ABSTRACT
Title
Antimutagenic activity of 1,8-cineol, α-terpineol and β–caryophyllene oxide
Authors
A. Di Sottoa, S. Di Giacomoa, F. Durazzia, M.G. Sarpietrob, S. Ottimob, F. Castellib, G. Mazzantia
a Dept. of Physiology and Pharmacology, Sapienza - University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy
b Dept. of Drug Sciences, University of Catania, Viale A. Doria 6, 95125 Catania, Italy
a Dept. of Physiology and Pharmacology, Sapienza - University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy
b Dept. of Drug Sciences, University of Catania, Viale A. Doria 6, 95125 Catania, Italy
Abstract
Among natural substances, terpenes, in particular monoterpenes and sesquiterpenes, have shown many biological activity, among which antiproliferative and antimutagenic ones (Hassan et al., 2010;Di Sotto et al., 2008 and 2010). On the basis of these findings and considering the importance of identifying natural substances with chemopreventive properties, present study aimed to investigate the potential antimutagenic activity of three terpenes, 1,8-cineol, α-terpineol and β-caryophyllene oxide, frequently used as flavouring agents in cosmetics and detergents and as food additives (De Vincenzi et al., 1996).
The experiments were carried out by the bacterial reverse mutation assay (Edenharder et al., 1997) against the mutagens 2-nitrofluorene (2NF), sodium azide (SA) and methyl methanesulfonate (MMS), on Salmonella typhimurium TA98 and TA100, and on Escherichia coli WP2uvrA strains, also in presence of the metabolic activator S9, using 2-aminoanthracene (2AA) as mutagen. To investigate the mechanism of action, the substances resulted antimutagenic were tested for their antioxidant activity and their capability to interact with multilamellar vesicles of dimyristoylphosphatidylcholine (DMPC MLVs); moreover the kinetic of absorption by DMPC MLVs was determined. Antioxidant activity was tested by DPPH- and ABTS-assays (Gülçin et al., 2007; Kim et al., 2002), crocin-bleaching assay (Di Majo et al., 2008), and ferrozine-assay (Mladĕnka et al., 2010). The interaction and the absorption of the compounds by DMPC MLVs were evaluated by differential scanning calorimetry (Sarpietro et al., 2009).
Test substances inhibited the chemically-induced mutagenesis in all strains, even thought with different spectrum of activity and potency. 1,8-Cineol exerted a weak antimutagenic activity, α-terpineol selectively inhibited the effect of 2AA in TA100 (up to 77.4%), while β-caryophyllene oxide inhibited 2NF in TA98 (up to 68.0%), MMS in WP2uvrA (up to 58.3%), and 2AA in TA100 (up to 68.0%). β-Caryophyllene oxide was devoid of antioxidant activity, conversely α-terpineol showed a remarkable ferrous-ions chelating activity; the effect was concentrations-dependent and reached the maximum of 90.6% (1.15 mM): the EC50 value was of 0.5 ±0.01 mM (Slope = 1.92 ±0.12; R2= 0.955; P<0.0001). Both α-terpineol and β-caryophyllene oxide interacted with DMPC MLVs, even thought α-terpineol exerted a higher effect; this difference appeared more evident in the kinetic of absorption, due to their physicochemical characteristics of lipophilicity and solubility.
On the basis of these results we hypothesize that the antimutagenic activity of α-terpineol against 2AA in TA100 could be due to its capability to inhibit 2AA-biotransformation to mutagen, to protect the cell from oxidative DNA damage or to interfere with the permeability of membrane; we exclude that α-terpineol promote the reparation of DNA-damage because TA100 is an error-prone strain. The antimutagenicity of β-caryophyllene oxide, observed in all strains and against different mutagens, could be due to aspecific mechanisms such as membrane-permeability alteration, block of the mutagen-interaction with DNA or chemical or enzymatic mutagen-deactivation; conversely the involvement of antioxidant mechanisms can be excluded.
These results represent a starting point in evaluating the chemopreventive activity of these natural substances.
Reference
De Vincenzi et al. (1996) Fitoterapia 67, 241–251.
Di Majo et al., (2008) Food Chem 111, 45-49.
Di Sotto et al., (2008) Mutat Res 653, 130-133.
Di Sotto et al., (2010) Mutat Res 699, 23-28.
Edenharder et al. (1997) Food Chem Toxicol 35, 357–372.
Gülçin et al. (2007) Phytother Res 21, 354-361.
Hassan et al. (2010) Anticancer Res 30, 1911-1919.
Kim et al. (2002) J Agric Food Chem 50, 3713-3717.
Mladěnka et al. (2010) Biochimie 92, 1108-1114.
Sarpietro et al., (2009) Int J Pharm 382, 73-79.
The experiments were carried out by the bacterial reverse mutation assay (Edenharder et al., 1997) against the mutagens 2-nitrofluorene (2NF), sodium azide (SA) and methyl methanesulfonate (MMS), on Salmonella typhimurium TA98 and TA100, and on Escherichia coli WP2uvrA strains, also in presence of the metabolic activator S9, using 2-aminoanthracene (2AA) as mutagen. To investigate the mechanism of action, the substances resulted antimutagenic were tested for their antioxidant activity and their capability to interact with multilamellar vesicles of dimyristoylphosphatidylcholine (DMPC MLVs); moreover the kinetic of absorption by DMPC MLVs was determined. Antioxidant activity was tested by DPPH- and ABTS-assays (Gülçin et al., 2007; Kim et al., 2002), crocin-bleaching assay (Di Majo et al., 2008), and ferrozine-assay (Mladĕnka et al., 2010). The interaction and the absorption of the compounds by DMPC MLVs were evaluated by differential scanning calorimetry (Sarpietro et al., 2009).
Test substances inhibited the chemically-induced mutagenesis in all strains, even thought with different spectrum of activity and potency. 1,8-Cineol exerted a weak antimutagenic activity, α-terpineol selectively inhibited the effect of 2AA in TA100 (up to 77.4%), while β-caryophyllene oxide inhibited 2NF in TA98 (up to 68.0%), MMS in WP2uvrA (up to 58.3%), and 2AA in TA100 (up to 68.0%). β-Caryophyllene oxide was devoid of antioxidant activity, conversely α-terpineol showed a remarkable ferrous-ions chelating activity; the effect was concentrations-dependent and reached the maximum of 90.6% (1.15 mM): the EC50 value was of 0.5 ±0.01 mM (Slope = 1.92 ±0.12; R2= 0.955; P<0.0001). Both α-terpineol and β-caryophyllene oxide interacted with DMPC MLVs, even thought α-terpineol exerted a higher effect; this difference appeared more evident in the kinetic of absorption, due to their physicochemical characteristics of lipophilicity and solubility.
On the basis of these results we hypothesize that the antimutagenic activity of α-terpineol against 2AA in TA100 could be due to its capability to inhibit 2AA-biotransformation to mutagen, to protect the cell from oxidative DNA damage or to interfere with the permeability of membrane; we exclude that α-terpineol promote the reparation of DNA-damage because TA100 is an error-prone strain. The antimutagenicity of β-caryophyllene oxide, observed in all strains and against different mutagens, could be due to aspecific mechanisms such as membrane-permeability alteration, block of the mutagen-interaction with DNA or chemical or enzymatic mutagen-deactivation; conversely the involvement of antioxidant mechanisms can be excluded.
These results represent a starting point in evaluating the chemopreventive activity of these natural substances.
Reference
De Vincenzi et al. (1996) Fitoterapia 67, 241–251.
Di Majo et al., (2008) Food Chem 111, 45-49.
Di Sotto et al., (2008) Mutat Res 653, 130-133.
Di Sotto et al., (2010) Mutat Res 699, 23-28.
Edenharder et al. (1997) Food Chem Toxicol 35, 357–372.
Gülçin et al. (2007) Phytother Res 21, 354-361.
Hassan et al. (2010) Anticancer Res 30, 1911-1919.
Kim et al. (2002) J Agric Food Chem 50, 3713-3717.
Mladěnka et al. (2010) Biochimie 92, 1108-1114.
Sarpietro et al., (2009) Int J Pharm 382, 73-79.