Antibacterial and cytotoxic activities of extracts from (Tunisian)Rhamnus alaternus (Rhamnaceae)

Abstract

The petroleum ether, chloroformic, ethyl acetate, methanolic, Total Oligomers Flavonoids (TOF) enriched extracts, water extract as well as its fractions A 1 , A 2 , A 3 obtained from aerial parts of Rhamnus alaternus, a Tunisian-Mediterranean medicinal species, were investigated for the contents of phenolic compounds, cytotoxic activity against the K562 human chronic myelogenous leukaemia cell line and L1210 leukaemia murine cells and for antibacterial activity against Gram positive and Gram negative bacterial reference strains. A pronounced cytotoxic effect on both the cell lines was shown in the TOF, ethyl acetate, methanolic, aqueous extracts and A 2 fraction, with respectively IC 50 values 75, 232, 298, 606 and 571 µg/ml on K562 cells and 198, 176, 767, 560 and 614 µg/ml on L1210 cell line. Significant activity against bacterial reference strains: Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Salmonella enteritidis and Salmonella typhimurium was shown with ethyl acetate, TOF extracts and A2 fraction. The antimicrobial and cytotoxic activities showed by R. alaternus depended on the chemical composition of the tested extracts.

Antioxidant and free radical-scavenging properties of three flavonoids isolated from the leaves of Rhamnus alaternus L. (Rhamnaceae) : A structure-activity relationship study

“…Likewise it appears from the IC 50 values of superoxide anions measured in the presence of TOF and methanolic extracts (respectively 138 and 183 lg/ml) that TOF extract is the most potent superoxide scavenger (Ben Ammar et al, 2007a), as it was enriched in polyphenolic compounds compared with the methanolic extract (Ben Ammar et al, 2007b). The antioxidant and free radical-scavenging potential of the flavonoids (1-3) tested in this study could justify and explain the same activities obtained with the original extracts, as these flavonoids are the major components of the TOF and the methanolic extracts.…”

“…We have also reported others biological activities of R. alaternus extracts: antibacterial and antiproliferative. In human cells, extracts of R. alaternus leaves modulate the expression levels of genes implicated in both DNA repair and oxidative defence systems (Ben Ammar et al, 2007a, 2007b.…”

Evaluation of mutagenic and antimutagenic activities of oligorutin and oligoesculin

“…Similarly, esculin did not show any mutagenicity in the strains S. typhimurium TA104 and S. typhimurium TA102. The absence of mutagenicity in the presence of rutin, oligorutin fractions, esculin and oligoesculin fractions, in the two S. typhimurium strains TA102 and TA104, with and without (S9) activation system at any tested dose of the different fractions, indicated that DNA did not seem to be a relevant target for these molecules (Ben Ammar et al, 2007).…”

Flavonoid profile, antioxidant and cytotoxic activity of different extracts from Algerian Rhamnus alaternus L. bark

“…Rhamnus alaternus leaves contain many active compounds,[ 3 4 5 ] and experimental studies have demonstrated that extracts of R. alaternus leaves possess different biological activities. [ 6 7 8 9 10 11 12 13 14 15 ]…”