title: Evaluation of the antioxidant activity of soybean extract by different in vitro methods and investigation of this activity after its incorporation in topical formulations.
abstract: Chemoprevention by natural products is an emerging therapeutic approach for free radical-mediated diseases including cancer. This is a consequence of its wide applicability and acceptance. In the present study, the antioxidant activity of the soybean extract (Isoflavin Beta) and of formulations added with this extract were evaluated using stable free radical 2,2-diphenyl-1-pycrylhydrazyl (DPPH*) and deoxyribose as well as the lipid peroxidation inhibition assays. For all the assays the extract showed a dose-dependent activity, and IC50 of 21.03 microg/mL in lipid peroxidation inhibition, 161.8 microg/mL in DPPH*, and 33.5 ng/mL in hydroxyl radical scavenging assay. The antioxidant activity of the extract added in the formulations could not be assessed using the deoxyribose assay. However, the lipid peroxidation inhibition and DPPH* scavenging assays could be successfully applied for the antioxidant activity evaluation of the formulations added with soybean extract to protect the skin against free radicals, which can be generated by the ultraviolet radiation exposure.
authors.affiliation: Department of Pharmaceutical Science, Faculty of Pharmaceutical Sciences of Ribeirao Preto, USP, Brazil. sangeo@fcfrp.usp.br
authors.forename: Sandra Regina
authors.initials: SR
authors.lastname: Georgetti
authors.forename: Rúbia
authors.initials: R
authors.lastname: Casagrande
authors.forename: Fabiana Testa
authors.initials: FT
authors.lastname: Moura-de-Carvalho Vicentini
authors.forename: Waldiceu A
authors.initials: WA
authors.lastname: Verri
authors.forename: Maria José Vieira
authors.initials: MJ
authors.lastname: Fonseca
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D001713:Biphenyl Compounds / Q000737:chemistry*; D019343:Citric Acid / Q000737:chemistry; D003855:Deoxyribose / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D016166:Free Radical Scavengers; D006834:Hydrazines / Q000737:chemistry*; D017665:Hydroxyl Radical; D020128:Inhibitory Concentration 50; D007501:Iron / Q000737:chemistry; D015227:Lipid Peroxidation; D008297:Male; D010851:Picrates; D051381:Rats; D017208:Rats, Wistar; D013025:Glycine max
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D006834:Hydrazines; D010851:Picrates; D019343:Citric Acid; D017665:Hydroxyl Radical; D003855:Deoxyribose; C004931:1,1-diphenyl-2-picrylhydrazyl; D007501:Iron