An oxygen electrode method to determine efficacy of plant derived material to inhibit lipid peroxidation

摘要

A method is described to assay the efficacy of natural plant materials to inhibit lipid peroxidation. Using an aqueous system employing linoleic acid in an emulsion with AAPH (2,2'-azobis(2-aminidinopropane) dihydrochloride) as a free radical initiator, steady state rates of oxygen uptake may be established. The rate of oxygen uptake is proportional to the rate of lipid peroxidation. The addition of aqueous solutions of plant extracts, either crude or refined may be observed to inhibit the rate ofoxygen uptake if the product is an effective antioxidant. The system is dynamic, inexpensive and can be used by a technician with minimal training time. A permanent record is available using graph paper, or a more sophisticated record can be obtain by interfacing with a data input computer. Calculations are made directly on the graph paper by measuring ratios of run/rise and comparing percentage increase or decrease of reaction rates. The role of iron in biological systems is becoming increasingly complex, but more and more is being discovered about both the beneficial and deleterious aspects of iron. The need for safe and effective iron chelators in human health is becoming more apparent. This method can be used to screen natural products for both antioxidant and chelating activity.