Impact of Fixed Oil on Ostwald Ripening of Anti-Oral Cancer Nanoemulsions Loaded with Amomum kravanh Essential Oil

Abstract

Recently, essential oil from Amomum kravanh (AMO) was reported to exert anti-oral cancer effects. Although it was more effective after being loaded into nanoemulsions, AMO without an Ostwald ripening inhibitor was unable to form stable nanoemulsions because of the Ostwald ripening phenomenon. In this study, we examined the influence of Ostwald ripening inhibitors, such as fixed oils and polyethylene glycol 4000 (PEG 4000), on nanoemulsion properties prepared by a phase inversion temperature method. Several fixed oils, including virgin coconut oil (VCO), palm oil (PMO), olive oil (OLO), and PEG 4000, were evaluated, and their Ostwald ripening inhibitory effects were compared. The results suggest that the type and ratio of AMO:fixed oils influence the formation and characteristics of nanoemulsions. PEG 4000 was unable to produce nanoemulsions; however, stable nanoemulsions with small droplet sizes were observed in preparations containing OLO and VCO at an AMO:fixed oil ratio of 80:20, which may be the result of specific molecular interactions among the components. Using an MTT assay, we demonstrated that the AMO:OLO (80:20) nanoemulsion produced the most significant cytotoxic effect on oral cancer cells with a percentage of 99.68 ± 0.56%. Furthermore, the AMO:OLO 80:20 nanoemulsion inhibits metastasis and induces oral cancer cell death through the intrinsic apoptosis pathway. In conclusion, AMO nanoemulsion with anti-oral cancer activity was successfully produced by varying the amount and type of fixed oils. In the future, this discovery may lead to the development of stable nanoemulsions employing additional volatile oils.

Nanoemulsion-Based Orodispersible Film Formulation of Guava Leaf Oil for Inhibition of Oral Cancer Cells

“…Nanoemulsions prepared from GLO:VCO of 50:50 to 70:30 presented a small droplet size of approximately 50 nm, whereas the other GLO:VCO ratios resulted in a larger droplet size (80-150 nm). These results were consistent with those of previous studies reporting that the droplet size of essential oil nanoemulsion depends on the oil phase composition, especially the ratio of the essential oil to fixed oil [21,22]. After the temperature-cycling test, the droplet size of the GLO:VCO, at ratios ranging from 50:50 to 80:20, was not significantly different from the initial measurements, whereas 90:10-100:0 tended to increase after storage.…”

“…As reported in previous studies, essential oils without fixed oil incorporation were unable to generate nanoemulsions with a droplet size in the nano range. Fixed oil was necessary to prevent Ostwald ripening during emulsion formation [21,22]. To achieve the smallest droplet size, the ratio of GLO to VCO in the range of 50:50 to 100:0 was analyzed before ODF fabrication.…”

Cinnamon essential oil and its emulsion as efficient antibiofilm agents to combat Acinetobacter baumannii

“…Similar results were obtained for cinnamon EO on normal rat fibroblasts (cell line F2408), where nontoxic concentration was approximatively 10 μg/ml, while the higher ones were cytotoxic ( Unlu et al, 2010 ). A higher level of EM induced cytotoxicity could be due to the small size of particles and their easier passage into the cells ( Weerapol et al, 2022 ). Although both EO and EM showed a cytotoxic effect, that does not exclude them from further research which should be performed to minimize cytotoxicity and enable their possible use.…”

Unveiling the Molecular Dynamics, Anticancer Activity, and Stability of Spearmint Oil Nanoemulsions with Triglycerides

“…Several previous studies have used fixed oils as Ostwald ripening inhibitors, including corn oil, 11 peanut oil, 12 and virgin coconut oil. 13 In our previous study, the impact of different fixed oils, including virgin coconut oil, palm oil, olive oil, soybean oil, and perilla oil, on the formation and stability of SMO nano- emulsions was investigated. Interestingly, it was found that the presence of 20% fixed oil, particularly perilla oil, led to the rearrangement of different molecules, bringing them into close proximity (within 5 Å).…”

“…These triglycerides not only improve stability but also promote the formation of nanoemulsions with small droplet sizes when prepared using the phase inversion temperature method. Several previous studies have used fixed oils as Ostwald ripening inhibitors, including corn oil, peanut oil, and virgin coconut oil …”