GABRIELA STANCIU, ELISABETA CHIRILA, SIMONA DOBRINAS, TICUTA NEGREANU-PIRJOL STUDIES REGARDING THE DETERMINATION OF ANTIOXIDANT PROPERTIES OF NEW PLANT EXTRACTS FOR COSMETIC PURPOSES
This paper deals with recent original studies regarding the evolution in time of antioxidative properties for some alcoholic extracts of plant material from Constanta district, Romania: poplar leaf-buds, sea buckthorn male buds, snowdrop flowers and violet flowers, some of them reported for the first time as cosmetic raw materials to our knowledge. The total phenolic contents (TPC) and antioxidant capacity of lipid soluble substances (ACL) have been measured using modified Folin Ciocalteu, respectively photochemiluminescence methods in plant extracts after 1, 2, 3, 4, 5, 6, 7, 15 and 30 days of contact time of plant material with ethanol. In poplar leaf-buds TPC varied from 0.304 to 0.413 mg GAE/g dry weight, in sea buckthorn male buds from 0.087 to 0.333 mg GAE/g dry weight, in violet flowers from 0.226 to 0.269 mg GAE/g dry weight and in snowdrop flowers from 0.080 to 0.133 mg GAE/g dry weight. The results show that the ACL of the alcoholic extracts is high and increases continuously for poplar (from 183.85 to 391.48 nmol/mg dry weight) and sea buckthorn (from 30.71 to 246.70 nmol/mg dry weight). The other samples have a slightly increasing trend of ACL: from 119.19 to 125.08 nmol/mg dry weight (violet) and from 104.37 to 135.73 nmol/mg dry weight (snowdrop). The highest antioxidant capacity measured as TPC and ACL from the studied plant extracts belongs to poplar leaf buds, followed by sea buckthorn male buds, violet and snowdrop flowers. All the studied plant materials have high concentration of phenolic compounds that contribute to antioxidant properties explaining their use for cosmetic purposes.
Keywords: total phenolic compounds, antioxidant capacity, photochemiluminescence, plant extracts