Effects of dexamethasone and acetylsalicylic acid on inflammation caused by Complete Freund's adjuvant in the naked mole rat (Heterocephalus glaber)

Abstract

The naked mole rat (NMR) is a fossorial rodent that has been observed to have a unique nociceptive system in comparison to others. In this study, we explored on characterization of chronic inflammation in the NMR using Complete Freund's adjuvant (CFA) and investigated the effects of dexamethasone and acetylsalicylic acid on the resulting inflammation. The NMRs were injected with 0.1 ml of CFA subcutaneously in the right hind paw, and an equivalent volume of normal saline was injected to the control group. Swelling of the injected right hind limb was observed within 24 h of injection, which involved the tibiotarsal joint, palmar surface and the digits of the injected paw. Swelling persisted for 6 weeks of experimentation and peaked between day 14 and 21. The resulting inflammation affected the mobility, stance and joint rigidity of CFA treated NMRs in comparison to the control group. Treatment of the chronic phase of the inflammation from the 11 th day with dexamethasone and acetylsalicylic acid showed no statistical significance in paw circumference compared to the control group, other than on a few, negligible occasions. The present data showed that CFA was able to induce chronic inflammation in the NMR, and the NMR could thus be established as a model for chronic inflammation. There is, however, need for more sensitive parameters to evaluate the effects of anti-inflammatory drugs.

Integrating network pharmacology and experimental verification to reveal the anti-inflammatory ingredients and molecular mechanism of pycnogenol

“…For example, dexamethasone binds to the cytoplasmic GC receptor to form a heterodimer that translocated from the cytosol to the nucleus, where it transactivates or transrepresses target genes, leading to cell-cycle arrest and apoptosis ( Zhang et al, 2023 ); aspirin is known to block cyclooxygenase activity ( Nyambuya et al, 2023 ). Therefore, treatment of the chronic inflammation, dexamethasone and aspirin showed no effect ( Thuo et al, 2022 ). Different from traditional anti-inflammatory agents, PYC could affect inflammation via multi-components, -targets and -mechnism, which avoid drug resistance and is suitable for long-term use.…”

Evaluation of hematoprotective, hepatoprotective, and anti-inflammatory potentials of chia seed (Salvia hispanica L.) extract in rats

“…Inflammatory paw edema was induced by a single sub-plantar injection of 100 μL carrageenan (CAR) into the left hind paws of the rats, which was freshly prepared as a 1 % solution in distilled water. Dexamethasone (DEX) (3 mg/kg BW, IP) was employed as a reference standard anti-inflammatory drug ( Thuo et al, 2022 ). Treatment with the extracts was performed by oral administration of CSE mixed with the calculated amount of feed during feed formulation.…”

Table3.XLSX

“…For example, dexamethasone binds to the cytoplasmic GC receptor to form a heterodimer that translocated from the cytosol to the nucleus, where it transactivates or transrepresses target genes, leading to cell-cycle arrest and apoptosis (Zhang et al, 2023); aspirin is known to block cyclooxygenase activity (Nyambuya et al, 2023). Therefore, treatment of the chronic inflammation, dexamethasone and aspirin showed no effect (Thuo et al, 2022). Different from traditional anti-inflammatory agents, PYC could affect inflammation via multi-components, -targets and -mechnism, which avoid drug resistance and is suitable for longterm use.…”