Vitamin C, Hydrocortisone, and the Combination Thereof Significantly Inhibited Two of Nine Inflammatory Markers Induced by Escherichia Coli But Not by Staphylococcus Aureus – When Incubated in Human Whole Blood

Vitamin C combined with hydrocortisone is increasingly being used to treat septic patients, even though this treatment regimen is based on questionable evidence. When used, a marked effect on key players of innate immunity would be expected, as sepsis is featured by a dysregulated immune response. Here, we explored the effect of vitamin C and hydrocortisone alone and combined, in an ex vivo human whole-blood model of Escherichia coli- or Staphylococcus aureus-induced inflammation. Inflammatory markers for activation of complement (terminal C5b-9 complement complex [TCC]), granulocytes (myeloperoxidase), platelets (β-thromboglobulin), cytokines (tumor necrosis factor [TNF], IL-1β, IL6, and IL-8), and leukocytes (CD11b and oxidative burst) were quantified, by enzyme-linked immunosorbent assay, multiplex technology, and flow cytometry. In E. coli- and S. aureus-stimulated whole blood, a broad dose-titration of vitamin C and hydrocortisone alone did not lead to dose–response effects for the central innate immune mediators TCC and IL-6. Hence, the clinically relevant doses were used further. Compared to the untreated control sample, two of the nine biomarkers induced by E. coli were reduced by hydrocortisone and/or vitamin C. TNF was reduced by hydrocortisone alone (19%, P = 0.01) and by the combination (31%, P = 0.01). The oxidative burst of monocytes and granulocytes was reduced for both drugs alone and their combination, (ranging 8–19%, P < 0.05). Using S. aureus, neither of the drugs, alone nor in combination, had any effects on the nine biomarkers. In conclusion, despite the limitation of the ex vivo model, the effect of vitamin C and hydrocortisone on bacteria-induced inflammatory response in human whole blood is limited and following the clinical data.