Glucosamine inhibits decidualization of human endometrial stromal cells and decreases litter sizes in mice.
Tsai, J. H., Schulte, M., O'Neill, K., Chi, M. M. Y., Frolova, A. I. & Moley, K. H. (2013). Biology of Reproduction, 89(1), 16, 1-10.
Embryo implantation in the uterus depends on decidualization of the endometrial stromal cells (ESCs), and glucose utilization via the pentose phosphate pathway is critical in this process. We hypothesized that the amino sugar glucosamine may block the pentose phosphate pathway via inhibition of the rate-limiting enzyme glucose-6-phosphate dehydrogenase in ESCs and therefore impair decidualization and embryo implantation, thus preventing pregnancy. Both human primary and immortalized ESCs were decidualized in vitro in the presence of 0, 2.5, or 5 mM glucosamine for 9 days. Viability assays demonstrated that glucosamine was well tolerated by human ESCs. Exposure of human ESCs to glucosamine resulted in significant decreases in the activity and expression of glucose-6-phosphate dehydrogenase and in the mRNA expression of the decidual markers prolactin, somatostatin, interleukin-15, and left-right determination factor 2. In mouse ESCs, expression of the decidual marker Prp decreased upon addition of glucosamine. In comparison with control mice, glucosamine-treated mice showed weak artificial deciduoma formation along the stimulated uterine horn. In a complementary in vivo experiment, a 60-day-release glucosamine (15, 150, or 1500 μg) or placebo pellet was implanted in a single uterine horn of mice. Mice with a glucosamine pellet delivered fewer live pups per litter than those with a control pellet, and pup number returned to normal after the end of the pellet-active period. In conclusion, glucosamine is a nonhormonal inhibitor of decidualization of both human and mouse ESCs and of pregnancy in mice. Our data indicate the potential for development of glucosamine as a novel, reversible, nonhormonal contraceptive.
Cuticle hydrolysis in four medically important fly species by enzymes of the entomopathogenic fungus Conidiobolus coronatus.
Boguś, M. I., Włóka, E., Wrońska, A., Kaczmarek, A., Kazek, M., Zalewska, K., Ligeza-Zuber, M. & Gołębiowski, M. (2016). Medical and Veterinary Entomology, 31(1), 23-35.
Entomopathogenic fungi infect insects via penetration through the cuticle, which varies remarkably in chemical composition across species and life stages. Fungal infection involves the production of enzymes that hydrolyse cuticular proteins, chitin and lipids. Host specificity is associated with fungus–cuticle interactions related to substrate utilization and resistance to host-specific inhibitors. The soil fungus Conidiobolus coronatus (Constantin) (Entomophthorales: Ancylistaceae) shows virulence against susceptible species. The larvae and pupae of Calliphora vicina (Robineau-Desvoidy) (Diptera: Calliphoridae), Calliphora vomitoria (Linnaeus), Lucilia sericata (Meigen) (Diptera: Calliphoridae) and Musca domestica (Linnaeus) (Diptera: Muscidae) are resistant, but adults exposed to C. coronatus quickly perish. Fungus was cultivated for 3 weeks in a minimal medium. Cell-free filtrate, for which activity of elastase, N-acetylglucosaminidase, chitobiosidase and lipase was determined, was used for in vitro hydrolysis of the cuticle from larvae, puparia and adults. Amounts of amino acids, N-glucosamine and fatty acids released were measured after 8 h of incubation. The effectiveness of fungal enzymes was correlated with concentrations of compounds detected in the cuticles of tested insects. Positive correlations suggest compounds used by the fungus as nutrients, whereas negative correlations may indicate compounds responsible for insect resistance. Adult deaths result from the ingestion of conidia or fungal excretions.
Extraction of Glycosaminoglycans Containing Glucosamine and Chondroitin Sulfate from Chicken Claw Cartilage.
Widyaningsih, T. D., Rukmi, W. D., Sofia, E., Wijayanti, S. D., Wijayanti, N., Ersalia, R., Rochmawati, N. & Nangin, D. (2016). Research Journal of Life Science, 3(3), 181-189.
Chicken cartilage (claw) is a waste of chicken cuts which are widely available in Indonesia. Cartilage part of chicken claw becomes a potential source of chondroitin sulfate (CS) and glucosamine (GS). This study aims to determine the most optimal extraction methods of CS and GS from cartilage of chicken claw. Various types of extraction methods used in this study are taken from the extraction by using boiling water (2 and 2.5 hours), acetic acid (7 and 17 hours), as well as proteolysis by papain (24 and 48 hours). Parameters observed include chemical characteristics of powdered cartilage of chicken claw as well as CS and GS levels in powdered cartilage of chicken claw extract. The results of this research show that the levels of CS and GS of chicken claw cartilage powder were 2.17% and 13%. Meanwhile, the highest GS level was obtained from the extraction with water treatment for 2.5 hours which was 8.1%. The treatment and duration of extraction will significantly affect the number of GS which was produced. The highest content of CS was obtained from the extraction with the enzyme treatment for 48 hours which was 2.47%. The best treatment is the extraction with water treatment for 2.5 hours which were the extracts with GS levels of 8.1% and 2.03% CS was selected through the analysis of multiple attribute.