Experimental investigation of the strong stability, antibacterial and anti-inflammatory effect and high bioabsorbability of a perilla oil or linseed oil nanoemulsion system

Abstract

Perilla oil (PO) and linseed oil (LO) are very rich in nutrients and have great potential market value. Using the Cremophor RH40-Span80 preparation system to make a perilla oil nanoemulsion (PON) or linseed oil nanoemulsion (LON) can improve the bioavailability and stability of these oils. The effect of different reaction conditions on the stability of the emulsion was investigated. The results showed that the PON and LON have good stability at pH ≥ 7, different storage temperatures (4 °C, 25 °C, 37 °C and 55 °C) and different NaCl concentrations (0, 2, 4, 6, 8 M). Meanwhile, it was found that the content of the lipid peroxidation product malondialdehyde (MDA) in the nanoemulsion did not change significantly over 7 days, further demonstrating the stability of the nanoemulsion. Through anti-inflammatory and antibacterial tests, it was found that the PON and LON have an effective inhibitory effect on inflammation; moreover, the PON inhibits the growth of Escherichia coli, Salmonella enteritidis and Pseudomonas tolaasii, and the LON has an inhibitory effect on Staphylococcus aureus and Pseudomonas tolaasii (inhibition zone > 10 mm). In addition, we found that there were no pathological differences in the heart, liver, spleen and kidney of Kunming mice between the PO and PON groups and the LO and LON groups. Furthermore, after intraperitoneal injection of P 407 into mice, the comparison between PON and PO and between LON and LO showed that the blood lipid levels of the mice in the PON and LON treatment groups increased, indicating that the absorption capacity of the small intestine of the mice for the PON and LON was enhanced. Therefore, the preparation of the PON and LON has good development prospects and opens up opportunities in the development of the food industry.

Scheme 1. Strong stability, antibacterial, anti-inflammatory effect and high bioabsorbability of a perilla oil or linseed oil nanoemulsion system.

Fig. 1. Pseudoternary phase diagram for (a) is perilla oil nanoemulsion and (b) is linseed oil nanoemulsion.

Fig. 2. Influence of storage temperature on the particle size and zeta potential of nanoemulsions prepared with a Cremophor RH40/Span80 mass ratio of 3 : 1, where (a and b) is perilla oil nanoemulsion and (c and d) is linseed oil nanoemulsion.

Fig. 3. Influence of pH on the particle size and zeta potential of the nanoemulsions prepared with a Cremophor RH40/Span80 mass ratio of 3 : 1, where (a and b) is perilla oil nanoemulsion and (c and d) is linseed oil nanoemulsion.

Fig. 4. Influence of NaCl concentration on the particle size and zeta potential of the nanoemulsions prepared with a Cremophor RH40/Span80 mass ratio of 3 : 1, where (a and b) is perilla oil nanoemulsion and (c and d) is linseed oil nanoemulsion.

Fig. 5. The MDA content of perilla oil nanoemulsion (PON) and linseed oil nanoemulsion (LON).

Fig. 6. (a) is the cytotoxicity test result for perilla oil nanoemulsion (PON), (b) is the result of linseed oil nanoemulsion (LON) cytotoxicity test, and (c) is the result of cell anti-inflammatory test. ***, p < 0.001; ****(####), p < 0.0001.

Fig. 7. (a) and (b) shows changes in body weight and food intake in mice within 7 days; (c) shows the results of the gut transit test; (d) shows H&E staining results in an acute toxicity test in mice. Magnification, ×200 and ×400; scale bars: 50 μm. Error bars represent the standard deviation. **, p < 0.01; ns, not significant.

Fig. 8. (a)–(d) shows the levels of TG, TC, HDL-c and LDL-c in the plasma of mice in each sample group, wherein figures (a)–(d) are the results for male mice. *, p < 0.05; ns, not significant.