Conventional oligonucleotides are opened at both ends and thereby unstable. Their stability against catabolic enzymes is increased by phosphorothioate modification, but such phosphorothioate causes toxicity. The present invention provides oligonucleotides and medicaments in which these problems are improved. That is, it provides staple oligonucleotides and medicaments containing the same as the active ingredient. Specifically, it provides transcription factor inhibitors, antisense oligonucleotides and siRNAs. More specifically, it provides agents for preventing, treating or improving inflammation, autoimmune diseases, central diseases, reperfusion injury in ischaemic diseases, worsened prognosis after organ transplantation or organ surgery, or restenosis after PTCA. Further specifically, it provides agents for preventing, treating or improving arthritis, dermatitis, nephritis, hepatitis, renal failure, cystitis, prostatitis, urethritis, ulcerative colitis, Crohn disease, chronic rheumatoid arthritis, osteoarthritis, atopic dermatitis, contact dermatitis, psoriasis, cutaneous ulcer or decubitus.