Soybean germ oil inhibits oxidosqualene cyclase in 3T3 fibroblasts

Abstract

Soybean germ oil (SGO) could take an important place among nutraceuticals if the finding were confirmed that a daily intake of SGO helps to maintain a normal level of serum cholesterol. Adapting the rice milling technology to the soybean refining process, we achieved a rapid and efficient separation of soybean bran and cotyledon from the hypocotyle. Our soybean germ was no less than 95% hypocotyle. SGO obtained from it by typical hexane extraction was very rich in tocopherols (total content 4.35 g/kg) and phytosterols (b-sitosterol 57.4%, D-7-stigmastenol 20.2%, D-7-avenasterol 6.8%, stigmasterol 6.2%, campesterol 5.4%, D-7-campesterol 1.2%, D-5-avenasterol 0.95%, etc.; total sterols 44.3 g/kg). The most prominent fatty acids were linoleic (56.2%), linolenic (15.5%) and oleic acid (10.6%). Although isoflavones abound in soybean germ (17.7 g/kg), only traces of them passed into the hexane extract (7 mg/kg). In murine 3T3 fibroblasts, SGO was found to reduce the incorporation of [ 14 C]acetate into sterols, by inhibiting oxidosqualene cyclase.

The characterization of soybean germ oil and the antioxidative activity of its phytosterols

“… 1 Currently, soybean germ is not commonly used for human consumption but is mainly used an ingredient in animal feeds. 2 It is rich in various nutrients including polyunsaturated fatty acids, protein, phytosterols, 3 tocopherols, 4 isoflavones and saponins. 5 In this regard, recent research has demonstrated that soybean germ protein could decrease weight due to body fat and increase the muscle weight of hind limbs in experimental animals, 6 while soybean germ oil could reduce blood cholesterol 7 and prevent UVB-induced cutaneous erythema.…”