Chemical composition and acaricidal activity of the essential oils from Vitex agnus-castus L. (Verbenaceae) and selected monoterpenes

Abstract

Tetranychus urticae is considered one of the main plagues in the world. Its occurrence in Pernambuco was registered for the first time in 1985 and it has caused considerable damage to the farmers, attacking different cultures of agricultural interest. The essential oils from different parts of Vitex agnus-castus harvested in the Atlantic forest in the state of Pernambuco, Brazil, were obtained by hydrodistillation and the acaricidal potential was evaluated against Tetranychus urticae using two methods under laboratory conditions. Gas chromatography-mass spectrometry revealed the presence of 47 components accounting for 98.8 ± 0.0%, 93.0 ± 0.1% and 97.4 ± 1.0% of the essential oils from the leaves, fruit and inflorescence, respectively. The compounds 1,8-cineole and β-(E)-farnesene were the major components of the oils from the leaves (17.6 ± 0.3% and 13.6 ± 0.2%, respectively) and fruit (17.5 ± 0.1% and 15.4 ± 0.0%, respectively). β-(E)-farnesene (13.5 ± 0.1%) and β-caryophyllene (11.7 ± 0.1%) were the major components of the oils from the flowers. Acaricidal action varied depending on the part of the plant and method employed. Through fumigation, the oil from the leaves (CL 50 = 0.61 μL L -1 of air) was approximately six fold more toxic than the oil from the fruit. However, through residual contact, the oil from the fruit (CL 50 = 137.11 μLmL -1 ) was 1.1 fold more toxic than the oil from the leaves. The relationship between the chemical composition of the oils and acaricidal activity is also presented.

Acaricidal properties of essential oils from agro‐industrial waste products from citric fruit against Tetranychus urticae

“…In the present study, T. urticae was more susceptible to the Citrus oils when using the fumigation method, which is in agreement with data reported by Neves and Camara () and Moraes, da Camara, Santos, and Fagg () for T. urticae exposed to EOs from Lamiaceae and Myrtaceae, respectively. One explanation for the greater toxicity by fumigation is that the effect of the oil is faster through the airways in the form of vapours (Lorini, Krzyzanowski, França‐Neto, Henning, & Henning, ) than by residual contact, as the oil needs to penetrate the tegument layers to have an effect on the pest (Enan, ).…”

“…However, studies have been conducted on the effect of EOs from other plants species on T. urticae through residual contract, reporting both better and worse results in comparison with the present findings. For instance, the oils from Piper aduncum (LC 50 = 7.17 μl/ml ≅ 7.00 mg/ml) (Araújo et al, ) and oils from the green (LC 50 = 7.44 μl/ml) and ripe (LC 50 = 7.29 μl/ml) fruits of Schinus terebinthifolius (Nascimento, Camara, & Moraes, ) were more toxic than the four Citrus oils investigated herein, whereas the oil from Vitex agnus‐castus (Neves & Camara, ) was less toxic. In other studies using the same population of T. urticae , the oils from Lippia gracilis (LC 50 = 29.70 μl/ml) (Born, da Camara, de Melo, & de Moraes, ) and Aristolochia trilobata (LC 50 = 62.54 mg/ml) (de Melo, Camara, Silva Lima, Moraes, & Alves, ) were more toxic than the C. reticulata , C. reticulata × C. sinensis and C. aurantiifolia oils, but less toxic than the C. limon oil.…”

“…In comparison, the EO from C. aurantiifolia investigated herein was more toxic, causing a 50% mortality rate at a concentration of 11.24 µl/L of air. Moreover, the oils from Vitexagnus ‐ castus (Neves & Camara, ) and Rosmarinus officinalis (Esmaeily, Bandani, Zibaee, & Sharifian, ) were less toxic to T. urticae than the Citrus oils.…”

(−)-β-Caryophyllene, a CB2 Receptor-Selective Phytocannabinoid, Suppresses Motor Paralysis and Neuroinflammation in a Murine Model of Multiple Sclerosis

“…(−)-β-caryophyllene (BCP), a functional non-psychoactive CB2 receptor agonist [12,13,14], is found in, for example, plant-derived oleoresins, essential oils, solutes, distillates, extracts, fermentations, infusions, and leachates, from several plants [15,16,17,18,19,20,21,22,23,24,25]. Furthermore, BCP showed analgesic, anti-inflammatory, neuroprotective, anti-depressive, anxiolytic, and anti-nephrotoxicity effects [12,13,26,27,28,29,30,31].…”

Comparative toxicity of essential oil and blends of selected terpenes of Ocotea species from Pernambuco, Brazil, against Tetranychus urticae Koch

“…Moreover, few studies are found in the literature on the acaricidal activity of the chemical constituents of essential oils and their role in the biological activity of such oils. Using the acaricidal action of individual chemical constituents, it is possible to prepare artificial blends through the selection of the best combination of compounds for use in the integrated management of the two-spotted spider mite as well as investigate the degree of contribution of each compound in the artificial oil (Neves and da Camara 2016, Jiang et al 2009, Miresmailli et al 2006.…”