Inhibition by essential oils of Mentha viridis and Mentha pulegium (Lamiaceae) in proteolysis, fibrinogenolysis and coagulation caused by venomous snakes

Snake venoms are widely used as laboratory tools for studies of physiological, pharmacological and toxicological mechanisms. Venoms used here are rich sources of several classes of proteases that act on factors of the coagulation cascade, fibrinogenolysis and fibrinolysis, altering the hemostatic processes, and phospholipases A(2) which are involved mainly in inflammatory and clotting processes. Natural products such as essential oils are made up of active ingredients with wide application in the food, pharmaceutical and cosmetic industries. Thus, this study evaluates the essential oils from Mentha viridis and Mentha pulegium on coagulation, fibrinogenolysis and degradation of azocasein, induced by Bothrops sp and Lachesis muta muta venoms. These oils were achieved by hydrodistillation and presented, respectively, as the main constituents linalool (40.70 %), carvone (13.52 %) and alpha-terpinene (8.56 %); pulegone (50.01 %), menthol (31.90 %) and menthone (16.56 %). The essential oils were previously incubated with Bothrops alternatus venom, for two different times, then plasma was added and time was recorded. The M. viridis oil presented greater anticlotting potential. Meanwhile, the M. pulegium oil presented anticlotting or proclotting activity dependent on the dose tested. The incubation time also influenced the effect of the oils on the coagulation time. At azocaseinolytic assay, the oil from M. pulegium reduced the activity for all evaluated venoms. The highest inhibition was of 39.99 %; on activity induced by B. jararacussu, M. viridis reduced the activity in 57.72 %. On B. moojeni, the major inhibition observed was of 74.67 %. The fibrinogenolysis induced by B. moojeni venom was totally inhibited by both oils in the evaluated proportions. The results show the presence in oils of protease inhibitors, considering serine and metalloproteases (acting on clotting factors or with hemorrhagic activity), as well as phospholipase A(2) (enzymes involved in inflammation and clotting processes) inhibitors of wide application in medical and biotechnology areas.