Essential oils fromOcimum basilicumcultivars: analysis of their composition and determination of the effect of the major compounds onHaemonchus contortuseggs

Abstract

The continuous use of synthetic anthelmintics against gastrointestinal nematodes (GINs) has resulted in the increased resistance, which is why alternative methods are being sought, such as the use of natural products. Plant essential oils (EOs) have been considered as potential products for the control of GINs. However, the chemical composition and, consequently, the biological activity of EOs vary in different plant cultivars. The aim of this study was to evaluate the anthelmintic activity of EOs from cultivars of Ocimum basilicum L. and that of their major constituents against Haemonchus contortus. The EOs from 16 cultivars as well the pure compound linalool, methyl chavicol, citral and eugenol were used in the assessment of the inhibition of H. contortus egg hatch. In addition, the composition of three cultivars was simulated using a combination of the two major compounds from each. The EOs from different cultivars showed mean Inhibition Concentration (IC50) varying from 0.56 to 2.22 mg/mL. The cultivar with the highest egg-hatch inhibition, Napoletano, is constituted mainly of linalool and methyl chavicol. Among the individual compounds tested, citral was the most effective (IC50 0.30 mg/mL). The best combination of compounds was obtained with 11% eugenol plus 64% linalool (IC50 0.44 mg/mL), simulating the Italian Large Leaf (Richters) cultivar. We conclude that different cultivars of O. basilicum show different anthelmintic potential, with cultivars containing linalool and methyl chavicol being the most promising; and that citral or methyl chavicol isolated should also be considered for the development of new anthelmintic formulations.

In vitro and in silico β-lactamase inhibitory properties and phytochemical profile of Ocimum basilicum cultivated in central delta of Egypt

“…The stereochemistry was identified as E based on the coupling constant for the trans protons J H7–H8 =16 Hz (Spekreijse et al. 2012 ; Sitrallah et al 2016 ).…”

Deciphering the anti-filarial potential of bioactive compounds from Ocimum sanctum : a combined experimental and computational study

“… 2015 ; Sousa et al. 2021 ). In another study, Eugenol and other essential oils of OS have shown anthelminthic activity against the free-living nematode Caenorhabditis elegans (Asha et al.…”

“…A previous in vitro study (Sousa et al. 2021 ) on nematode Haemonchus contortus showed the anti-helminthic potential of O. basilicum essential oils. Although the anthelminthic activities of Ocimum species and its essential oils have been studied, nevertheless, the anti-filarial effect of Ocimum sp.…”

Natural products as anthelmintics: safeguarding animal health

“…42 An H. contortus egg hatching assay revealed weak activity for 3.12 (IC 50 187 mg mL −1 ) 43 and 3.13 (IC 50 186 mg mL −1 ) 43 and even lower levels of activity for R-carvone (3.15) (IC 50 302 mg mL −1 ), 43 Scarvone (3.16) (IC 50 362 mg mL −1 ) 43 and citral (3.17) (IC 50 353 mg mL; 43 IC 50 300 mg mL −1 ). 44 The monoterpene (3R,6R)-linalool oxide acetate (3.18) isolated from Ajania nubigena (Asteraceae) inhibited motility of the mouse whipworm T. muris (IC 50 20 mg mL −1 ). 45 The sesquiterpene a-santonin (3.19) (C. elegans ED 50 280 mg mL −1 ) 46 rst isolated by Kahler in 1830 from the medicinal Artemisia cina (Asteraceae, "Wormseed") 47,48 has found historic application as an anthelmintic, however, like many early anthelmintics, its use was discontinued aer more potent anthelmintics were developed with reduced side effects.…”

“…42 An H. contortus egg hatching assay revealed weak activity for 3.12 (IC 50 187 μg mL −1 ) 43 and 3.13 (IC 50 186 μg mL −1 ) 43 and even lower levels of activity for R -carvone ( 3.15 ) (IC 50 302 μg mL −1 ), 43 S -carvone ( 3.16 ) (IC 50 362 μg mL −1 ) 43 and citral ( 3.17 ) (IC 50 353 μg mL; 43 IC 50 300 μg mL −1 ). 44…”