897Resear ch Arti cle Received: 24October 2 00 8 Revi sed: 11 December 2 00 8 Accept ed: 30 D ec em be r 2008 Publi she d o nl i ne in Wi ley Int erscien ce : 23 F eb r uary 200 9 (www.inter science.wiley.co m) DOI 10.1002/jsfa.3532 Chemical composition and antioxidant and radical-scavenging activities ofPeriploca laevigata root bark extracts Haj ji Moh ame d, ∗ Masmoudi Ons, El louz-Tri ki Yosra, Si al a Rayda, Gharsall ah Neji and Nasri MoncefAbstract BACKGROUND: The root powder ofPeriploca laevigata is used for preparing soft drinks and as an aromatic in Tunisia. The infusion or decoction of its root bark has widespread use in folk medicine. The plant is used to treat digestive disorders and hypert ensive eff ect s as wel l as other hea lth proble ms. RESULTS: The antioxidant activities of extracts ofP. laevigata root bark obtained with solvents of different polarity were investigated using assays of 1,1-diphenyl-2-picrylhydrazyl radical-scavenging activity, ferric-reducing capacity, β-carotene- bleaching ability, hydroxyl radical-sca vengi ng activ ity and lipi d peroxi dation inhib ition. The methanol extrac t, with the highest amount of total phenolics and flavonoids, showed the highest antioxidant activities in all assays, followed by the water extract . Gas chromatogr aphy/ mass spectrome try was used to deter mine the compos ition of the water and methanol extracts. Thirty-four compounds were identified in the methanol extract, with pr oflavine (516.2 g kg −1 dry matter (DM)) and 4-met hoxysa licyl aldehyde (198.3 g kg −1 DM)beingthe mostabundant. Sixteen compoundswereident ified in thewaterextra ct, of which 4-hydroxy-3 -methoxyphe nethy lene glyc ol (351.2 g kg −1 DM) was the mai n component . CONCLUSION: As far as is known, this is the first report on the chemical composition and biological activities of phenolic extrac ts from P. laevigata. The results of the study indi cate that the rootbark of this pl ant mi ght bea goodcandidat e for further invest igati on in devel oping new antioxidant s. c 2009 Societ y of Chemic al Industr y Keywords: Periploca laevigata; root bark; phenolic composition; antioxidant activity; gas chromatography/ mass spectrometry INTRODUCTION Oxid ation of poly unsat urat ed fatty acids, whic h occu rs duri ng stor age, proces sing and heat treatment of raw materia ls and fur the r storage of fina l products , is one of the major factors resu ltingin losse s of fatt y foodquality by formationof compounds withnegativeeffectsonthearomaandnutritionalvalueoffoods. 1,2 In ord er to prolon g thestor agelife of foods,synthet ic ant iox ida nts are widely used in industrial processing. Moreover, it has been shown that antioxidants and free radical scavengers are crucial in the prevent ion of patho logi es such as cance r, hear t disea ses, biolog ica l damage in living tis sue s and neuro deg enerat ive diseases, in which reactive oxygen species or free radicals are implicated. 3 The two mos t commonly used synthe tic ant ioxidants are butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT), whi ch areadded to fat ty andoily foo ds to pre vent oxi dat ive deterioration. 4 However, use of these chemical compounds has begun to be restricted because of their induction of DNA damage and their toxicity. 5,6 Moreover, both BHT and BHA appear to be involved in tumour promotion. 7 In recent years there has been great interest in finding new antioxidants from natural sources for use in food and medicinal materials to replace synthetic antioxidants. Vitamins, which are pres ent naturall y in vege table s, frui ts and seeds, posse ss the abili ty to redu ce oxidativedamageassociate d withmany dise ases , including cancer, cardiovascular diseases, atheroscle rosis, etc. 8 Recently, the ability of phenolic substances, including flavonoids and phenolic acids, to act as antioxidants has been extensively investigated. 9 Phenoliccompound s are deri vatives of the pent ose phos phate , shiki mateand phenylpro panoid pathways in plant s. 10 Theyexhibit a wide range of physiological properties, such as antioxidant, antiallergen ic, antiartherog enic, anti-inflammat ory, antimicrobial, antithrombo tic, cardioprot ective and vasodilatory effects. 3,11,12 The bioact ivi ty of phe nol ics may be relat ed to the ir abi lit y to che lat e me tal s, inhibi t lipoxyge nas e and scavenge fre e radicals. 13 Periploca laevigata is an important grazing species in the dry season. In Tunisia it is predominantly found in the south of the ∗ Correspondence to: Hajji Mohamed, Laboratoire de G´enie Enzymatique et de Microbiologie, Ecole Nationale d’Ing´enieurs de Sfax, BP ‘W’ 3038 Sfax, Tunisia. E-mail: hajjimed1989@yahoo .frLabor atoire de G´enie Enzymati que et de Micro biolog ie, Ecole Nationale d’Ing´eni eur s deSfax,BP ‘W’3038 Sfa x, Tunisi a J Sci Foo d Agr ic2009; 89: 897 – 905 www.soci.org c 2009 Society of Chemical Industry
