Evaluation of the stability of the extract dracunculifolia Baccharis (Asteraceae) in antioxidant activity and the modulatory action of this plant on the oxidative metabolism of neutrophils

• Grant number: 11/17110-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2011
• End date: May 31, 2013
• Field of knowledge: Health Sciences - Pharmacy - Pharmacognosy
• Principal Investigator: Yara Maria Lucisano Valim
• Grantee: Marcia Akemi Okuro
• Host Institution: Faculdade de Ciências Farmacêuticas de Ribeirão Preto (FCFRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Neutrophils or Polymorphonuclear (PMN) are phagocytic cells with functions highly potent bactericidal and fungicidal. These cells are capable of killing microorganisms through mechanisms independent of oxygen (with degranulation and release of antimicrobial molecules) and oxygen-dependent (with the production of reactive oxygen species). However, in situations of intense cellular activation, the large release of cytotoxic molecules can produce deleterious effects in tissues. Then, there is a continual search for new drugs with anti-inflammatory and antioxidant activities. Previous studies in our laboratory showed that the extract of Baccharis dracunculifolia has significant antioxidant activity on activated PMNs. However, the influence of seasonality on the chemical constitution of Baccharis dracunculifolia can change the range of biological effects played by its extracts and fractions, which represents a factor that hinders the standardization of the plant's effects. Moreover, it is very important to assess if the activity of these extracts on the neutrophil metabolism is not altered by the storage of these materials. Thus, this project aims to compare the effects of dry extracts obtained at different periods on the oxidative metabolism of human neutrophils stimulated by tests performed luminol enhanced chemiluminescence (lumCL) and lucigenina enhanced (lucCL). In addition, it the effect of extracts on the enzyme myeloperoxidase done activities, which stands as a key enzyme in the production of reactive oxygen species (ROS), will be also investigated.(AU)