Essential Oil of Myrtus communis L. effects In Vitro and In Vivo Evaluation against Chickpea Blight (Ascochyta rabiei) Disease

In this study, (Myrtus communis L.) was explored in vitro and in vivo for controlling blight disease using two chickpea genotypes ILC 3279, INRA 199 and a local cultivar Bouazza. Blight caused by Ascochyta rabiei Pass. Lab. is major disease affecting chickpea production. To control this disease, chemical harmful fungicides are used hence, developing natural plant protection products as an alternative has become important regarding the environmental impact. The effect of essential oil (EO) extracted from myrtle leaves by hydrodistillation was evaluated on the growth of Ascochyta rabiei Pass. Lab. mycelium, by dilution method using chickpea culture medium added with 0, 200, 300, 500 and 1000 ppm. The radial growth of A. rabiei Pass.Lab. was inhibited at 40.9, 68.18 and 96.69%25 with 200, 300 and 500 ppm respectively. Myrtle essential oil used at 1000 ppm inhibited the fungus growth completely (100%25). In vitro EO efficacy was investigated using detached leaflets method inoculated with 5 micro%253Bl pathogen spore solution of 106 spores %252F ml concentration. Efficacy was investigated using 750 ppm EO solution. Disease (DS) Severity and disease incidence (DI) on detached leaflets were determined. Highest disease incidence was observed on Bouazza (100%25) followed by ILC 3279 (84.28%25) and INRA 199 (17.5%25). Myrtle essential oil showed an efficacy in all cases and decreased significantly disease incidence for Bouazza, ILC 3279 and INRA 199 to 63.33, 56.66 and 16%25 respectively. Disease severity showed the same profile, Bouazza noted the highest rate followed by ILC 3279 and INRA 199 with 60, 40 and 21%25 respectively and EO showed a significant efficacy and reduced these disease severity rates to 52 32 and 18 %25. The bioassay conducted in vivo under greenhouse conditions with plants including a negative control with any treatment and two other batches inoculated by hand held sprayer, a spore solution with a concentration of 106 spores%252F ml and treated or not with myrtle EO. Disease incidence percentage (DIP) decreased significantly under common myrtle EO compared to control in INRA 199 and ILC 3279 for severity percent index (SPI) no significant difference was observed for all genotypes under Myrtus communis L. essential oil treatment effect. This study showed Myrtus communis L. essential oil efficacy on chickpea blight disease in vitro on fungal radial growth and in vivo either on deatached leaflets or whole plants under greenhouse condition. This natural product reduced significantly blight disease incidence and severity. And to control disease, myrtle essential oil extraction as fungicide is a promising alternative against this disease

Antioxidant Activity of Myrtus communis L. and Myrtus nivellei Batt. & Trab. Extracts: A Brief Review

Myrtus communis L. (myrtle) and Myrtus nivellei Batt. & Trab. (Saharan myrtle) have been used in folk medicine for alleviating some ailments. M. communis is largely distributed in the Mediterranean Basin, whereas M. nivellei is confined in specific zones of the central Saharan mountains. The chemical composition and antioxidant activity of berry and leaf extracts isolated from myrtle are deeply documented, whereas those isolated from Saharan myrtle extracts are less studied. In both species, the major groups of constituents include gallic acid derivatives, flavonols, flavonol derivatives, and hydroxybenzoic acids. In coloured berries, anthocyanins are also present. In M. nivellei extracts are reported for some compounds not described in M. communis so far: 2-hydroxy-1,8-cineole-β-d-glucopyranoside, 2-hydroxy-1,8-cineole 2-O-α-l-arabinofuranosyl (1→6)-β-d-glucopyranoside, rugosin A, and rugosin B. Berries and leaves extracts of both species had antioxidant activity. Comparative studies of the antioxidant activity between leaf and berry myrtle extracts revealed that leaf extracts are best antioxidants, which can be assigned to the galloyl derivatives, flavonols, and flavonols derivatives, although the ratio of these groups of compounds might also have an important role in the antioxidant activity. The anthocyanins present in myrtle berries seem to possess weak antioxidant activity. The antioxidant activity of sample extracts depended on various factors: harvesting time, storage, extraction solvent, extraction type, and plant part used, among other factors. Leaf extracts of myrtle revealed to possess anti-inflammatory activity in several models used. This property has been attributed either to the flavonoids and/or hydrolysable tannins, nevertheless nonprenylated acylphloroglucinols (e.g., myrtucommulone and semimyrtucommulone) have also revealed a remarkable role in that activity. The biological activities of myrtle extracts found so far may direct its use towards for stabilizing complex lipid systems, as prebiotic in food formulations, and as novel therapeutic for the management of inflammation

Composition, chemical variability and effect of distillation time on leaf and fruits essential oils of Myrtus communis from north western Algeria

The chemical variability of the essential oils isolated from Myrtus communis L. leaves and fruits collected from the North western Algeria was evaluated along with a hydrodistillation timecourse study of the essential oil main components. M. communis essential oils were isolated by hydrodistillation and analyzed by Gas Chromatography (GC) and Gas Chromatography-Mass Spectrometry (GC-MS). The essential oils yields ranged between 0.28% and 0.77% (w/d.w.). Although in variable ranges the leaf (L) and the fruits (F) essential oils were characterized by the dominance of the same compounds: α-pinene (23–49% and 21–43% for L and F, respectively), 1,8-cineole (10–24% and 5-31% for L and F, respectively); limonene (11–30% and 9–35% for L and F, respectively); and linalool (2–32% and 1–7% for L and F, respectively). For the first time, Algerian linalool-rich myrtle essential oils (>30%) are described. Higher relative amounts of α-pinene, 1,8-cineole, limonene and linalool can be obtained with shorter distillation times