| dc.description.abstract | Nature is a wide source of biologically active compounds investigated with the
purpose to be used as drugs due to their biological activity and also useful in
pharmaceutical discovery and drug design. Nowadays, medicinal plants play a major role
in primary health care as therapeutic remedies in many developing countries.
The aim of my PhD project was the phytochemical and biological investigation of
three plant species, used in Bolivian traditional medicine, but few scientific studies were
reported, such as: Azorella glabra Wedd., Minthostachys diffusa Epl. and Senecio clivicolus
Wedd.
On the basis of ethnobotanical uses, the samples were firstly analysed for their
total content of polyphenols, flavonoids and terpenoids and for their in vitro antioxidant
activity using different complementary assays. In particular, radical scavenging activity
was tested against biological radicals such as nitric oxide (NO) and superoxide (SO)
together with neutral or cationic (DPPH and ABTS) radicals; ferric reducing power and
lipid peroxidation inhibitory capacity (FRAP and Beta-Carotene Bleaching tests) were also
determined.
Oxidative stress is involved in different diseases, such as diabetes and
neurodegenerative diseases. Then, the inhibitory ability of samples was investigated
against α-amylase and α-glucosidase enzymes involved in diabetes and against
acetylcholinesterase and butyrylcholinesterase enzymes considered as strategy for the
treatment of Parkinson’s or Alzheimer’s diseases.
Moreover, cytotoxicity studies on cancer and non-cancer cell lines were carried
out.
The antioxidant, antidiabetic, anticholinesterase and cytotoxic activities and the
phytochemical profile were performed on aerial parts of A. glabra, M. diffusa and S.
clivicolus for the first time.
Among all samples, the ethyl acetate fraction of S. clivicolus showed the highest
antioxidant activity; instead, M. diffusa samples showed the highest antidiabetic potential
and anti-cholinesterase activities. To confirm the inhibitory cholinesterase effects of the
terpenes identified from M. diffusa, in silico docking analysis were also carried out.
Moreover, the A. glabra samples were tested for the first time on Multiple
Myeloma (MM) cell lines using several assays. The chloroform fraction of A. glabra
reduced the cell viability, and arrested the cell cycle on MM cells in G0/G1 phase,
characteristic feature of apoptosis.
Instead, the ethyl acetate fraction of S. clivicolus was tested on hepatocellular
carcinoma HepG2 cell line showed the ability to induct cell death via the mitochondrial
apoptotic pathway.
In conclusion, this first report on A. glabra, M. diffusa and S. clivicolus
phytochemical characterization and biological activity evaluation, demonstrates as these
Bolivian plant species could be considered a source of health promoting compounds.
Some of the results obtained during this study might partially explain their
ethnobotanical use, evidencing a potential economic added value for extract future use in
the field of biotechnology applied to environmental, agricultural, health, pharmaceutical
and cosmeceutical development. [edited by Author] | it_IT |
