Nano-Lipids Based on Ginger Oil and Lecithin as a Potential Drug Delivery System

Abstract

Lipid nanoparticles based on lecithin are an interesting part of drug delivery systems. However, the stability of lecithin nano-lipids is problematic due to the degradation of lecithin, causing a decrease in pH. In this study, the modification of the conventional nano-lipid-based soybean lecithin was demonstrated. Ginger-oil-derived Zingiber officinale was used along with lecithin, cholesterol and span 80 to fabricate nano-lipids (GL nano-lipids) using a thin-film method. TEM and a confocal microscope were used to elucidate GL nano-lipids' liposome-like morphology. The average size of the resultant nano-lipid was 249.1 nm with monodistribution (PDI = 0.021). The ζ potential of GL nano-lipids was negative, similarly to as-prepared nano-lipid-based lecithin. GL nano-lipid were highly stable over 60 days of storage at room temperature in terms of size and ζ potential. A shift in pH value from alkaline to acid was detected in lecithin nano-lipids, while with the incorporation of ginger oil, the pH value of nano-lipid dispersion was around 7.0. Furthermore, due to the richness of shogaol-6 and other active compounds in ginger oil, the GL nano-lipid was endowed with intrinsic antibacterial activity. In addition, the sulforhodamine B (SRB) assay and live/dead imaging revealed the excellent biocompatibility of GL nano-lipids. Notably, GL nano-lipids were capable of carrying hydrophobic compounds such as curcumin and performed a pH-dependent release profile. A subsequent characterization showed their suitable potential for drug delivery systems.

Keywords: drug delivery system; essential oil; ginger oil; lecithin; nano-lipid.

Figure 1

GC-MS chromatogram of edible ginger oil (A) and HPLC chromatograms of the representative ginger oil extracts in compared to standard 6-shogaol (B).

Figure 2

Morphology of GL nano-lipids according to TEM image (A) and confocal microscopy image labeled with DiL C18 (B). Size distribution (C) and ζ potential values (D) as obtained by DLS of GL nano-lipids at 25 °C.

Figure 3

Hydrodynamic size PDI value (A) and zeta potential (B) of GL nano-lipid solution during storage time: 0 day, 30 days and 60 days at room temperature (~25 °C). Results are presented as mean  ±  standard deviation, (n  =  9).

Figure 4

pH value (A) and visual observations (B) of GL nano-lipid and L-nano-lipid solutions during storage time: 0 day, 30 days and 60 days at 25 °C. Boxes represent pH value with a probability between 25% and 75%; the line inside the box indicates the median pH value of solution, and bullets indicate data.

Figure 5

(A) The cytotoxicity of MSCs treated with different GL nano-lipid concentrations (0 mg/mL, 0.5 mg/mL, 1 mg/mL, 5 mg/mL and 10 mg/mL) in respected to non-treated MSCs. (B) The cytotoxicity of MSCs in function of time when incubated with 5 mg/mL GL nano-lipid and HEPES buffer. Results are presented as mean  ±  standard deviation (n  =  3). (C) Con-focal microscopy images of MSCs up to 72 h incubation at 37 °C with GL nano-lipid (5 mg/mL) and HEPES buffer. AO: green color; PI: Red color; AO/PI: Merged color; Scale bar = 150 µm.

Figure 6

(A) Visual observations and confocal microscopy image (B) of Cur/GL nano-lipids. (C) In vitro release profiles of curcumin from GL nano-lipids at pH 7.4 (red line) and at pH 5.5 (black line) in 37 °C. Data are presented as mean ± SD (n = 3).