Activation of the mitochondrial apoptotic pathway contributes to methotrexate-induced small intestinal injury in rats

Mito-TEMPO mitigates 5-fluorouracil-induced intestinal injury via attenuating mitochondrial oxidative stress, inflammation, and apoptosis: an in vivo study

BACKGROUND

Recent evidences highlight role of mitochondria in the development of 5-fluorouracil (5-FU)-induced intestinal toxicity. Mitochondria-targeted antioxidants are well-known for their protective effects in mitochondrial oxidative stress- mediated diseases. In the present study, we investigated protective effect of Mito-TEMPO in 5-FU-induced intestinal toxicity.

METHODS

Mito-TEMPO (0.1 mg/kg b.w.) was administered intraperitoneally to male BALB/c mice for 7 days, followed by co-administration of 5-FU for next 4 days (intraperitoneal 12 mg/kg b.w.). Protective effect of Mito-TEMPO on intestinal toxicity was assessed in terms of histopathological alterations, modulation in inflammatory markers, apoptotic cell death, expression of 8-OhDG, mitochondrial functional status and oxidative stress.

RESULTS

5-FU administered animals showed altered intestinal histoarchitecture wherein a shortening and atrophy of the villi was observed. The crypts were disorganized and inflammatory cell infiltration was noted. Mito-TEMPO pre-protected animals demonstrated improved histoarchitecture with normalization of villus height, better organized crypts and reduced inflammatory cell infiltration. The inflammatory markers and myeloperoxidase activity were normalized in mito-TEMPO protected group. A significant reduction in intestinal apoptotic cell death and expression of 8-OhDG was also observed in mito-TEMPO group as compared to 5-FU group. Further, mtROS, mtLPO and mitochondrial antioxidant defense status were improved by mito-TEMPO.

CONCLUSION

Mito-TEMPO exerted significant protective effect against 5-FU-induced intestinal toxicity. Therefore, it may be used as an adjuvant in 5-FU chemotherapy.

Dioscin ameliorates methotrexate-induced liver and kidney damages via adjusting miRNA-145-5p-mediated oxidative stress

Dioscin, one natural product, has various pharmacological actions. However, its effects on methotrexate (MTX)-induced hepatorenal damages still remain unknown. In the present study, the data manifested that dioscin restored the viabilities of L-02 and NRK-52E cells, reduced ALT, AST, Cr, BUN levels, and ameliorated histopathological changes of liver and kidney. Besides, dioscin decreased ROS levels in cells, and adjusted SOD, MDA, GSH and GSH-Px levels in rats. Dioscin reduced the expression levels of miR-145-5p which directly targeted Sirt5, and then regulated the expression levels of SOD1, Nrf2, Gst, Keap1, HO-1, GCLC and NQO1. MiR-145-5p mimic in cells deteriorated ROS levels and decreased Sirt5 expression to accentuate oxidative stress by regulating the expression levels of SOD1, Nrf2, Keap1, which were all reversed by dioscin. Moreover, MTX-induced hepatorenal damage were worsened in mice by Sirt5 siRNA or miR-145-5p agomir, which were also alleviated by dioscin. Dioscin relieved MTX-induced hepatorenal damages through regulating miR-145-5p-medicated oxidative stress, which should be considered as one effective drug to treat the disorder in future.