Gland Extracts Research Articles

Murine vaginal secretory responses to a male volatile chemical messenger.

Many species use chemical messengers to communicate a remarkable range of information. Mice appear to make particular use of chemical messengers, including effects on estrous cycling and initiation, pregnancy, aggression, stress and of course attraction. Behavioral studies have helped identify several candidate messengers, or pheromones, that mediate attraction in mice. One question is whether attractive chemical messengers induced a physical vaginal secretory response. The preparation hypothesis posits that increased vaginal secretion would lubricate and protect the vagina in response to the prospect of imminent coitus, but this has been difficult to assess experimentally, particularly in mice. We developed a rapid, sensitive, minimally invasive method of quantifying vaginal moisture in mice and used this model to test vaginal secretory responses to male bedding. We report that female mice experience an increase in vaginal moisture after exposure to male, but not female, bedding. This response is induced by either physical or airborne exposure to male urine, to preputial gland extract, and to the preputial gland-derived pheromone alpha/beta farnesenes. This vaginal response is diurnally regulated, seen only during their active phase. The response is sensitive to the estrous phase, with a clear response during estrus but not during metestrus. We conclude that mice may serve as a model for aspects of vaginal function and that this assay will be readily applicable to other small animals. The identification of a pheromone-mediated vaginal secretory response offers a window into the regulation of the vaginal environment and the neurobiology of sexual responses in mice.

Nearctic female Agriotes pubescens and Palearctic female A. lineatus (Coleoptera: Elateridae) produce the same sex pheromone.

In central Canada, surveys for the three invasive (Palearctic) Agriotes species-A. obscurus, A. lineatus, and A. sputator-commonly collect A. pubescens, a North American native (Nearctic) click beetle (Coleoptera: Elateridae) that generally co-occurs with Nearctic A. mancus. Despite the abundance of A. pubescens on farmland, its life history and potential economic impact remain largely unknown. Here, we report the identification and field testing of the A. pubescens sex pheromone. We collected headspace volatiles from a single female beetle on Porapak Q, then extracted the female's pheromone gland, and analyzed aliquots of both Porapak extract and pheromone gland extract by gas chromatographic-electroantennographic detection (GC-EAD) and by GC-mass spectrometry. In GC-EAD recordings of gland extract, two esters-geranyl butanoate and geranyl octanoate-elicited antennal responses from A. pubescens males. In a field experiment in Quebec, traps baited with a 1:1 blend of these esters captured approximately 100× more A. pubescens males than traps baited with a single ester. This is the same trap lure used for capturing A. lineatus. In this experiment, and in a similar one run in British Columbia, heterospecific pheromone components added to conspecific pheromone lures reduced captures of A. mancus, A. sputator, A. lineatus, and A. obscurus by 29%, 96%, 44%, and 71%, respectively. These data indicate that, in North America, lures containing pheromone components of multiple Agriotes congeners may not be optimally attractive to all target species.

Fate and impact at molecular level of diatrizoic acid and iohexol contrast agents in Dreissena polymorpha mollusks.

Iodinated contrast media (ICMs) used in X-ray imaging for medical diagnostics are released into wastewater and then encountered in river water at concentrations ranging from several dozen to hundreds of µg/L, and even thousands of µg/L in hospital effluents. ICMs are considered as emerging pollutants as their occurrence and impact on ecosystems and the environment are poorly documented. Even if they are considered inert for humans, aquatic organisms are continuously exposed to ICMs, and their potential deleterious effects are therefore questioned as we have recently demonstrated that they enter into organisms such as the zebra mussels. To answer this question, Dreissena polymorpha were exposed to two ICMs of different osmolality, diatrizoic acid and iohexol, at an environmental concentration (100µg/L) for 21days before a depuration phase of 4days. The occurrence, fate, and impact of both ICMs in these organisms were studied using a metallomic approach. Thus, iodine as well as endogenous copper and zinc were quantified and analyzed in cytosolic extracts of digestive glands, gills, and gonads of mussels by size exclusion chromatography coupled to ICP MS. This work shows that a subcellular fractionation is necessary to distinguish variations in total element content. The cytosolic iodoprotein chromatographic pattern was consistent for the three organs and confirmed the presence of ICMs in cytosols. Additionally, this exploratory work tends to show a weak biological effect of ICMs with a substantial variation of the profile of Cu-binding proteins mostly in the gill cytosol and to a lesser extent, in the digestive gland cytosol.

The serine protease inhibitor HAMpin-1 produced by the ectoparasite Hyalomma anatolicum salivary gland modulates the host complement system

Ticks are notable vectors of diseases affecting both humans and animals, with Hyalomma anatolicum being of particular significance due to its wide distribution and capability to transmit a variety of pathogens, including Theileria annulata, and Crimean–Congo haemorrhagic fever (CCHF) virus. This study aimed to investigate the inhibitory effects of Hyalomma anatolicum salivary gland extract (HaSGE) and the identification of its key component on the complement system of the host's innate immune defense. We demonstrated that HaSGE exerts a dose-dependent inhibition on the complement activation in a host-specific manner. Mechanistic studies revealed that HaSGE interferes with blocking the deposition and cleavage of complement proteins C3 and C5, thus preventing the formation of the membrane attack complex (MAC). Further, we identified a serine protease inhibitor, HAMpin-1, from the HaSGE through proteomic analysis and characterized its structure, function, and interaction with complement proteins. HAMpin-1 exhibited potent inhibitory activity against chymotrypsin and cathepsin-G, and notably, it is the first serpin from ticks shown to inhibit the classical and lectin pathways of the complement system. The expression of HAMpin-1 was highest in the salivary glands, suggesting its crucial role in blood feeding and immune evasion. Our findings revealed one of the potential mechanisms employed by H. anatolicum to modulate host immune responses at the interface, offering new insights into tick-host interactions.

Mandibular gland proteomics of the Mexican alligator lizard, Abronia graminea, and the red-lipped arboreal alligator lizard, Abronia lythrochila

A useful approach to deepen our knowledge about the origin and evolution of venom systems in Reptilia has been exploring the vast biodiversity of this clade of vertebrates in search of orally produced proteins with toxic actions, as well as their corresponding delivery systems. The occurrence of toxins in anguimorph lizards has been demonstrated experimentally or inferred from reports of the toxic effects of the oral secretions of taxa within the Varanidae and Helodermatidae families. In the present study, we have focused on two alligator lizards of the Anguidae family, the Mexican alligator lizard, Abronia graminea, and the red-lipped arboreal alligator lizard, A. lythrochila. In addition, the fine morphology of teeth of the latter species is described. The presence of a conserved set of proteins, including B-type natriuretic peptides, cysteine-rich secretory proteins, group III phospholipase A2, and kallikrein, in submandibular gland extracts was demonstrated for both Abronia species. These proteins belong to toxin families found in oral gland secretions of venomous reptile species. This finding, along with previous demonstration of toxin-producing taxa in both paleo- and neoanguimorpha clades, provides further support for the existence of a handful of conserved toxin families in oral secretions across the 100+ million years of Anguimorpha cladogenesis.

Unveiling the Enigmatic nature of six neglected Amazonian Leishmania (Viannia) species using the hamster model: Virulence, Histopathology and prospection of LRV1.

American tegumentary leishmaniasis (ATL) is highly endemic in the Amazon basin and occurs in all South American countries, except Chile and Uruguay. Most Brazilian ATL cases are due to Leishmania (Viannia) braziliensis, however other neglected Amazonian species are being increasingly reported. They belong to the subgenus L. (Viannia) and information on suitable models to understand immunopathology are scarce. Here, we explored the use of the golden hamster Mesocricetus auratus and its macrophages as a model for L. (Viannia) species. We also studied the interaction of parasite glycoconjugates (LPGs and GIPLs) in murine macrophages. The following strains were used: L. (V.) braziliensis (MHOM/BR/2001/BA788), L. (V.) guyanensis (MHOM/BR/85/M9945), L. (V.) shawi (MHOM/BR/96/M15789), L. (V.) lindenbergi (MHOM/BR/98/M15733) and L. (V.) naiffi (MDAS/BR/79/M5533). In vivo infections were initiated by injecting parasites into the footpad and were followed up at 20- and 40-days PI. Parasites were mixed with salivary gland extract (SGE) from wild-captured Nyssomyia neivai prior to in vivo infections. Animals were euthanized for histopathological evaluation of the footpads, spleen, and liver. The parasite burden was evaluated in the skin and draining lymph nodes. In vitro infections used resident peritoneal macrophages and THP-1 monocytes infected with all species using a MOI (1:10). For biochemical studies, glycoconjugates (LPGs and GIPLs) were extracted, purified, and biochemically characterized using fluorophore-assisted carbohydrate electrophoresis (FACE). They were functionally evaluated after incubation with macrophages from C57BL/6 mice and knockouts (TLR2-/- and TLR4-/-) for nitric oxide (NO) and cytokine/chemokine production. All species, except L. (V.) guyanensis, failed to generate evident macroscopic lesions 40 days PI. The L. (V.) guyanensis lesions were swollen but did not ulcerate and microscopically were characterized by an intense inflammatory exudate. Despite the fact the other species did not produce visible skin lesions there was no or mild pro-inflammatory infiltration at the inoculation site and parasites survived in the hamster skin/lymph nodes and even visceralized. Although none of the species caused severe disease in the hamster, they differentially infected peritoneal macrophages in vitro. LPGs and GIPLs were able to differentially trigger NO and cytokine production via TLR2/TLR4 and TLR4, respectively. The presence of a sidechain in L. (V.) lainsoni LPG (type II) may be responsible for its higher proinflammatory activity. After Principal Component analyses using all phenotypic features, the clustering of L. (V.) lainsoni was separated from all the other L. (Viannia) species. We conclude that M. auratus was a suitable in vivo model for at least four dermotropic L. (Viannia) species. However, in vitro studies using peritoneal cells are a suitable alternative for understanding interactions of the six L. (Viannia) species used here. LRV1 presence was found in L. (V.) guyanensis and L. (V.) shawi with no apparent correlation with virulence in vitro and in vivo. Finally, parasite glycoconjugates were able to functionally trigger various innate immune responses in murine macrophages via TLRs consistent with their inflammatory profile in vivo.

Identification of the Female Sex Pheromone of Grammodes Geometrica (Lepidoptera: Erebidae: Erebinae).

The female sex pheromone of Grammodes geometrica (Lepidoptera: Erebidae: Erebinae) was identified as a 2:100:4 mixture of (3Z,6Z,9Z)-3,6,9-icosatriene (T20), (3Z,6Z,9Z)-3,6,9-henicosatriene (T21), and (3Z,6Z,9Z)-3,6,9-tricosatriene (T23) through chemical and electrophysiological analyses of female gland extracts. T23 is a novel sex pheromone component in Erebinae species. Field trapping tests demonstrated optimal male captures in attractant-baited traps when using a 2:100:4 blend of T20, T21 and T23, with a significant decrease in captures observed when T20 or T23 were removed from the full blend. Traps were set in early August, but males began to be captured in early September. The seasonal prevalence showed a bimodal peak, occurring on September 11 and October 9. These findings provide valuable insights into the chemical communication and ecological dynamics of this species within the subfamily Erebinae.

Behavioural responses and characterization of preputial gland extract of black rat, Rattus rattus

Behavioural responses and characterization of preputial gland extract of black rat, Rattus rattus

Identification of the Sex Pheromone of the Asparagus Moth, Parahypopta Caestrum (Lepidoptera, Cossidae)

Chemical, electrophysiological, and field trapping experiments were carried out to identify the female-produced sex pheromone of the asparagus moth, Parahypopta caestrum, a very serious pests of asparagus cultivations in southern Europe. Gas chromatography coupled with mass spectrometry and electroantennogram detection (GC-MS-EAD) analysis of hexane and solid-phase microextraction (SPME) extracts of sex pheromone glands of calling females consistently detected four compounds eliciting EAG responses in male moth antennae. According to their GC retention times, mass spectra, and comparative EAG analyses with reference standards, these EAD-active compounds were identified as (Z)-9-tetradecenol (Z9-14:OH), (Z)-5-tetradecenyl acetate (Z5-14:Ac), (Z)-7-tetradecenyl acetate (Z7-14:Ac), and (Z)-9-tetradecenyl acetate (Z9-14:Ac), respectively. In the SPME extracts from the head-space of individual abdominal tips, Z9-14:Ac, Z5-14:Ac, Z7-14:Ac, and Z9:14 OH were detected in the ratio of 82:9:5:4. In EAG dose-response experiments, Z9-14:Ac was the strongest antennal stimulant at different doses tested. In field trapping experiments, Z9-14:Ac, Z7-14:Ac, and Z5-14:Ac proven to be essential for male attraction and a their 85:5:10 blend loaded onto green rubber septum dispensers was significantly more effective than single-, two-, and any other three-component blend of these compounds. The addition of Z9-14:OH to the optimal blend resulted in a significant reduction of male catches. The attractive blend here identified allowed for an effective and accurate monitoring of P. caestrum flight activity in southern Italy.

Sex Pheromone of the Saturniid Moth Hemileuca nevadensis from Southern California.

The major and possibly only component of the sex attractant pheromone of the moth Hemileuca nevadensis (Lepidoptera: Saturniidae) from southern California was determined to be (E10,Z12)-hexadecadienal (E10,Z12-16:Ald). Detectable quantities of the analogs (E10,Z12)-hexadecadien-1-yl acetate (E10,Z12-16:Ac) and (E10,Z12)-hexadecadien-1-ol (E10,Z12-16:OH) were also present in solvent extracts of sex pheromone glands, and stimulated male antennae in coupled gas chromatography-electroantennogram detector (GC-EAD) assays. GC-EAD traces from solid phase microextraction (SPME) wipe samples of sex pheromone glands of calling females confirmed the presence of E10,Z12-16:Ald and traces of E10,Z12-16:OH on the gland surface, but E10,Z12-16:Ac was not detected. Despite evidence for the presence of all three compounds in extracts, behavioral responses to synthetic compounds in the field suggested that only E10,Z12-16:Ald is required for optimal attraction.

Comparing carp pituitary gland extract and ovaprim in induced breeding of stinging Catfish

Comparing carp pituitary gland extract and ovaprim in induced breeding of stinging Catfish

In Vitro Assessment of the Anti-Proliferative and Anti-Viability Effects of Salivary Gland Extracts from Hyalomma ticks (Acari: Ixodidae) on Human Colorectal Cancer Cells.

The saliva and salivary glands of ticks possess a wide range of immuno-pharmacologically active molecules that effectively modulate the activity of enzymes, antibodies, and amines that have a role in different biological processes. Derived components from saliva and salivary glands of hard ticks Ixodidae have been characterized as potential natural sources for discovering promising anti-cancer drug candidates. The anti-cancer activity of salivary gland extracts (SGEs) from Hyalomma anatolicum, Hyalomma dromedarii, Hyalomma marginatum, and Hyalomma schulzei was assessed. MTT assays and flow cytometry were done on the HT-29 colorectal cancer cell line to evaluate the anti-viability and proliferative inhibition. Based on the MTT assay results, the SGEs from Hy. dromedarii had the highest and lowest substantial anti-viability effects on the HT-29 cancer cell and human foreskin fibroblast (HFF) normal cell, respectively. The cytometric assessment revealed a significant increase in the apoptosis and necrosis ratio of the HT-29 cancer cells after treatment with Hy. dromedarii SGEs. The results demonstrated that Hy. dromedarii SGEs have significant anti-proliferative, anti-viability, and apoptotic potential. The result of this study suggests that Hy. dromedarii SGEs is an appropriate candidate for further investigations to identify and purify the mechanisms and molecules involved in the anti-cancer activity of the SGEs.

In-vitro assessment of cutaneous immune responses to aedes mosquito salivary gland extract and dengue virus in Cambodian individuals.

Dengue virus (DENV) poses a global health threat, affecting millions individuals annually with no specific therapy and limited vaccines. Mosquitoes, mainly Aedes aegypti and Aedes albopictus worldwide, transmit DENV through their saliva during blood meals. In this study, we aimed to understand how Aedes mosquito saliva modulate skin immune responses during DENV infection in individuals living in mosquito-endemic regions. To accomplish this, we dissociated skin cells from Cambodian volunteers and incubated them with salivary gland extract (SGE) from three different mosquito strains: Ae. aegypti USDA strain, Ae. aegypti and Ae. albopictus wild type (WT) in the presence/absence of DENV. We observed notable alterations in skin immune cell phenotypes subsequent to exposure to Aedes salivary gland extract (SGE). Specifically, exposure lead to an increase in the frequency of macrophages expressing chemokine receptor CCR2, and neutrophils expressing CD69. Additionally, we noted a substantial increase in the percentage of macrophages that became infected with DENV in the presence of Aedes SGE. Differences in cellular responses were observed when Aedes SGE of three distinct mosquito strains were compared. Our findings deepen the understanding of mosquito saliva's role in DENV infection and skin immune responses in individuals regularly exposed to mosquito bites. This study provides insights into skin immune cell dynamics that could guide strategies to mitigate DENV transmission and other arbovirus diseases.

Gonadotropic Activity of Pituitary Extract of African Catfish, Clarias gariepinus, in Mammals using Immature Wistar Rats as Models.

The pituitary glands normally produce and stores gonadotropic hormones (GnH) that are responsible for ovulation and spermiation in animals. However, whether fish pituitary extracts can elicit same effects in treated animals need elucidation as a prelude to their practical usage in animals. The aim of this study was to investigate the oestrus-inducing potential of the pituitary gland extract of the Africa Catfish (Clarias gariepinus) in immature Wistar rats. The experiment involved the use of 18 immature female Wistar rats and 10 male catfish brood stocks with the use of six Wistar rats per groups as follows: Group A had human chorionic gonadotropin (hCG) treatment. Group B had only normal saline treatment as the control whereas Group C had the C. gariepinus pituitary extract administration to induce oestrus with treatments occurring twice six hours apart in each group. There was an obvious expression of visible signs of heat and the presence of uterine horn oedema with significant (p < 0.05) increase in reproductive tract weight and uterine width and length. However, only progesterone levels increased significantly (p < 0.05) in the hCG and the C. gariepinus pituitary extract treated groups compared to other assayed hormones. These results showed that C. gariepinus pituitary extract has the capacity to induce oestrus in Wistar rats because of its gonadotropic effects, which needs further investigations at higher doses and for longer exposure periods for possible oestrus induction and synchronization in higher mammals. Further favourable results could herald the possible patent of the catfish pituitary extract for either experimental or commercial use in mammals.

Structural and functional comparisons of salivary α-glucosidases from the mosquito vectors Aedes aegypti, Anopheles gambiae, and Culex quinquefasciatus

Mosquito vectors of medical importance both blood and sugar feed, and their saliva contains bioactive molecules that aid in both processes. Although it has been shown that the salivary glands of several mosquito species exhibit α-glucosidase activities, the specific enzymes responsible for sugar digestion remain understudied. We therefore expressed and purified three recombinant salivary α-glucosidases from the mosquito vectors Aedes aegypti, Anopheles gambiae, and Culex quinquefasciatus and compared their functions and structures. We found that all three enzymes were expressed in the salivary glands of their respective vectors and were secreted into the saliva. The proteins, as well as mosquito salivary gland extracts, exhibited α-glucosidase activity, and the recombinant enzymes displayed preference for sucrose compared to p-nitrophenyl-α-D-glucopyranoside. Finally, we solved the crystal structure of the Ae. aegypti α-glucosidase bound to two calcium ions at a 2.3 Ångstrom resolution. Molecular docking suggested that the Ae. aegypti α-glucosidase preferred di- or polysaccharides compared to monosaccharides, consistent with enzymatic activity assays. Comparing structural models between the three species revealed a high degree of similarity, suggesting similar functional properties. We conclude that the α-glucosidases studied herein are important enzymes for sugar digestion in three mosquito species.

Structure, Synthesis, and Bioassays of Sex Pheromone for Pyrausta machaeralis (Lepidoptera: Crambidae).

The leaf skeletonizer, Pyrausta machaeralis (Lepidoptera: Crambidae), is a serious insect pest of teak (Tectona grandis) in China. The application of insect pheromones is widely applied as an environmentally friendly technology for integrated pest management (IPM). In the present study, crude extracts of sex pheromone glands of calling P. machaeralis females were collected and then analyzed using gas chromatography/electroantennographic detection (GC/EAD) and gas chromatography-mass spectrometry (GC-MS). The combination of infrared spectroscopy (IR) and nuclear magnetic resonance (NMR) spectrometry was used for structure identification. Afterward, their electrophysiological and behavioral activity was evaluated in the laboratory and field. Herein, we eventually determined two active components, E-11-tetradecenyl acetate (E11-14:Ac) and Z-11-tetradecenyl acetate (Z11-14:Ac), at a ratio of 96:4, as the sex pheromone of P. machaeralis. The identification of sex pheromones would facilitate the development of efficient strategies for monitoring and controlling the field populations of P. machaeralis.

Blacklegged ticks, Ixodes scapularis, reduce predation risk by eavesdropping on communication signals of Formica oreas thatching ants.

Ticks spend most of their life inhabiting leaf litter and detritus where they are protected from sun but preyed upon by ants. Ants secrete chemical communication signals to coordinate group tasks such as nest defence. Ticks that avoid ant semiochemicals-as indicators of ant presence-would reduce predation risk by ants. We tested the hypotheses that: (i) chemical deposits from the thatching ant Formica oreas deter blacklegged ticks, Ixodes scapularis, (ii) deterrent semiochemicals originate from the ants' poison and/or Dufour's gland(s), and (iii) tick-deterrent semiochemicals serve as alarm-recruitment pheromone components in F. oreas. In two-choice olfactometer bioassays, filter paper soiled with ant chemical deposits significantly deterred female and male ticks. Poison and Dufour's gland extracts deterred ticks in combination but not alone. Gas chromatographic-mass spectrometric analyses of gland extracts revealed formic acid as the major constituent in the poison gland and eight hydrocarbons as constituents in the Dufour's gland. Synthetic formic acid and hydrocarbons deterred ticks only when combined. F. oreas workers sprayed both formic acid and hydrocarbons when distressed. A synthetic blend of these compounds elicited alarm-recruitment responses by F. oreas in behavioural bioassays. All results combined indicate that ticks eavesdrop on the ants' communication system.

A bio-inspired approach for the synthesis of few-layer graphene using beetle defensive gland extract.

Graphene exhibits remarkable properties and holds substantial promise for diverse applications. Its unique combination of thermal, chemical, physical, and biological properties makes it an appealing material for a wide range of uses. But, the lack of an economical and environmentally friendly approach to synthesize good-quality graphene represents an immense challenge for the scientific community. What makes this research unique is the utilization of the defensive gland extract from the beetle species Luprops tristis (Order: Coleoptera, Family: Tenebrionidae) to synthesize a few layers of graphene (FLG). This innovative incorporation of natural resources and exploration of biologically inspired methods provides an eco-friendly and cost-effective alternative to conventional graphene production techniques. The exfoliated graphene displayed antimicrobial effects against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria, with particularly potent bactericidal activity. Additionally, the cytotoxicity assay demonstrated the anti-cancer properties of biosynthesized graphene against Daltons Lymphoma Acetic (DLA) cells.

Bioactive compounds in pituitary gland extracts

Bioactive compounds in pituitary gland extracts

Aggregation Role of Mandibular Gland Secretions in the Giant Tropical Ant Paraponera clavata (Formicidae: Paraponerinae)

Social insects exhibit sophisticated behavioral repertoires to maintain communication and regulate colony activities. To elucidate the behavioral mechanisms of social insects is essential a thorough understanding of morphophysiological characteristics, such as the functionality of exocrine gland secretions. In this study, it was analyzed whether the mandibular gland secretions influence the aggregation behavior of workers of the ant Paraponera clavata. Associated behavioral acts were also studied. Bioassays indicated that mandibular gland extract triggers aggregation behaviors in P. clavata workers. The observed behavioral acts include mandible opening, raising of the antennae, antennal contact with treated filter paper, selfgrooming, cleaning of the abdominal tip, and allogrooming. These observations demonstrate the potential multifunctionality of compounds secreted by mandibular glands within the behavioral repertoire of P. clavata.