Suppression of SOS response in E. coli PQ 37, antioxidant potential and antiproliferative action of methanolic extract of Pteris vittata L. on human MCF-7 breast cancer cells

Pteris vittata L. from the foothills of Kangra district, Himachal Pradesh, India has been investigated for its potential to combat reactive oxygen species and DNA damaging agents. DPPH radical, superoxide anion radical, ABTS+. radical cation decolorization, reducing power, deoxyribose degradation, plasmid nicking and lipid peroxidation assays were carried out to evaluate the antioxidant potential of methanolic of P. vittata L. (PME). The extract showed a significant potential in scavenging the free radicals and an IC50 of 64.425 µg/ml and 90.143 µg/ml was obtained in superoxide radical scavenging and reducing power assays respectively. PME inhibited lipid peroxidation with an IC50 of 34.35 µg/ml and protected the plasmid DNA from damage by hydroxyl radicals to varying degrees. Percentage inhibition of 81.22 and 89.36 at a concentration of 160 µg/ml was obtained in non site specific and site specific deoxyribose degradation assays respectively. PME significantly inhibited 4NQO induced mutagenicity in Escherichia coli PQ 37 and a decrease in induction factor was observed with increasing concentration. The amount of total phenolic and flavonoid content were also determined and HPLC analysis was carried out for the identification of phytoconstituents. A dose dependent decrease in viability of MCF-7 cells was observed with GI50 value of 153.967 µg/ml.