Name: Vanessa Silva dos Santos
Type: MSc dissertation
Publication date: 20/12/2021
Advisor:

Name	Role
Maria do Carmo Pimentel Batitucci	Advisor *

Examining board:

Name	Role
Hildegardo Seibert França	Internal Examiner *
JEAN CARLOS VENCIONECK DUTRA	External Examiner *
Juliana Macedo Delarmelina	External Alternate *
Maria do Carmo Pimentel Batitucci	Advisor *
Silvia Tamie Matsumoto	Internal Alternate *

Summary: The use of plants for the treatment of diseases has followed the history of human survival for
thousands of years. According to the World Health Organization (WHO) it is estimated that a
large part of the population of developing countries still uses plants for medicinal purposes,
even without proven clinical indication, as an alternative to synthetic drugs in the treatment of
various diseases. Moringa oleifera Lam. (Moringaceae), is originally from northwestern India,
its cultivation spread throughout the tropics, being found in some countries of the African
continent, Asia, and South America. Reactive oxygen species (ROS) can be generated from
natural biological events or by exposure to exogenous factors. The imbalance between ROS
and antioxidants available in the cell can lead to oxidative stress, responsible for triggering
harmful events to the body. One of the most effective ways to maintain balance between free
radicals and antioxidant systems is by ingesting synthetic antioxidant compounds trough
supplementation or food. However, due to the chemical instability attributed to synthetic
antioxidants, there is a growing demand for antioxidants of natural origin, which have low
toxicity and fewer adverse effects. Many of the biological activities observed in plant extracts
are related to compounds derived from secondary metabolism of plants, which may vary
qualitatively and quantitatively depending on the stage of plant development and the parts, like
stem and leaves, used. In order to understand the influence of these on the production of
phytocompounds and on the biological activities presented by M. oleifera, the present work
aims to characterize its antioxidant performance by methods of capture and reduction of ions
and metal chelating properties, correlating this performance to the chemical compounds present
in this plant with the crude ethanol extracts of M. oleifera in vegetative, flowering and fruiting
and its different parts (stem and leaf).
Keywords: Free radicals; Phenols; Flavonoids; Tannins; ABTS; DPPH; Fe2+ chelation.