Invenţia se referă la medicină şi biochimie şi poate fi folosită pentru aprecierea activităţii atero-protective a substanţelor biologic active. Esenţa invenţiei constă în aceea că substanţele biologic active în diferite concentraţii se amestecă cu o soluţie ce conţine enzima PON1/arilesteraza în soluţie tampon fosfat cu pH-ul 7,4, apoi se incubează la temperatura de 37°C, timp de 5...10 min, după care se adaugă un mediu de reacţie ce conţine p-nitrofenil acetat, CaCl2 şi cloramină T în soluţie tampon fosfat cu pH-ul 7,4 cu obţinerea probei de cercetat. The invention relates to medicine and biochemistry and can be used for assessing the athero-protective activity of biologically active substances. Summary of the invention consists in that biologically active substances in various concentrations are mixed with a solution comprising PON1/arylesterase enzyme inphosphate buffer solution with the pH 7.4, then incubated at 37°C for 5…10 min, after which is added a reaction medium comprising pnitrophenylacetate, CaCl2 and chloramine T phosphate buffer solution with the pH 7.4 to obtain the test sample, the control sample is prepared identically as the test sample, but the test substance is replaced with an equivalent amount of buffer phosphate solution with the pH 7.4, and the blank sample is prepared identically as the control sample, but the reaction medium does not contain the PON1/arylesterase enzyme, then is determined the initial absorption of A1 at 405…410 nm, after which the samples are incubated at 37°C, for 30 min and is redetermined the absorption of A2 at 405…410 nm, then is calculated the percentage of activation of PON1/arylesterase of the test substances, at the same time, the higher the percentage of activation of the corresponding concentration of the test substances the higher the athero-protective activity.