Involvement of IL-6/JAK/STAT3/SOCS3, SIRT1, and Cytoglobin Signaling in Diacerein Protective Effect against Intestinal Injury Induced by Methotrexate.

Despite its wide applications, methotrexate (MTX) causes significant intestinal toxicity by inducing oxidative stress, inflammatory cascades, and apoptosis. Diacerein (DIA) is a pain-relieving and anti-inflammatory medication with favorable antioxidant properties. We investigated DIA protective effects on MTX-induced intestinal toxicity. Rats were divided into five groups: Control, DIA (50 mg/kg), MTX (single dose of 20 mg/kg; i.p. on 5th day), DIA (25 mg/kg) + MTX, and DIA (50 mg/kg) + MTX. Compared to the MTX-treated group, DIA alleviated MTX-induced intestinal histopathological abrasions and inflammatory cell infiltration, improving average villous length and crypt depth. Furthermore, DIA exhibited potent antioxidative properties, evident by decreasing lipid peroxidation and increasing SOD activity and GSH content, and upregulating the expression of SIRT1 and cytoglobin. In addition, DIA ameliorated MTX-induced intestinal inflammation demonstrated by decreasing IL-6 and TNF-α mediated via suppressing NF-κBp65, phosphorylation of JAK1/STAT3, and upregulation of SOCS3 expression compared to the MTX-treated group. Furthermore, DIA inhibited intestinal apoptotic alterations by reducing cleaved caspase-3 protein expression. These results suggest that DIA, in a dose-dependent manner, could be an effective treatment for reducing intestinal toxicity by MTX via exerting an antioxidant effect, anti-inflammatory properties, and antiapoptotic activity with possible involvement of NF-κBp65, IL-6/JAK1/STAT3/SOCS3, SIRT1, and cytoglobin signaling.