Relation between Chemical Composition or Antioxidant Activity and Antihypertensive Activity for Six Essential Oils

Abstract

Six essential oils (EOs), Juniperus phoenicea (leaves and berries), Thymus capitatus, Lauris nobilis, Melaleuca armillaris, and Eucalyptus gracilis, were screened for their antioxidant and antihypertensive activity as well as their chemical compositions. We identified and quantified 24 compounds (representing 99.8% of total oil) for J. phoenicea leaves, 14 compounds (representing 98.8% of total oil) for J. phoenicea berries, 11 compounds (representing 99.6% of total oil) for T. capitatus, 32 compounds (representing 98.9% of total oil) for L. nobilis, 32 compounds (representing 98.7% of total oil) for M. armillaris, and 26 compounds (representing 99.3% of total oil) for E. gracilis. In the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, the antioxidant activity was in the range of 0.59 to 2183.6 mg/L, whereas T. capitatus (1.24 ± 0.05 mg/L) gave the best activity in the 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonate assay. Antihypertensive activity was evaluated by testing the vasorelaxing capacity of EOs on rat aorta precontracted by phenylephrine (10(-6) M). T. capitatus and L. nobilis were most active for an antihypertensive activity (29 ± 3 and 59 ± 2 mg/L, respectively). Correlations between chemical composition or antioxidant activity and/or antihypertensive activity were studied. Significant correlation has been found for antihypertensive activity and p-cymene (R(2) = 0.86), β-elemene (R(2) = 0.90), and β-myrcene (R(2) = 0.76). A good correlation has been found between antihypertensive activity and antioxidant activity by DPPH assay (R(2) = 0.98). Antioxidant activity can contribute to the prevention of the increase of the blood pressure. According to the literature, no study has been reported until now of correlation between antihypertensive activity and antioxidant activity. Natural EOs can find its interest and application in a medicinal area.

Antibacterial, antioxidant and hypoglycaemic effects ofThymus capitatus(L.) Hoffmanns. et Link leaves' fractions

“…Achour et al 25 demonstrated the presence of carvacrol as main component, followed by p-cymene, c-terpinene, linalyl acetate, 1,8-cineole, b-myrcene, terpinen-4-ol and a-terpinene. Yvon et al 9 identified 11 compounds in T. capitatus oil. The main constituent is thymol, followed by p-cymene and c-terpinene.…”

“…T. satureioides and T. pallidus essential oils showed IC 50 values of 0.32 and 11.6 mg/mL, respectively, in DPPH assay 32 . The essential oil obtained from the leaves of Tunisian T. capitatus showed IC 50 values of 0.59 and 1.24 mg/L in DPPH and ABTS assay, respectively 9 . Recently, Tabti et al 31 compared the antioxidant potential of Algerian T. capitatus essential oil, ethanol extract and n-hexane extract.…”

“…Thymus species are used in traditional medicine as tonic, antiseptic, antitussive and carminative as well as for treating colds and in pharmaceutical, cosmetic and perfume industry for preservation of several food products or as spice 1,3,4 . Different studies on Thymus species, and in particular of the essential oil, demonstrated the antibacterial, antihypertensive, antioxidant, hepatoprotective, antitumor and hypoglycaemic activities [5][6][7][8][9] . Moreover, in veterinary medicine more than 280 plant species, mainly in the form of decoctions or dietary supplements, have been used for the treatment of various diseases such as gastrointestinal, respiratory and skin diseases, wounds or inflammation.…”

Medicinal plants of the family Lamiaceae as functional foods - a review

“…(Nayak et al 2013), Marrubium vulgare L. (Boudjelal et al 2011), Salvia hispanica L. (Munoz et al 2013) have proven to be effective, while Salvia elegans Vahl. (Jimenez et al 1988), thymus capitatus (L.) Hoffmanns & Link (Yvon et al 2012), Salvia hispanica L. (Mihailovic-Stanojevic et al 2013), and thymus serpyllum L. (Jovanovic et al 2005) can be used for hypertension.…”

Influence of harvesting time on composition of the essential oil of Thymus capitatus (L.) Hoffmanns. & Link. growing wild in northern Sicily and its activity on microorganisms affecting historical art crafts

“…Several papers have been published on the chemical composition of the essential oil of T. capitatus (Cosentino et al, 1999;Arras and Usai, 2001;Miceli et al, 2006;El Ajjouri et al, 2008;Figueiredo et al, 2008;Blanco et al, 2010;Napoli et al, 2010;Tawaha and Hudaib, 2012;Yvon et al, 2012;BallesterCosta et al, 2013;Chedia et al, 2013;Saoud et al, 2013;Hortigo´n-Vinagre et al, 2014;Bouayad Alam et al, 2014). It is very rich in the terpenes thymol, carvacrol, and p-cymene.…”