Mol2Net-04 Antiviral activity of the essential oil of conyza - PDF document

Mol2Net-04 , 2018 , BIOCHEMPHYS-01 (pages 1- x, type of paper, doi: xxx-xxxx http://sciforum.net/conference/mol2net-4 SciForum Mol2Net-04 Antiviral activity of the essential oil of conyza canadensis Manel Ben Ali 1, 2 *, Lobna Daoud 1 , Adel Hadj Brahim 1 , Houda Hmani 1 , Mouna Jlidi 1 , Samir Bejar 1 and Mamdouh Ben Ali 1,2 1 Laboratory of Microbial Biotechnology and Engineering Enzymes (LBMIE), Center of Biotechnology of Sfax (CBS), University of Sfax, Road of Sidi Mansour km 6, PO Box 1177 Sfax 3018, Tunisia E-Mails: lobna.daoudm@gmail.com (Lobna daoud); adelhadjibrahim@gmail.com (Adel Hadj brahim); houda_enis@yahoo.fr (Houda hmani); jlidimanno@yahoo.fr (Mouna Jlidi) ; samir.bejar@cbs.rnrt.tn (Samir Bejar) 2 Astrum Biotech, Business incubator, Center of Biotechnology of Sfax (CBS), University of Sfax, Road of Sidi Mansour km 6, PO Box 1177 Sfax 3018, Tunisia; E-Mail: mamdouh.benali@cbs.rnrt.tn; * Corresponding author: E-Mail: manel.benali@gmail.com Received: / Accepted: / Published: Abstract: In this study, we were interested in the characterization of Conyza canadensis essential oil composition and evaluation of the an tiviral activity from Conyza’s plant extracts. Terpenoids, phenols, sesquiterpenoids and triterpenoids were the major compounds identified from plant essential oil analyzed by gas-chromatography coupled to mass spectrometry. The test of activities of the extracts from different parts (leave, flower and stalk) of Conyza canadensis revealed that this plant has a remarkable antiviral activity. This activity was evaluated for inhibition of Dengue virus (DV), West Nile virus (WNV), Hepatitis C virus (HCV) and Human Immunodeficiency virus (HIV) polymerases. Due to his important antiviral activity, the crude methanolic stalk extract (89% of inhibition) was subjected to silica gel column chromatography to obtain eleven fractions (A-K). None of those fractions, test ed at 50 μg/ml, was active against HCV and HIV polymerases but six fractions (B, C, D, E, I and J) were active against DEN and WN polymerases. These results were confirmed at lower concentration (10 μg/ml). Keywords: conyza canadensis; essential oil; antiviral activity 1. Introduction Viral infections are an important health problem are increasing and the difficulty of virus latency all over the world, both in developed and remains unsolved. The screening of plants as a developing countries, due to their morbidity and possible source of antivirals has led to the mortality. discovery of potent inhibitors of in vitro viral growth [1,2,3,4,5] The development of a new antiviral drug is a and the use of the difficult task taking into account the poor ethnopharmacological approach enhances the selective toxicity and fast selection of resistant probability of identifying new bioactive plant compounds [6,7] viral variants with the existing drugs. Frequencies of viral resistance to antiviral drugs

Mol2Net , 2018 , 1( Section A, B, C, etc. ), 1- x, type of paper, doi: xxx-xxxx 2 Due to useful and reputations importance of the against four viruses polymerases belonging to plant conyza Canadensis , we are interesting in two viruses family: the flaviviridae ( dengue , this paper to the evaluation of the antiviral west nile , HCV) and retrovirtidaea (HIV). activities of extracts of different parts this plant 2. Results and Discussion Analysis of the of Conyza essential oil (whole plant) by mass spectrometry coupled with gas chromatography (GC/MS) resulted in the identification of a dozen products of different chemical families (table 2-1): This analysis shows that the essential oil of Erigeron canadensis is quite rich in compounds of which the most abundant are Citronellol (22.03%), beta-maaliène (13.35%), butyl hydroxy toluene (12.12%), 2-cyclopentyl-P-cresol (11.12%) , geraniol (5.9%), Alloaromadendrène (4.64%) and Aromandrène (3.9%). The effect of the methanol extracts, at 50µg/ml, of the different plant parts was tested on DEN, HCV and HIV polymerase. Off all the extracts tested, only the extracts of the leaves and stalks extract exhibited the antiviral activity against Dengue and HCV viruses. The most active extract was the stalks methanolic extract of Conyza Canadensis against Dengue virus with 87% inhibition percentage. No significant antiviral activity was deducted against HIV virus for leaves, flowers and stalks extract (Figure1). 100 100 100 80 80 80 inhibition percentage percentage inhibition percentage inhibition 60 60 60 40 40 40 20 20 20 0 0 0 leaves flow ers stalks leaves flow ers stalks leaves flow ers stalks extracts HCV extracts extracts DENGUE HIV Figure 1. Variation of DENGUE virus (DEN), hepatitis C virus (HCV) and Human immunodeficiency virus (HIV) inhibition by methanolic extracts of each plant parts. Results are expressed as percentages of inhibition relative to each part. Due to his important antiviral activity, the crude methanolic stalks extract was subjected to silica gel column chromatography to produce nine fractions (A - I) which were again tested for their anti- polymerase character of DEN, WN, HCV and HIV viruses (figure 2). 100 100 80 80 % of inhibition % of inhibition 60 60 40 40 20 20 0 0 A B C D E F G H I A B C D E F G H I DENGUE fractions WN fractions

Mol2Net-04 , 2018 , BIOCHEMPHYS-01 (pages 1- x, type of paper, doi: xxx-xxxx http://sciforum.net/conference/mol2net-4 100 100 80 % of inhibition 80 % of inhibition 60 60 40 40 20 20 0 A B C D E F G H I 0 A B C D E F G H I fractions HIV fractions HCV Figure 2 : Variation of DENGUE virus (DEN), hepatitis C virus (HCV) and Human immunodeficiency virus (HIV) inhibition by the methanolic stalks extract’s fra ctions. Results are expressed as percentages of inhibition relative to each fraction. We found that none of the nine fractions was active against HCV and HIV viruses polymerases but the fractions (B, C,D,E) were active against DEN and WN viruses polymerases. All the fractions are tested at 50µg/ ml concentrations. To be sure of the antiviral character of these fractions, each one was tested again tested against the four polymerases studied but with 10µg/ml as concentration. The variation of inhibition shows that fractions C,D and E displayed the best selective antiviral activity against dengue and West Nile. 3. Materials and Methods Plant parts: leaves, flowers or stalks, were dried methanol in Methylene dichloride respectively at room temperature for 2 – 3 weeks. Dried plant CH 2 Cl 2 / MeOH to afford fractions (A, B, C, D, Material was chopped and extracted by E, F, G, H, I) tested for antiviral activity. maceration with methylene dichloride (CH 2 Cl 2 ) The antiviral activity is tested according to then methanol (MeOH) for 24h. determined protocols with precise operating We are interested in this paper to the methanol conditions to each type of polymerase used. extracts. After filtration the crude extracts were Measurement of the inhibition degree of a evaporated to dryness in a vacuum evaporator studied extract is done by calculating the number under reduced pressure then tested for antiviral of remaining tritium-labelled phosphates activity. (introduced as nucleotides and intervening during Stalks methanol extract (SM) was found to have the polymerization reaction) after the reaction in the most potent antiviral activity. Therefore, a presence of the extract. This number will be part of this extract (5 g) was further fractionated compared to which present in the absence of by column chromatography on silica gel-60 and extract after the same reaction, under the same eluted step-wise with increasing amounts of conditions. 4. Conclusions Due to the antiviral test activity, Conyza Canadensis stalks methanolic extract C,D and E fractions deserve a special attention in further studies such characterisation of the active compounds and new antiviral assays. References and Notes 1. Vanden Berghe, D., Vlietinck, A., Van Hoof, L. Plant products as potential antiviral agents. Bulletin de l’Institute Pasteur 1986; 84, 101 – 147. 2. Tabba, H., Shihman, Chang, R., Smith, K. Isolation,purification and partial characterization of prunellin, an anti-HIV component from aqueous extracts of Prunella v ulgaris . Antiviral Research 1986, 11, 263 – 274. 3. Hudson, J.B. Antiviral Compounds from Plants . CRC Press, Boca Raton, FL.1989

Mol2Net-04 , 2018 , BIOCHEMPHYS-01 (pages 1- x, type of paper, doi: xxx-xxxx http://sciforum.net/conference/mol2net-4 4 4. Garcı´a, G., Campos, R., de Torres, R., Broussalis, A., Ferraro, G., Martino, V., Coussio, J. Antiherpetic activity of some Argentine medicinal plants. Fitoterapia , 1990, 6, 542 – 546. 5. Cavallaro, L., Garcı´a, G., Broussalis, A., Martino, V., Ferraro, G., Co ussio, J., de Torres, R., Campos, R., 1995. Antiherpetic in vitro activity of Gamochaeta simplicicaulis . Phytotherapy Research, 1995, 9, 176 – 179. 6. Vlietinck, A., Vanden Berghe, D. Can ethnopharmacology contribute to the development of antiviral. Journal of Ethnopharmacology , 1991, 32, 141 – 153. 7. Baker, J., Borris, R., Carte´, B., Cragg, G., Gupta, M., Iwu, M., Madulid, D., Tyler, V., 1995. Natural product drug discovery and development: New perspectives on international collaboration. Journal of Natural Products 58, 1325 – 1357