Antioxidant potential, cytotoxic activity and phenolic content of Clematis flammula leaf extracts

Abstract

Five fractions of Clematis flammula, a plant widely used in the Mediterranean traditional medicine, were isolated from the leaves using a selective extraction procedure and their total antioxidant capacity was measured by both the ABTS and ORAC tests. Furthermore, their capacities to inhibit microsomal lipid peroxidation and to scavenge the hydroxyl radical were assessed. The cytotoxic potential of the crude ethanolic extract and the aqueous fraction obtained from chloroform was also evaluated on three human hepatoma cell lines CHL, PLC and HuH7. The results showed a stronger antioxidant capacity for the two aqueous phases obtained from ethyl acetate and chloroform concerning ABTS (7.9 and 10.5 mmoles Trolox eq/g of plant extract, respectively), ORAC (487 and 387 mmoles Trolox eq/g of plant extract, respectively) and hydroxyl radical scavenging activity (IC 50 = 56.5 and 48.4 µg/mL, respectively), compared to their organic counterparts which, however, inhibited microsomal lipid peroxidation more efficiently (IC 50 = 390.7 and 523.5 µg/mL, respectively). The ethanol crude extract exhibited a fairly good cytotoxic potential on the two cell lines CHL and PLC (IC 50 = 58.5 and 47.3 µg/mL, respectively), in contrast to the aqueous phase obtained from chloroform (IC 50 = 457.7 and 304.9 µg/mL, respectively). A positive correlation was also found between the phenol content and the different activities. These results provide experimental support for the therapeutic virtues of Clematis flammula leaf extracts.

Antioxidant, Anticancer Activity, and Other Health Effects of a Nutritional Supplement (Galaxy(r))

“…Similar studies with total phenolics have also shown mixed results. Some studies of total phenolics contained in traditional fruit, have shown to be highly correlated with anticancer activity (Silva et al, 2006;Atmani et al, 2011) and they (phenolics) are also highly correlated with ORAC values (Atmani et al, 2011;Kalt et al, 2003). However, some researchers have shown that there is no correlation between total phenolics and anticancer activity (Thompson et al, 2009;Sun et al, 2002;Weber et al, 2001).…”

In vitro assessment of antibiotic-resistance reversal of a methanol extract from Rosa canina L

“…A similar observation was reported by Davis et al [30] and thus supports the safe use of this botanical as complementary and alternative therapy in the prevention or treatment of certain health problems. The weak toxic effect could be linked to its hydrophilic nature inhibiting the interaction with the cell membranes where signal transduction pathways occur [31].…”

In vitro evaluation and comparison of antioxidant and antibacterial activities of leaf extracts of Hopea ponga (Dennst.) Mabberly

“…[15] The reaction mixture contained 1,750 µl phosphate buffer solution (pH 7.4), 50 µl 2-deoxy-2-ribose of 80 mM, 50 µl Ethylenediaminetetraacetic acid (EDTA) of 4 mM, 50 µl FeCl 3 of 4 mM, 50 µl H 2 O 2 of 20 mM, 50 µl ascorbic acid of 4 mM and 200 µl of extract of various concentration was vortexed and allowed to incubate for one hour at 37°C. One ml of 2% trichloroacetic acid (TCA) and 1 ml of 1% thiobarbituric acid (TBA) were added and kept in a boiling bath for 15 min.…”

“…[15] A solution of 2 mM hydrogen peroxide was prepared using distilled water. Extracts of 62.5, 125, 250, 500, 1,000 µg/ml concentrations were added to 600 µl hydrogen peroxide and incubated for 30 min at 37°C.…”