A composition for preventing or treating immune diseases comprising dandelion(Taraxacum offininale) water extract is provided to suppress the generation of nitrogen oxide (NO) and iNOS(inducible nitrogen oxide synthetase) by accelerating the expression of mRNA(messenger RNA) of heme oxygenase-1(HO-1) and protein and increasing the enzyme activity. A composition for preventing or treating immune diseases comprising dandelion(Taraxacum offininale) water extract as an active ingredient. The dandelion water extract is obtained by heating after mixing organic dandelion powder and water, filtering after decompression, freezing and drying them. The one day dose of the active compound is 0.000001-1 mg/kg, preferably 0.001-500 mg/kg, more preferably 10-300 mg/kg. The immunization disease is acute and chronic infection, acute and chronic bronchitis, osteoarthritis, rheumatoid arthritis, sinusitis, gastroenteritis, colitis, cystitis, urethritis, dermatitis, conjunctivitis, pericarditis, peritonitis, synovitis, pleurisy, tendinitis, cholecystitis, vaginitis or uveitis.본 발명은 민들레 (dandelion (Taraxacum offininale)) 열수추출물을 유효성분으로 함유하는 면역질환의 예방 또는 치료용 조성물에 관한 것으로, 본 발명의 조성물은 헴옥시게나제-1 (heme oxygenase-1, HO-1)의 mRNA 및 단백질 발현을 촉진시키고 효소 활성을 증가시킴으로써 일산화질소 (NO) 및 iNOS (inducible NOS)의 생성을 억제하고 과산화수소에 의한 세포손상을 감소시키므로, 산화적 스트레스 감소를 통한 면역질환의 예방 및 치료에 효과적으로 사용될 수 있다.
