in wild-type Mycobacterium neoaurum ATCC 25795 ( Mn) and the mutant strains producing steroid intermediates. Transcriptome and proteome studies indicated that several metabolic activities were noticeably dynamic, including cholesterol degradation, central carbon metabolism, cell envelope biosynthesis, glycerol metabolism, and transport. Interestingly, a poor overall correlation between mRNA and translation profiles was found, which might contribute to the metabolic adaptation in cholesterol catabolism. A gene cluster covering 111 genes was discovered to encode for cholesterol catabolism in Mn. Generally, transcription and/or translation of the genes in KstR1 regulon was upregulated, and the induction of genes in KstR2 regulon was not as significant as that of KstR1 regulon. Several induced genes showing potential roles for cholesterol catabolism were found. Further identification of these genes and investigation of the correlation among key metabolic activities could help for the development of efficient steroid-producing strains.

Serodiagnostic Potential of Alpha-Enolase From Sarcoptes scabiei and Its Possible Role in Host-Mite Interactions

Infestation of the epidermis with the highly contagious ectoparasite, Sarcoptes scabiei, causes scabies, which is characterized by intense itching, pruritus, and secondary infection. This condition affects humans, livestock, and wildlife worldwide, incurring large economic losses and reducing the quality of human life. In the present study, we cloned the alpha-enolase, a key enzyme in the glycolytic and gluconeogenesis pathways, from S. scabiei var. cuniculi, characterized it and produced soluble recombinant enolase protein (rSsc-eno). We determined the localization of Ssc-eno in isolated mites and mites in lesioned skin. The results showed that native enolase was intensely localized in the tegument of the mouthparts, the entire legs, and the whole mites' body, as well as in the gut and reproduction system. Interestingly, we found that native enolase was widely distributed in mites in lesioned skin, with obvious high protein intensity compared with isolated mites. Building on good immunoreactivity, an indirect enzyme-linked immunosorbent assay (ELISA) based on rSsc-eno showed 92% sensitivity and 95.8% specificity, compared with other indirect ELISA in this study, rSsc-eno based ELISA is better in detecting scabies in rabbits. Besides, this method can detect S. scabiei infection as early as 1 week post infection. Compared with other detection methods, such as traditional microscopic examination and recently published universal conventional PCR, rSsc-eno ELISA was more effective to detect early infection in rabbits. Additionally, in vitro incubation experiments demonstrated the concentration-dependent acaricidal activity of rabbit anti-rSsc-eno sera against larval mites, suggested its potential as a vaccine candidate.

Application of Sustainable Natural Resources in Agriculture: Acaricidal and Enzyme Inhibitory Activities of Naphthoquinones and Their Analogs against Psoroptes cuniculi

As important secondary plant metabolites, naphthoquinones exhibit a wide range of biological activities. However, their potential as sustainable alternatives to synthetic acaricides has not been studied. This study for the first time investigates the acaricidal activity of naphthoquinones against Psoroptes cuniculi in vitro. Furthermore, the in vivo activity, the skin irritation effects, the cytotoxicity and the inhibitory activities against mite acetylcholinesterase (AChE) and glutathione S-transferase (GST) of the two compounds that displayed the best insecticidal activity in vitro were evaluated. Among fourteen naphthoquinones and their analogs, juglone and plumbagin were observed to possess the strongest acaricidal activities against P. cuniculi with LC50 values of 20.53 ppm and 17.96 ppm, respectively, at 24 h. After three treatments, these two chemicals completely cured naturally infested rabbits in vivo within 15 days, and no skin irritation was found in any of the treated rabbits. Compared to plumbagin, juglone presented no or weak cytotoxicity against HL-7702 cells. Moreover, these two chemicals significantly inhibited AChE and GST activity. These results indicate that juglone has promising toxicity against P. cuniculi, is safe for both humans and animals at certain doses, and could be used as a potential alternative bio-acaricide for controlling the development of psoroptic mange in agricultural applications.

Expression and characterisation of a Sarcoptes scabiei protein tyrosine kinase as a potential antigen for scabies diagnosis

Scabies is a disease that harms humans and other animals that is caused by the itch mite Sarcoptes scabiei burrowing into the stratum corneum of the skin. In the early stages of scabies, symptoms are often subclinical and there are no effective diagnostic methods. Herein, we cloned, expressed and characterised an S. scabiei protein tyrosine kinase (SsPTK) and evaluated its diagnostic value as a recombinant antigen in rabbit during the early stages of Sarcoptes infestation. The SsPTK protein is ~30 kDa, lacks a signal peptide, and shares high homology with a PTK from the rabbit ear mite Psoroptes ovis cuniculi. The protein was widely distributed at the front end of mites, particularly in the chewing mouthparts and legs. Indirect ELISA using recombinant SsPTK showed good diagnostic value, with 95.2% (40/42) sensitivity and 94.1% (48/51) specificity for detecting anti-PTK antibody in serum samples from naturally-infested rabbits. More importantly, PTK ELISA could diagnose infection in the early stages (infestation for 1 week) with an accuracy of 100% (24/24). SsPTK therefore shows potential as a sensitive antigen for the early diagnosis of parasitic mite infestation.