Pengaruh Asam Lemak Jenuh, Tidak Jenuh dan Asam Lemak Trans terhadap Kesehatan

Dewasa ini pola makan modern sering dihubungkan dengan meningkatnya kadar kolesterol di dalam darah. Tingginya kolesterol darah dapat memicu munculnya penyakit degeneratif seperti stroke dan penyakit jantung koroner. Jenis makanan yang diduga berpengaruh terhadap timbulnya penyakit degeneratif yaitu makanan yang mengandung asam lemak jenuh dan asam lemak trans. Asam lemak trans memiliki pengaruh hampir 2 kali lipat dalam meningkatkan rasio K-LDL/K-HDL dibandingkan dengan asam lemak jenuh. Perubahan pada rasio kolesterol total/HDL-K atau K-LDL/K-HDL merupakan prediktor CHD (Coronary Heart Disease).Kata kunci : Asam lemak jenuh, asam lemak trans, penyakit degenatifAbstractNowadays modern meal pattern is related to the increase of cholesterol level in the blood. The high blood cholesterol can lead to degenerative diseases such as stroke and coronary heart disease. Foods that suspected to influence the occurrence of degenerative diseases are saturated fatty acid and trans fatty acid. Trans fatty acid can influence almost twice higher in increasing ratio of K-LDL/K-HDL compared to saturated fatty acid. The change in ratio of total cholesterol/ HDL-K or K-LDL/K-HDL is predictor of coronary heart disease.Keywords : Saturated fatty acid, trans fatty acid, degenerative diseases

NodFE-Dependent Fatty Acids That Lack an α-β Unsaturation Are Subject to Differential Transfer, Leading to Novel Phospholipids

In Rhizobium leguminosarum, the nodABC and nodFEL operons are involved in the production of lipo-chitin oligosaccharide signals that mediate host specificity. A nodFE-determined, highly unsaturated C18:4 fatty acid (trans-2, trans-4, trans-6, cis-11-octadecatetraenoic acid) is essential for the ability of the signals to induce nodule meristems and pre-infection thread structures on the host plant Vicia sativa. Of the nod genes, induction of only nodFE is sufficient to modify fatty acid biosynthesis to yield trans-2, trans-4, trans-6, cis-11-octadeca-tetraenoic acid, with an absorbance maximum of 303 nm. This unusual C18:4 fatty acid is not only found in the lipo-chitin oligosaccharides but is also associated with the phospholipids (O. Geiger, J. E. Thomas-Oates, J. Glushka, H. P. Spaink, and B. J. J. Lugtenberg, 1994, J. Biol. Chem. 269:11090-11097). Here we report that the phospholipids can contain other nodFE-derived fatty acids, a C18:3 trans-4, trans-6, cis-11-octadecatrienoic acid that has a characteristic absorption maximum at 225 nm, and a C18:2 octadecadienoic acid. Neither this C18:3 nor this C18:2 fatty acid has to date been observed attached to lipo-chitin oligosaccharides, suggesting that an as yet unknown acyl transferase (presumably NodA), responsible for the transfer of the fatty acyl chain to the glycan backbone of the lipo-chitin oligosaccharides, does not transfer all fatty acids synthesized by the action of NodFE to the lipo-chitin oligosaccharides. Rather, it must have a preference for α-β unsaturated fatty acids during transfer.