Combined effect of methotrexate and bifidobacteria metabolites on TNFα AND IFNγ production by human peripheral blood mononuclears

Methotrexate (Mtx) is a first-line drug for the treatment of numerous rheumatic and non-rheumatic disorders, including oncological disdiseases. However, therapeutic efficacy of Mtx is limited by severe toxicity to many organs (myelo-, hepato-, nephrotoxicity, mucositis, enteritis, dysbiosis at various human biotopes, etc.). Recently, a number of studies showed that some metabolites of Bifidobacteria and Lactobacilli are able to enhance effect of chemotherapeutic drugs and limit their toxic properties. The aim of the present work was to study the possible potentiating action of Bifidobacteria cell-free supernatants and methotrexate upon secretion of pro-inflammatory TNFα and IFNγ cytokines by human peripheral blood mononuclear cells (PBMCs). The immunoregulatory effects upon production of TNFα and IFNg  was evaluated in the in vitro model of cultured PBMC supplemented with Bifidobacteria metabolites, methotrexate, or their combination. Analysis of the combined effect of Bifidobacteria metabolites and Mtx on the cytokine production revealed their synergism towards the key pro-inflammatory cytokines (TNFα and IFNγ). We found an increase against the control cultures (with Mtx only), inhibition of the early pro-inflammatory cytokine TNFα production. On the contrary, we revealed an increased secretion of IFNγ which regulates the effector cells. The results obtained with these cytokines suggest the presence of a potentiating effect of Bifidobacteria metabolites upon anti-inflammatory and immunoregulatory properties of methotrexate. Thus, Bifidobacteria metabolites can be considered a promising agent which potentiates the therapeutic action of methotrexate by suppressing TNFα secretion and stimulating IFNγ by immunocompetent cells. Further studies of the combined effects of Mtx and metabolites from the intestinal microbiota upon the cytokine production by effector cells could be recommended, aiming to enhance therapeutic effect of methotrexate and limit its toxic properties using the Bifidobacteria metabolites.