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1. ABSTRACT
The free radicals (FRS) result from cell metabolism as well as from
extracellular processes. FRS exerts some functions necessary for cell homeostasis
maintenance. When produced in excess they can damage to the DNA which has been
implied in mutagenesis and carcinogenesis. Scientific studies suggest that many
dietary phytochemicals may play important roles as chemopreventive agents in
prevention of many diseases, including cancers.
The purpose of this study was to realise an isolation directed to the
identification of the antiradical and/or chemopreventive compounds of the
methanolics extracts from Spirulina maxima and Hedeoma drummondii, in order to
determine the antiradical activity was used the DPPH and ABTS reduction assays
and the ferric reducing-antioxidant power (FRAP) assay, total phenolic and flavonoid
content were determined too. The MeOH extract from H. drummondii showed the
most efficient free radical scavenging effects. The assay-guided fractionation of the
crude extract allowed the identification of three major active constituents identified
as: chlorogenic, caffeic and rosmarinic acid.
The antiproliferative activity from crude extracts of both species were
examined in cancer cell lines of mama and cervix (MCF-7 and HeLa, respectively)
and a normal cell line (Vero), all extracts showed selectivity against tumor cell lines,
again, the methanolic extract of H. drummondii was the most active; the crude
extract, polar fractions and antiradical compounds of these, exhibited significant
cytotoxicity.
The antigenotoxic effect of antiradicals compounds were investigated using
the comet assay in precision cut hamster kidney slices. At non cytotoxic
concentrations of the phenolics acids (PA) prevented the DNA damage induced by
oxidative stress .
In conclusion, the PA isolation from Hedeoma drummondii efficiently
protects DNA against genotoxicity of HgCl 2 damage and inhibited the growth of
cancer cell lines probed. The chemopreventive effects of PA it is may be relation
whit your radicals scavenging capacity.
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