Carbon monoxide is typically dangerous because it binds to the hemoglobin in red blood cells with a much higher affinity than oxygen. In high doses, carbon monoxide prevents oxygen from binding to red blood cells, leading to oxygen deprivation and ultimately, death.
In low doses, however, researchers have noticed that carbon monoxide has beneficial effects in a number of diseases (1). In particular, low doses of carbon monoxide can trigger the expression of the gene heme oxygenase 1 (HO-1), which activates anti-inflammatory and anti-oxidative stress pathways.
DrugDeliveryNrews published on the team at Hillhurst Biopharmaceuticals are experts in formulating therapeutic gases into liquid treatments so that they are easy for people to take and are formulated in precise dosages. By working with their collaborators at Augusta University led by ophthalmology researcher Pamela Martin, the scientists at Hillhurst Biopharmaceuticals created a low dose carbon monoxide oral drug called HBI-002. When the researchers gave mice with retinal ischemia oral HBI-002, the drug stopped any further damage to the retina, and the mice’s visual function improved (2).
The Cyclodextrin News has published on a special cyclodextrin dimer modified with iron(II)porphyrin (from Doshisha University) as artificial hemoglobin able to bind and detect low concentrations of CO in the body (3). It would be interesting to find cyclodextrin-assisted formulation(s) of CO.
- Ryter, S.W. and Choi, A.M.K. Targeting heme oxygenase-1 and carbon monoxide for therapeutic modulation of inflammation. Transl Res 167, 7-34 (2016).https://doi.org/10.1016/j.trsl.2015.06.011
- Jadeja, R. et al. HBI-002 treatment improves retinal ischemia-reperfusion injury in mice. Invest Ophthalmol Vis Sci 63, 2983-F0224 (2022). https://iovs.arvojournals.org/article.aspx?articleid=2780627