Indomethacin-induced gut damage in a surrogate insect model, Galleria mellonella

Abstract

Indomethacin is a non-steroidal anti-inflammatory drug that causes gastric ulceration and increased 'leakiness' in rat models, and is used routinely as a toxicology assay to screen novel compounds for repair and restitution properties. We set out to establish conditions for indomethacin-induced gut damage in wax-moth (Galleria mellonella) larvae with a view to reducing the need for rodents in such experimentation. We administered indomethacin (0.5-7.5 µg/larva; 2-30 mg/kg) to G. mellonella via intrahaemocoelic injection and gavage (force-feeding) and monitored survival and development, blood cell (haemocyte) numbers, and changes in gut permeability. Increased levels of gut leakiness were observed within the first 4-to 24 h by tracking fluorescent microspheres in the faeces and haemolymph (blood equivalent). Additionally, we recorded varying levels of tissue damage in histological sections of the insect midgut, including epithelial sloughing and cell necrosis. Degeneration of the midgut was accompanied by significant increases in detoxification-associated activities (superoxide dismutase and glutathione-S-transferase). Herein, we present the first evidence that G. mellonella larvae force-fed indomethacin display broad symptoms of gastric damage similar to their rodent counterparts.

The Antioxidant Peptide Salamandrin-I: First Bioactive Peptide Identified from Skin Secretion of Salamandra Genus (Salamandra salamandra)

“…Peptides that have no toxicity in this model have been demonstrated by several studies [66][67][68]. Another way to study the toxic effects in the G. mellonella model is through histological analysis [69]. The lack of melanization in larvae 0 and 7 days after treatment demonstrates that the animals were in good physiological condition ( Figure 7B).…”

“…Considering the global trend to minimize the use of vertebrates in experimentation, there is constant need to develop alternative model systems in vitro, in vivo, or in silico. One such in vivo alternative is the larvae of the greater wax-moth, G. mellonella [69].…”

Txp40, a protein from Photorhabdus akhurstii, conferred potent insecticidal activity against the larvae of Helicoverpa armigera, Spodoptera litura and S. exigua

“…A hypothesis to explain this finding is that access of the toxin to midgut from hemocoel was via permeable smooth septate junctions in the midgut–hemocoel barrier, or possibly the toxin targeted receptor proteins that are present in the smooth septate intercellular junctions of the insect midgut (but not in the foregut/hindgut and in mammals) . An increased level of gut leakiness coupled with midgut epithelial sloughing in G. mellonella due to intra‐hemocoelic injection of indomethacin drug was demonstrated by Emery et al …”

Get a look at Galleria

“…There were increases in circulating immune cells, while fluorescent microspheres revealed more gut leakiness. There was also evidence of tissue damage in the midgut, such as cellular necrosis and epithelial sloughing, along with heightened detoxification activity 5 .…”