Antioxidant, antimicrobial and cytotoxic properties of four different extracts derived from the roots of Nicotiana tabacum L.

Abstract

IntroductionFew studies have investigated the biological activities of Nicotiana tabacum L. and most of these studies have focused on its leaves. This is perhaps due to the fact that tobacco smoking is a major risk factor for lung cancer. Therefore, we aimed to investigate, for the first time, the antioxidant, anticancer and antimicrobial activities of extracts derived from the roots of N. tabacum. MethodsAntioxidant activity was assessed employing 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) method. Antimicrobial activity was tested using broth-microdilution, agar-dilution and Agar-well diffusion methods. Anti-proliferative and apoptotic activities were evaluated utilizing colorimetric methods. ResultsHexane, acetone and methanol extracts and trolox exhibited a potent and significant antioxidant activity with IC50 values of 2, 6, 21 and 2 μg/ml respectively. Acetone extract had the strongest antimicrobial activity followed by hexane and then methanol extracts. Both hexane and acetone extracts had strong and significant anti-proliferative effects followed by methanol extract. This could be due to a growth arrest or cell death. To clarify this, we investigated the effect of acetone extract on caspase-3 activity and it appeared to have a 2 times stronger apoptotic effect than the chemotherapeutic medicine, doxorubicin. ConclusionIn the current study we demonstrate for the first time that organic extracts derived from the roots of N. tabacum possessed antioxidant, anticancer and antimicrobial properties. Our data draws attention to N. tabacum as a promising source of bioactive molecules that can be utilized in pharmaceutical industry, despite the fact that tobacco smoking is a major risk factor for lung cancer.