The Essential Oil of Rocket Seeds Maintains Its Antibacterial Effects After Encapsulation in Nanoliposomes

Introduction

It has been demonstrated that the essential oil (EO) of Eruca sativa seeds could be potentially used as an antiseptic agent. However, the application of EOs is restricted because of their chemical instability and volatility. Encapsulation in liposomes is an efficient technique for the protection of the oils.

Methods

The EO of the seeds was obtained using the hydro-distillation method. Liposomal formulation of the oil was prepared using thin layer method.

Results

GC/MS analysis indicated that erucin (1-isothiocyanato-4-methylsulfanylbutane) was the main compound of the oil, accounting for 88.86%. The prepared oil-loaded liposomes had more negative zeta potential (−17.13 mV) compared with the empty liposomes (−9.26 mV), indicating the higher stability of the liposomal oil. SEM imaging confirmed that the encapsulation of the oil does not cause any distortion in the structure of the liposomes, in comparison to the oil-free liposomes. The seed oil showed antimicrobial activities at 20 μg/ml (against Staphylococcus aureus, Enterobacter aerogenes, and Escherichia coli) and 80 μg/ml (against Enterococcus faecalis, Pseudomonas aeruginosa, and Klebsiella pneumonia), while the minimum inhibitory concentration values of the liposomal EO were 160 μg/ml against E faecalis, 80 μg/ml against P aeruginosa and K pneumonia, and 20 μg/ml against S aureus, E aerogenes, and E coli.

Conclusions

Antibacterial experiments revealed that the EO of Eruca sativa seeds maintained its antibacterial effect after loading into the liposomes. Moreover, encapsulation in liposomes could improve the sustainability of the oil and increased the bioavailability of its active chemical compounds.